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HomeMy WebLinkAboutCT 13-04; GOLDEN SURF; PRELIMINARY GEOTECHNICAL INVESTIGATION; DWG 496-4A; 2011-11-30RECEIV~~D FEB O 7 ?.Oi7 LAND DEVELOPMENT ENGINEEF{ING PRELIMINARY GEOTECHNICAL EVALUATION PASEd POINT MINOR SUBDIVISION, 6798 PASEO DEL NORTE CITY OF CARLSBAD, SAN DIEGO COUNTY, CA_!JFORNIA FOR GOLDEN SURF HOLDINGS, LTD C/0 KARNAK PLANNING AND DESIGN 2525 PIO PICO DRIVE, SUITE 102 CARLSBAD, CALIFORNIA 92008 W.0. 6309-A-SC NOVEMBER 30, 2011 c:;~r 13 -/0-1 /) IV/; 41~ -~f /J Geotechnical • Geologic • Coastal • Environmental 5741 Palmer Way • Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 • www.geosoilsinc.com Golden Surf Holdings, ltd c/o Karnak Planning and Design 2525 Pio Pico Drive, Suite 102 Carlsbad, California 92008 November 30, 2011 Attention: Mr. Robert Richardson W.O. 6309-A-SC Subject: Preliminary Geotechnical Evaluation, Paseo Point Minor Subdivision, 6798 Paseo Del Norte, City of Carlsbad, San Diego County, California Dear Mr. Richardson: In accordance with your request and Mr. Farzan Demoubed's authorization, GeoSoils, Inc. (GSI) has performed a preliminary geotechnical eva·luation of the subject site with respect to the proposed minor residential subdivision. The purpose of the study was to evaluate the onsite soils and geologic conditions, and their effects on the proposed site development from a geotechnical viewpoint. EXECUTIVE SUMMARY Based on our review of the available data (see Appendix A), field exploration, laboratory testing, and geologic and engineering analysis, the proposed development of the property appears to be feasible from a geotechnical viewpoint, provided the recommendations presented in the text of this report are properly incorporated into the design and construction of the project. The most significant elements of this study are summarized below: • Based on a conversation with you and a review of the Tentative Parcel Map prepared by Conway and Associates, Inc. ([C&A], 2011), itisourunderstandingthat proposed site development will consist of preparing the site for the construction of a new single-family residential structure and two residential duplexes with associated site improvements (underground utilities, walls, driveways, walkways, etc.). GSI anticipates that the proposed residences will be one-to two-stories and consist of wood-frame and/or masonry construction with concrete slab-on-grade floors. " Soils considered unsuitable for the support of settlement-sensitive improvements (i.e., residential structures, underground utilities, walls, pavements, etc.) and/or engineered fill include surficial undocumented artificial fill, Quaternary-age colluvium (topsoil), and weathered Quaternary-age terrace deposits. Unweathered Quaternary-age terrace deposits are considered acceptable for the support of settlement-sensitive improvements and/or engineered fill in their existing state; however, they locally may be expansive. Based on the available data, the thickness of unsuitable soils across the site is anticipated to range between approximately 3112 and 5% feet. However, localized areas of thicker unsuitable soils cannot be precluded and should be anticipated. .. All vegetation and/or deleterious materials should be removed from the site and properly disposed of, where located within the influence of new settlement-sensitive improvements and/or planned fills. Undocumented artificial fill, Quaternary-age colluvium, and weathered terrace deposits should be removed to expose suitable, unweathered terrace deposits prior to fill placement. The removed soils may be reused as engineered fill provided that major concentrations of vegetation and/or debris have been removed prior to their placement. " It should be noted that the 201 o California Building Code ([201 o CBC], California Building Standards Commission [CBSC], 2010) indicates that remedial grading be performed across all areas under the purview of the grading permit, not just within the influence of the proposed residential structures. Relatively thick unsuitable soils may also necessitate a special zone of consideration on perimeter/confining areas. This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite or offsite. Thus, any settlement-sensitive improvements, constructed within this zone may require deepened foundations, additional reinforcement, etc., or will retain some potential for settlement and associated distress. Property boundaries and/or adjacent, offsite improvements may limitthe extent of remedial grading. Should unmitigated soils remain within the property boundaries at the conclusion of grading, the potential for settlement- sensitive improvements, constructed within the influence of these soils, to experience settlement-associated distress should be anticipated and be properly disclosed to all interested/affected parties. 0 Temporary excavations greater than 4 feet but less than 20 feet in overall height should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils provided that groundwater and/or running sands are not present. All temporary excavations should be observed by a licensed engineering geologist or geotechnical engineer prior to worker entry. If temporary slopes conflict with property boundaries, shoring or alternating slot excavations may be necessary. The need for shoring or alternating slot excavations should be further evaluated during the grading plan review stage, but is considered likely on the eastern and northern property lines. Golden Surf Holdings, Ltd File:wp12\6300\6309a.pge W.O. 6309-A-SC Page Two The expansion indices of tested onsite soils varies between <5 and 72. As such, on a preliminary basis, some of the onsite soils are considered to be expansive per Section 1803.5.2 of the 201 O California Building Code ([201 O CBC], California Building Standards Commission [CBSC], 2010). Conventional foundation systems may be used for the support of the planned residential structures provided that soils within the influence of the foundation possess an expansion index (E.I.) of 20 or less and a plasticity index (P.I.) that is less than 15. Foundations within the influence of expansive soils should be designed and constructed in accordance with the minimum guidelines presented herein, and as presented in Sections 1808.6.1 or 1808.6.2 of the 201 O CBC. Foundation systems used for the mitigation of expansive soils typically incorporate the post-tension institute (PTI) and wire reinforcement institute (WRI) methodologies. Preliminary recommendations for the design and construction of conventional, post-tension (PT), and mat foundations are included herein. Final foundation design will be provided at the conclusion of grading, based on the E.I. and P.I. of soils exposed near pad grade. As an alternative to the use of PT and mat foundations, expansive soils may be stockpiled and removed from the site during remedial grading. The removed expansive soils may be replaced with import materials possessing an E.I. of 20 or less and a P .I. less than 15, if warranted for the balance of earthwork quantities. .. Soil pH, saturated resistivity, and soluble sulfate, and chloride testing was performed on representative samples of the onsite soils. Testing indicates that these soils are moderately alkaline with respect to soil acidity/alkalinity, are corrosive to ferrous metals when saturated, present negligible ("not applicable") sulfate exposure to concrete (per Table 4.2.1 of ACI 318-08), and are below action levels for chlorides exposure (per State of California Department of Transportation, 2003). Additional comments and recommendations should be obtained from a qualified corrosion engineer. • Regional groundwater was not encountered during our field exploration and is not expected to be a major factor during construction of the proposed improvements. Regional groundwater is anticipated to generally be coincident with Mean Sea Level (MSL) or approximately 158% feet below the lowest existing site elevation. However, due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site in the future, both during and subsequent to development, especially along boundaries of contrasting permeabilities (i.e., clayey and sandy fill lifts, fill/terrace deposit contacts, joints/fractures, discontinuities, etc.), and should be anticipated. This potential should be disclosed to all interested/affected parties. Thus, more onerous slab design is necessary for any new slab-on-grade floor (State of California, 2011). Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report. It should be noted that these recommendations should be implemented if the transmission of water or water vapor through the slab is undesirable. Should these mitigative measures not be implemented, then the potential for water or vapor Golden Surf Holdings, Ltd File:wp12\6300\6309a.pge W.O. 6309-A-SC Page Three to pass through the foundations and slabs and resultant distress cannot be precluded, and would need to be disclosed to all interested/affected parties. .. No landslides or adverse geologic structure, associated with deep-seated landsliding, were encountered during our field exploration. In addition, a review of regional geologic maps and stereoscopic aerial photographs did not indicate the presence of landslide debris nor geomorphic expressions, suggestive of previous landsliding. Further, the terrace deposits that underlie the site are typically moderately to well indurated and generally considered non-susceptible to deep- seated landslides. Therefore, it is our professional opinion that the potential for deep-seated landslides to adversely affectthe proposed development is considered very low. However, the onsite earth materials are considered erosive. Thus, there is some potential for shallow, surficial slope failures to occur along graded slopes. However, provided that the recommendations in this report are incorporated into the civil engineering and landscape designs and surface runoff waters are directed away from the tops of slopes, this potential would be greatly reduced. .. Our evaluation and experience with similar sites indicates that the site currently has a very low potential for liquefaction, due to the relatively dense nature of the Quaternary-age terrace deposits and the depth to the regional water table below the lowest site elevation. The potential for seismic densification to affect the planned development is considered very low, provided the recommendations in this report are properly followed. However, some seismic densification of the adjoining un- mitigated site(s) may adversely influence planned improvements at the perimeter of the site. .. The seismic acceleration values and design parameters provided herein should be considered during the design of the proposed development. The adverse effects of seismic shaking on the structure(s) will likely be wall cracks, some foundation/slab distress, and some seismic settlement. However, it is anticipated that the structure will be repairable in the event of the design seismic event. This potential should be disclosed to all interested/affected parties. 0 Our evaluation indicates there are no known active faults crossing the site. In addition, other than moderate to strong seismic shaking produced from an earthquake on a nearby active fault, other geologic and secondary seismic hazards have a very low potential to affect the proposed site development. 0 Adverse geologic features that would preclude project feasibility were not encountered. The recommendations presented in this report should be incorporated into the design and construction considerations of the project. Golden Surf Holdings, Ltd File:wp12\6300\6309a.pge W.O. 6309-A-SC Page Four The opportunity to be of service is greatly appreciated. If you have any questions concerning this report, or if we may be of further assistance, please do not hesitate to contact any of the undersigned. Respectfully submitted, RB/JPF/DWS/jh Distribution: (4) Addressee Golden Surf Holdings, Ltd File:wpl 2\6300\6309a.pge GeoSoils, lneo W.O. 6309-A-SC Page Five TABLE OF CONTENTS SCOPE OF SERVICES ................................................... 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ......................... 1 SITE EXPLORATION ..................................................... 3 REGIONAL GEOLOGY ................................................... 3 SITE GEOLOGIC UNITS .................................................. 3 Artificial Fill -Undocumented (Map Symbol -Afu) ........................ 4 Quaternary-age Colluvium (Not Mapped) ............................... 4 Quaternary-age Paleosol (Not Mapped) ................................ 4 Quaternary-age Terrace Deposits (Map Symbol -Qt) ..................... 4 GEOLOGIC STRUCTURE ................................................. 5 GROUNDWATER ........................................................ 5 MASS WASTING/LANDSLIDE SUSCEPTIBILITY ............................... 5 FAUL TING AND REGIONAL SEISMICITY ..................................... 6 Regional Faults .................................................... 6 Local Fau Its ....................................................... 6 Seismicity ........................................................ 6 Deterministic Maximum Credible Site Acceleration .................. 6 Historical Site Acceleration ..................................... 7 Probabilistic Site Acceleration .................................. 7 Seismic Shaking Parameters ......................................... 7 LIQUEFACTION POTENTIAL .............................................. 8 Liquefaction ...................................................... 8 Seismic Densification ............................................... 9 Summary ......................................................... 9 Other Geologic/Secondary Seismic Hazards ........................... 1 O LABORATORY TESTING ................................................. 1 O General ......................................................... 10 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O Expansion Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Atterberg Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Particle -Size Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Shear Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Saturated Resistivity, pH, and Soluble Sulfates, and Chlorides ............. 12 Corrosion Summary ......................................... 12 EMBANKMENT FACTORS (SHRINKAGE/BULKING) ........................ · ... 13 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS .................... 13 EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................... 16 General ......................................................... 16 Demolition/Grubbing .............................................. 16 Remedial Removals (Removal of Potentially Compressible Surficial Materials) 17 Overexcavation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Alternative Earthwork Mitigation of Expansive Soils ...................... 17 Temporary Slopes ................................................ 18 Engineered Fill Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Graded Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Import Fill Materials ............................................... 19 PRELIMINARY FOUNDATION RECOMMENDATIONS .......................... 19 General ......................................................... 19 General Foundation Design ......................................... 20 Foundation Settlement ....................................... 21 PRELIMINARY FOUNDATION CONSTRUCTION RECOMMENDATIONS ........... 21 Conventional Foundations -Expansion Index of 20 or Less with a Plasticity Index Less Than 15 ............................................... 21 Post-Tensioned Foundations ........................................ 22 Soil Moisture ............................................... 23 Perimeter Cut-Off Walls ....................................... 23 Post-Tensioned Foundation Design ............................. 24 Soil Support Parameters ...................................... 24 Mat Foundations .................................................. 25 Mat Foundation Design ....................................... 25 Slab Subgrade Pre-moistening -Mat Foundations ................. 26 CORROSION .......................................................... 26 SOIL MOISTURE TRANSMISSION CONSIDERATIONS ........................ 26 WALL DESIGN PARAMETERS CONSIDERING EXPANSIVE SOILS ............... 28 Conventional Retaining Walls ....................................... 28 Restrained Walls ............................................ 28 Cantilevered Walls ........................................... 29 Earthquake Loads (Seismic Surcharge) ............................... 29 Retaining Wall Backfill and Drainage .................................. 30 Wall/Retaining Wall Footing Transitions ............................... 30 Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge Table of Contents Page ii TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS AND EXPANSIVE SOILS ...... 34 Expansive Soils and Slope Creep .................................... 34 Top of Slope Walls/Fences ......................................... 34 New Asphaltic Concrete (AC) Pavement ......................... 38 Pavement Grading Recommendations ................................ 38 General ................................................... 38 Subgrade .................................................. 38 Aggregate Base ............................................. 39 Paving .................................................... 39 Drainage .................................................. 40 DEVELOPMENT CRITERIA ............................................... 40 Slope Deformation ................................................ 40 Slope Maintenance and Planting ..................................... 40 Drainage ........................................................ 41 Erosion Control ................................................... 41 Landscape Maintenance ........................................... 42 Gutters and Downspouts ........................................... 42 Subsurface and Surface Water ...................................... 42 Site Improvements ................................................ 43 Tile Flooring ..................................................... 43 Additional Grading ................................................ 43 Footing Trench Excavation ......................................... 43 Trenching/Temporary Construction Backcuts .......................... 43 Utility Trench Backfill .............................................. 44 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING ........................................................ 44 OTHER DESIGN PROFESSIONALS/CONSULTANTS .......................... 45 PLAN REVIEW ......................................................... 46 LIMITATIONS .......................................................... 46 FIGURES: Figure 1 -Site Location Map ......................................... 2 Detail 1 -Typical Retaining Wall Backfill and Drainage Detail .............. 31 Detail 2 -Retaining Wall Backfill and Subdrain Detail Geotextile Drain ....... 32 Detail 3 -Retaining Wall and Subdrain Detail Clean Sand Backfill ........... 33 Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, Inc .. Table of Contents Page iii A IT ACHMENTS: Plate 1 -Geotechnical Map ................................. Rear of Text Appendix A -References ................................... Rear of Text Appendix B -Test Excavation Logs ........................... Rear of Text Appendix C -EQFAUL T, EQSEARCH, and PHGA ............... Rear of Text Appendix D -Laboratory Data ............................... Rear of Text Appendix E -General Earthwork, Grading Guidelines, and Preliminary Criteria .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, lneo Table of Contents Page iv PRELIMINARY GEOTECHNICAL EVALUATION PASEO POINT MINOR SUBDIVISION, 6798 PASEO DEL NORTE CITY OF CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of the available geologic literature for the site (see Appendix A). 2. Geologic site reconnaissance, subsurface exploration with four exploratory test excavations (see Appendix B), sampling, and mapping. 3. General areal seismicity evaluation (see Appendix C). 4. Appropriate laboratory testing of representative soil samples (Appendix D). 5. Engineering and geologic analysis of data collected. 6. Preparation of this report. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The subject site consists of relatively vacant land, located east and northeast of 6798 Paseo Del Norte in the City of Carlsbad, San Diego County, California (see Figure 1, Site Location Map). The site is bounded by Camino de las Ondas to the south and by existing residential development to the remaining quadrants. Topographically, the site is located upon a gently to moderately inclined slope that descends to the northeast at an overall gradient on the order of 9:1 (horizontal:vertical [h:v]). However, the slope steepens to approximately 2:1 (h:v) near the site's southwest corner. According to the 10-scale "Tentative Parcel Map" prepared by Conway and Associates, Inc. (C&A, 2011), site elevations vary between approximately 158% and 17 4 % feet Mean Sea Level (MSL) for an overall relief of approximately 20 feet. Existing structures include an approximately 4-foot high retaining wall and a staircase. Site vegetation consists of weeds and grasses with sparse trees. Based on a conversation with the you and a review of the 10-scale "Tentative Parcel Map" prepared by C&A (2011), it is our understanding that proposed development will consist of preparing the site for the construction of a new single-family residence and two new residential duplexes with associated site improvements (underground utilities, walls, driveways, walkways, etc.). GSI anticipates that the proposed residences will be one-to two-stories and consist of wood-frame and/or masonry construction with concrete slab-on-grade floors. Cut and fill grading will be necessary to achieve the design grades. C&A (2011) indicates that maximum cut and fill thicknesses will be on the order of 6% and 7% feet, respectively. C&A (2011) shows maximum height cut and fill slopes on the order GeoSoils, lne .. SITE I I ;• I I :... Base Map: TOPO!® ©2003 National Geographic, U.S.G.S Encinitas Quadrangle, California --San Diego Co., 7.5 Minute, dated 1997, current, 1999. \\ ~>\\_ \\ SITE satTH CARLS8AD ST"ATE 8EACII ' Base Map: The Thomas Guide, San Diego Co., Street Guide and Directory, 2005 Edition, by Thomas Bros. Maps, page 1127. Reproduced with permission granted by Thomas Bros. Maps This map Is copyrighted by Thomas Bros. Maps. It Is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without pennlss/on. All rights reserved. N w.o. c. 6309-A-SC SITE LOCATION MAP Figure 1 of 7 and 8 feet, respectively. Graded slopes will be inclined at 2: 1 (h:v) gradients or flatter. C&A (2011) also indicates the use of retaining walls, up to approximately 8112 feet in overall height, to locally facilitate grade differentials. Sewage disposal is anticipated to be tied into the municipal system. SITE EXPLORATION Surface observations and subsurface explorations were performed on September 23, 2011, by a representative of this office. A survey of line and grade for the subject site was not conducted by this firm at the time of our site reconnaissance. Near-surface soil and geologic conditions were explored with four exploratory test excavations within the site. A rubber-tire backhoe was used to complete the test excavations. The approximate locations of the exploratory test excavations are shown on the Geotechnical Map (see Plate 1) which uses C&A (2011) as a base. Logs of the test excavations are presented in Appendix B. REGIONAL GEOLOGY The subject property is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. It is characterized by steep, elongated mountain ranges and valleys thattrend northwesterly. The mountain ranges are underlain by basement rocks consisting of pre-Cretaceous metasedimentary rocks, Jurassic metavolcanic rocks, and Cretaceous plutonic rocks of the southern California batholith. In the San Diego County region, deposition occurred during the Cretaceous Period and Cenozoic Era in the continental margin of a forearc basin. Sediments, derived from Cretaceous-age plutonic rocks and Jurassic-age volcanic rocks, were deposited into the narrow, steep, coastal plain and continental margin of the basin. These rocks have been uplifted, eroded, and deeply incised. During early Pleistocene time, a broad coastal plain was developed. During mid-to late-Pleistocene time, this plain was uplifted, eroded, and incised. Alluvial deposits have since filled the lower valleys, and young marine sediments are currently being deposited/eroded within coastal and beach areas. Regional mapping by Kennedy and Tan (2005) indicates that the site is underlain by old paralic deposits. SITE GEOLOGIC UNITS The site geologic units encountered during our subsurface investigation and site reconnaissance included undocumented artificial fill, Quaternary-age colluvium (topsoil), and Quaternary-age terrace deposits (weathered and unweathered). The earth materials are generally described below from the youngest to the oldest. The distribution of these materials across the site is shown on Plate 1 . Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lne .. W.O. 6309-A-SC November 30, 2011 Page 3 Artificial Fill -Undocumented (Map Symbol -Afu) A thin veneer of undocumented artificial fill was encountered locally, near the southern margin of the site. Although not directly observed in the subsurface explorations, artificial fill may also occur near the northwestern portion of the site and southwest of the existing retaining wall. Where observed, the undocumented fill consisted of a dark yellowish brown silty sand. The fill was generally dry, dense, slightly porous, and non-uniform. The thickness of the undocumented fill was on the order of 1 % feet thick, where encountered. The undocumented fill is considered unsuitable for the support of the proposed settlement-sensitive improvements and/or planned fill in its existing state. Removal and recompaction of these materials is recommended where settlement-sensitive improvements and/or planned fill will occur within its influence. Quaternary-age Colluvium (Not Mapped) Quaternary-age colluvium (topsoil) was encountered in all of the test pits. The colluvium generally consisted of a brown, dark grayish brown, grayish brown sand with varying amounts of silt. The colluvium was dry to damp and loose to dense. In general, the thickness of the colluvium was on the order of 11h to 2% feet. The colluvium is considered potentially compressible in its existing state and therefore should be removed and recompacted, if settlement-sensitive improvements and/or planned fill are proposed within its influence. Quaternary-age Pal eosol (Not Mapped) A Quaternary-age paleosol (i.e., buried soil horizon) was observed underlying the colluvium in Test Pit TP-3 and developed within the underlying weathered terrace deposits. The paleosol consisted of a dark reddish brown clayey sand that was damp and dense. It generally exhibited angular blocky ped structure with abundant clay films on ped faces. The paleosol was slightly porous. Based on its absence within the other test pits, GSI believes that areal extent of the paleosol is limited to the northeast corner of the site. Where encountered, the thickness of the paleosol was approximately 2 feet. The paleosol may be potentially compressible in its existing state and therefore should be removed and recompacted, if settlement-sensitive improvements and/or planned fill are proposed within its influence. Quaternary-age Terrace Deposits (Map Symbol -Qt) Quaternary-age terrace deposits were encountered underlying the surficial soils in all of the test pits Where locally weathered, the terrace deposits typically consisted of brown to dark yellowish brown sand with silt. The weathered terrace deposits were generally damp and medium dense to dense. Weathered terrace deposits exhibited porosity. Unweathered terrace deposits generally consisted of a dark yellowish brown and brown silty sand with minor clay to a reddish yellow and gray clayey sand. The unweathered terrace deposits were damp to moist and dense to very dense. Weathered terrace Golden Surf Holdings, LLC Paseo Point, Carlsbad File: e:\wp 12\6300\6309a.pge GeoSoils, lne. W.O. 6309-A-SC November 30, 2011 Page4 deposits are considered potentially compressible in their existing state and therefore should be removed and recompacted if settlement-sensitive improvements and/or planned fills are proposed within their influence. The thickness of the weathered terrace deposits was on the order of 1 % to 2114 feet. Unweathered terrace deposits are considered suitable for the support of settlement-sensitive improvements and/or planned fill in their existing state. GEOLOGIC STRUCTURE A observed within the test pits, the terrace deposits were thickly bedded to massive and regionally sub-horizontal to horizontal. GROUNDWATER Regional groundwater was not encountered during our field exploration and is not expected to be a major factor during construction of the proposed minor subdivision. Regional groundwater is anticipated to generally be coincident with MSL or approximately 158112 feet below the lowest existing site elevation. However, due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site in the future, both during and subsequent to development, especially along boundaries of contrasting permeabilities (i.e., sandy/clayey fill lifts, fill/terrace deposits contacts, bedding, joints/fractures, discontinuities, etc.), and should be anticipated. This potential should be disclosed to all interested/affected parties. Thus, more onerous slab design is necessary for any new slab-on-grade floor (State of California, 2011 ). Recommendations for reducing the amount of water and/or water vapor through slab-on-grade floors are provided in the "Soil Moisture Considerations" sections of this report. It should be noted that these recommendations should be implemented if the transmission of water or water vapor through the slab is undesirable. Should these mitigative measures not be implemented, then the potential for water or vapor to pass through the foundations and slabs and resultant distress cannot be precluded, and would need to be disclosed to all interested/affected parties. MASS WASTING/LANDSLIDE SUSCEPTIBILITY According to regional landslide susceptibility mapping by Tan and Giffen (1995), the site is located within landslide susceptibility Subarea 3-1 which is characterized as being "generally susceptible" to landsliding. Based on our review of Kennedy and Tan (2005), no landslide debris has been mapped within the site. In addition, GSI did not observe geomorphic expressions indicative of deep-seated landslides during our review of available stereoscopic aerial photographs Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Ince W.O. 6309-A-SC November 30, 2011 Page 5 (United States Department of Agriculture [USDA], 1953). Further, landslide debris or adverse geologic structure were not encountered during our field investigation. Given the above positive evidence, the moderately to well indurated nature of the terrace deposits that underlie the site, and the site's position with respect to any ascending or descending slopes, it is our opinion that the potential for deep-seated landslides to adversely affect the proposed development is considered very low. However, the onsite earth materials are considered erosive. Thus, there is some potential for shallow, surficial slope failures to occur along graded slopes. However, provided that the recommendations in this report are incorporated into the civil engineering and landscape designs and surface runoff waters are directed away from the tops of slopes, this potential would be greatly reduced. FAUL TING AND REGIONAL SE!SMICITY Regional Faults Our review indicates that there are no known active faults crossing this site, and the site is not within an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007). However, the site is situated in a region of active faulting. These include, but are not limited to: the San Andreas fault; the San Jacinto fault; the Elsinore fault; the Coronado Bank fault zone; and the Newport-Inglewood -Rose Canyon fault zone (NIRCFZ). Portions of the nearby NIRCFZ are located in an Alquist-Priolo Earthquake Fault Zone (Bryant and Hart, 2007). The location of these, and other major faults relative to the site, are indicated on the California Fault Map in Appendix C. The possibility of ground acceleration, or shaking at the site, may be considered as approximately similar to the southern California region as a whole. Major active fault zones that may have a significant affect on the site, should they experience activity, are listed in Appendix C (modified from Blake, 2000a). local Faults No faults was observed to transect the site during the field investigation nor review of regional geologic maps. The closest known active fault to the site is the Rose Canyon fault, located approximately 4.7 miles (7.5 kilometers) away (Blake, 2000a). Seismicity Deterministic Maximum Credible Site Acceleration The acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999) has been incorporated into EQFAUL T (Blake, 2000a). EQFAUL Tis a computer program developed by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. Golden Surf Holdings, LLC Paseo Point, Carlsbad Ale: e:\wp12\6300\6309a.pge GeoSoils, Inc .. W.O. 6309-A-SC November 30, 2011 Page 6 The program estimates the closest distance between each fault and a given site. If a fault is found to be within a user-selected radius, the program estimates peak horizontal ground acceleration that may occur at the site from an upper bound ("maximum credible") earthquake on that fault. Site acceleration (g) was computed by one user-selected acceleration-attenuation relation that is contained in EQFAULT. Based on the EQFAULT program, a peak horizontal ground acceleration from an upper bound event at the site may be on the order of 0.65 g. The computer printouts of pertinent portions of the EQFAULT program are included within Appendix C. Historical Site Acceleratio1111 Historical site seismicity was evaluated with the acceleration-attenuation relation of Bozorgnia, Campbell, and Niazi (1999), and the computer program EQSEARCH (Blake, 2000b). This program performs a search of the historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 1 OD-kilometer radius, between the years 1800 through December 201 o. Based on the selected acceleration-attenuation relationship, a peak horizontal ground acceleration is estimated, which may have effected the site during the specific event listed. Based on the available data and the attenuation relationship used, the estimated maximum (peak) site acceleration during the period 1800 through December 201 O was 0.34 g. A historic earthquake epicenter map and a seismic recurrence curve are also estimated/generated from the historical data. Computer printouts of the EQSEARCH program are presented in Appendix C. Probabilistic Site Acceleration A probabilistic seismic hazards analysis was performed using 2008 Interactive Deaggregations (201 O Beta) Seismic Hazard Analysis tool available at the USGS website (https://geohazards.usgs.gov/deaggniV2008/) which evaluates the site specific probabilities of exceedance for selected spectral periods. For this study, GSI used spectral periods of 0.0, 0.2, 0.5, 1.0, and 2.0 seconds. Based on a review of these data, and considering the relative seismic activity of the southern California region as a whole, a probabilistic seismic hazard assessment is presented herein. Printouts from this analysis are also included in Appendix C. Seismic Shaking Parameters Based on the site conditions, the following table summarizes the site-specific design criteria obtained from the 201 o CBC (CBSC, 2010), Chapter 16 Structural Design, Section 1613, Earthquake Loads. The computer program Seismic Hazard Curves and Uniform Hazard Response Spectra, provided by the United States Geologic Survey ([U.S.G.S.], 2011) was utilized for design. The short spectral response utilizes a period of 0.2 seconds. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Ine .. W.O. 6309-A-SC November 30, 2011 Page? :j(:,;'Ji\·:::,:,. r·:t:(' :(:/ •t ,:::.2o~c>'c;:e,c·~EISMIC:DE~IGI\! ~AijAJlll.l;Tl;R_S·i',::·' 1:,\· ,::::;,·, : : ,' .. ' . -, 1 :·.· .. : , !f;i::'j:'.<1\::(it:::.i\):)\'/ ')i\'. ,,, , .,', ,•·,,.l '',"• ,, ' •'n Ii•-,-.' ' -~,,'•I',,. ,. ,, ,•,,•, ' ,,I' ···' PARAMETER::·:,.-: >:,:;,,,,.,:·,:.·.:,:I,,'', ·,',,·i,' ALUE:). ,'/. IBG-06 REFERENCE.· Site Class D Table 1613.5.2 Spectral Response -(0.2 sec), s. 1.275g Figure 1613.5(3) Spectral Response -(1 sec), S1 0.481 g Figure 1613.5(4) Site Coefficient, Fa 1.0 Table 1613.5.3(1) Site Coefficient, Fv 1.519 Table 1613.5.3(2) Maximum Considered Earthquake Spectral 1.275g Section 1613.5.3 Response Acceleration (0.2 sec), SMs (Eqn 16-37) Maximum Considered Earthquake Spectral 0.731g Section 1613.5.3 Response Acceleration (1 sec}, SM, (Eqn 16-38} 5% Damped Design Spectral Response 0.850g Section 1613.5.4 Acceleration (0.2 sec), S08 (Eqn 16-39) 5% Damped Design Spectral Response 0.487g Section 1613.5.4 Acceleration (1 sec), S01 (Eqn 16-40) i\i::J:\:,ii[1(l;:i\:f:1ii:~fi:,:;!ii[.,::,;;:::;c;;:}:':::ii;'/'\t'G".\GENE'i=tA:LsE(sMIC::01:s1GN'i'PABAMETERS':!'i::•::?)~}t;:.):q:r:::::,,:::::.::•:: \·;{,/!" .,, ){ ... . , .... Distance to Seismic Source (Rose Canyon fault) from Blake 4.0mi. (6.5 km) (2000a} Upper Bound Earthquake (Rose Canyon fault) Mw 6.9* Probabilistic Horizontal Site Acceleration ([PHSA] 10% probability 0.27g of exceedance in 50 years) Probabilistic Horizontal Site Acceleration ([PHSA] 0.49g 2% probability of exceedance in 50 years) I* International Conference of Building Officials {ICB01 1998) I Conformance to the criteria above for seismic design does not constitute any kind of guarantee or assurance that significant structural damage or ground failure will not occur in the event of a large earthquake. The primary goal of seismic design is to protect life, not to eliminate all damage, since such design may be economically prohibitive. Cumulative effects of seismic events are not addressed in the 201 O CBC (CBSC, 2010) and regular maintenance and repair following locally significant seismic events (i.e., Mw5.0) will likely be necessary. UQUEFACTiON POTENTIAL Liquefaction Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in relatively cohesion less soils. These soils may thereby acquire a high degree of mobility, which can lead to vertical deformation, lateral movement, lurching, sliding, and as a result of seismic Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Inca W.O. 6309-A-SC November 30, 2011 Page 8 loading, volumetric strain and manifestation in surface settlement of loose sediments, sand boils and other damaging lateral deformations. This phenomenon occurs only below the water table, but after liquefaction has developed, it can propagate upward into overlying non-saturated soil as excess pore water dissipates. One of the primary factors controlling the potential for liquefaction is depth to groundwater. Typically, liquefaction has a relatively low potential at depths greater than 50 feet and is unlikely and/or will produce vertical strains well below 1 percent for depths below 60 feet when relative densities are 40 to 60 percent and effective overburden pressures are two or more atmospheres (i.e., 4,232 psf [Seed, 2005]). The condition of liquefaction has two principal effects. One is the consolidation of loose sediments with resultant settlement of the ground surface. The other effect is lateral sliding. Significant permanent lateral movement generally occurs only when there is significant differential loading, such as fill or natural ground slopes within susceptible materials. No such loading conditions exist at the site. Liquefaction susceptibility is related to numerous factors and the following five conditions should be concurrently present for liquefaction to occur: 1) sediments must be relatively young in age and not have developed a large amount of cementation; 2) sediments must generally consist of medium-to fine-grained, relatively cohesionless sands; 3) the sediments must have low relative density; 4) free groundwater must be present in the sediment; and 5) the site must experience a seismic event of a sufficient duration and magnitude, to induce straining of soil particles. Only one or two of these conditions have the potential to affect the site. Seismic Densification Seismic densification is a phenomenon that typically occurs in low relative density granular (i.e., SP, SM) soils that are above the groundwater table. These unsaturated granular soils are susceptible if left in the original density (unmitigated), and are generally dry of the optimum water content (as defined by the ASTM D 1557). During seismic induced ground shaking, these natural or artificial soils deform under loading and volumetrically strain, potentially resulting in ground surface settlements. Some densification of the adjoining un-mitigated properties may influence improvements at the perimeter of the site. Special setbacks and/or foundations may be utilized if significant structures/improvements are placed close to the perimeter of the site. Our evaluation assumed that the current conditions will not be significantly modified by future grading at the time of the design earthquake, which is a reasonably conservative assumption. Summary It is the opinion of GSI that the susceptibility of the site to experience damaging deformations from seismically-induced liquefaction and densification is relatively low owing to the dense, nature of the terrace deposits that underlie the site in the near-surface. In Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lne .. W.O. 6309-A-SC November 30, 2011 Page 9 addition, the recommendations for remedial earthwork and foundations would further reduce any significant liquefaction/densification potential. Some seismic densification of the adjoining un-mitigated site(s) may adversely influence planned improvements at the perimeter of the site. However, given the remedial earthwork and foundation recommendations provided herein, the potential for the planned building to be affected by significant seismic densification or liquefaction of offsite soils may be considered low. Other Geo~ogic/Secondary Seismic Hazards The following list includes other geologic/seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or mitigated as a result of site location, soil characteristics, and typical site development procedures: 0 Subsidence " Dynamic Settlement " Surface Fault Rupture '" Ground Lurching or Shallow Ground Rupture " Tsunami " Seiche It is important to keep in perspective that in the event of an upper bound or maximum credible earthquake occurring on any of the nearby major faults, strong ground shaking would occur in the subject site's general area. Potential damage to any structure(s) would likely be greatest from the vibrations and impelling force caused by the inertia of a structure's mass than from those induced by the hazards considered above. Following implementation of remedial earthwork and design of foundations described herein, this potential would be no greater than that for other existing structures and improvements in the immediate vicinity that comply with current and adopted building standards. LABORATORY TESTING General Laboratory tests were performed on representative samples of the onsite earth materials in order to evaluate their physical characteristics. The test procedures used and results obtained are presented below. Classification Soils were classified visually according to the Unified Soils Classification System (Sowers and Sowers, 1979). The soil classifications are shown on the Test Pit Logs in Appendix B. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 10 Expansion Potential Expansion index testing was performed on a representative sample of site soil in general accordance with ASTM D 4829. The results of expansion index testing are presented in the following table. Please note that the 201 O California Building Code (CBC) does not provide classification of soil expansion indices. As such, GSI used the 2001 CBC for this purpose only. The results of expansion index testing are presented in the following table. TP-2 @ W -4' and TP-3@8%'-9% (Composite} TP-3@2%'-4112' <5 72 Very Low Medium * -per Table 1 B-1-B of the 2001 California Building Code (International Conference of Building Officials, 2001) Atterberg Limits Tests were performed on a representative fine-grained soil sample (paleosol) to evaluate its liquid limit, plastic limit, and plasticity index (Pl) in general accordance with ASTM D 4318. The test results indicate that the onsite soils are plastic. Test results are presented in the following table. r{:l(;ij~sffe,:tv.1ti'No~!:f TP-3@21h'-4%' 49 20 29 Particle -Size Analysis An evaluation was performed on a representative, soil sample (paleosol) in general accordance with ASTM D 422-63. The grain-size distribution curve is presented in Appendix D. The testing was utilized to evaluate the soil classification in accordance with the Unified Soil Classification System (USCS). The results of the particle size analysis indicate that the tested soil is a clayey sand (SC). Shear Testing Shear testing was performed in a direct shear machine of the strain-control type. The rate of deformation is approximately 0.05 inches per minute. Relatively undisturbed and remolded samples of the onsite earth materials were sheared under varying confining Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lne .. W.O. 6309-A-SC November 30, 2011 Page 11 loads in order to evaluate the Coulomb shear strength parameters, angle of internal friction, and cohesion. Remolded samples were tested at 90 percent of the laboratory standard (ASTM D 1557). The testing was performed on an undisturbed ring sample of the unweathered terrace deposits and a remolded ring sample of a composite mix of the colluvium, weathered terrace deposits, and unweathered terrace deposits. The shear testing results are presented in Appendix D. TP-1 @ 5% (Undisturbed) 373 35 123 36 TP-2 .@ %' -4' and 373 30 194 31 TP-3 @ 8%' -91h Remolded Composite Saturated Resistivity. pH, and Soluble Sulfates. and Chlorides GSI conducted sampling of onsite earth materials for general soil corrosivity and soluble sulfates, and chlorides testing. The testing included evaluation of soil pH, soluble sulfates, chlorides, and saturated resistivity. Test results are presented in Appendix D and the following table: TP-3 @2%'-4W TP-2@W-4W and TP-3@8W-9% (Composite Corrosion Summary 8.11 8.23 1,150 0.0340 89 2,100 0.0260 78 Laboratory testing indicates that tested samples of the onsite soils are moderatelyalkaline with respect to soil acidity/alkalinity, are corrosive to exposed, buried metals when saturated, present negligible sulfate exposure to concrete, and are below the action level for chloride exposure (per State of California Department of Transportation, 2003). Reinforced concrete mix design for foundations, slab-on-grade floors, and pavements should minimally conform to "Exposure Class C1" in Table 4.3.1 of ACI 318-08, as concrete Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge GeoSoils, lneo W.O. 6309-A-SC November 30, 2011 Page 12 would likely be exposed to moisture. It should be noted that GSI does not consult in the field of corrosion engineering. Therefore, additional comments and recommendations may be obtained from a qualified corrosion engineer based on the level of corrosion protection required for the project, as determined by the project architect and/or structural engineer. EMBANKMENT FACTORS (SHRINKAGE/BULKING) The volume change of excavated materials upon compaction as engineered fill is anticipated to vary with material type and location. The overall earthwork shrinkage and bulking may be approximated by using the following parameters: Undocumented Artificial Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5% to 10% shrinkage Quaternary Colluvium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3% to 8% shrinkage Weathered Terrace Deposits ......................... 2% to 3% shrinkage or bulk Unweathered Terrace Deposits ............................ 2% to 3% shrinkage It should be noted that the above factors are estimates only, based on preliminary data. Colluvium may achieve higher shrinkage if organics or clay content is higher than anticipated. Final earthwork balance factors could vary. In this regard, it is recommended that balance areas be reserved where grades could be adjusted up or down near the completion of grading in order to accommodate any yardage imbalance for the project. PREUMINARY CONCLUSIONS AND RECOMMENDATIONS Based on our field exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the site appears suitable for the proposed development from a geotechnical engineering and geologic viewpoint, provided that the recommendations presented in the following sections are properly incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the currently proposed development are: " Earth materials characteristics and depth to competent bearing material. " On-going expansion/corrosion potentials of site soils. " Potential for perched groundwater to occur during and after development. " Non-structural zone on un-mitigated perimeter conditions (improvements subject to distress). .. Temporary slope stability. " Regional seismic activity. The recommendations presented herein consider these as well as other aspects of the site. The engineering analyses, performed, concerning site preparation and the recommendations presented herein have been completed using the information provided and obtained during our field work. In the event that any significant changes are made to Golden Surf Holdings, LLC Paseo Point, Carlsbad File: e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 13 proposed site development, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the recommendations of this report are evaluated or modified in writing by this office. Foundation design parameters are considered preliminary until the foundation design, layout, and structural loads are provided to this office for review. 1. Soil engineering, observation, and testing services should be provided during earthwork to aid the contractor in removing unsuitable soils and in his effort to compact the fill. 2. Geologic observations should be performed during any grading to verify and/or further evaluate geologic conditions. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted. 3. In general, remedial grading excavations for the removal and re-compaction of potentially compressible, near-surface soils are anticipated to be on the order of 31h to 5% feet across a majority of the site. However, local deeper remedial grading excavations cannot be precluded and should be anticipated. Remedial grading excavations should be completed below a 1 :1 (h:v) projection down from the bottom, outermost edge of proposed settlement-sensitive improvements and/or limits of planned fills. 4. Laboratory testing indicates thatthe expansion index of tested samples of the onsite earth materials range from <5 to 72. Atterberg limits testing indicates that the P .I. of a tested sample of the onsite soils is 29. Thus, some of the onsite soils are considered expansive per Section 1803.5.2 of the 2010. Based on visual soil classification during the field exploration and laboratory testing, expansive soil conditions are generally associated with the Quaternary-age paleosol exposed in Test Pit TP-3 (see Appendix Band Plate 1). On a preliminary basis conventional foundations may be used to support the planned residential structures provided the soils within the influence of the foundation exhibit an expansion index of 20 or less and a P.l. less than 15. Building foundations within the influence of expansive soils should be designed and constructed in accordance with Sections 1808.6.1 or 1808.6.2 of the 201 O CBC. Foundation systems used for the mitigation of expansive soils typically incorporate the post-tension institute (PTI) and wire reinforcement institute (WRI) methodologies. Preliminary recommendations for the design and construction of conventional, post-tension (PT), and mat foundations are included herein. Final foundation design will be provided at the conclusion of grading, based on the E.I. and P.1. of soils exposed near pad grade. As an alternative to the use of PT and mat foundations, expansive soils may be stockpiled and removed from the site during remedial grading. The removed expansive soils may be replaced with import materials possessing an E.I. of20 or less and a P.l. lessthan 15, if warranted for the balance of earthwork quantities. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoHs, lne .. W.O. 6309-A-SC November 30, 2011 Page 14 5. Soil pH, saturated resistivity, soluble sulfate, and chloride testing was performed on representative samples of the onsite soils. Testing indicates that the soils are moderately alkaline with respect to soil acidity/alkalinity, are corrosive to exposed, buried metals when saturated, possess negligible sulfate exposure to concrete, and are below the action level for chloride exposure (per State of California Department of Transportation, 2003). Reinforced concrete mix design for foundations, slab-on-grade floors, and pavements should minimally conform to "Exposure Class C1" in Table 4.3.1 of ACI 318-08, as concrete would likely be exposed to moisture. GSI does not consult in corrosion engineering. Therefore, additional comments and recommendations may be obtained from a qualified corrosion engineer based on the level of corrosion protection desired or required for the project, as determined by the project architect and/or structural engineer. 6. In general and based upon the available data to date, regional groundwater is not expected to be encountered during construction of the proposed site improvements nor is it anticipated to adversely affect site development. However, there is potential for perched water conditions to manifest along zones of contrasting permeabilities (i.e., sandy/clayey fill lifts, fill/terrace deposits contacts, bedding, discontinuities, etc.) during and after construction. The potential for perched water to occur should be disclosed to all interested/affected parties. 7. It should be noted, that the 201 O CBC (CBSC, 201 O) indicates that removals of unsuitable soils be performed across all areas to be graded, not just within the influence of the proposed addition. Relatively deep removals may also necessitate a special zone of consideration, on perimeter/confining areas. This zone would be approximately equal to the depth of removals, if removals cannot be performed onsite and offsite. Thus, any settlement-sensitive improvements (walls, curbs, flatwork, etc.), constructed within this zone, may require deepened foundations, reinforcements, etc., or will retain some potential for settlement and associated distress. This will require proper disclosure to all interested/affected parties, should this condition exist at the conclusion of grading. Based on our review of C&A (2011) and the available subsurface data, retaining walls constructed near property lines will require deepened footings that penetrate potentially compressible soils and embed into unweathered terrace deposits. Based on the available subsurface data , this would require the retaining wall footings at the perimeter of the site to on the order of 4 % to 6114 feet below finish grade for a minimum 1 foot embedment into unweathered terrace deposits. 8. Unsupported temporary excavation walls ranging between 4 and 20 feet in gross overall height should be constructed in accordance with CAL-OSHA guidelines for Type B soils, provided groundwater or running sands are not present. On a preliminary basis, unsupported temporary excavations walls may be constructed at gradients no steeper than 1 :1 (horizontal:vertical) provided groundwater and/or running sands are not present. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 15 9. The seismicity-acceleration values provided herein should be considered during the design and construction of the proposed development. 10. General Earthwork, Grading Guidelines, and Preliminary Criteria are provided at the end of this report as Appendix E. Specific recommendations are provided below. EARTHWORK CONSTRIUCTION RECOMMENDATIONS General Remedial earthwork will be necessary for the support of the proposed settlement-sensitive improvements (i.e., residential structures, walls, underground utilities, pavements,etc.). Remedial grading should conform to the guidelines presented in Appendix J of the 201 O CBC, the requirements of the City of Carlsbad, and the Grading Guidelines presented in Appendix E, except where specifically superceded in the text of this report. In case of conflict, the more onerous code or recommendations should govern. Prior to grading, a GSI representative should be present at the pre-construction meeting to provide additional grading guidelines, if needed, and review the earthwork schedule. During earthwork construction, all site preparation and the general grading procedures of the contractor should be observed and the fill selectively tested by a representative(s) of GSI. If unusual or unexpected conditions are exposed in the field, they should be reviewed by this office and, if warranted, modified and/or additional recommendations will be offered. All applicable requirements of local and national construction and general industry safety orders, the Occupational Safety and Health Act (OSHA), and the Construction Safety Act should be met. It is the onsite general contractor's and individual subcontractors' responsibility to provide a safe working environment for our field staff who are onsite. GSI does not consult in the area of safety engineering. GSI also recommends that the contractor(s) take precautionary measure to protect work, especially during the rainy season. Failure to do so may result in additional remedial earthwork. Demolition/Grubbing 1. Vegetation, and any miscellaneous deleterious debris generated from the demolition of existing site improvements should be removed from the areas of proposed grading/earthwork. 2. Cavities or loose soils remaining after demolition and site clearance should be cleaned out and observed by the geotechnical consultant. The cavities should be replaced with fill materials that have been moisture conditioned to at least optimum moisture content and compacted to at least 90 percent of the laboratory standard. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 16 Remedial Removals (Removal of Potentially Compressible Surficeai Materiais) Where planned fills or settlement-sensitive improvements are proposed, potentially compressible undocumented artificial fill, Quaternary colluvium, and weathered terrace deposits should be removed to expose unweathered terrace deposits. Removed soils may be reused as properly engineered fill provided that major concentrations of organic and/or deleterious materials have been removed prior to placement. In general, the remedial grading excavations to removed potentially compressible soils are anticipated to be on the order of 31h to 51h feet across a majority of the site. However, local deeper remdial excavations cannot be precluded and should be anticipated. The removal of potentially compressible soils should be performed below a 1 :1 (h:v) projection down from the bottom, outermost edge of proposed settlement-sensitive improvements and/or limits of planned fills. Once the unsuitable soils have been removed, the exposed terrace deposits should be scarified approximately 6 to 8 inches, moisture conditioned as necessary to achieve the soil's optimum moisture content and then be re-compacted to at least 90 percent of the laboratory standard prior to fill placement. All remedial removal excavations should be observed by the geotechnical consultant prior to scarification. Overexcavation In areas of the building footprints where fill/terrace deposit transition conditions occur or where planned plus remedial fills do not allow for 2 feet of engineered fill beneath the footings, the terrace deposits should be overexcavated to at least 2 feet below the lowermost foundation element (as approved by GSI field personnel) and be replaced with engineered fill compacted to at least 90 percent of the laboratory standard (ASTM D 1557). The bottom of the overexcavation should be sloped toward the street or private road, scarified at least 6 to 8 inches, moisture-conditioned as necessary to achieve the soil's optimum moisture content, and then be recompacted to at least 90 percent of the laboratory standard prior to fill placement. Overexcavation should be laterally completed to at least 5 feet outside the outermost foundation element of settlement-sensitive improvements. Overexcavations should be observed by the geotechnical consultant prior to scarification. The maximum to minimum fill thickness within the influence of the proposed residential structures should not exceed a ratio of 3:1 (maximum:minimum). Alternative Earthwork Mitigation of Expansive Soils As previously indicated, the Quaternary-age paleosol, developed on the weathered terrace deposits, encountered in Test Pit TP-3, is considered expansive and plastic, and may require special foundation design and construction if placed or left within the influence of the planned residential structures. As an alternative to the use of special foundation systems to mitigate expansive soil effects, the paleosol may be stockpiled and removed from the site during remedial grading. If necessary, expansive soils may be replaced with import materials possessing an E.I. of 20 or less and a P.I. less than 15. Based on the available data, such earthwork mitigation would allow for the use of conventional foundations to support the residential structures. In addition, the recommended earthwork Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Inc .. W.O. 6309-A-SC November 30, 2011 Page 17 mitigation would also reduce the potential for retaining walls and pavements to be adversely affected by expansive soils. Temporary Slopes Temporary slopes for excavations greater than 4 feet but less than 20 feet in overall height should conform to CAL-OSHA and/or OSHA requirements for Type "B" soils. Temporary slopes, up to a maximum height of ±20 feet, may be excavated at a 1 :1 (h:v) gradient, or flatter, provided groundwater and/or running sands are not exposed. Construction materials or soil stockpiles should not be placed within 'H' of any temporary slope where 'H' equals the height of the temporary slope. All temporary slopes should be observed by a licensed engineering geologist and/or geotechnical engineer prior to worker entry into the excavation. Based on the exposed field conditions, inclining temporary slopes to flatter gradients or the use of shoring may be necessary if adverse conditions are observed. If temporary slopes conflict with property boundaries, shoring or alternating slot excavations may be necessary. The need for shoring or alternating slot excavations could be further evaluated during the grading plan review stage, but is considered likely on the eastern and northern property lines. Engineered Fill Placement Engineered fill should be placed in thin lifts, moisture conditioned, and mixed to achieve the soil's optimum moisture content, and then be mechanically compacted to at least 90 percent of the laboratory standard (ASTM D 1557). Engineered fill placement should be observed and selectively tested for moisture content and compaction by the geotechnical consultant. Graded Slopes At this time graded (cut and fill) slopes are anticipated to be 8 feet or less in overall height and inclined at gradients no steeper than 2:1 (h:v). It is our professional opinion that graded slopes will be grossly and surficially stable following the completion of construction provided that site drainage is directed away from the tops of slopes and the slope faces are protected with deep-rooted vegetative cover capable of surviving the prevailing climate without only the amount of irrigation water necessary to sustain plant vigor. Vegetative cover should be provided as soon as possible following slope construction. In the interim, GSI recommends the slope faces be covered with City of Carlsbad approved erosion control devices. Graded slope stability should be further evaluated during the grading plan review stage. Graded fill slopes should be properly keyed and benched, and be compacted to at least 90 percent relative compaction, including the slope face. All graded cut slopes should be observed by this office following construction. Although unlikely, if adverse geologic conditions (daylighted, out-of-slope bedding and/or joints/fractures, highly weathered terrace deposits, thick unsuitable soils, etc.) are noted in the slope face, GSI would provide Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnco W.O. 6309-A-SC November 30, 2011 Page 18 recommendations for mitigation. Mitigation measures may included but not necessarily be limited to inclining the slope to gradients flatter than any adverse geologic structure or stabilization fills. ~mport Fill Materials Any import fill materials used on this project should possess an E.I. of 20 or less with a P.I. less than 15. All import fill material should be evaluated by GSI prior to placement within the site. At least three (3) business days of lead time will be necessary for the required laboratory testing. PREUMINARY FOUNDATION RECOMMENDATIONS General The foundation design and construction recommendations are based on laboratory testing and engineering evaluations of onsite earth materials by GSI. The following preliminary foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. The onsite soils expansion indices vary between <5 and 72, with a plasticity index of 29. If earthwork mitigation of the expansive paleosol is not performed (as recommended herein), it is possible that blended engineered fill materials, placed near pad grade, may be expansive per Section 1803.5.2 of the 201 O CBC. This would require that the planned residential structures be supported by foundations designed and constructed in accordance with Sections 1808.6.1 or 1808.6.2 of the 201 O CBC. The likelihood of the ability to use conventional foundations to support the planned residential structures would greatly increase if the recommended removal and replacement of the expansive paleosol were performed during grading. The decision to incorporate earthwork or special foundations to mitigate expansive soil effects should be based on a cost versus benefit analysis. In the following sections, GSI provides design and construction recommendations for conventional, post-tensioned, and mat foundations. This report presents minimum design criteria for the design of foundations, concrete slab-on-grade floors, and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer. Recommendations by the project's design-structural engineer or architect, which may exceed the geotechnical consultant's recommendations, should take precedence over the following minimum requirements. The foundation systems recommended herein may be used to support the proposed residences provided they are founded in compacted fill tested and approved by GSI. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained in the 201 O CBC. In the eventthat the information concerning the proposed development plan is not correct, or any changes in the design, location or loading conditions of the proposed structure are made, the conclusions and recommendations contained in this report shall not be Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 19 considered valid unless the changes are reviewed and conclusions of this report are modified or approved in writing by this office. The information and recommendations presented in this section are not meant to supercede design by the project structural engineer or civil engineer specializing in structural design. Upon request, GSI could provide additional input/consultation regarding soil parameters, as they relate to foundation design. General Foundation Design 1. The foundation systems should be designed and constructed in accordance with guidelines presented in the 201 O CBC. 2. An allowable bearing value of 1,500 pounds per square foot (psf) may be used for the design of footings that maintain a minimum width of 12 inches and a minimum depth of 12 inches (below the lowest adjacent grade) and are founded into properly engineered fill. This value may be increased by 20 percent for each additional 12 inches in footing depth to a maximum value of 2,500 psf. These values may be increased by one-third when considering short duration seismic or wind loads. Isolated pad footings should have a minimum dimension of at least 24 inches square and a minimum embedment of 24 inches below the lowest adjacent grade into properly engineered fill. Foundation embedment excludes any landscaped zone, topsoil/colluvium, weathered terrace deposits, concrete slabs-on-grade, and/or slab underlayment. 3. Passive earth pressure may be computed as an equivalent fluid having a density of 150 pcf, with a maximum earth pressure of 1,500 psf for footings founded into properly engineered fill. 4. For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a concrete to soil contact when multiplied by the dead load. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. All footing setbacks from slopes should comply with Figure 1808.7.1 of the 2010 CBC. GSI recommends a minimum horizontal setback distance of 7 feet as measured from the bottom, outboard edge of the footing to the slope face. 7. Footings for structures adjacent to retaining walls should be deepened so as to extend below a 1 :1 projection from the heel of the wall. Alternatively, walls may be designed to accommodate structural loads from buildings or appurtenances as described in the "Retaining Wall" section of this report. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge GeoSoils, Inc .. W.O. 6309-A-SC November 30, 2011 Page 20 8. Code-compliant foundations may be conventional-type if soils within the influence of the foundation have an E.I. of 20 or less and a P.I. less than 15. f ouindaition Settlement Provided the recommendations in this report are properly followed, foundation systems should be minimally designed to accommodate a differential settlement of at least 1 inch in a 40-foot span. PRELIMINARY FOUNDATION CONSTRUCTION !RECOMMENDATIONS The following foundation construction recommendations are presented as a minimum criteria from a soils engineering viewpoint. Conventional foundations may be used to support the planned residential structures provided the soils within the upper 7 feet of pad grade possess an E.1. of 20 or less and a P.1. less than 15. Otherwise, post-tension or mat foundations would be necessary to mitigate expansive soil effects in accordance with Sections 1808.6.1 or 1808.6.2 of the 201 O CBC. Conventional Foundations -Expansion Index of 20 or less with a Plasticity Index less Than 15 1. Exterior and interior footings should be founded into engineered fill at a minimum depth of 12 or 18 inches below the lowest adjacent grade for a one-or two-story floor loads, respectively. For one-and two-story floor loads, footing widths should be 12 and 15 inches, respectively. Isolated, exterior column and panel pads, or wall footings, should be at least 24 inches, square, and founded at a minimum depth of 24 inches into properly compacted fill. All footings should be minimally reinforced with four No. 4 reinforcing bars, two placed near the top and two placed near the bottom of the footing. 2. All interior and exterior column footings, and perimeter wall footings, should be tied together via grade beams in at least one direction. The grade beam should be at least 12 inches square in cross section, and should be provided with a minimum of one No.4 reinforcing bar at the top, and one No.4 reinforcing bar at the bottom of the grade beam. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 3. A grade beam, reinforced as previously recommended and at least 12 inches square, should be provided across large (garage) entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 4. A minimum concrete slab-on-grade thickness of 5 inches is recommended. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnco W.O. 6309-A-SC November 30, 2011 Page 21 5. Concrete slabs should be reinforced with a minimum of No. 3 reinforcement bars placed at 18-inch on centers, in two horizontally perpendicular directions (i.e., long axis and short axis). 6. All slab reinforcement should be supported to ensure proper mid-slab height positioning during placement of the concrete. "Hooking" of reinforcement is not an acceptable method of positioning. 7. Specific slab subgrade pre-soaking is not required for these soil conditions. However, moisture conditioning the upper 12 inches of the slab subgrade to at least optimum moisture should be considered. 8. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction of 90 percent of the laboratory standard (ASTM D 1557), whether the soils are to be placed inside the foundation perimeter or in the yard/right-of-way areas. This material must not alter positive drainage patterns that direct drainage away from the structural areas and toward the street. 9. Reinforced concrete mix design should conform to "Exposure Class C1" in Table 4.3.1 of ACl-318-08 since concrete would likely be exposed to moisture. Post-Tensioned Foundations Post-tension foundations may be used to mitigate the damaging effects of expansive soils on the planned building's foundation and slab-on-grade floor if complete earthwork mitigation of such soils is not a preferred alternative. They may also be used for increased performance of foundations constructed on non-detrimentally expansive soils. The post-tension foundation designer may elect to exceed these minimal recommendations to increase slab stiffness performance. Post-tension (Pl) design may be either ribbed or mat-type. The latter is also referred to as uniform thickness foundation (UTF). The use of a UTF is an alternative to the traditional ribbed-type. The UTF offers a reduction in grade beams (i.e., that method typically uses a single perimeter grade beam and possible "shovel" footings), but has a thicker slab than the ribbed-type. The use of block outs along the living area/garage walls would be necessary for cable tensioning. Therefore, the project designer and structural engineer should evaluate the feasibility the use of post- tensioned foundations for this project. The information and recommendations presented in this section are not meant to supercede design by a registered structural engineer or civil engineer qualified to perform post-tensioned design. Post-tensioned foundations should be designed using sound engineering practice and be in accordance with local and 201 O CBC requirements. Upon request, GSI can provide additional data/consultation regarding soil parameters as related to post-tensioned foundation design. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnco W.O. 6309-A-SC November 30, 2011 Page 22 From a soil expansion/shrinkage standpoint, a common contributing factor to distress of structures using post-tensioned slabs is a "dishing" or "arching" of the slabs. This is caused by the fluctuation of moisture content in the soils below the perimeter of the slab primarily due to onsite and offsite irrigation practices, climatic and seasonal changes, and the presence of expansive soils. When the soil environment surrounding the exterior of the slab has a higher moisture content than the area beneath the slab, moisture tends to migrate inward, underneath the slab edges to a distance beyond the slab edges referred to as the moisture variation distance. When this migration of water occurs, the volume of the soils beneath the slab edges expand and cause the slab edges to lift in response. This is referred to as an edge-lift condition. Conversely, when the outside soil environment is drier, the moisture transmission regime is reversed and the soils underneath the slab edges lose their moisture and shrink. This process leads to dropping of the slab at the edges, which leads to what is commonly referred to as the center lift condition. A well-designed, post-tensioned slab having sufficient stiffness and rigidity provides a resistance to excessive bending that results from non-uniform swelling and shrinking slab subgrade soils, particularly within the moisture variation distance, near the slab edges. Other mitigation techniques typically used in conjunction with post-tensioned slabs consist of a combination of specific soil pre-saturation and the construction of a perimeter "cut-off' wall grade beam. Soil pre-saturation consists of moisture conditioning the slab subgrade soils prior to the post-tension slab construction. This effectively reduces soil moisture migration from the area located outside the building toward the soils underlying the post-tension slab. Perimeter cut-off walls are thickened edges of the concrete slab that impedes both outward and inward soil moisture migration. Soil Moisture Specific pre-moistening and moisture testing of the slab subgrade is recommended for expansive soil conditions (E. I. > 20 and P. I. of 15 or greater). The moisture content of the subgrade soils should be equal to, or greater than optimum moisture to a depth equivalent to the exterior footing depth in the slab areas (typically 12 and 18 inches for very low to low (El= Oto 50) and medium (El= 51 to 90} expansive soils, respectively). Pre-moistening and/or pre-soaking should be evaluated· by the soils engineer 72 hours prior to vapor retarder placement. Perimeter Cut-Off Walls Perimeter cut-off walls should be 12 and 18 inches deep for very low to low and medium expansive soil conditions, respectively. The cut-off walls may be integrated into the slab design or independent of the slab. The cut-off walls should be a minimum of 6 inches thick. The bottom of the perimeter cut-off wall should be designed to resist tension, using cable or reinforcement per the structural engineer. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnco W.O. 6309-A-SC November 30, 2011 Page 23 Post-Tensioned Foundation Desugn The following recommendations for design of post-tensioned slabs have been prepared in general compliance with the requirements of the recent Post Tensioning lnstitute's (PTl's) publication titled "Design of Post-Tensioned Slabs on Ground, Third Edition" (PTI, 2004), together with it's subsequent addendums (PTI, 2008). Soil Support Parameters The recommendations for soil support parameters have been provided based on the typical soil index properties for soils that are very low to medium in expansion potential. The soil index properties are typically the upper bound values based on our experience and practice in the southern California area. The following table presents suggested minimum coefficients to be used in the Post-Tensioning Institute design method. Thomthwaite Moisture Index -20 inches/year Correction Factor for Irrigation 20 inches/year Depth to Constant Soil Suction 7 feet Constant soil Suction (pf) 3.6 Moisture Velocity 0.7 inches/month Plasticitv Index (P.I.) 15-35 Based on the above, the recommended soil support parameters are tabulated below: em center lift 9.0 feet 8.7 feet em edge lift 5.2 feet 4.5 feet Ym center lift 0.3 inches 0.49 inches Ym edge lift 0.7 inch 1.3 inch Bearing Value <1> 1,000 psf 1,000 psf Lateral Pressure 250 psf 175 psf Subgrade Modulus (k) 1 00 pci/inch 85 pci/inch Minimum Perimeter 12 inches 18inches Footing Embedment <2> <1> Internal bearing values within the perimeter of the post-tension slab may be increased to 2,000 psf for a minimum embedment of 12 inches, then by 20 percent for each additional foot of embedment to a maximum of 2,500 psf (fill). !2> As measured below the lowest adjacent compacted subgrade surface without landscape layer or sand underlayment. Note: The use of o en bottomed raised lanters ad·acent to foundations will re uire more onerous desi n arameters. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoil.s, lneo W. 0. 6309-A-SC November 30, 2011 Page 24 The parameters are considered minimums and may not be adequate to represent all expansive soils/drainage conditions such as adverse drainage and/or improper landscaping and maintenance. The above parameters are applicable provided the structure has positive drainage that is maintained away from the structure. In addition, no trees with significant root systems are to be planted within 15 feet of the perimeter of foundations. Therefore, it is important that information regarding drainage, site maintenance, trees, settlements, and effects of expansive soils be passed on to future all interested/affected parties. The values tabulated above may not be appropriate to account for possible differential settlement of the slab due to other factors, such as excessive settlements. If a stiffer slab is desired, alternative Post-Tensioning Institute ([PTI] third edition) parameters may be recommended. Mat Fol.llndations In lieu of using a post-tensioned foundation to resist expansive soil effects, the Client may consider a mat -type foundation which uses steel bar reinforcement instead of post.: tensioned cables. The structural engineer may supersede the following recommendations based on the planned building loads and use. Mat Foundation Design The design of mat foundations should incorporate the vertical modulus of subgrade reaction. This value is a unit value for a 1-foot square footing and should be reduced in accordance with the following equation when used with the design of larger foundations. This is assumes that a compacted · fill layer with an average relative compaction of 90 percent of the laboratory (ASTM D 1557), overlying dense terrace deposits underlies the footings. K =K [8+1]2 R S 28 where: K8 = unit subgrade modulus KR = reduced subgrade modulus B = foundation width (in feet) The modulus of subgrade reaction to be used in mat foundation design for various expansive soil conditions are presented in the following table. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Iraeo 85 ci/inch W.O. 6309-A-SC November 30, 2011 Page 25 Slab Subgrade Pre-moistening -Mat Foundations The moisture content of the subgrade soils should be equal to or greater than optimum moisture to a depth of 12 and 18 inches for very low to low and medium expansive soils, respectively. Pre-moistening and/or pre-soaking should be evaluated by the soils engineer 72 hours prior to vapor retarder placement. CORROSION Upon completion of grading, additional testing of soils (including import materials) for corrosion to concrete and metals should be performed prior to the construction of utilities and foundations. SOIL MOISTURE TRANSMISSION CONSIDERATIONS GSI has evaluated the potential for vapor or water transmission through the concrete floor slab, in light of typical floor coverings and improvements. Please note that slab moisture emission rates range from about 2 to 27 lbs/ 24 hours/1,000 square feet from a typical slab (Kanare, 2005), while floor covering manufacturers generally recommend about 3 lbs/24 hours as an upper limit. The recommendations in this section are not intended to preclude the transmission of water or vapor through the foundation or slabs. Foundation systems and slabs shall not allow water or water vapor to enter into the structure so as to cause damage to another building component or to limit the installation of the type of flooring materials typically used for the particular application (State of California, 2011 ). These recommendations may be exceeded or supplemented by a water "proofing" specialist, project architect, or structural consultant. Thus, the client will need to evaluate the following in light of a cost vs. benefit analysis (owner expectations and repairs/replacement), along with disclosure to all interested/affected parties. It should also be noted that vapor transmission will occur in new slab-on-grade floors as a result of chemical reactions taking place within the curing concrete. Vapor transmission through concrete floor slabs as a result of concrete curing has the potential to adversely affect sensitive floor coverings depending on the thickness of the concrete floor slab and the duration of time between·the placement of concrete, and the floor covering. It is possible that a slab moisture sealant may be needed prior to the placement of sensitive floor coverings if a thick slab-on-grade floor is used and the time frame between concrete and floor covering placement is relatively short. Considering the E.I. test results presented herein, and known soil conditions in the region, the anticipated typical water vapor transmission rates, floor coverings, and improvements (to be chosen by the Client and/or project architect) that can tolerate vapor transmission rates without significant distress, the following alternatives are provided: Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 26 " Concrete slabs should be a minimum of 5 inches thick . ., Concrete slab underlayment should consist of a 1 O to 15-mil vapor retarder, or equivalent, with all laps sealed per the 201 O CBC and the manufacturer's recommendation. The vapor retarder should comply with the ASTM E 17 45 - Class A or B criteria, and be installed in accordance with ACI 302.1 R-04 and ASTM E 1643. The 1 Oto 15-mil vapor retarder (ASTM E 17 45 -Class A or B) shall be installed per the recommendations of the manufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). " Concrete slabs, including the garage areas, shall be underlain by 2 inches of clean, washed sand (SE> 30) above a 15 mil vapor retarder (ASTM E-1745 -Class A or Class B, per Engineering Bulletin 119 [Kanare, 2005]) installed per the recommendationsofthemanufacturer, including all penetrations (i.e., pipe, ducting, rebar, etc.). The manufacturer shall provide instructions for lap sealing, including minimum width of lap, method of sealing, and either supply or specify suitable products for lap sealing (ASTM E 1745), and per code. ACI 302.1 R-04 (2004) states "If a cushion or sand layer is desired between the vapor retarder and the slab, care must be taken to protect the sand layer from taking on additional water from a source such as rain, curing, cutting, or cleaning. Wet cushion or sand layer has been directly linked in the past to significant lengthening of time required for a slab to reach an acceptable level of dryness for floor covering applications." Therefore, additional observation and/or testing will be necessary for the cushion or sand layer for moisture content, and relatively uniform thicknesses, prior to the placement of concrete. 0 The vapor retarder shall be underlain by 2 inches of sand (SE _2: 30) placed directly on the prepared, moisture conditioned, subgrade and should be sealed to provide a continuous retarder under the entire slab, as discussed above. As discussed previously, GSI indicated this layer of import sand may be eliminated below the vapor retarder, .if laboratory testing indicates thatthe slab subgrade soil have a sand equivalent (SE) of 30 or greater. ~ Concrete should have a maximum water/cement ratio of 0.50. This does not supercede Table 4.3.1 of Chapter 4 of the ACI (2008) for corrosion or other corrosive requirements. Additional concrete mix design recommendations should be provided by the structural consultant and/or waterproofing specialist. Concrete finishing and workablity should be addressed by the structural consultant and a waterproofing specialist. " Where slab water/cement ratios are as indicated herein, and/or admixtures used, the structural consultant should also make changes to the concrete in the grade Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\630D\6309a.pge GeoSoils, lneo W.O. 6309-A-SC November 30, 2011 Page 27 beams and footings in kind, so that the concrete used in the foundation and slabs are designed and/or treated for more uniform moisture protection. The owner(s) should be specifically advised which areas are suitable for tile flooring, vinyl flooring, or other types of water/vapor-sensitive flooring and which are not suitable. In all planned floor areas, flooring shall be installed per the manufactures recommendations. 0 Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer and should be consistent with the specified floor coverings indicated by the architect. Regardless of the mitigation, some limited moisture/moisture vapor transmission through the slab should be anticipated. Construction crews may require special training for installation of certain product(s), as well as concrete finishing techniques. The use of specialized product(s) should be approved by the slab designer and water-proofing consultant. A technical representative of the flooring contractor should review the slab and moisture retarder plans and provide comment prior to the construction of the foundations or improvements. The vapor retarder contractor should have representatives onsite during the initial installation. WALL DESIGN PARAMETERS CONSIDERING EXPANSIVE SO~LS Conventional Retaining Walls The design parameters provided below assume that either very low expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials with an expansion index up to 50 are used to backfill any retaining wall. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the plans. Building walls, below grade, should be water-proofed. The foundation system for the proposed retaining walls should be designed in accordance with the recommendations presented in this and preceding sections of this report, as appropriate. Footings should be embedded a minimum of 18 inches below the lowest adjacent grade (excluding landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. As indicated previously, planned retaining wall footings near the perimeter of the site will likely need to be deepened into unweathered terrace deposits for adequate vertical and lateral bearing support. Recommendations for specialty walls (i.e., crib, earthstone, geogrid, etc.) can be provided upon request, and would be based on site specific conditions. Restrained Walls Any retaining walls that will be restrained prior to placing and compacting backfill material or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\63DD\6309a.pge GeoSoils, lnee W.O. 6309-A-SC November 30, 2011 Page 28 pressure (EFP) of 55 pounds per cubic foot (pct) and 65 pct for select and native backfill, respectively. The design should include any applicable surcharge loading. For areas of male or re-entrant corners, the restrained wall design should extend a minimum distance of twice the height of the wall (2H) laterally from the corner. Cantilevered Walls The recommendations presented below are for cantilevered retaining walls up to 1 O feet high. Design parameters for walls less than 3 feet in height may be superceded by City of Carlsbad and/or County of San Diego standard design. Active earth pressure may be used for retaining wall design, provided the top of the wall is not restrained from minor deflections. An equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are given below for specific slope gradients of the retained material. These do not include other superimposed loading conditions due to traffic, structures, seismic events or adverse geologic conditions. When wall configurations are finalized, the appropriate loading conditions for superimposed loads can be provided upon request. Level(1l 2 to 1 45 65 ,,, iif ~"'!, 55 70 (1) Level backfill behind a retaining wall is defined as compacted earth materials, properly drained, without a slope for a distance of 2H behind the wall, where H is the height of the wall. (2) SE> 30, P.I. < 15, E.I. < 21, and< 10% passing No. 200 sieve. (3l E.I. =Oto 50, SE> 30, P.I. < 15, E.I. < 21, and< 15% assing No. 200 sieve. Earthquake Loads (Seismic Surcharge) Given the nature of the site soils and the anticipated level of potential earthquake shaking given herein, GSI recommends that for walls retaining more than, or equal to, 6 feet of soil and are 6 feet or less from structures, or may inhibit ingress/egress for the site roads or lots, are incorporated into the building (stepped foundations or truck loading docks), or critical access pathways (i.e., collector streets, fire access roads, etc.), a seismic surcharge (increment) of 16H should be used where H is the height of the wall and the surcharge is applied as a uniform pressure for restrained walls. For cantilever walls, this distribution may be taken as an inverted triangular distribution. This complies with a 0.27g Probabilistic Horizontal Site Acceleration (PHSA) 10 percent probability of exceedance in 50 years. The resulting wall design should be safe from seismic induced overturning with a minimum factor-of-safety (F.O.S.) of 1.1 to 1.3. Basement walls, or utility or below grade storage areas, if proposed, will need to be evaluated as retaining walls, as well as part of Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, Inc .. W.O. 6309-A-SC November 30, 2011 Page 29 the wall design from a seismic standpoint per the 2010 CBC (CBSC, 2010) and Section 15.6.1 of ASCE 7-05 (ASCE, 2006). Retaining Wall Backfill and Drainage Positive drainage must be provided behind all retaining walls in the form of gravel wrapped in geofabric and outlets. A backdrain system is considered necessary for retaining walls that are 2 feet or greater in height. Details 1, 2, and 3, present the backdrainage options discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or %-inch to 11h-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind the base of the walls and upward at least 1 foot. For native backfill that has up to E.I. = 50, continuous Class 2 permeable drain materials should be used behind the wall. This material should be continuous (i.e., full height) behind the wall, and it should be constructed in accordance with the enclosed Detail 1 (Typical Retaining Wall Backfill and Drainage Detail). For limited access and confined areas, (panel) drainage behind the wall may be constructed in accordance with Detail 2 (Retaining Wall Backfill and Subdrain Detail Geotextile Drain). Materials with an expansion index (E.I.) potential of greater than 50 should not be used as backfill for retaining walls. For more onerous expansive situations, backfill and drainage behind the retaining wall should conform with Detail 3 (Retaining Wall And Subdrain Detail Clean Sand Backfill). Outlets should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than ± 100 feet apart, with a minimum of two outlets, one on each end. The use of weep holes, only, in walls higher than 2 feet, is not recommended. The surface of the backfill should be sealed by pavement or the top 18 inches compacted with native soil (E.I. ~ 50). Proper surface drainage should also be provided. For additional mitigation, consideration should be given to applying a water-proof membrane to the back of all retaining structures. The use of a waterstop should be considered for all concrete and masonry joints. Wall/Retaining Wall Footing Transitions Site walls are anticipated to be founded on footings designed in accordance with the recommendations in this report. Should wall footings transition from cut to fill, the civil designer may specify either: a) A minimum of a 2-foot overexcavation and recompaction of cut materials for a distance of 2H, from the point of transition. b) Increase of the amount of reinforcing steel and wall detailing (i.e., expansion joints or crack control joints) such that a angular distortion of 1 /360 for a distance of 2H on either side of the transition may be accommodated. Expansion joints should be placed no greater than 20 feet on-center, in accordance with the structural Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 30 (1) Waterproofing membrane --- CMU or reinforced-concrete \ wall \ _t_ ±12 inches Proposed grade t - sloped to drain per precise civil drawings (5) Weep hole (1) Waterproofing membrane. (2) Gravel= Clean, crushed, % to 1~ inch. Structural f coting or settlement-sensitive improvement Provide surf ace drainage via an engineered V-ditch (see civil plans for details) 2:1 (h:v) slope . ·. : .. , ... • .. · . · ... : . . . . .... • ... · ·:. : Native backfill 1:1 (h=v) or flatter backcut to be properly benched (6) Footing (3) Filter fabric: Mirafi 140N or approved equivalent. • 4 (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient sloped to suitable, approved outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-f oot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE A Detail 1 (1) Waterproofing membrane (optional)---, CMU or reinf creed-concrete wall l 6 inches -t (5) Weep hole Proposed grade sloped to drain per precise civil drawings ~~~,~\':§(\~~'03\~\ Footing and wall design by others~-- Structural footing or settlement-sensitive improvement Provide surface drainage via engineered V-ditch (see civil plan details) 2=1 (h=v) slope Native backfill 1=1 (h:v) or flatter backcut to be properly benched --(6) 1 cubic foot of %-inch crushed rock (7) Footing (1) Waterproofing membrane (optional): Liquid boot or approved mastic equivalent. (2) Drain= Miradrain 6000 or J-drain 200 or equivalent for non-waterproofed walls; Miradrain 6200 or J-drain 200 or equivalent for waterproofed walls (all perforations down). (3) Filter fabric= Mirafi 140N or approved equivalent; place fabric flap behind core. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole: Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surface. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Gravel: Clean, crushed, % to 1~ inch. (7) Footing= If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE B Detail 2 .• .I,) (1) Waterproofing membrane --~ CMU or reinforced-concrete wall\ --=i= ±12 inches l (5) Weep hole H [Proposed grade sloped to drain per precise civil drawings --(0,~\\);(\\~\/". Footing and wall design by others Structural footing or settlement-sensitive improvement ,-----Provide surface drainage 2=1 (h:v) slope ...................... . . . . . . . . . . . . . . . . . . . . . . :· .. · :._, : •, .· . · ... . . ....... · .. ·' ·:· : ( ::.; J~ (6;a~ 1 ::~e backfiU sand backfill (2) Gravel (4) Pipe 1:1 (h=v) or flatter backcut to be properly benched (7) Footing (1) Waterproofing membrane: Liquid boot or approved masticequivalent. (2) Gravel: Clean, crushed, % to 1~ inch. (3) Filter fabric= Mirafi 140N or approved equivalent. (4) Pipe: 4-inch-diameter perforated PVC, Schedule 40, or approved alternative with minimum of 1 percent gradient to proper outlet point (perforations down). (5) Weep hole= Minimum 2-inch diameter placed at 20-foot centers along the wall and placed 3 inches above finished surf ace. Design civil engineer to provide drainage at toe of wall. No weep holes for below-grade walls. (6) Clean sand backfill: Must have sand equivalent value (S.E.) of 35 or greater; can be densified by water jetting upon approval by geotechnical engineer. (7) Footing: If bench is created behind the footing greater than the footing width, use level fill or cut natural earth materials. An additional "heel" drain will likely be required by geotechnical consultant. (8) Native backfill: If E.I. (21 and S.E. 2_35 then all sand requirements also may not be required · and will be reviewed by the geotechnical consultant. RETAINING WALL DETAIL -ALTERNATIVE C Detail 3 engineer's/wall designer's recommendations, regardless of whether or nottransition conditions exist. Expansion joints should be sealed with a flexible, non-shrink grout. c) Embed the footings entirely into native formational material (i.e., deepened footings). If transitions from cut to fill transect the wall footing alignment at an angle of less than 45 degrees (plan view), then the designer should follow recommendation 11a11 (above) and until such transition is between 45 and 90 degrees to the wall alignment. TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS AND EXPANSBVE SOBlS Expansive Soils and Slope Creep Some of the soils at the site are likely to be expansive and therefore, become desiccated when allowed to dry. Such soils are susceptible to surficial slope creep, especially with seasonal changes in moisture content. Typically in southern California, during the hot and dry summer period, these soils become desiccated and shrink, thereby developing surface cracks. The extent and depth of these shrinkage cracks depend on many factors such as the nature and expansivity of the soils, temperature and humidity, and extraction of moisture from surface soils by plants and roots. When seasonal rains occur, water percolates into the cracks and fissures, causing slope surfaces to expand, with a corresponding loss in soil density and shear strength near the slope surface. With the passage of time and several moisture cycles, the outer 3 to 5 feet of slope materials experience a very slow, but progressive, outward and downward movement, known as slope creep. For slope heights greater than 1 O feet, this creep related soil movement will typically impact all rear yard flatwork and other secondary improvements that are located within about 15 feet from the top of slopes, such as swimming pools, concrete flatwork, etc., and in particular top of slope fences/walls. This influence is normally in the form of detrimental settlement, and tilting of the proposed improvements. The dessication/swelling and creep discussed above continues over the life of the improvements, and generally becomes progressively worse. Accordingly, the developer should provide this information to all interested/affected parties. Top of Slope Walls/Fences Due to the potential for slope creep for slopes higher than about 1 o feet, some settlement and tilting of the walls/fence with the corresponding distresses, should be expected. To mitigate the tilting of top of slope walls/fences, we recommend that the walls/fences be constructed on a combination of grade beam and caisson foundations. The grade beam should be at a minimum of 12 inches by 12 inches in cross section, supported by drilled caissons, 12 inches minimum in diameter, placed at a maximum spacing of 6 feet on center, and with a minimum embedment length of 7 feet below the bottom of the grade Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge GeoSoils~ lnco W.O. 6309-A-SC November 30, 2011 Page 34 beam. The strength of the concrete and grout should be evaluated by the structural engineer of record. The proper ASTM tests for the concrete and mortar should be provided along with the slump quantities. The concrete used should be appropriate to mitigate sulfate corrosion, as warranted. The design of the grade beam and caissons should be in accordance with the recommendations of the project structural engineer, and include the utilization of the following geotechnical parameters: Creep Zone: Creep load: Point of Fixity: Passive Resistance: Allowable Axial Capacity: · Shaft capacity : Tip capacity: 5-foot vertical zone below the slope face and projected upward parallel to the slope face. The creep load projected on the area of the grade beam should be taken as an equivalent fluid approach, having a density of 60 pcf. For the caisson, it should be taken as a uniform 900 pounds per linear foot of caisson's depth, located above the creep zone. Located a distance of 1.5 times the caisson's diameter, below the creep zone. Passive earth pressure of 300 psf per foot of depth per foot of caisson diameter, to a maximum value of 4,500 psf may be used to determine caisson depth and spacing, provided that they meet or exceed the minimum requirements stated above. To determine the total lateral resistance, the contribution of the creep prone zone above the point of fixity, to passive resistance, should be disregarded. 350 psf applied below the point of fixity over the surface area of the shaft. 4,500 psf. EXPANSIVE SOILS, DRIVEWAY. FlATWORK, AND OTHER IMPROVEMENTS Some of the soil materials on site are likely to be expansive. The effects of expansive soils are cumulative, and typically occur over the lifetime of any improvements. On relatively level areas, when the soils are allowed to dry, the dessication and swelling process tends to cause heaving and distress to flatwork and other improvements. The resulting potential for distress to improvements may be reduced, but not totally eliminated. To that end, it is recommended that the developer should notify all interested/affected parties of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnee W.O. 6309-A-SC November 30, 2011 Page 35 1. The subgrade area for concrete slabs should be compacted to achieve a minimum 90 percent relative compaction, and then be presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum moisture content, to a depth of 18 inches below subgrade elevation. The moisture content of the subgrade should be proof tested within 72 hours prior to pouring concrete. 2. Concrete slabs should be cast over a relatively non-yielding surface, consisting of a 4-inch layer of crushed rock, gravel, or clean sand, that should be compacted and level prior to pouring concrete. The layer should wet-down completely prior to pouring concrete, to minimize loss of concrete moisture to the surrounding earth materials. 3. Exterior slabs should be a minimum of 4 inches thick. Driveway slabs and approaches should additionally have a thickened edge (12 inches) adjacent to all landscape areas, to help impede infiltration of landscape water under the slab. 4. The use of transverse and longitudinal control joints are recommended to help control slab cracking due to concrete shrinkage or expansion. Two ways to mitigate such cracking are: a) add a sufficient amount of reinforcing steel, increasing tensile strength of the slab; and, b) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. In order to reduce the potential for unsightly cracks, slabs should be reinforced at mid-height with a minimum of No. 3 bars placed at 18 inches on center, in each direction. The exterior slabs should be scored or saw cut, 112 to% inches deep, often enough so that no section is greater than 1 O feet by 1 O feet. For sidewalks or narrow slabs, control joints should be provided at intervals of every 6 feet. The slabs should be·separated from the foundations and sidewalks with expansion joint filler material. 5. No traffic should be allowed upon the newly poured concrete slabs until they have been properly cured to within 75 percent of design strength. Concrete compression strength should be a minimum of 2,500 psi. 6. Driveways, sidewalks, and patio slabs adjacent to the house should be separated from the house with thick expansion joint filler material. In areas directly adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints should be additionally sealed with flexible mastic. 7. Planters and walls should not be tied to the house. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge W.O. 6309-A-SC November 30, 2011 Page 36 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. 9. Any masonry landscape walls that are to be constructed throughout the property should be grouted and articulated in segments no more than 20 feet long. These segments should be keyed or doweled together. 10. Utilities should be enclosed within a closed utilidor (vault) or designed with flexible connections to accommodate differential settlement and expansive soil conditions. 11. Positive site drainage should be maintained at all times. Finish grade on the lots should provide a minimum of 1 to 2 percent fall to the street, as indicated herein. It should be kept in mind that drainage reversals could occur, including post-construction settlement, if relatively flat yard drainage gradients are not periodically maintained by the homeowner or homeowners association. 12. Due to expansive soils, air conditioning (NC) units should be supported by slabs that are incorporated into the building foundation or constructed on a rigid slab with flexible couplings for plumbing and electrical lines. NC waste water lines should be drained to a suitable non-erosive outlet. 13. Shrinkage cracks could become excessive if proper finishing and curing practices are not followed. Finishing and curing practices should be performed per the Portland Cement Association Guidelines. Mix design should incorporate rate of curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. PRELIMINARY PAVEMENT DESIGN New Pavements New asphaltic concrete pavement sections were analyzed using an assumed R-value and an assumed traffic index (T.I.) value. For preliminary planning purposes, the following AC pavement structural sections are provided in the following table. Final pavement structural sections should be based on R-value testing of soils exposed near the subgrade elevation following grading and underground utility construction. Golden Surf Holdings, LLC Paseo Point, Carlsbad Flle:e:\wp12\6300\6309a.pge GeoSoils, Inc .. W.O. 6309-A-SC November 30, 2011 Page 37 New Asphaitic Concrete (AC) Pavement <1lTI values have been assumed for planning purposes herein and should be confirmed by the design team during future plan development. <2lDenotes standard Caltrans Class 2 aggregate base R > 78, SE >22 . The recommended pavement sections provided above are meant as minimums. If thinner or highly variable pavement sections are constructed, increased maintenance and repair could be expected. If the ADT (average daily traffic) beyond that intended, as reflected by the traffic index used for design, increased maintenance and repair could be required for the pavement section. Best management construction practices should be in effect at all times. Pavement Grading Recommendations General Subgrade preparation and aggregate base preparation should be performed in accordance with the recommendations presented below, and the minimum subgrade (upper 12 inches) and Class 2 aggregate base compaction should generally be 95 percent of the maximum dry density (ASTM D 1557). If adverse conditions (i.e., saturated ground, etc.) are encountered during preparation of subgrade, special construction methods may need to be employed. These recommendations should be considered preliminary. Further R-value testing and pavement design analysis should be performed upon completion of grading and underground utility trench backfill. All section changes should be properly transitioned. If adverse conditions are encountered during the preparation of subgrade materials, special construction methods may need to be employed. Subgrade Within street areas, all surficial deposits of loose soil material generated underground utility construction should be removed or re-compacted as recommended. After the loose soils Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lne .. W.O. 6309-A-SC November 30, 2011 Page 38 are removed, the exposed ground should be scarified to a depth of 12 inches, moisture conditioned as necessary and compacted to 95 percent of maximum laboratory density, as determined by ASTM Test Method D 1557. Deleterious material, excessively wet or dry pockets, concentrated zones of oversized rock fragments, and any other unsuitable materials encountered during roadway grading should be removed. The compacted fill material should then be brought to the elevation of the proposed subgrade for the pavement. The subgrade should be proof-rolled in order to ensure a uniformly firm and unyielding surface. All grading and fill placement should be observed by the project soil engineer and/or his representative. Aggregate Base Compaction tests are required for the recommended aggregate base section. The minimum relative compaction required will be 95 percent of the maximum laboratory density as determined by ASTM Test Method D 1557. Base aggregate should be in accordance to the "Standard Specifications for Public Works Construction" (green book) current edition. Paving Prime coat may be omitted if all of the following conditions are met: 1. The asphalt pavement layer is placed within two weeks of completion of base and/or sub base course. 2. Traffic is not routed over completed base before paving. 3. Construction is completed during the dry season of May through October. 4. The base is free of dirt and debris. If construction is performed during the wet season of November through April, prime coat may be omitted if no rain occurs between completion of base course and paving and the time between completion of base and paving is reduced to three days, provided the base is free of dirt and debris. Where prime coat has been omitted and rain occurs, traffic is routed over base course, or paving is delayed, measures shall be taken to restore base course, subbase course, and subgrade to conditions that will meet specifications as directed by the soil engineer. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lneo W.O. 6309-A-SC November 30, 2011 Page 39 Drainage Positive drainage should be provided for all surface water to drain towards an approved drainage facility. Positive site drainage should be maintained at all times. Water should not be allowed to pond or seep into the ground. If planters or landscaping are adjacent to paved areas, measures should be taken to minimize the potential for water to enter the pavement section. These measures may include but not limited to subdrainage devices, thickened curbs, or concrete cut-off walls. DEVELOPMENT CRITERIA Slope Deformation Compacted fill slopes designed using customary factors of safety for gross or surficial stability and constructed in general accordance with the design specifications should be expected to undergo some differenti~I vertical heave or settlement in combination with differential lateral movement in the out-of-slope direction, after grading. This post-construction movement occurs in two forms: slope creep, and lateral fill extension (LFE). Slope creep is caused by alternate wetting and drying of the fill soils which results in slow downslope movement. This type of movement is expected to occur throughout the life of the slope, and is anticipated to potentially affect improvements or structures (e.g., separations and/or cracking), placed near the top-of-slope, up to a maximum distance of approximately 15 feet from the top-of-slope, depending on the slope height. This movement generally results in rotation and differential settlement of improvements located within the creep zone. LFE occurs due to deep wetting from irrigation and rainfall on slopes comprised of expansive materials. Although some movement should be expected, long-term movement from this source may be minimized, but not eliminated, by placing the fill throughout the slope region, wet of the fill's optimum moisture content. It is generally not practical to attempt to eliminate the effects of either slope creep or LFE. Suitable mitigative measures to reduce the potential of lateral deformation typically include: setback of improvements from the slope faces (per the 201 O CBC), positive structural separations (i.e., joints) between improvements, and stiffening and deepening of foundations. Expansion joints in walls should be placed no greater than 20 feet on-center, and in accordance with the structural engineer's recommendations. All of these measures are recommended for design of structures and improvements. The ramifications of the above conditions, and recommendations for mitigation, should be provided to all interested/affected parties. Slope Maintenance and Planting Water has been shown to weaken the inherent strength of all earth materials. Slope stability is significantly reduced by overly wet conditions. Positive surface drainage away Golden Surf Holdings, LLC Paseo Point, Carlsbad File: e:\wp 12\6300\6309a.pge GeoSoils, lne .. W.O. 6309-A-SC November 30, 2011 Page 40 from slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Over-watering should be avoided as it adversely affects site improvements, and causes perched groundwater conditions. Graded slopes constructed utilizing onsite materials would be erosive. Eroded debris may be minimized and surficial slope stability enhanced by establishing and maintaining a suitable vegetation cover soon after construction. Compaction to the face offill slopes would tend to minimize short-term erosion until vegetation is established. Plants selected for landscaping should be light weight, deep rooted types that require little water and are capable of surviving the prevailing climate. Jute-type matting or other fibrous covers may aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those recommended above will increase the potential for perched water, staining, mold, etc., to develop. A rodent control program to prevent burrowing should be implemented. Irrigation of natural (ungraded) slope areas is generally not recommended. These · recommendations regarding plant type, irrigation practices, and rodent control should be provided to all interested/affected parties. Over-steepening of slopes should be avoided during building construction activities and landscaping. Drainage Adequate surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, and slopes. Surface drainage should be sufficient to mitigate ponding of water anywhere on the property, and especially near structures and tops of slopes. Surface drainage should be carefully taken into consideration during fine grading, landscaping, and building construction. Therefore, care should be taken that future landscaping or construction activities do not create adverse drainage conditions. Positive site drainage within the property should be provided and maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and tops of slopes, and not allowed to pond and/or seep into the ground. In general, site drainage should conform to Section 1804.3 of the 201 O CBC. Consideration should be given to avoiding construction of planters adjacent to structures (buildings, pools, spas, etc.). Building pad drainage should be directed toward the street or other approved area(s). Although not a geotechnical requirement, roof gutters, down spouts, or other appropriate means may be utilized to control roof drainage. Down spouts, or drainage devices should outlet a minimum of 5 feet from structures or into a subsurface drainage system. Areas of seepage may develop due to irrigation or heavy rainfall, and should be anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop, recommendations for minimizing this effect could be provided upon request. Erosion Control Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth materials have a moderate to high erosion potential. Consideration should be given to providing hay bales and silt fences for the temporary control of surface water, from a geotechnical viewpoint. Golden Surf Holdings, LLC Paseo Point, Carlsbad File: e:\wp12\6300\6309a.pge GeoSoils, lnee W.O. 6309-A-SC November 30, 2011 Page 41 landscape Maintenance Only the amount of irrigation necessary to sustain plant life should be provided. Over-watering the landscape areas will adversely affect proposed site improvements. We would recommend that any proposed open-bottom planters adjacent to proposed structures be eliminated for a minimum distance of 1 O feet. As an alternative, closed-bottom type planters could be utilized. An outlet placed in the bottom of the planter, could be installed to direct drainage away from structures or any exterior concrete flatwork. If planters are constructed adjacent to structures, the sides and bottom of the planter should be provided with a moisture barrier to prevent penetration of irrigation water into the subgrade. Provisions should be made to drain the excess irrigation water from the planters without saturating the subgrade below or adjacent to the planters. Graded slope areas should be planted with drought resistant vegetation. Consideration should be given to the type of vegetation chosen and their potential effect upon surface improvements (i.e., some trees will have an effect on concrete flatwork with their extensive root systems). From a geotechnical standpoint leaching is not recommended for establishing landscaping. If the surface soils are processed for the purpose of adding amendments, they should be recompacted to 90 percent minimum relative compaction. Gutters and Downspouts As previously discussed in the drainage section, the installation of gutters and downspouts should be considered to collect roof water that may otherwise infiltrate the soils adjacent to the structures. If utilized, the downspouts should be drained into PVC collector pipes or other non-erosive devices (e.g., paved swales or ditches; below grade, solid tight-lined PVC pipes; etc.), that will carry the water away from the house, to an appropriate outlet, in accordance with the recommendations of the design civil engineer. Downspouts and gutters are not a requirement; however, from a geotechnical viewpoint, provided that positive drainage is incorporated into project design (as discussed previously). Subsurface and Surface Water Subsurface and surface water are not anticipated to affect site development, provided that the recommendations contained in this report are incorporated into final design and construction and that prudent surface and subsurface drainage practices are incorporated into the construction plans. Perched groundwater conditions along zones of contrasting permeabilities may not be precluded from occurring in the future due to site irrigation, poor drainage conditions, or damaged utilities, and should be anticipated. Should perched groundwater conditions develop, this office could assess the affected area(s) and provide the appropriate recommendations to mitigate the observed groundwater conditions. Groundwater conditions may change with the introduction of irrigation, rainfall, or other factors. Golden Surf Holdings, LLC Paseo Point, Carlsbad Flle:e:\wp12\6300\6309a.pge GeoSoils, Inc~ W.O. 6309-A-SC November 30, 2011 Page 42 Site Improvements If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. Pools and/or spas should not be constructed without specific design and construction recommendations from GSI, and this construction recommendation should be provided to all interested/affected parties. This office should be notified in advance of any fill placement, grading of the site, or trench backfilling after rough grading has been completed. This includes any grading, utility trench and retaining wall backfills, flatwork, etc. Tile Flooring Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small cracks in a conventional slab may not be significant. Therefore, the designer should consider additional steel reinforcement for concrete slabs-on-grade where tile will be placed. The tile installer should consider installation methods that reduce possible cracking of the tile such as slipsheets. Slipsheets or a vinyl crack isolation membrane (approved by the Tile Council of America/Ceramic Tile Institute) are recommended between tile and concrete slabs on grade. Additional Grading This office should be notified in advance of any fill placement, supplemental regrading of the site, or trench backfilling after rough grading has been completed. This includes completion of grading in the street, driveway approaches, driveways, parking areas, and utility trench and retaining wall backfills. Footing Trench Excavation All footing excavations should be observed by a representative of this firm subsequent to trenching and prior to concrete form and reinforcement placement. The purpose of the observations is to evaluate that the excavations have been made into the recommended bearing material and to the minimum widths and depths recommended for construction. If loose or compressible materials are exposed within the footing excavation, a deeper footing or removal and recompaction of the subgrade materials would be recommended at that time. Footing trench spoil and any excess soils generated from utility trench excavations should be compacted to a minimum relative compaction of 90 percent, if not removed from the site. Trenching/Temporary Construction Backcuts Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge GeoSoils, lnec W.O. 6309-A-SC November 30, 2011 Page 43 [except as specifically superceded within the text of this report]), should be anticipated. All excavations should be observed by an engineering geologist or soil engineer from GSI, prior to workers entering the excavation or trench, and minimally conform to CAL-OSHA, state, and local safety codes. Should adverse conditions exist, appropriate recommendations would be offered at that time. The above recommendations should be provided to any contractors and/or subcontractors, or homeowners, etc., that may perform such work. Utility Trench Backfill 1 . All interior utility trench backfill should be brought to at least 2 percent above optimum moisture content and then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. As an alternative for shallow (12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of 30 or greater may be utilized and jetted or flooded into place. Observation, probing and testing should be provided to evaluate the desired results. 2. Exterior trenches adjacent to, and within areas extending below a 1 : 1 plane projected from the outside bottom edge of the footing, and all trenches beneath hardscape features and in slopes, should be compacted to at least 90 percent of the laboratory standard. Sand backfill, unless excavated from the trench, should not be used in these backfill areas. Compaction testing and observations, along with probing, should be accomplished to evaluate the desired results. 3. All trench excavations should conform to CAL-OSHA, state, and local safety codes. 4. Utilities crossing grade beams, perimeter beams, or footings should either pass below the footing or grade beam utilizing a hardened collar or foam spacer, or pass through the footing or grade beam in accordance with the recommendations of the structural engineer. SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING We recommend that observation and/or testing be performed by GSI at each of the following construction stages: " During grading/recertification. .. During excavation. During placement of subdrains or other subdrainage devices, prior to placing fill and/or backfill. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoiis, lne .. W.O. 6309-A-SC November 30, 2011 Page44 .. After excavation of building footings, retaining wall footings, and free standing walls footings, prior to the placement of reinforcing steel or concrete. 0 Prior to pouring any slabs or flatwork, after presoaking/presaturation of building pads and other flatwork subgrade, before the placement of concrete, reinforcing steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen, etc.). " During retaining wall subdrain installation, prior to backfill placement. 0 During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. During slope construction/repair. 0 When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. .. When any developer or homeowner improvements, such as flatwork, spas, pools, walls, etc., are constructed, prior to construction. 0 A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in order to provide concise and clear documentation of site work, and/or to comply with code requirements. OTHER DESIGN PROFESSIONALS/CONSULTANTS The design civil engineer, structural engineer, post-tension designer, architect, landscape architect, wall designer, etc., should review the recommendations provided herein, incorporate those recommendations into all their respective plans, and by explicit reference, make this report part of their project plans. This report presents minimum design criteria for the design of slabs, foundations and other elements possibly applicable to the project. These criteria should not be considered as substitutes for actual designs by the structural engineer/designer. Please note that the recommendations contained herein are not intended to preclude the transmission of water or vapor through the slab or foundation. The structural engineer/foundation and/or slab designer should provide recommendations to not allow water or vapor to enter into the structure so as to cause damage to another building component, or so as to limit the installation of the type of flooring materials typically used for the particular application. The structural engineer/designer should analyze actual soil-structure interaction and consider, as needed, bearing, expansive soil influence, and strength, stiffness and deflections in the various slab, foundation, and other elements in order to develop appropriate, design-specific details. As conditions dictate, it is possible that other Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp12\6300\6309a.pge GeoSoils, lnea W.O. 6309-A-SC November 30, 2011 Page 45 influences will also have to be considered. The structural engineer/designer should consider all applicable codes and authoritative sources where needed. If analyses by the structural engineer/designer result in less critical details than are provided herein as minimums, the minimums presented herein should be adopted. It is considered likely that some, more restrictive details will be required. If the structural engineer/designer has any questions or requires further assistance, they should not hesitate to call or otherwise transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or improvement's designer should confirm to GSI and the governing agency, in writing, that the proposed foundations and/or improvements can tolerate the amount of differential settlement and/or expansion characteristics and other design criteria specified herein. PLAN REVIEW Final project plans (grading, precise grading, foundation, retaining wall, landscaping, etc.), should be reviewed by this office prior to construction, so that construction is in accordance with the conclusions and recommendations of this report. Based on our review, supplemental recommendations and/or further geotechnical studies may be warranted. LIMITATIONS The materials encountered on the project site and utilized for our analysis are believed representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during mass grading. Site conditions may vary due to seasonal changes or other factors. Inasmuch as our study is based upon our review and engineering analyses and laboratory data, the conclusions and recommendations are professional opinions. These opinions have been derived in accordance with current standards of practice, and no warranty, either express or implied, is given. Standards of practice are subject to change with time. GSI assumes no responsibility or liability for work or testing performed by others, or their inaction; or work performed when GSI is not requested to be onsite, to evaluate if our recommendations have been properly implemented. Use of this report constitutes an agreement and consent by the user to all the limitations outlined above, notwithstanding any other agreements that may be in place. In addition, this report may be subject to review by the controlling authorities. Thus, this report brings to completion our scope of services for this portion of the project. All samples will be disposed of after 30 days, unless specifically requested by the client, in writing. Golden Surf Holdings, LLC Paseo Point, Carlsbad File:e:\wp 12\6300\6309a.pge GeoSoHs~ Ine .. W.O. 6309-A-SC November 30, 2011 Page 46 "- Afu Qt GS/ LEGEND AR71F/C/AL FILL -UND0CUMEN1ED QUA TERNARY TERRACE DEPOSITS, CIRCLED WHERE BUR/ill APPROX/MAT£ LOCA 710N OF GEOLOGIC CONTACT M U W M W s---I I ~<-== 7" = 20· ~ Q A.; ~J . ~ 2~ ·~ ~ 0, ~ ;e .... .:0 j fJ A£ 0. u :! GEOTECHNICAL MAP Plate 1 w.o. 6309-A-SC I DATE: 11/11 lscALE: 1"=20' . APPENDIXA REFERENCES APPENDIX A REFERENCES ACI Committee 318, 2008, Building code requirements for structural concrete (ACl318-08) and commentary, dated January. ACI Committee 302, 2004, Guide for concrete floor and slab construction, ACI 302.1 R-04, dated June. American Society for Testing and Materials, 1998, Standard practice for installation of water vapor retarder used in contact with earth or granular fill under concrete slabs, Designation: E 1643-98 (Reapproved 2005). __ , 1997, Standard specification for plastic water vapor retarders used in contact with soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved 2004). American Society of Civil Engineers, 2006, Minimum design loads for buildings and other structures, ASCE Standard ASCE/SEI 7-05. Blake, Thomas F., 2000a, EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version. __ , 2000b, EQSEARCH, A computer program for the estimation of peak horizontal acceleration from California historical earthquake catalogs; Updated to December 2009, Windows 95/98 version. Bozorgnia, Y., Campbell K.W., and Niazi, M., 1999, Vertical ground motion: Characteristics, relationship with horizontal component, and building-code implications; Proceedings of the SMIP99 seminar on utilization of strong-motion data, September 15, Oakland, pp. 23-49. Bryant, W.A., and Hart, E.W., 2007, Fault-rupture hazard zones in California, Alquist-Priolo earthquake fault zoning act with index to earthquake fault zones maps; California Geological Survey, Special Publication 42, interim revision. California Building Standards Commission, 2010, California building code. Conway and Associates, Inc., 2011, Preliminary grading plan, Paseo Point, Tentative Parcel Map, Sheet 2 of 3, 10-scale, dated September 20. International Conference of Building Officials, 2001, California building code, California code of regulations title 24, part 2, volume 1 and 2. , 1998, Maps of known active fault near-source zones in California and adjacent portions of Nevada. Jennings; C.W., 1994, Fault activity map of California and adjacent areas: California Division of Mines and Geology, Map Sheet No. 6, scale 1 :750,000. Kanare, H.M., 2005, Concrete floors and moisture, Engineering Bulletin 119, Portland Cement Association. Kennedy, M.P, and Tan, S.S, 2005, Geologic map of the Oceanside 301 x 601 quadrangle, California, United States Geological Survey. Romanoff, M., 1957, Underground corrosion, originally issued April 1. Seed, 2005, Evaluation and mitigation of soil liquefaction hazard "evaluation of field data and procedures for evaluating the risk of triggering (or inception) of liquefaction", in Geotechnical earthquake engineering; short course, San Diego, California, April 8-9. Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. State of California, 2011, Civil Code, Sections 895 et seq. State of California Department of Transportation, Division of Engineering Services, Materials Engineering, and Testing Services, Corrosion Technology Branch, 2003, Corrosion Guidelines, Version 1.0, dated September. Tan, S.S., and Giffen, D.G., 1995, Landslide hazards in the northern part of the San Diego Metropolitan area, San Diego County, California, Landslide hazard identification map no. 35, Plate 35E, Department of Conservation, Division of Mines and Geology, DMG Open File Report 95-04. Tan, S.S., and Kennedy, M.P., 1996, Geologic maps of the northwestern part of San Diego County, California: California Division of Mines and Geology, Open File Report 96-02. United States Department of Agriculture, 1953, Aerial photographs, flight date August 21, photos nos. AXN-8M-15 and -16, scale 1"=2,000'±. United States Geological Survey, 2011, Seismic hazard curves and uniform hazard response spectra -v5.1.0, dated February 2 __ , 1999, Encinitas quadrangle, San Diego County, California, 7.5 minute series, 1 :24,000 scale. Golden Surf Holdings, LLC Flle:e:\wp12\6300\6309a.pge GeoSoils, lne. Appendix A Page2 APPENDIX B . TEST EXCAVATION LOGS. UNIFIED SOIL CLASSIFICATION SYSTEM ID > Ql "iii 0 fil ~ ci oz CI) C: -0 0 -~ 1.il <I! C: Cl ]i ~ ~ aj ~ 8 'g <I! -5 ID 0 2 ID > Ql "iii 0 0 en N '5 . CI) ~ 1.il en c: m -~ ~ C, 0.. II) Ql C: 0 II: E 0 ~ 0 LO Major Divisions Highly Organic Soils c: en nl -0 a, C: -<II t) UJ Unified Soil Classification Cobbles 3" Group Symbols GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT Typical Names Well-graded gravels and gravel- sand mixtures, little or no fines Poorly graded gravels and gravel-sand mixtures, little or no fines Silty gravels gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well-graded sands and gravelly sands, little or no fines Poorly graded sands and gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts, very fine sands, rock flour, silty or clayey fine sands Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts Inorganic clays of high plasticity, fat clays Organic clays of medium to high plasticity Peat, mucic, and other highly organic soils 3/4" #4 Gravel CONSISTENCY OR RELATIVE DENSITY CRITERIA Standard Penetration Test Penetration Resistance N Relative (blows/ft) Density 0-4 Very loose 4-10 Loose 10-30 Medium 30-50 Dense > 50 Very dense Standard Penetration Test Penetration Resistance N (blows/ft) <2 2-4 4-8 8-15 15-30 >30 #10 Sand Unconfined Compressive Strength Consistency (tons/ff} Very Soft <0.25 Soft 0.25-.050 Medium 0.50-1.00 Stiff 1.00-2.00 Very Stiff 2.00-4.00 Hard >4.00 #40 #200 U.S. Standard Sieve Silt or Clay coarse I fine coarse I medium I tine MOISTURE CONDITIONS Dry Slightly Moist Moist Very Moist Wet Absence of moisture: dusty, dry to the touch Below optimum moisture content for compaction Near optimum moisture content Above optimum moisture content Visible free water; below watertable BASIC LOG FORMAT: MATERIAL QUANTITY trace 0-5 % few 5-10% little 10-25 % some 25-45% OTHER SYMBOLS C Core Sample S SPTSample B Bulk Sample .!: Groundwater Qp Pocket Penetrometer Group name, Group symbol, (grain size), color, moisture, consistency or relative density. Additional comments: odor, presence of roots, mica, gypsum, coarse grained particles, etc. EXAMPLE: Sand {SP), fine to medium grained, brown, moist, loose, trace silt, little fine gravel, few cobbles up to 4" in size, some hair roots and rootlets. File:Mgr: c;\SoilClassif.wpd PLATE B-1 llll ~lllf il!Utf1t1r1t,- TP-1 I 160 I 0-1% SM 1%-3% SP 3%-5% SP 5114-8 SC/SM UNO@ I 5112 UNO = Undisturbed TP-2 171 0-1% SP 1%-4 SP 4-6% SM UNO@ 6112 UNO = Undisturbed W.O. 6309-A-SC Golden Surf Holdings, LLC 6798 Paseo del Norte, Carlsbad Logged By: RB September 23, 2011 LOG OF EXPLORATORY TEST PITS 12.4 5.3 ARTIFICIAL FILL: SIL TY SAND, dark yellowish brown, dry, dense; slightly porous, trace organics, non-uniform. QUATERNARY COLLUVIUM: SAND with minor SILT, dark grayish brown, damp, dense; slightly porous, trace organics. WEATHERED QUATERNARY TERRACE DEPOSITS: SAND with minor SILT, brown, damp, medium dense; slightly porous. 115.3 I QUATERNARY TERRACE DEPOSITS: CLAYEY SAND/SILTY SAND, 107.8 brown, damp becoming moist with depth, dense. Total Depth= 8' No Groundwater/Caving Encountered Backfilled 9-23-2011 QUATERNARY COLLUVIUM: SAND with minor SILT, grayish brown, dry, medium dense; porous, abundant organics. WEATHERED QUATERNARY TERRACE DEPOSITS: SAND with minor SILT, dark yellowish brown, damp, dense; slightly porous. QUATERNARY TERRACE DEPOSITS: SILTY SAND with minor CLAY, dark yellowish brown, damp, dense. Total Depth: 6W No Groundwater/Caving Encountered Backfilled 9-23-2011 PLATE 8-2 Ill iillili. TP-3 159% 0-2Y2 SP 2V2-41h CL 4V2-9V2 SC TP-4 164 0-1 % SP 11h-31h SP 3%-5 SM UND@21h Bulk @2112-4112 Bulk @ 8%-91h W.O. 6309-A-SC Golden Surf Holdings, LLC 6798 Paseo del Norte, Carlsbad Logged By: RB September 23, 2011 LOG OF EXPLORATORY TEST PITS 12.4 115.3 QUATERNARY COLLUVIUM: SAND, dark grayish brown, dry, dense; porous, abundant organics. WEATHERED TERRACE DEPOSITS (PALEOSOL): SANDY CLAY, dark reddish brown, damp, hard; coarse, angular, blocky structure, clay film on ped faces, argillic. QUATERNARY TERRACE DEPOSITS: CLAYEY SAND, reddish yellow and gray, moist, very dense. Total Depth = 9%' No Groundwater/Caving Encountered Backfilled 9-23-2011 QUATERNARY COLLUVIUM: SAND with SILT, brown, dry, loose; porous, abundant organics. WEATHERED QUATERNARY TERRACE DEPOSITS: SAND with SILT, dark yellowish brown, damp, medium dense; porous. QUATERNARY TERRACE DEPOSITS: SILTY SAND with minor CLAY, dark yellowish brown, moist, very dense. Total Depth= 5' No Groundwater/Caving Encountered Backfilled 9-23-2011 PLATE 8-3 APPENDIXC EQFAULT, EQSEARCH, AND PHGA *********************** * 'I: * E Q F A u L T * * * J. Version 3.00 * -/( .c *********************** DETERMINISTIC ESTIMATION OF PEAi( ACCELERATION FROM DIGITIZED FAUL TS JOB NUMBER: 6309-A-SC JOB NAME: GOLDEN SURF HOLDINGS, LLC CALCULATION NAME: 6309 . DATE: 09-26-2011 FAULT-DATA-FILE NAME: c:\Program Files\EQFAULTl\CGSFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.1107 SITE LONGITUDE: 117.3086 SEARCH RADIUS: 62.14 mi ATTENUATION RELATION: 11) Bozorgnia Campbell Niazi (1999) Hor.-Pleist. Soil-car. UNCERTAINTY (M=Median, S=Sigma): s Number of sigmas: 1.0 DISTANCE MEASURE: cdist SCOND: 1 Basement Depth: .00 km Campbell SSR: 0 Campbell SHR: 0 COMPUTE PEAi< HORIZONTAL ACCELERATION FAULT-DATA FILE USED: c:\Program Files\EQFAULTl\CGSFLTE.DAT MINIMUM DEPTH VALUE (km): 3.0 Page 1 W.O. 6309-A-SC Plate C-1 EQFAULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 !ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE !------------------------------- ABBREVIATED I DISTANCE I MAXIMUM I PEAK IEST. SITE FAULT NAME I mi (km) I EARTHQUAl(E I SITE I INTENSITY I I MAG.(MW) I ACCEL. g IMOD.MERC. ================================l==============l==========l==========I========= ROSE CANYON I 4.7( 7.5) I 7.2 I 0.652 I x NEWPORT-INGLEWOOD (Offshore) I 7.9( 12.7)1 7.1 I 0.467 I x CORONADO BANK I 20.1( 32.4)1 7.6 I 0.285 I IX ELSINORE (JULIAN) I 25.2( 40.5)1 7.1 I 0.164 I VIII ELSINORE (TEMECULA) I 25.2( 40.5) 6.8 I 0.134 I VIII ELSINORE (GLEN IVY) I 36.9( 59.4) 6.8 I 0.090 I VII PALOS VERDES I 38.5( 61.9)1 7.3 I 0.122 I VII SAN JOAQUIN HILLS I 38.8( 62.5)1 6.6 I 0.106 I VII EARTHQUAKE VALLEY I 42. 4( 68. 2) I 6. 5 I O. 064 I VI SAN JACINTO-ANZA I 48.0( 77.3)1 7.2 I 0.090 I VII SAN JACINTO-SAN JACINTO VALLEY J 49.1( 79.0)I 6.9 I 0.072 I VI NEWPORT-INGLEWOOD CL.A.Basin) I 49.5( 79.6)1 7.1 I 0.082 I VII CHINO-CENTRAL AVE. (Elsinore) I 51. 3 ( 82. 5) I 6. 7 I O. 084 I VII SAN JACINTO-COYOTE CREEK I 52.2( 84.0)I 6.6 I 0.055 I VI WHITTIER I 55.2( 88.8)1 6.8 I 0.059 I VI ELSINORE (COYOTE MOUNTAIN) I 55.7( 89.7)1 6.8 I 0.058 I VI ******************************************************************************* -END OF SEARCH-16 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT rs ABOUT 4.7 MILES (7.5 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.6521 g Page 2 W.O. 6309-A-SC Plate C-2 GeoSoils, Inc. 1000 900 800 700 600 500 400 300 200 100 0 CALIFORNIA FAULT MAP GOLDEN SURF HOLDINGS, LLC -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 6309-A-SC Plate C-3 -i,j) -C: 0 ¥ ca 1-, Q) a, (,) CJ <:::( .1 MAXIMUM EARTHQUAKES GOLDEN SURF HOLDINGS, LLC ====:=:=::::::===:=::::::::===:=:=::::::===:=::::::~; j~ ~ H-~-i---t--t-t-t-t+t+~--t----,,-+-t-t-t+tt-~-t--.-t-+-t-+-++++~-+---11-+~H-++11 I~ • ~ <Ii ~ i1 H-~-t---t-+-t-tt+t+~-+---,-+-+-t-++H-~-t---+-+-t-1-++t+~-+---11-+~H-++1~ H-~-t---t-+-t-t-t+t+~-+--;-+-t-t-++H-~-t---+--t-+-1-++++~-+---11-+~H-++1~ ,~ ~ H-~+--+--t-+-tt+t+~-+--;-+-t-t-t+H-~+--+-+-t-1-++++~-+---11-+~H-++1~ .01 -+r-~r-t--t-t-+++-1+--+--t-+-+-H-H-l---t--+-+-H-H-H-~+-+-1-+++~1 ~--1-1--+--+-++H+--l----+-+++++--+-+-+-+-H-+++--+--+-l-l~I .001 .1 10 Distance (mi) 100 W.O. 6309-A-SC Plate C-4 GeoSoHs, lne .. ************************* ~ * * E Q s E A R C H -/r -/r -Jr ~ Version 3.00 '~ * -/r ************************* ESTIMATION OF PEAK ACCELERATION FROM CALIFORNIA EARTHQUAKE CATALOGS JOB NUMBER: 6309-A-SC JOB NAME: .GOLDEN SURF HOLDINGS, LLC EARTHQUAKE-CATALOG-FILE NAME: ALLQUAKE.DAT SITE COORDINATES: SITE LATITUDE: 33.1107 SITE LONGITUDE: 117.3086 SEARCH DATES: START DATE: 1800 END DATE: 2010 SEARCH RADIUS: 62 .1 mi 100.0 km DATE: 09-26-2011 ATTENUATION RELATION: 11) Bozorgnia Campbell Niazi (1999) Hor.-Pleist. Soil-car. UNCERTAINTY (M=Median, S=Sigma): s Number of Sigmas: 1.0 ASSUMED SOURCE TYPE: ss [SS=Strike-slip, DS=Reverse-slip, BT=Blind-thrust] SCOND: 1 Depth source: A Basement Depth: .00 km Campbell SSR: 0 Campbell SHR: O COMPUTE PEAK HORIZONTAL ACCELERATION MINIMUM DEPTH VALUE (km): 3.0 Page 1 W.O. 6309-A-SC Plate C-5 GeoSoils, lneo EARTHQUAKE SEARCH RESULTS Page 1 I I TIME I I I SITE I SITE I APPROX. FILE I LAT. I LONG. I DATE I (UTC) I DEPTH I QUAKE I ACC. I MM I DISTANCE CODE I NORTH I WEST I I H M sec I Cl<m) I MAG. g I INT. I mi [l<m] ----+-------+--------+----------+--------+-----+-----+-------+----+------------DMG l33.0000l117.3000lll/22/1800l2130 0.01 0.01 6.50 0.343 I IX I 7.7( 12.3) MGI l33.0000l117.0000I09/21/1856I 730 0.01 0.01 5.00 0.057 VI I 19.4( 31.3) MGI l32.8000J117.1000I05/25/1803I O O 0.0, 0.01 5.00 0.044 I VI I 24.6( 39.6) DMG 132.7000 117.2000105/27/1862120 0 0.0 0.01 5.90 0.064 I VI I 29.0( 46.7) T-A l32.6700l117.1700l12/00/1856I O O 0.01 0.01 5.00 0.035 I VI 31.5( 50.6) T-A 32.6700l117.1700l10/21/1862I O O 0.0, 0.01 5.00 0.035 VI 31.5( 50.6) T-A 32.6700l117.1700I05/24/1865I O O o.o 0.01 5.00 0.035 I VI 31.5( 50.6) PAS 32.9710,117.8700107/13/198611347 8.2 6.01 5.30 0.038 I VI 33.9( 54.5) DMG 33.2000 116.7000101/01/19201 235 0.01 0.01 5.00 0.030 I VI 35.7( 57.5) DMG 32.8000l116.8000l10/23/1894l23 3 0.01 0.01 5.70 0.045 I VI I 36.4( 58.6) DMG 33.7000lll7.4000I04/ll/1910I 757 0.01 0.01 5.00 0.026 I VI 41.0( 66.0) DMG 33.7000l117.4000I05/13/1910I 620 0.01 0.01 5.00 0.026 V 41.0( 66.0) DMG 33.7000l117.4000I05/15/1910l1547 0.01 0.0, 6.00 0.048 VI 41.0( 66.0) MGI 33.2000l116.6000l10/12/1920l1748 0.01 0.0 5.301 0.031 VI 41.4( 66.7) DMG 33.69901117.5110105/31/19381 83455.41 10.01 5.501 0.034 VI 42.3( 68.0) DMG 33.71001116.9250I09/23/1963 144152.6 16.51 5.001 0.023 Iv 1 46.9( 75.5) DMG 33.7500l117.0000I06/06/191812232 0.01 0.01 5.001 0.022 IV I 47.6( 76.6) DMG 33.7500,117.0000104/21/1918 223225.01 0.01 6.801 0.069 VI 47.6( 76.6) DMG 33.5750 117.9830103/11/19331 518 4.0 0.01 5.201 0.024 IV I 50.4( 81.1) MGI l33.80001117.6000I04/22/1918l2115 0.01 0.01 5.001 0.021 Iv I 50.5C 81.2) DMG 133.8000 117.0000l12/25/1899,1225 0.01 0.01 6.401 0.049 VI I 50.8( 81.8) DMG 133.00001116.4330I06/04/1940 1035 8.31 o.ol 5.101 0.022 Iv 1 51.2c 82.5) GSP 33.5290l116.5720I06/12/2005l154146.5I 14.0 5.201 0.023 IV I 51.4( 82.7) DMG l33.61701117.9670I03/ll/1933I 154 7,81 0.01 6.301 0.045 VI I 51.6( 83.0) PDG 133.4200ll16.4890I07/07/2010l235333.5I 14.0I 5.501 0.027 VI 51.9( 83.5) PAS 33.50101116.5130,02/25/19801104738.51 13.61 5.501 0.027 VI 53.2( 85.7) GSP 133.5080 116.5140 10/31/2001,075616.61 15.01 5.101 0.021 IV I 53.4( 86.0) DMG 133.6170 118.0170103/14/1933 19 150.0I 0.0 5.101 0.021 IV I 53.8( 86.5) DMG 133.5000 116.5000109/30/1916 211 0.01 0.01 5.001 0.020 IV I 53.8( 86.6) DMG 133.9000 117.2000112/19/18801 0 0 0.01 0.01 6.001 0.035 VI 54.9( 88.3) DMG 133.3430lll6.3460I04/28/1969l232042.9I 20.01 5.801 0.029 VI 57.9( 93.1) DMG 33.6830l118.0SOOI03/ll/19331 658 3.01 0.0 5.501 0.024 VI 58.2( 93.7) DMG l33.7000l118.0670I03/ll/1933 51022.0 0.01 5.101 0.019 IV I 59.7( 96.1) DMG l33.7000l118.0670I03/ll/1933I 85457.0 0.01 5.101 0.019 IV I 59.7( 96.1) T-A l32.2500lll7.5000l01/13/1877l20 0 0.01 0.01 5.001 0.017 IV I 60.5( 97.3) DMG l34.0000l117.2500I07/23/1923I 73026.0I 0.01 6.251 0.036 VI 61.5( 99.0) DMG l33.4000lll6.3000I02/09/1890ll2 6 0.01 0.01 6.301 0.038 VI 61.6( 99.1) ******************************************************************************* -END OF SEARCH-37 EARTHQUAKES FOUND WITHIN THE SPECIFIED SEARCH AREA. TIME PERIOD OF SEARCH: 1800 TO 2010 LENGTH OF SEARCH TIME: 211 years THE EARTHQUAKE CLOSEST TO THE SITE IS ABOUT 7.7 MILES (12.3 l<m) AWAY. LARGEST EARTHQUAKE MAGNITUDE FOUND IN THE SEARCH RADIUS: 6.8 Page 2 W.O. 6309-A-SC GeoSoils, lne. Plate C-6 LARGEST EARTHQUAKE SITE ACCELERATION FROM THIS SEARCH: 0.343 g COEFFICIENTS FOR GUTENBERG & RICHTER RECURRENCE RELATION: a-value= 0.755 b-val ue= 0. 344 beta-value= 0.793 TABLE OF MAGNITUDES AND EXCEEDANCES: Earthquake I Number of Times I cumulative Magnitude I Exceeded I No. I Year -----------+-----------------+------------ 4.0 I 37 I o.17619 4.5 I 37 I 0.17619 5 . o I 3 7 I o. 17 619 5. 5 I 15 I o. 07143 6.0 I 8 I o.03810 6 . 5 I 2 I o. 009 5 2 Page 3 W.O. 6309-A-SC GeoSoils, lne .. Plate C-7 (/) -C (I) ~ -0 I., Q) .a E ::r z ~ ;:: lU ::r E E ::s CJ EARTHQUAKE RECURRENCE CURVE GOLDEN SURF HOLDINGS, LLC r~~-;--~-;-~--Jf--~t--~-1-~-t-~-1-~-+~---1-~--,1----1t ~= ......... --+~-t~--ll--~+-~+-~-1-~-l-~-+~-+~~~--l~ I II I I I I I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I Ii Ii~' $E::!'-~T:1h'!'\r,-;1~~~~,,.~,:.~J ~"t':::)~.u."·I.L",~; ~j~·¢Vt:'JS~t:,1 ·"'~~--:·~~'-~:.·,·~~ i"-,:...,··r.~~;~ '!"".-.f-'!l'a\~' ~,v~,~; ;Q;,,'7:":-!,;~;S;';i-;~ ~ 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 Magnitude (M) W.O. 6309-A-SC Plate C-8 GeoSoils, lne. 1000 900 800 700 600 500 400 300 200 100 0 EARTHQUAKE EPICENTER MAP GOLDEN SURF HOLDINGS, LLC LEGEND M = 4 (.J M = 5 D M =6 6 M =7 <._) M = 8 -400 -300 -200 -100 0 100 200 300 400 500 600 W.O. 6309-A-SC Plate C-9 GeoSoils, lne. ?E 0 ,, . ~~ -40 mCf> 0~ ~ en oO 2010ed 34· 33' 32' PASEO_POINT Geographic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.2685 g PGA Exceedance Return Time: 475 year Max. significant source distance 136. km. View angle is 35 degrees above horizon Gridded-source hazard accum. in 45° intervals Soil site. Vs30(m/s) -300.0 0 • 0 • I! • • • 0 50 100 km D • c:J 8.2 7.9 7.6 7.3 7.0 M 6.7 6.4 6.1 5.8 5.5 @MH 2011 Oct 19 20:27:19 j Site Coords:-117.308 33.1107 (yellow disk) Vs30= 300.0. Max annual ExcdRate .3470E-03 (column height prop. to ExRate). Red diamonds: historical earthquakes, M>6 34· 33 32 20l0ed • 34· "E ~ ..c: ~ 0 g 0 ~ u ~ Ill 33" ca () .E u > PASEO_POINT Geographic Deagg. Seismic Hazard for 0.00-s Spectral Accel, 0.4939 g PGA Exceedance Return Time: 2475 year Max. significant source distance 116. km. View angle is 35 degrees above horizon Gridded-source hazard accum . in 45° intervals Soil site. Vs30(m/s) -300.0 CJ -i-• • CJ CJ • B ~ ~ / • CJ • • • li1 C i;;i ·t ~ la • • 1:1 Cl • • 0 ISO km 8.3 8.0 7.7 7.4 7.1 M 6.8 6.5 6.2 5.9 5.6 34 33 ijJ.iiH 2011 Oct 19 20:24:32 ! Sita Coords:•117.308 33.1107 (yellow disk) Vs30= 300.0. Max annual ExcdRate .1238E-03 (column height prop. to ExRate). Red diamonds: historical earthquakes, M>6 APPENDIX D LABORATORY DATA U.S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I HYDROMETER 6 4 3 2 1.5 1 3/4 1/23/B 3 ii. 6 a10 1416 20 30 40 50 60 100 140 200 100 I II I I II I I I I I 95 \ 90 : \ 85 80 \ 75 :\ 70 : j:65 \ ' (.'.) ~60 I\,. ~55 "" 0:: : W50 z E45 : z ~40 0:: w a..35 30 25 20 : 15 : 10 : : : 5 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS I GRAVEL SAND I COBBLES I I I SILT OR CLAY coarse fine coarse medium fine Sample Depth Range Visual Classification/USCS CLASSIFICATION LL PL Pl Cc Cu • TP-3 2.5 2.5-4.5 CLAYEY SAND(SC) 49 20 29 Sample Depth 0100 D60 030 010 %Gravel %Sand %Silt %Clay :: . § TP-3 2.5 4.75 0.206 0.0 50.3 49.7 I-0 (!) ai ::i VJ ::, .., Q. (!) GRAIN SIZE DISTRIBUTION ai GeoSoils, Inc. 0 "' <O ~ ~,~sit-57 41 Palmer Way Project: GOLDEN SURF HOLDINGS Carlsbad, CA 92008 Telephone: (760) 438-3155 Number: 6309-A-SC ti Fax: (760) 931-0915 (!) Date: December 2011 Plate: D -1 VJ ::, --, a. (!) g CD ~ :; :; (!) a: w m a: w ~ "' ::, 60 50 [i) 40 0 z - ~ Q 30 I-rn ::s 0.. 20 10 0 0 Sample 9 TP-3 <tit ~-,·· ,~ CL / / / / / .. / / / / / / / , V / / / / / / / ,,/ V CL-~L / ML I I 20 40 Depth/El. LL PL Pl Fines 2.5 49 20 29 50 GeoSoils, Inc. 57 41 Palmer Way Carlsbad, CA 92008 Telephone: (760) 438-3155 Fax: (760) 931-0915 / :,r / _/ / CH / / / / V / / / / / / / / / / / V MH 60 80 100 LIQUID LIMIT uses CLASSIFICATION CLAYEY SAND(SC) A TTERBERG LIMITS1 RESULTS Project: GOLDEN SURF HOLDINGS Number: 6309-A-SC Date: December 2011 Plate: D -2 3,000 0 2,500 ~] 2,000 / ~ V ._ U) /; 0.. :r: I-C) z UJ 1,500 a:: / I-U) ~ a:: <( UJ I U) E 1,000 / ~ / J 500 / / 0 0 500 1,000 1,500 2,000 2,500 3,000 NORMAL PRESSURE, psf Sample Depth/El. Range Classification Primary/Residual Sample Type yd MC% C ~ • TP-1 5.5 Clayey Sand Primary Shear Undisturbed 120.2 7.7 373 35 ~ D TP-1 5.5 Residual Shear Undisturbed 120.2 7.7 123 36 I-D (!J w :5 en ::::, ..., Note: Sample lnnundated Prior To Test D.. (!J ai 0 "' DIRECT SHEAR TEST co GeoSoils, Inc. tt: ; ~;tit)§~-5741 Palmer Way Project: GOLDEN SURF HOLDINGS Carlsbad, CA 92008 Telephone: (760) 438'-3155 Number: 6309-A-SC g; Fax: (760) 931-0915 D Date: December 2011 Plate: D - 3 en ::::, "' ::, ..., C. Cl m 0 M (!) ~ :r: "' t; w et: 5 "' ::, - 3,000 2,500 2,000 /. V' .... ,0 Ul a. J: I-(!) z w 1,500 0:: ~ V I-en 0:: <( w J: / en 1,000 ~ ~ 500 / / 0 0 500 1,000 1,500 2,000 2,500 3,000 NORMAL PRESSURE, psf Sample Depth/El. Range Classification Primary/Residual Sample Type yd MC% C <I> • TP-2 0.5 0.5-4.5 Silty Sand Primary Shear Remolded 117.5 9.0 373 30 D TP-2 0.5 Residual Shear Remolded 117.5 9.0 194 31 Note: Sample lnnundated Prior To Test GeoSoils, Inc. DIRECT SHEAR TEST ~~:,:~,' ·.;~•ij~p 57 41 Palmer Way Project: GOLDEN SURF HOLDINGS Carlsbad, CA 92008 ,!it}:: Telephone: (760) 438-3155 Number: 6309-A-SC Fax: (760) 931-0915 Date: December 2011 Plate: D-4 Cal Land Engineering, Inc. dba Quartech Consultant Geotec~nical, Environmental, anc/ Civil Eng!neering SUMMARY OF LABORATORY TEST DATA GeoSoifs, Inc. 5741 Palmer Way, Suite D Carlsbad, CA 92010 Client: Golden Surf Geo Soils W.O. 6309-A-SC TP-3 @ 2.5'-4.5' TP-2 @ 0.5'-4.5' & TP-3 @ 8.5'-9.5' (Mix) QCI Project No.: 11-029-11 c Date: November 10, 2011 Summarized by: ABK Corrosivity Test Results 8.11 89 0.0340 1,150 8.23 78 0.0260 2,100 576 East Lambert Road, Brea, California 92821; Tel: 714-671-1050; Fax: 714-671-1090 PLATE D-5 APPENDIX E GENERAL EARTHWORK, G.RADING GUIDELINES, AND PRELIMINARY CRITERIA GENERAL EARTHWORK, GRADING GUIDELINES, AND PRELIMINARY CRITERIA General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to be filled, placement of fill, installation of subdrains, excavations, and appurtenant structures or flatwork. The recommendations contained in the geotechnical report are part of these earthwork and grading guidelines and would supercede the provisions contained hereafter in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new or revised recommendations which could supercede these guidelines or the recommendations contained in the geotechnical report. Generalized details follow this text. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications and latest adopted code. In the case of conflict, the most onerous provisions shall prevail. The project geotechnical engineer and engineering geologist (geotechnical consultant), and/or their representatives, should provide observation and testing services, and geotechnical consultation during the duration of the project. EARTHWORK OBSERVATIONS AND TESTING Geotechnical Consultant Prior to the commencement of grading, a qualified geotechnical consultant (soil engineer and engineering geologist) should be employed for the purpose of observing earthwork procedures and testing the fills for general conformance with the recommendations of the geotechnical report(s), the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so that an evaluation may be made that the work is being accomplished as specified. It is the responsibility of the contractor to assist the consultants and keep them apprised of anticipated work schedules and changes, so that they may schedule their personnel accordingly. All remedial removals, clean-outs, prepared ground to receive fill, key excavations, and subdrain installation should be observed and documented by the geotechnical consultant prior to placing any fill. It is the contractor's responsibility to notify the geotechnical consultant when such areas are ready for observation. Laboratory and field Tests Maximum dry density tests to determine the degree of compaction should be performed in accordance with American Standard Testing Materials test method ASTM designation D-1557. Random or representative field compaction tests should be performed in accordance with test methods ASTM designation D-1556, D-2937 or D-2922, and D-3017, at intervals of approximately ±2 feet of fill height or approximately every 1,000 cubic yards placed. These criteria would vary depending on the soil conditions and the size of the project. The location and frequency of testing would be at the discretion of the geotechnical consultant. Contractor's Responsibility All clearing, site preparation, and earthwork performed on the project should be conducted by the contractor, with observation by a geotechnical consultant, and staged approval by the governing agencies, as applicable. It is the contractor's responsibility to prepare the ground surface to receive the fill, to the satisfaction of the geotechnical consultant, and to place, spread, moisture condition, mix, and compact the fill in accordance with the recommendations of the geotechnical consultant. The contractor should also remove all non-earth material considered unsatisfactory by the geotechnical consultant. Notwithstanding the services provided by the geotechnical consultant, it is the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the earthwork in strict accordance with applicable grading guidelines, latest adopted codes or agency ordinances, geotechnical report(s), and approved grading plans. Sufficient watering apparatus and compaction equipment should be provided by the contractor with due consideration for the fill material, rate of placement, and climatic conditions. If, in the opinion of the geotechnical consultant, unsatisfactory conditions such as questionable weather, excessive oversized rock or deleterious material, insufficient support equipment, etc., are resulting in a quality of work that is not acceptable, the consultant will inform the contractor, and the contractor is expected to rectify the conditions, and if necessary, stop work until conditions are satisfactory. During construction, the contractor shall properly grade all surfaces to maintain good drainage and prevent ponding of water. The contractor shall take remedial measures to control surface water and to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. SITE PREPARATION All major vegetation, including brush, trees, thick grasses, organic debris, and other deleterious material, should be removed and disposed of off-site. These removals must be concluded prior to placing fill. In-place existing fill, soil, alluvium, colluvium, or rock materials, as evaluated by the geotechnical consultant as being unsuitable, should be removed prior to any fill placement. Depending upon the soil conditions, these materials may be reused as compacted fills. Any materials incorporated as part of the compacted fills should be approved by the geotechnical consultant. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge Appendix E Page2 Any underground structures such as cesspools, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, or other structures not located prior to grading, are to be removed or treated in a manner recommended by the geotechnical consultant. Soft, dry, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to firm ground and approved by the geotechnical consultant before compaction and filling operations continue. Overexcavated and processed soils, which have been properly mixed and moisture conditioned, should be re-compacted to the minimum relative compaction as specified in these guidelines. Existing ground, which is determined to be satisfactory for support of the fills, should be scarified (ripped) to a minimum depth of 6 to 8 inches, or as directed by the geotechnical consultant. After the scarified ground is brought to optimum moisture content, or greater and mixed, the materials should be compacted as specified herein. If the scarified zone is greater than 6 to 8 inches in depth, it may be necessary to remove the excess and place the material in lifts restricted to about 6 to 8 inches in compacted thickness. Existing ground which is not satisfactory to support compacted fill should be overexcavated as required in the geotechnical report, or by the on-site geotechnical consultant. Scarification, disc harrowing, or other acceptable forms of mixing should continue until the soils are broken down and free of large lumps or clods, until the working surface is reasonably uniform and free from ruts, hollows, hummocks, mounds, or other uneven features, which would inhibit compaction as described previously. Where fills are to be placed on ground with slopes steeper than 5: 1 (horizontal to vertical [h:v]), the ground should be stepped or benched. The lowest bench, which will act as a key, should be a minimum of 15 feet wide and should be at least 2 feet deep into firm material, and approved by the geotechnical consultant. In fill-over-cut slope conditions, the recommended minimum width of the lowest bench or key is also 15 feet, with the key founded on firm material, as designated by the geotechnical consultant. As a general rule, unless specifically recommended otherwise by the geotechnical consultant, the minimum width of fill keys should be equal to 1/;, the height of the slope. Standard benching is generally 4 feet (minimum) vertically, exposing firm, acceptable material. Benching may be used to remove unsuitable materials, although it is understood that the vertical height of the bench may exceed 4 feet. Pre-stripping may be considered for unsuitable materials in excess of 4 feet in thickness. All areas to receive fill, including processed areas, removal areas, and the toes of fill benches, should be observed and approved by the geotechnical consultant prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. Golden Surf Holdings, LLC File:e:\wp12\6300\63D9a.pge GeoSoHs, lne. Appendix E Page3 COMPACTED FILLS Any earth materials imported or excavated on the property may be utilized in the fill provided that each material has been evaluated to be suitable by the geotechnical consultant. These materials should be free of roots, tree branches, other organic mat;ter, or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the geotechnical consultant. Soils of poor gradation, undesirable expansion potential, or substandard strength characteristics may be designated by the consultant as unsuitable and may require blending with other soils to serve as a satisfactory fill material. Fill materials derived from benching operations should be dispersed throughout the fill area and blended with other approved material. Benching operations should not result in the benched material being placed only within a single equipment width away from the fill/bedrock contact. Oversized materials defined as rock, or other irreducible materials, with a maximum dimension greater than 12 inches, should not be buried or placed in fills unless the location of materials and disposal methods are specifically approved by the geotechnical consultant. Oversized material should be taken offsite, or placed in accordance with recommendations of the geotechnical consultant in areas designated as suitable for rock disposal. GSI anticipates that soils to be utilized as fill material forthe subject project may contain some rock. Appropriately, the need for rock disposal may be necessary during grading operations on the site. From a geotechnical standpoint, the depth of any rocks, rock fills, or rock blankets, should be a sufficient distance from finish grade. This depth is generally the same as any overexcavation due to cut-fill transitions in hard rock areas, and generally facilitates the excavation of structural footings and substructures. Should deeper excavations be proposed (i.e., deepened footings, utility trenching, swimming pools, spas, etc.), the developer may consider increasing the hold-down depth of any rocky fills to be placed, as appropriate. In addition, some agencies/jurisdictions mandate a specific hold-down depth for oversize materials placed in fills. The hold-down depth, and potential to encounter oversize rock, both within fills, and occurring in cut or natural areas, would need to be disclosed to all interested/affected parties. Once approved by the governing agency, the hold-down depth for oversized rock (i.e., greater than 12 inches) in fills on this project is provided as 1 O feet, unless specified differently in the text of this report. The governing agency may require that these materials need to be deeper, crushed, or reduced to less than 12 inches in maximum dimension, at their discretion. To facilitate future trenching, rock (or oversized material), should not be placed within the hold-down depth feet from finish grade, the range of foundation excavations, future utilities, or underground construction unless specifically approved by the governing agency, the geotechnical consultant, and/or the developer's representative. If import material is required for grading, representative samples of the materials to be utilized as compacted fill should be analyzed in the laboratory by the geotechnical consultant to evaluate it's physical properties and suitability for use onsite. Such testing Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, lne. Appendix E Page4 should be performed three (3) days prior to importation. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the geotechnical consultant as soon as possible. Approved fill material should be placed in areas prepared to receive fill in near horizontal layers, that when compacted, should not exceed about 6 to 8 inches in thickness. The geotechnical consultant may approve thick lifts if testing indicates the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer should be spread evenly and blended to attain uniformity of material and moisture suitable for compaction. Fill layers at a moisture content less than optimum should be watered and mixed, and wet fill layers should be aerated by scarification, or should be blended with drier material. Moisture conditioning, blending, and mixing of the fill layer should continue until the fill materials have a uniform moisture content at, or above, optimum moisture. After each layer has been evenly spread, moisture conditioned, and mixed, it should be uniformly compacted to a minimum of 90 percent of the maximum density as evaluated by ASTM test designation D-1557, or as otherwise recommended by the geotechnical consultant. Compaction equipment should be adequately sized and should be specifically designed for soil compaction, or of proven reliability to efficiently achieve the specified degree of compaction. Where tests indicate that the density of any layer of fill, or portion thereof, is below the required relative compaction, or improper moisture is in evidence, the particular layer or portion shall be re-worked until the required density and/or moisture content has been attained. No additional fill shall be placed in an area until the last placed lift of fill has been tested and found to meet the density and moisture requirements, and is approved by the geotechnical consultant. In general, per the 1997 UBC and/or latest adopted version of the California Building Code (CBC}, fill slopes should be designed and constructed at a gradient of 2:1 (h:v), or flatter. Compaction of slopes should be accomplished by over-building a minimum of 3 feet horizontally, and subsequently trimming back to the design slope configuration. Testing shall be performed as the fill is elevated to evaluate compaction as the fill core is being developed. Special efforts may be necessary to attain the specified compaction in the fill slope zone. Final slope shaping should be performed by trimming and removing loose materials with appropriate equipment. A final evaluation of fill slope compaction should be based on observation and/or testing of the finished slope face. Where compacted fill slopes are designed steeper than 2:1 (h:v), prior approval from the governing agency, specific material types, a higher minimum relative compaction, special reinforcement, and special grading procedures will be recommended. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge Appendix E Page 5 If an alternative to over-building and cutting back the compacted fill slopes is selected, then special effort should be made to achieve the required compaction in the outer 1 O feet of each lift of fill by undertaking the following: 1. An extra piece of equipment consisting of a heavy, short-shanked sheepsfoot should be used to roll (horizontal) parallel to the slopes continuously as fill is placed. The sheepsfoot roller should also be used to roll perpendicular to the slopes, and extend out over the slope to provide adequate compaction to the face of the slope. 2. Loose fill should not be spilled out over the face of the slope as each lift is compacted. Any loose fill spilled over a previously completed slope face should be trimmed off or be subje.ct to re-rolling. 3. Field compaction tests will be made in the outer (horizontal) ±2 to ±8 feet of the slope at appropriate vertical intervals, subsequent to compaction operations. 4. After completion of the slope, the slope face should be shaped with a small tractor and then re-rolled with a sheepsfoot to achieve compaction to near the slope face. Subsequent to testing to evaluate compaction, the slopes should be grid-rolled to achieve compaction to the slope face. Final testing should be used to evaluate compaction after grid rolling. 5. Where testing indicates less than adequate compaction, the contractor will be responsible to rip, water, mix, and recompact the slope material as necessary to achieve compaction. Additional testing should be performed to evaluate compaction. SUBDRAIN INSTALLATION Subdrains should be installed in approved ground in accordance with the approximate alignment and details indicated by the geotechnical consultant. Subdrain locations or materials should not be changed or modified without approval of the geotechnical consultant. The geotechnical consultant may recommend and direct changes in subdrain line, grade, and drain material in the field, pending exposed conditions. The location of constructed subdrains, especiallythe outlets, should be recorded/surveyed by the project civil engineer. Drainage at the subdrain outlets should be provided by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the geotechnical consultant. If directed by the geotechnical consultant, further excavations or overexcavation and refilling of cut areas should be performed, and/or remedial grading of Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge Appendix E Page 6 cut slopes should be performed. When fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope should be observed by the geotechnical consultant prior to placement of materials for construction of the fill portion of the slope. The geotechnical consultant should observe all cut slopes, and should be notified by the contractor when excavation of cut slopes commence. If, during the course of grading, unforeseen adverse or potentially adverse geologic conditions are encountered, the geotechnical consultant should investigate, evaluate, and make appropriate recommendations for mitigation of these conditions. The need for cut slope buttressing or stabilizing should be based on in-grading evaluation by the geotechnical consultant, whether anticipated or not. Unless otherwise specified in geotechnical and geological report(s), no cut slopes should be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. Additionally, short-term stability of temporary cut slopes is the contractor's responsibility. Erosion control and drainage devices should be designed by the project civil engineer and should be constructed in compliance with the ordinances of the controlling governmental agencies, and/or in accordance with the recommendations of the geotechnical consultant. COMPLETION Observation, testing, and consultation by the geotechnical consultant should be conducted during the grading operations in order to state an opinion that all cut and fill areas are graded in accordance with the approved project specifications. After completion of grading, and after the geotechnical consultant has finished observations of the work, final reports should be submitted, and may be subject to review by the GOntrolling governmental agencies. No further excavation or filling should be undertaken without prior notification of the geotechnical consultant or approved plans. All finished cut and fill slopes should be protected from erosion and/or be planted in accordance with the project specifications and/or as recommended by a landscape architect. Such protection and/or planning should be undertaken as soon as practical after completion of grading. PRELIMINARY OUTDOOR POOL/SPA DESIGN RECOMMENDATIONS The following preliminary recommendations are provided for consideration in pool/spa design and planning. Actual recommendations should be provided by a qualified geotechnical consultant, based on site specific geotechnical conditions, including a subsurface investigation, differential settlement potential, expansive and corrosive soil potential, proximity of the proposed pool/spa to any slopes with regard to slope creep and lateral fill extension, as well as slope setbacks per code, and geometry of the proposed Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, lne .. Appendix E Page 7 improvements. Recommendations for pools/spas and/or deck flatwork underlain by expansive soils, or for areas with differential settlement greater than 1/4-inch over 40 feet horizontally, will be more onerous than the preliminary recommendations presented below. The 1 :1 (h:v) influence zone of any nearby retaining wall site structures should be delineated on the project civil drawings with the pool/spa. This 1 :1 (h:v) zone is defined as a plane up from the lower-most heel of the retaining structure, to the daylight grade of the nearby building pad or slope. If pools/spas or associated pool/spa improvements are constructed within this zone, they should be re-positioned (horizontally or vertically) so that they are supported by earth materials that are outside or below this 1: 1 plane. If this is not possible given the area of the building pad, the owner should consider eliminating these improvements or allow for increased potential for lateral/vertical deformations and associated distress that may render these improvements unusable in the future, unless they are periodically repaired and maintained. The conditions and recommendations presented herein should be disclosed to all homeowners and any interested/affected parties. General 1. The equivalent fluid pressure to be used for the pool/spa design should be 60 pounds per cubic foot (pcf) for pool/spa walls with level backfill, and 75 pcf for a 2:1 sloped backfill condition. In addition, backdrains should be provided behind pool/spa walls subjacent to slopes. 2. Passive earth pressure may be computed as an equivalent fluid having a density of 150 pcf, to a maximum lateral earth pressure of 1,000 pounds per square foot (psf). 3. An allowable coefficient of friction between soil and concrete of 0.30 may be used with the dead load forces. 4. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 5. Where pools/spas are planned near structures, appropriate surcharge loads need to be incorporated into design and construction by the pool/spa designer. This includes, but is not limited to landscape berms, decorative walls, footings, built-in barbeques, utility poles, etc. 6. All pool/spa walls should be designed as "free standing" and be capable of supporting the water in the pool/spa without soil support. The shape of pool/spa in cross section and plan view may affect the performance of the pool, from a geotechnical standpoint. Pools and spas should also be designed in accordance with Section 1806.5 of the 1997 USC. Minimally, the bottoms of the pools/spas, should maintain a distance H/3, where His the height of the slope (in feet), from the slope face. This distance should not be less than 7 feet, nor need not be greater than 40 feet. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSofls, lne .. Appendix E Page 8 7. The soil beneath the pool/spa bottom should be uniformly moist with the same stiffness throughout. If a fill/cut transition occurs beneath the pool/spa bottom, the cut portion should be overexcavated to a minimum depth of 48 inches, and replaced with compacted fill, such that there is a uniform blanket that is a minimum of 48 inches below the pool/spa shell. If very low expansive soil is used for fill, the fill should be placed at a minimum of 95 percent relative compaction, at optimum moisture conditions. This requirement should be 90 percent relative compaction at over optimum moisture if the pool/spa is constructed within or near expansive soils. The potential for grading and/or re-grading of the pool/spa bottom, and attendant potential for shoring and/or slot excavation, needs to be considered during all aspects of pool/spa planning, design, and construction. 8. If the pool/spa is founded entirely in compacted fill placed during rough grading, the deepest portion of the pool/spa should correspond with the thickest fill on the lot. 9. Hydrostatic pressure relief valves should be incorporated into the pool and spa designs. A pool/spa under-drain system is also recommended, with an appropriate outlet for discharge. 1 O. All fittings and pipe joints, particularly fittings in the side of the pool or spa, should be properly sealed to prevent water from leaking into the adjacent soils materials, and be fitted with slip or expandible joints between connections transecting varying soil conditions. 11. An elastic expansion joint (flexible waterproof sealant) should be installed to prevent water from seeping into the soil at all deck joints. 12. A reinforced grade beam should be placed around skimmer inlets to provide support and mitigate cracking around the skimmer face. 13. In order to reduce unsightly cracking, deck slabs should minimally be 4 inches thick, and reinforced with No. 3 reinforcing bars at 18 inches on-center. All slab reinforcement should be supported to ensure proper mid-slab positioning during the placement of concrete. Wire mesh reinforcing is specifically not recommended. Deck slabs should not be tied to the pool/spa structure. Pre-moistening and/or pre-soaking of the slab subgrade is recommended, to a depth of 12 inches (optimum moisture content), or 18 inches (120 percent of the soil's optimum moisture content, or 3 percent over optimum moisture content, whichever is greater), for very low to low, and medium expansive soils, respectively. This moisture content should be maintained in the subgrade soils during concrete placement to promote uniform curing of the concrete and minimize the development of unsightly shrinkage cracks. Slab underlayment should consist of a 1-to 2-inch leveling course of sand (S.E.>30) and a minimum of 4 to 6 inches of Class 2 base compacted to 90 percent. Deck slabs within the H/3 zone, where H is the height of the slope (in feet), will have an increased potential for distress relative to other areas outside of the H/3 zone. If distress is undesirable, Golden Surf Holdings, LLC File:e:\wp12\B300\6309a.pge Appendix E Page 9 improvements, deck slabs or flatwork should not be constructed closer than H/3 or 7 feet (whichever is greater) from the slope face, in order to reduce, but not eliminate, this potential. 14. Pool/spa bottom or deck slabs should be founded entirely on competent bedrock, or properly compacted fill. Fill should be compacted to achieve a minimum 90 percent relative compaction, as discussed above. Prior to pouring concrete, subgrade soils below the pool/spa decking should be throughly watered to achieve a moisture content that is at least 2 percent above optimum moisture content, to a depth of at least 18 inches below the bottom of slabs. This moisture content should be maintained in the subgrade soils during concrete placement to promote uniform curing of the concrete and minimize the development of unsightly shrinkage cracks. 15. In order to reduce unsightly cracking, the outer edges of pool/spa decking to be bordered by landscaping, and the edges immediately adjacent to the pool/spa, should be underlain by an 8-inch wide concrete cutoff shoulder (thickened edge) extending to a depth of at least 12 inches below the bottoms of the slabs to mitigate excessive infiltration of water under the pool/spa deck. These thickened edges should be reinforced with two No. 4 bars, one at the top and one at the bottom. Deck slabs may be minimally reinforced with No. 3 reinforcing bars placed at 18 inches on-center, in both directions. All slab reinforcement should be supported on chairs to ensure proper mid-slab positioning during the placement of concrete. 16. Surface and shrinkage cracking of the finish slab may be reduced if a low slump and water-cement ratio are maintained during concrete placement. Concrete utilized should have a minimum compressive strength of 4,000 psi. Excessive water added to concrete prior to placement is likely to cause shrinkage cracking, and should be avoided. Some concrete shrinkage cracking, however, is unavoidable. 17. Joint and sawcut locations for the pool/spa deck should be determined by the design engineer and/or contractor. However, spacings should not exceed 6 feet on center. 18. Considering the nature of the onsite earth materials, it should be anticipated that caving or sloughing could be a factor in subsurface excavations and trenching. Shoring or excavating the trench walls/backcuts at the angle of repose (typically 25 to 45 degrees), should be anticipated. All excavations should be obseNed by a representative of the geotechnical consultant, including the project geologist and/or geotechnical engineer, prior to workers entering the excavation or trench, and minimally conform to Cal/OSHA ("Type C" soils may be assumed), state, and local safety codes. Should adverse conditions exist, appropriate recommendations should be offered at that time by the geotechnical consultant. GSI does not consult in the area of safety engineering and the safety of the construction crew is the responsibility of the pool/spa builder. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, Inc .. Appendix E Page 10 19. It is imperative that adequate provisions for surface drainage are incorporated by the homeowners into their overall improvement scheme. Ponding water, ground saturation and flow over slope faces, are all situations which must be avoided to enhance long term performance of the pool/spa and associated improvements, and reduce the likelihood of distress. 20. Regardless of the methods employed, once the pool/spa is filled with water, should it be emptied, there exists some potential that if emptied, significant distress may occur. Accordingly, once filled, the pool/spa should not be emptied unless evaluated by the geotechnical consultant and the pool/spa builder. 21. For pools/spas built within (all or part) of the 1997 Uniform Building Code (UBC) setback and/or geotechnical setback, as indicated in the site geotechnical documents, special foundations are recommended to mitigate the affects of creep, lateral fill extension, expansive soils and settlement on the proposed pool/spa. Most municipalities or County reviewers do not consider these effects in pool/spa plan approvals. As such, where pools/spas are proposed on 20 feet or more of fill, medium or highly expansive soils, or rock fill with limited "cap soils" and built within 1997 UBC setbacks, or within the influence of the creep zone, or lateral fill extension, the following should be considered during design and construction: OPTION A: Shallow foundations with or without overexcavation of the pool/spa "shell," such that the pool/spa is surrounded by 5 feet of very low to low expansive soils (without irreducible particles greater that 6 inches), and the pool/spa walls closer to the slope(s) are designed to be free standing. GSI recommends a pool/spa under-drain or blanket system (see attached Typical Pool/Spa Detail). The pool/spa builders and owner in this optional construction technique should be generally satisfied with pool/spa performance under this scenario; however, some settlement, tilting, cracking, and leakage of the pool/spa is likely over the life of the project. OPTION B: Pier supported pool/spa foundations with or without overexcavation of the pool/spa shell such that the pool/spa is surrounded by 5 feet of very low to low expansive soils (without irreducible particles greater than 6 inches), and the pool/spa walls closer to the slope(s) are designed to be free standing. The need for a pool/spa under-drain system may be installed for leak detection purposes. Piers that support the pool/spa should be a minimum of 12 inches in diameter and at a spacing to provide vertical and lateral support of the pool/spa, in accordance with the pool/spa designers recommendations, local code, and the 1997 UBC. The pool/spa builder and owner in this second scenario construction technique should be more satisfied with pool/spa performance. This construction will reduce settlement and creep effects on the pool/spa; however, it will not eliminate these potentials, nor make the pool/spa "leak-free." Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge Appendix E Page 11 22. The temperature of the water lines for spas and pools may affect the corrosion properties of site soils, thus, a corrosion specialist should be retained to review all spa and pool plans, and provide mitigative recommendations, as warranted. Concrete mix design should be reviewed by a qualified corrosion consultant and materials engineer. 23. All pool/spa utility trenches should be compacted to 90 percent of the laboratory standard, under the full-time observation and testing of a qualified geotechnical consultant. Utility trench bottoms should be sloped away from the primary structure on the property (typically the residence). 24. Pool and spa utility lines should not cross the primary structure's utility lines (i.e., not stacked, or sharing of trenches, etc.). 25. The pool/spa or associated utilities should not intercept, interrupt, or otherwise adversely impact any area drain, roof drain, or other drainage conveyances. If it is necessary to modify, move, or disrupt existing area drains, subdrains, ortightlines, then the design civil engineer should be consulted, and mitigative measures provided. Such measures should be further reviewed and approved by the geotechnical consultant, prior to proceeding with any further construction. 26. The geotechnical consultant should review and approve all aspects of pool/spa and flatwork design prior to construction. A design civil engineer should review all aspects of such design, including drainage and setback conditions. Prior to acceptance of the pool/spa construction, the project builder, geotechnical consultant and civil designer should evaluate the performance of the area drains and other site drainage pipes, following pool/spa construction. 27. All aspects of construction should be reviewed and approved by the geotechnical consultant, including during excavation, prior to the placement of any additional fill, prior to the placement of any reinforcement or pouring of any concrete. 28. Any changes in design or location of the pool/spa should be reviewed and approved by the geotechnical and design civil engineer prior to construction. Field adjustments should not be allowed until written approval of the proposed field changes are obtained from the geotechnical and design civil engineer. 29. Disclosure should be made to homeowners and builders, contractors, and any interested/affected parties, that pools/spas built within about 15 feet of the top of a slope, and/or H/3, where H is the height of the slope (in feet), will experience some movement or tilting. While the pool/spa shell or coping may not necessarily crack, the levelness of the pool/spa will likely tilt toward the slope, and may not be esthetically pleasing. The same is true with decking, flatwork and other improvements in this zone. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, Inc .. Appendix E Page 12 30. Failure to adhere to the above recommendations will significantly increase the potential for distress to the pool/spa, flatwork, etc. 31. Local seismicity and/or the design earthquake will cause some distress to the pool/spa and decking or flatwork, possibly including total functional and economic loss. 32. The information and recommendations discussed above should be provided to any contractors and/or subcontractors, or homeowners, interested/affected parties, etc., that may perform or may be affected by such work. JOB SAFETY General At GSI, getting the job done safely is of primary concern. The following is the company's safety considerations for use by all employees on multi-employer construction sites. On-ground personnel are at highest risk of injury, and possible fatality, on grading and construction projects. GSI recognizes that construction activities will vary on each site, and that site safety is the prime responsibility of the contractor; however, everyone must be safety conscious and responsible at all times. To achieve our goal of avoiding accidents, cooperation between the client, the contractor, and GSI personnel must be maintained. In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of field personnel on grading and construction projects: Safety Meetings: GSI field personnel are directed to attend contractor's regularly scheduled and documented safety meetings. Safety Vests: Safety vests are provided for, and are to be worn by GSI personnel, at all times, when they are working in the field. Safety Flags: Two safety flags are provided to GSI field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. Flashing Lights: All vehicles stationary in the grading area shall use rotating or flashing amber beacons, or strobe lights, on the vehicle during all field testing. While operating a vehicle in the grading area, the emergency flasher on the vehicle shall be activated. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, lne .. Appendix E Page 13 Test Pits LocaUon, Orientation, and Clearance The technician is responsible for selecting test pit locations. A primary concern should be the technician's safety. Efforts will be made to coordinate locations with the grading contractor's authorized representative, and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractor's authorized representative (supervisor, grade checker, dump man, operator, etc.) should direct excavation of the pit and safety during the test period. Of paramount concern should be the soil technician's safety, and obtaining enough tests to represent the fill. Test pits should be excavated so that the spoil pile is placed away from oncoming traffic, whenever possible. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates the fill be maintained in a driveable condition. Alternatively, the contractor may wish to park a piece of equipment in front of the test holes, particularly in small fill areas or those with limited access. A zone of non-encroachment should be established for all test pits. No grading equipment should enter this zone during the testing procedure. The zone should extend approximately 50 feet outward from the center of the test pit. This zone is established for safety and to avoid excessive ground vibration, which typically decreases test results. When taking slope tests, the technician should park the vehicle directly above or below the test location. If this is not possible, a prominent flag should be placed at the top of the slope. The contractor's representative should effectively keep all equipment at a safe operational distance (e.g., 50 feet) away from the slope during this testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location, well away from the equipment traffic pattern. The contractor should inform our personnel of all changes to haul roads, cut and fill areas or other factors that may affect site access and site safety. In the event that the technician's safety is jeopardized or compromised as a result of the contractor's failure to comply with any of the above, the technician is required, by company policy, to immediately withdraw and notify his/her supervisor. The grading contractor's representative will be contacted in an effort to affect a solution. However, in the interim, no further testing will be performed until the situation is rectified. Any fill placed can be considered unacceptable and subject to reprocessing, recompaction, or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor bring this to the technician's attention and notify this office. Effective communication and coordination between the contractor's representative and the soil technician is strongly encouraged in order to implement the above safety plan. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, Inca Appendix E Page 14 Trench and Vertical Excavation It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Our personnel are directed not to enter any excavation or vertical cut which: 1) is 5 feet or deeper unless shored or laid back; 2) displays any evidence of instability, has any loose rock or other debris which could fall into the trench; or 3) displays any other evidence of any unsafe conditions regardless of depth. All trench excavations or vertical cuts in excess of 5 feet deep, which any person enters, should be shored or laid back. Trench access should be provided in accordance with Cal/OSHA and/or state and local standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraw and notify his/her supervisor. The contractor's representative will be contacted in an effort to affect a solution. All backfill not tested due to safety concerns or other reasons could be subjectto reprocessing and/or removal. If GSI personnel become aware of anyone working beneath an unsafe trench wall or vertical excavation, we have a legal obligation to put the contractor and owner/developer on notice to immediately correct the situation. If corrective steps are not taken, GSI then has an obligation to notify Cal/OSHA and/or the proper controlling authorities. Golden Surf Holdings, LLC File:e:\wp12\6300\6309a.pge GeoSoils, lnco Appendix E Page 15 lYPEA TYPE B Selection of alternate subdrain details, location, and extent of subdrains should be evaluated by the geotechnical consultant during grading. CANYON SUBDRAIN DETAIL Plate E-1 12-inch minimum 6-lnch minimum A-1 8-1 Filter material: Minimum volume of 9 cubic feet per lineal foot of pipe. FILTER MATERIAL Perforated pipe: 6-inch-diameter ABS or PVC pipe or approved substitute with minimum 8 perforations CJl,i-inch diameter) per lineal foot in bottom half of pipe (ASTM D-2751, SDR-35, or ASTM D-1527, Schd. 40). For continuous run ih excess of 500 feet, use 8-inch-diameter pipe (ASTM D-3034, SDR-35, or ASTM D-1785, Schd. 40). Sieve Size 1 inch % inch % inch No.4 No. 8 No. 30 No.50 No.200 Percent Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 AL TERNA TE 1: PERFORATED PIPE AND FIL TEA MA lERIAL \ ~\ -•-- Filter fabric \~ 6-lnch minimum \ ~/ I I /~~-~nch \----.L minimum A-2 6-inch minimum J- Gravel Material: 9 cubic feet per lineal foot. Perforated Pipe: See Alternate 1 Gravel: Clean %-inch rock or approved substitute. Filter Fabric: Mirafi 140 or approved substitute. 1 6-inch minimum ALTERNATE 2= PERFORATED PIPE, GRAVEL, AND FILTER FABRIC CANYON SUBDRAIN ALTERNATE DETAILS Plate E-2 Original ground surf ace to be restored with compacted fill I I~ Back-cut varies. For deep removals, backcut should be made no steeper than 1=1 (H=V), or flatter as necessary for safety considerations. 2D / ~--Toe of slope as shown on grading plan < .< S>: -:-:-. .:-~ <: · . ..._. = ··: ·· · .. : .. t.ompac1$d.Fill · = :., .. -<:.: .. :./~\: .. "·: .... , ..... , .. '·_::: .... ·.: · .... : .... ·,,~: ··· .. :··:: :·:. ·: . .. ..... .#/0~ / \.__Original ground surface 0~ ~ q_<. / D = Anticipated removal of unsuitable material .~-s / (depth per geotechnical engineer) ~~/ ""' Provide a 1:1 (H:V) minimum projection from toe of slope as shown on grading plan to the recommended removal depth. Slope height, site conditions, and/ or local conditions could dictate flatter projections. ~.c. FILL SLOPE TOEING OUT ON FLAT ALLUVIATED CANYON DETAIL Plate E-3 4~¥-co ~~~TJllS Proposed grade ~ ----- ~ Previously placed, temporary compacted fill for drainage only ---- Proposed additional compacted fill . . "~@I : r <>""- Ex,st,ng co "'~ ".' ::::.·:: ::::::: :::::::: ::.~:~' =· -~ -·. :. . mpacted fill '% \/.:/::/ ::/:);<'·· ., · : t!r.>Sllif'" ·' ·' ;: ': ·: ;, ·· · '-'lt ''''''':'''' ,:/, ' ' '' ' ' a.,le mater:,·a1 c· . . 0 '·:::'' :::::,< ',. ' ' ,. ' '' ' ' ' ' ' . "y::::·· ........ , .. , , ..... ,. ,., ............ ti,.be·rem .. ,,,.:.: -, .. .. · ·.. . ~ · .. · . , oved) . . ·. . . . . . :?: \\\%'v:,~ y ~~y,$i0'0?''*~\\\((~\V,\\ yA\0>"~~ y\\ <-' To be remo Bedrock or a addltional c;ed before placing native materi..\'proved mpacted fill REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL DETAIL Plate E-4 Blanket fill (if recommended by the geotechnical consultant) Design finish slope ----. I 15 foot I !minimum----\ Drainage per design civil engineer -110-foot minimum --/ -- 25-foot maximum/ ---z:::: ., t 15-foJtypical--..,._ ---/ -- 2 drain spacing / T · I 110 j . yp1ca l foot J __ = / 2-Percent Gradient _,_ --f~..,..-::v,-:: 2-foot minimum .A\\;/(' Toe key depth )-2-Percent Gradient--- 1------~ / v\ /,~ /\ 15-foot minimum L-or H/2 where His the [ elope height approved native material Subdrain as recommended by geotechnical consultant I :,:~:::0:::::_:::-::,~ 4-inch-diameter non-perforated outlet pipe and backdrain (see detail Plate E-6). Outlets to be spaced at 100-foot maximum intervals and shall extend 2 feet beyond the face of slope at time of rough grading completion. At the completion of rough grading. the design civil engineer should provide recommendations to convey any outlet's discharge to a suitable conveyance, utilizing a non-erosive device. TYPICAL STABILIZATION / BUTTRESS FILL DETAIL Plate E-5 I 2-toot I ,=a • • es, I minimum I 1 m~~:;~~ ___ __J_ . . l . L) . . =J -------4-inch minimu 2-inch J pipe minimum Filter Material: Minimum of 5 cubic feet per lineal foot of pipe or 4 cubic feet per lineal feet of pipe when placed in square cut trench. Alternative in Lieu of Filter Material: Gravel may be encased in approved filter fabric. Filter fabric shall be Mirafi 140 or equivalent. Filter fabric shall be lapped a minimum of 12 inches in all joints. Minimum 4-lnch-Oiameter Pipe: ABS-ASTM 0-2751, SOR 35; or ASTM 0-1527 Schedule 40, PVC-ASTM 0-3034, SOR 35; or ASTM 0-1785 Schedule 40 with a crushing strength of 1,000 pounds minimum, and a minimum of 8 uniformly-spaced perforations per foot of pipe. Must be installed with perforations down at bottom of pipe: Provide cap at upstream end of pipe. Slope at 2 percent to outlet pipe. Outlet pipe to be connected to subdrain pipe with tee or elbow. Notes= 1. Trench for outlet pipes to be backfilled and compacted with onsite soil. 2. Backdrains and lateral drains shall be located at elevation of every bench drain. First drain located at elevation just above lower lot grade. Additional drains may be required at the discretion of the geotechnical consultant. Filter Material shall be of the following specification or an approved equivalent. Sieve Size 1 inch %inch % inch No.4 No. 8 No. 30 No.SO No.200 Percent Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Gravel shall be of the following specification or an approved equivalent. Sieve Size 1~ inch No.4 No.200 Percent Passing 100 50 8 TYPICAL BUTTRESS SUBDRAIN DETAIL Plate E-6 Toe of slope as shown on grading plan Natural slope to be restored with compacted fill Backcut varies NOTES: ,,..--Proposed grade \ / / / / / / -----r Subdrain as recommended by geotechnical consultant / Compacted fill •,'· ·,·. 1. Where the natural slope approaches or exceeds the design slope ratio, special recommendations would be provided by the geotechnical consultant. 2. The need for and disposition of drains should be evaluated by the geotechnical consultant, based upon exposed conditions . • C ,. . FILL OVER NATURAL (SIDEHILL FILL) DETAIL Plate E-7 H = height of slope Cut/fill contact as shown on grading plan Cut/fill contact as shown on as-built plan Original (existing) grade Proposed grade / / / Compacted fill 4-foot minimum Subdrain as recommended by geotechnical consultant NOTE: The cut portion of the slope should be excavated and evaluated by the geotechnical consultant prior to construction of the fill portion. ic.llc~ m:· FILL OVER CUT DETAIL Plate E-8 Proposed finish grade ----. Natural slope ···7···<~ y· ,...,,..,..,....._...JY" ' ... :: :._ . . . .. . '· . : ;: .. \ . . . . . . '-: . :• .· . . .... . · .· ·,. ·· .. Remove'Uneui!able ( Typical benching (4-foot minimum) ~ompacted stablization fill .· .. :, .... ; -/ : .. ~ ~ ..::::::::-- - - -A\,.,\1:7.f;>_\'1 '~, ........ ,,, .. ,,,,,,.,,,,.,,.., ... ...,... --Bedrock or other approved native material / / Subdrain as recommended by geotechnical consultant NOTES= 1. Subdrains may be required as specified by the geotechnical consultant. 2 W shall be equipment width (15 feet) for slope heights less than 25 feet. For slopes greater than 25 feet, W shall be evaluated by the geotechnical consultant. At no time, shall W be less than H/2, where H is the height of the slope . • . a: .. STABLIZATION FILL FOR UNSTABLE MATERIAL EXPOSED IN CUT SLOPE DETAIL Plate E-9 . Proposed finish grade -~ Natural grade -------------------------,,,...-->- H -height of slope Typical benching (4-foot minimum) Subdrain as recommended by geotechnical consultant NOTES= 1. 15-foot minimum to be maintained from proposed finish slope face to back cut. minimum 2. The need and disposition of drains will be evaluated by the geotechnical consultant based on field conditions. 3. Pad overexcavation and recompaction should be performed if evaluated to be necessary by the geotechnical consultant. ,,;,~) •. fii' ·-·· '' c. .~f SKIN FILL OF NATURAL GROUND DETAIL Plate E-10 Reconstruct compacted fill slope at 2:1 or flatter (may increase or decrease pad area) Overexcavate and recompact replacement fill Back-cut varies Avoid and/or clean up spillage of materials on the natural slope Natural grade Subdrain as recommended by geotechnical consultant :,, .. .. NOTES: 1. Subdrain and key width requirements will be evaluated based on exposed subsurface conditions and thickness of overburden. 2. Pad overexcavation and recompaction should be performed if evaluated necessary by the geotechnical consultant. ~Jlac. DAYLIGHT CUT LOT DETAIL Plate E-11 Natural grade Proposed pad grade ·:.-: .. :. . ··: . . . . : ·:: ....... . -:;i;,·:•,S/'.:~tt-S-i~ -.·~:~·,.;· .. ,,~:··._· - - - - - _ l_ Subgrade at 2 percent gradient, draining toward street CUT LOT OR MATERIAL -TYPE TRANSITION Typical benching (4-foot minimum) Bedrock or approved native material Natural grade ... : ..... :·: ... _ .. :~ :,: J_ · __ ------ * Deeper overexcavation may be recommended by the geotechnical consultant in steep cut-fill transition areas, such that the underlying topography is no steeper than 3=1 (H:V) CUT-FILL LOT (DAYLIGHT TRANSITION) TRANSITION LOT DETAILS Plate E-12 VIEW NORMAL TO SLOPE FACE , (E) Hold-down depth Proposed finish grade ~ (E)~-~ 1:---~ / .,.CCC) cI:J / ~\ c:co ~ "'-._) minimum c::cx:) -=1 (8) cI:J / c:co cI:J I (A) I I Jg> c0---15-foot------c:co V._ cO minimum (D) c:co C:CO(F) ~0.~~~~~~~~\%~0-~\%< V-Bedrock or approved minimum native material VIEW PARALLEL TO SLOPE FACE j__ (E) Hold-down depth --~ t 15-foot minimum -----l ~ minimum NOTES: __ Proposed finish grade ""--__ __ __ I <9> I ---100-foot---i I maximum I (D) ~--~ ~ 3-foot minimum (J ~ Bedrock or approved native material A. One equipment width or a minimum of 15 feet between rows (or windrows). B. Height and width may vary depending on rock size and type of equipment. Length of windrow shall be no greater than 100 feet. C. If approved by the geotechnical consultant, windrows may be placed direclty on competent material or bedrock, provided adequate space is available for compaction. D. Orientation of windrows may vary but should be as recommended by the geotechnical engineer and/ or engineering geologist. Staggering of windrows is not necessary unless recommended. E. Clear area for utility trenches, foundations, and swimming pools; Hold-down depth as specified in text of report, subject to governing agency approval. F. All fill over and around rock windrow shall be compacted to at least 90 percent relative compaction or as recommen~ed. G. After fill between windrows is placed and compacted, with the lift of fill covering windrow, windrow should be proof rolled with a D-9 dozer or equivalent. VIEWS ARE DIAGRAMMA 1lC ONLY AND MAY BE SUPERSEDED BY REPORT RECOMMEND A 110NS OR CODE ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED • l!:o -OVERSIZE ROCK DISPOSAL DETAIL Plate E-13 ROCK DISPOSAL PITS Fill lifts compacted o9vr rock after embedment ,------- 1 ..... Granular material L · · _._._._._._._._._._ Large Rock ---,i...&.,,i,•-..i...• •••• I I I I Compacted Fill I ------1 '-Size of excavation to l be commensurate I with rock size I ROCK DISPOSAL LAYERS Granular soil to fill voids, densHied by flooding ~:-~ -.. ~ ;~~cte~fi~ _ Layer one rock high · -:~~ J~ _ t_ L._ Proposed finish grade -......._ :_»L'>-~\~--~--- • Hold-down depth ~ PR~LE ALONG LA YER -r = '-.._ '-.._ '-.._ (" Hold-down depth _t_ " 3-foot rillSlope l •• Clear zone TOP VIEW * Hold-down depth or below lowest utility as specified in text of report, subject to governing agency approval. •• Clear zone for utility trenches, foundations, and swimming pools, as specified in text of report. VIEWS ARE DIAGRAMMATIC ONLY AND MAY BE SUPERSEDED BY REPORT RECOMMENDATIONS OR CODE ROCK SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLEJ"ELY FILLED IN ROCK DISPOSAL DETAIL Plate E-14 Existing grade 5-foot-high impact/debris wall METHOD 1 1 Pad grade --_L __ --- Existing grade 5-foot-high impact/debris wall METHOD 2 "-. ~ Pad grade __ Existing grade 5-foot-wide catchment area r 5-toot-high METHOD 3 impact/ debris wall ?>.:~-__ ~---Pa_d_g_rad_e __ Existing grade "<"( 2:1 (h:v) slope cence ·\\)-.\Y: \ 2=1 (h=v) slope METHOD 4 ~, 'y-_;--Pad grade I . «:o . . \\\ "-_[_ ·-- 0 -::.,..,-: -<, ::..<-\\\ \,.,. /~/ /., NOTTO SCALE DEBRIS DEVICE CONTROL METHODS DETAIL Plate E-15 Rock-filled gabion basket Existing grade Filter fabric IJ1J~~~t] 5-foot minimum or as ~~~,!,1,,,,'11'<':1 recommended by ~~~~~ geotechnical consultant Drain rock Compacted fill Proposed grade Gabion impact or diversion wall should be constructed at the base of the ascending slope subject to rock fall. Walls need to be constructed with high segments that sustain impact and mitigate potential for overtopping, and low segment that provides channelization of sediments and debris to desired depositional area for subsequent clean-out. Additional subdrain may be recommended by geotechnical consultant. Fram GSA, 1987 i c,, . ROCK FALL MITIGATION DETAIL Plate E-16 • MAP VIEW NOTTO SCALE Concrete cut-off wall SEENOT~'-8------~--~J B I Top of slope ~ Gravity-flow, nonperforated subdrain I=== pipe (1ransverse) Toe of slope 4 I 1 steet Pool 4-inch perforated subdrain pipe (longitudinal) Coping 2-inch-thick sand layer A' 4-inch perforated subdrain pipe (transverse) Pool Direction of drainage B' CROSS SECTION VIEW Coping NOTTO SCALE SEE NOTES Pool encapsulated in 5-foot thickness of sand ----, 6-inch-thick gravel layer 4-inch perforated subdrain pipe B NOTES: Gravity-flow nonperforated subdrain pipe I I ---1 1 steet Coping B' 2-inch-thick sand layer Vapor retarder Perforated subdrain pipe 1. 6-inch-thick, clean gravel(% to~ inch) sub-base encapsulated in Mirafl 140N or equivalent, underlain by a 15-mil vapor retarder, with 4-inch-diameter perforated pipe longitudinal connected to 4-inch-diameter perforated pipe transverse. Connect transverse pipe to 4-inch-diameter nonperforated pipe at low point and outlet or to sump pump area. 2. Pools on fills thicker than 20 feet should be constructed on deep foundations; otherwise, distress (tilting, cracking, etc.) should be expected. 3. Design does not apply to infinity-edge pools/spas . • e . . TYPICAL POOL/SPA DETAIL Plate E-17 -t- NOTES: 2-foot x 2-foot x ,%-inch steel plate Standard %-inch pipe nipple welded to top of plate ---t--%-inch x 5-foot galvanized pipe, standard pipe threads top and bottom; extensions threaded on both ends and added in 5-foot increments 3-inch schedule 40 PVC pipe sleeve, add in 5-foot increments with glue joints bedding of compacted sand 1. Locations of settlement plates should be clearly marked and readily visible (red flagged) to equipment operators. 2. Contractor should maintain clearance of a 5-foot radius of plate base and withiin 5 feet (vertical) for heavy equipment. Fill within clearance area should be hand compacted to project specifications or compacted by alternative approved method by the geotechnical consultant (in writing, prior to construction). 3. After 5 feet (vertical) of fill is in place, contractor should maintain a 5-foot radius equipment clearance from riser. 4. Place and mechanically hand compact initial 2 feet of fill prior to establishing the initial reading. 5. In the event of damage to the settlement plate or extension resulting from equipment operating within the specified clearance area, contractor should immediately notify the geotechnical consultant and should be responsible for restoring the settlement plates to working order. 6. An alternate design and method of installation may be provided at the discretion of the geotechnical consultant. SETTLEMENT PLATE AND RISER DETAIL Plate E-18 Finish grade -~ ~c. ~~- Ll <J <J . Ll I I 3 to 6 feel <J .!I u <J Ll . .cl <J Ll "- .!l<J. <J Ll <J --%-inch-diameter X 6-inch-long carriage bolt or equivalent e.... 6-inch diameter X 312-inch-long hole '-----Concrete backfill -· ------------ TYPICAL SURFACE SETTLEMENT MONUMENT ~ Plate E-19 SIDE VIEW Spoil pile Test pit TOP VIEW Flag Flag Spoil pile Light '• . ". :·... .. :-. .; . ,,• · .. ::,-: . ·:>"' "'... .... £.--'c.-,...~4-L_jL.L..,{....J-~-4-J/ .. Vehicle -------50 feet-----<---------50 feet------11--t -------------~1ootee,l-------------- TEST PIT SAFETY DIAGRAM Plate E-20