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SDP 05-17; DONALD CONDOMINIUMS; UPDATE PRELIMINARY GEOTECHNICAL INVESTIGATION; 2006-06-27
Geotechnical • Coastal • Geologic • Environmental .•. U.PDATE'J?RELIMINAFW (il::OTECHNICAL·. INVE,STIGA,TION, ·2497 OCJ=A,N STREET, CARLSBAD • SAN DIEGO COUNTY, CALIFdRNIA • • • ·FOR R & M ENTERPRISES • • • • 24423 WHITAKER WAY MURRIETA, CALIFORNIA 92562-7.521 JUNE 27, 2006 Geotechnical • Coastal • Geologic • Environmental 5741 Palmer Way • Carlsbad, California 9201 0 • (760) 438-3155 • FAX (760) 931-0915 R & M Enterprises 24423 Whitaker Way Murrieta, California 92562-7521 Attention: Mr. Eric Beck June 27, 2006 W.O. 5181-A-SC Subject: Update Preliminary Geotechnical Investigation, 2497 Ocean Street, Carlsbad, San Diego County, California Dear Mr. Beck: In accordance with your request, GeoSoils, Inc. (GSI) is pleased to present the results of our update preliminary geotechnical investigation of the subject site. The purpose of our investigation was to update existing geotechnical site work completed by the C.W. La Monte Company, Inc. (CWLC, 2004), including an evaluation of the geologic and geotechnical conditions of the site, and to present preliminary recommendations for grading and foundation design/construction pertinent to the proposed two-unit residential condominium development. EXECUTIVE SUMMARY Based on our field exploration, geologic, and geotechnical engineering analysis, the proposed development appears feasible from a soils engineering and geologic viewpoint, provided that the recommendations presented herein are properly incorporated into the design and construction of the project. The most significant elements of our study are summarized below: • It is our understanding that the proposed development includes demolishing the existing structure and preparing the site for the construction of a two-unit, condominium-style residential structure, and associated exterior improvements. It is our understanding that no work is proposed with regard to the existing sea wall, and a garden "fieldstone" wall, located west of the proposed construction area. Grading appears to primarily include cut excavation for the purpose of constructing a basement/lower floor level. Additional improvements, consisting of a storm water collection tank, and underground utilities, are also proposed. • Earth materials, encountered onsite, consist of existing artificial fill, colluvium, and Quaternary-age terrace deposits which, in turn, are underlain by Eocene-age sediments belonging to the Santiago Formation. In areas proposed for settlement-sensitive improvements, all existing fill and colluvium should be removed and recompacted. Alternatively, foundations may be embedded/deepened into the underlying terrace deposits. Actual removal depths should be further evaluated during grading. • An existing garden "fieldstone" wall is located beyond (west of) the limits of the planned development, and should not significantly affect new construction. However, the wall appears to be distressed, and the potential for this structure to eventually topple seaward should not be precluded. It should be noted that the wall is also approximately located along the top of the coastal bluff. • Laboratory testing indicates that soils are generally very low in expansion potential (Expansion Index [E.1.] = Oto 20). On a preliminary basis, conventional foundations may be used for this type of soil condition. Final foundation design and construction recommendations will be provided atthe conclusion of grading, based upon the expansion potential offinish grade soils. Although not anticipated, iffinish grade soils exhibit a higher expansion potential, a plasticity index (P.I.) of 15, or greater, and/or if paleoliquefaction features are encountered during grading, additional stronger concrete, and/or foundation/slab reinforcement may be necessary. • Soil pH, soluble sulfates, and saturated resistivity testing indicates that site soils are mildly alkaline, present negligible sulfate exposure to concrete, and are moderately corrosive to ferrous metals when saturated. A corrosion specialist should be consulted for the appropriate mitigation recommendations, as needed, regarding foundations, piping, and where metals will come into contact with site soils, etc. • Regional groundwater was not encountered in our subsurface excavations; however, the regional groundwater table is anticipated to occur at depth beneath the site, at elevations near sea level. A perched groundwater table was encountered locally, along the contact between the overlying terrace deposits, and the underlying Santiago Formation. Groundwater is not expected to be a major factor in development of the site, provided the recommendations included herein are incorporated into final design and construction. Due to the nature of the site materials, seepage and/or perched groundwater conditions may develop throughout the site along boundaries of contrasting permeabilities (i.e., fill/terrace deposit/bedrock contacts), and should be anticipated. Again, this potential should be disclosed to all interested parties. Thus, supplemental slab details and design for moisture mitigation are warranted. • The seismic acceleration values and design parameters, provided herein, should be considered during the design of the proposed development. The adverse R & M Enterprises File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC Page Two 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 owners or future owners. • Adverse geologic structures (active faults, significant landslides, etc.) that would preclude project feasability were not encountered. • The geotechnical design parameters provided herein should be considered during project planning design and construction by the project structural engineer and/or architects. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact our office. Respectfully submitte GeoSoils, Inc. I . Cris Engineering ea o RGC/PLM/DWS/jk/jh Distribution: (3) Addressee David W. Skelly Civil Engineer, RC (2) Dall & Associates, Attention: Mr. Norbert Dall R & M Enterprises File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. - . RCE 4 -..........:~-.. ~ W.O. 5181-A-SC Page Three TABLE OF CONTENTS SCOPE OF SERVICES ................................................... 1 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ......................... 1 PREVIOUS WORK ....................................................... 3 FIELD STUDIES ......................................................... 4 REGIONAL GEOMORPHOLOGY ........................................... 4 REGIONAL GEOLOGY ................................................... 4 SITE GEOLOGIC UNITS .................................................. 5 Artificial Fill -(Map Symbol -Af) ....................................... 5 Colluvium (Not Mapped) ............................................ 6 Quaternary Terrace Deposits (Map Symbol -Qt) ......................... 6 Santiago Formation (Not Mapped) .................................... 6 SLOPE STABILITY ....................................................... 7 GROUNDWATER ........................................................ 7 FAUL TING AND REGIONAL SEISMICITY ..................................... 8 Regional Faults .................................................... 8 Seismicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 O PRELIMINARY SEISMIC DESIGN PARAMETERS ............................. 11 LIQUEFACTION POTENTIAL ............................................. 12 LABORATORY TESTING ................................................. 13 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 • Moisture-Density Relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Laboratory Standard ............................................... 13 Expansion Index (E.I.) Testing ....................................... 13 Atterberg Limits ................................................... 14 Shear Testing ........................ : ........................... 14 Grain Size Distribution ............................................. 14 Consolidation Test ................................................ 14 pH/Soluble Sulfates/Saturated Resistivity Testing ....................... 14 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS .................... 15 GeoSoils, Inc. EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................... 17 General Grading .................................................. 17 Demolition/Grubbing .............................................. 18 Treatment of Existing Ground ....................................... 18 Overexcavation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Fill Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 PRELIMINARY RECOMMENDATIONS -FOUNDATIONS ....................... 19 Conventional Foundations -Very Low (E.I. Oto 20) to Low (E.I. 21 to 50) Expansion Potentials With a P. I. Less Than 15 ............................. 20 Foundation Design .......................................... 20 Construction ............................................... 20 PIER FOUNDATIONS ................................................... 22 Foundations Design Criteria -Drilled Piers ............................. 22 Pier Construction ................................................. 23 FLOOR SLAB DESIGN RECOMMENDATIONS ............................... 24 SOIL MOISTURE CONSIDERATIONS ...................................... 24 SHORING DESIGN ..................................................... 25 Shoring of Excavations ............................................. 25 Underpinning (If Necessary) ........................................ 27 Open Excavations ................................................ 27 Lateral Pressure .................................................. 27 Excavation Observation (All Excavations) .............................. 29 Observation ..................................................... 30 WALL DESIGN PARAMETERS ............................................ 30 Conventional Retaining Walls ....................................... 30 Restrained Walls ............................................ 31 Cantilevered Walls ........................................... 31 Retaining Wall Backfill and Drainage .................................. 31 Wall/Retaining Wall Footing Transitions ............................... 35 DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS ....................... 36 DEVELOPMENT CRITERIA ............................................... 38 Drainage ........................................................ 38 Erosion Control ................................................... 38 Landscape Maintenance ........................................... 38 Gutters and Downspouts ........................................... 39 Subsurface and Surface Water ...................................... 39 Site Improvements ................................................ 39 R & M Enterprises File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. Table of Contents Page ii Tile Flooring ..................................................... 40 Additional Grading ................................................ 40 Footing Trench Excavation ......................................... 40 Trenching/Temporary Construction Backcuts .......................... 40 Utility Trench Backfill .............................................. 41 SUMMARY OF RECOMMENDATIONS REGARDING GEOTECHNICAL OBSERVATION AND TESTING ........................................................ 41 OTHER DESIGN PROFESSIONALS/CONSULTANTS .......................... 42 PLAN REVIEW ......................................................... 43 LIMITATIONS .......................................................... 43 FIGURES: Figure 1 -Site Location Map ......................................... 2 Figure 2 -California Fault Map ........................................ 9 Figure 3 -Lateral Earth Pressures .................................... 26 Figure 4 -Pier Analyses ............................................ 28 Detail 1 -Typical Retaining Wall Backfill and Drainage Detail .............. 32 Detail 2 -Retaining Wall Backfill and Subdrain Detail Geotextile Drain ....... 33 Detail 3 -Retaining Wall and Subdrain Detail Clean Sand Backfill ........... 34 ATTACHMENTS: Appendix A -References ................................... Rear of Text Appendix B -Test Pit and Boring Logs ........................ Rear of Text Appendix C -EQFAULT, EQSEARCH, and FRISKSP ............. Rear of Text Appendix D -Laboratory Data ............................... Rear of Text Appendix E -General Earthwork and Grading Guidelines ......... Rear of Text Plate 1 -Geologic Map ............................. Rear of Text in Folder Plate 2 -Cross Section A-A' . . . . . . . . . . . . . . . . . . . . . . . . . Rear of Text in Folder R & M Enterprises File:e:\wp9\5100\5181 a.upg GeoSoils, lne. Table of Contents Page iii UPDATE PRELIMINARY GEOTECHNICAL INVESTIGATION, 2497 OCEAN STREET, CARLSBAD SAN DIEGO COUNTY, CALIFORNIA SCOPE OF SERVICES The scope of our services has included the following: 1. Review of readily available soils and geologic data (see Appendix A). 2. Geologic site reconnaissance and geologic mapping. 3. Subsurface exploration consisting of the excavation of one hollow stem auger boring, three limited access, solid flight auger borings, and one hand dug test pit for geotechnical logging and sampling (see Appendix 8). Logs of previous site exploration (C.W. La Monte Company, Inc. [CWLC], 2004), are also included in Appendix B. 4. General areal seismicity evaluation (see Appendix C). 5. Laboratory testing of representative site soils (see Appendix D). 6. Appropriate engineering and geologic analysis of data collected and preparation of this report. SITE DESCRIPTION AND PROPOSED DEVELOPMENT The site consists of a gently to moderately west sloping lot, located west of Ocean Street (2497 Ocean Street), in Carlsbad, San Diego County, California (see Figure 1, Site Location Map). Topographically, the lot slopes gently to moderately westward. Elevations range from approximately 40 feet, National Geodetic Vertical Datum of 1929 (NGVD29) near Ocean Street, on the east side of the property, to approximately the Mean High Tide Line on the upper edge of the existing beach. A relatively steep break in slope occurs approximately 130 feet west of Ocean Street, at an approximate elevation of 16 to 18 feet NGVD29, where slope gradients transition from the flatter, upper portion of the property to a steeper slope descending down to beach level, at an approximately elevation of 11 feet NGVD29. Existing improvements consist of a single-family residential structure, primarily located within the flatter, upper portion of the property. The portion of the property located west of the residence (i.e, seaward) has been improved with at least two retaining walls, consisting of one "upper" wall which creates a grade break down to beach level, and a "lower" wall, apparently acting as a sea wall at beach level. The existing upper wall, or "fieldstone" wall, appears to be distressed (i.e., rotated seaward). The lower sea wall is located near the toe of slope (beach level) descending down and away from the fieldstone wall, and appears to be buried. A review of Roy J. Shlemon & Associates, Inc. (RJSA, 2003) and aerial photographs circa 1949 and 1960, and this study, indicate that the GeoSoils, Inc. ITE ~ ---------' ~ ~al \ i I I Base Map: TOPO!® ©2003 National Geographic, U.S.G.S. San Luis Rey Quadrangle, California-San Diego Co., 7.5-Minute, dated 1997, current 1999. SITE · Base Map: The Thomas Guide, San Diego Co. Street Guide and Directory, 2005 Edition, by Thomas Bros. Maps, page 1106. Reproduced with pennission 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, wh-for personal or resale, without permission. All rights Reserved N LOCATION AND SCALES APPROXIMATE W.O. 5181-S-SC SITE LOCATION MAP Figure 1 existing slope, descending from the base of the fieldstone wall to the beach, is a fill slope, placed against the former coastal bluff (now buried). Furthermore, it appears that the existing fieldstone wall is located along the top of this former bluff. The sea wall, fieldstone wall, and bluff are further discussed in GSI (2006). It is our understanding that the existing structure and appurtenances located within the future development envelope, will be demolished/removed, and the site prepared for the construction of a two-unit, condominium-style residential structure. The part of the property to the east of elevation contour line 21 to 22 feet NGVD29 (see Plate 1, Geologic Map), will be cleared of all existing structures (house, concrete driveway, walkways, steps, and walls/fences), and graded to a proposed lower floor elevation of approximately 24 feet NGVD29. Temporary shoring of the excavation sidealls will likely be necessaryforthe north, east and south sides of the excavation. The fieldstone garden wall, steps between it and the sea wall, and the sea wall will be left intact. It is anticipated that the proposed structure will use continuous footings and slab-on-grade floors, with wood-frame and/or masonry block construction. However, the use of specialized shallow foundations (i.e., post-tensioned and/or mat slab), or deep foundations (piers, piles, etc.) should not be precluded at this time. Building loads are assumed to be typical for this type of relatively light structure. It is anticipated that sewage disposal will be tied into the municipal system. It is our understanding that storm water runoff from the roof, driveways, etc., will be directed to an in-ground storage tank beneath the patio basement level, for treatment, reuse for landscaping, as needed, or pumped into the City storm drain system. Minor amounts of storm water runoff from semi-pervious pavers will be allowed to percolate into the ground. It is our understanding that this is a net "export" site, and our evaluation will address the suitability for the excavated onsite soil to be used as "beach nourishment" to landward of Mean High Water, or, if unsuitable, exported from the site. PREVIOUS WORK A previous phase of geotechnical site work was completed in 2004, by CWLC, with their findings, conclusions, and recommendations presented in a geotechnical report dated February 4, 2004 (CWLC, 2004). This phase of site work included subsurface exploration, laboratory testing, engineering analysis, and geotechnical recommendations for site development. A geotechnical and geomorphic peer review of a nearby property, located south of the subject site, was completed by RJSA (2003). This review work included a review of the geotechnical aspects of the nearby property, but more notably, an evaluation of site geomorphology, which is considered to be very similar to the subject site. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Inc. W.O. 5181-A-SC June 27, 2006 Page3 FIELD STUDIES Field studies conducted by GSI consisted of geologic mapping of the site, and subsurface exploration with one hollow stem auger boring, three limited access auger borings, and one hand excavated test pit for evaluation of near-surface soil geologic conditions. All borings were logged by an engineering geologist from our firm, who collected representative samples of soils for appropriate laboratory testing. The logs of the borings are presented in Appendix B, and the locations of the borings are presented on Plate 1 (Geologic Map), which uses the 1" = 201 scale topographic survey, prepared by Lintvedt, McColl & Associates (2006), as a base map. REGIONAL GEOMORPHOLOGY A review of aerial photographs (provided by Dall & Associates, photographs dated 1949 and 1960), site topography shown on Plate 1 , field observations (surface and subsurface), and a review of RJSA (2003), indicate that generally two topographic breaks are present between Ocean Street westward to the Pacific Ocean. These breaks in slope are generally observable from about Buena Vista Lagoon on the north, to Batiquitos Lagoon on the south (RJSA, 2003). The upper break appears to occur at an elevation of 37 to 40 feet NGVD29, and the lower, steeper break in slope occurs at an elevation of approximately 15 to 16 feet NGVD29. The toe of slope descending from the second slope break occurs at an approximately elevation of 11 to 12 feet. The upper slope break, including the relatively flay lying natural surfaces located to the east of the slope break, appears to be formed in the regionally extensive, late-Pliestocene-age (late Quaternary) coastal terrace deposits. The slope area, located between the upper, and lower slope breaks likely formed as a results of subarial erosion approximately 4 to 5 thousand years ago (ka), and that the slope surface has been relatively stable for the past 550 years (RJSA, 2003). The steeper slope located below the ·lower slope break appears to represent a coastal bluff formed in response to processes of wave action and erosion, over the past 4 to 5 ka. Based on our current evaluation, it appears that the bluff was filled against some time before 1949, creating a graded slope descending from the top of the former bluff, to beach level. In addition to the graded slope embankment, a sea wall also appears to have been q:mstructed along the toe of the fill slope. Based on our observations, it appears that the combination of fill embankment and sea wall have generally mitigated any landward retreat of the top of bluff since their construction, over 50 years ago. 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, R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page4 elongated mountain ranges and valleys thattrend northwesterly. The mountain ranges are generally 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 from the deposition of marine terrace deposits. 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 dep~sited/eroded within coastal and beach areas. Our evaluation indicates that the site is underlain by fill, Quaternary beach deposits, terrace deposits, which are, in turn, underlain with Eocene-age sedimentary bedrock. Terrace deposits may be subdivided into a lower, or basal, regressive marine sand, which transitions upward, into prograding continental deposits. Surficial deposits of dune (eolian) sand have since accumulated locally on the upper, relatively flat lying slopes formed on the terrace deposits. SITE GEOLOGIC UNITS The site geologic units encountered during the subsurface exploration consist of surficial deposits of artificial fill, colluvium, and Quaternary beach deposits. The surficial deposits are underlain by Quaternary-age terrace deposits, which, are in turn underlain by Eocene age sedimentary bedrock belonging to the Santiago Formation. The distribution of site geologic units is shown on Plate 1 (Geologic Map). The distribution of site earth materials in Cross Section A-A' is shown on Plate 2. Artificial Fill -(Map Symbol -Af) Existing artificial fill was observed locally as surficial backfills placed behind existing retaining walls, and as a small fill slope located below the existing fieldstone wall, and descending the beach. Where observed, fill materials consist of dry to slightly moist, and loose, brown sand with silt. Fills appear to range from approximately 2½ to 7 feet in thickness. All existing fill is considered unsuitable for the support of settlement-sensitive improvements and/or engineered fill in its existing state, as it may settle appreciably under loading. Therefore, it requires remediation in the form of removal and recompaction in areas of proposed development. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Pages Quaternary Beach Deposits (Map Symbol -Qb) Beach deposits occur along the western edge of the site and consist of sand with variable amounts of cobbles. These materials are typically loose, and are not suitable for the support of settlement-sensitive improvements. It should be noted that these deposits are located beyond the limits of the planned development and are not anticipated to significantly affect construction. Colluvium (Not Mapped) Colluvium was observed as a relatively thin surficial deposit of weathered soil across the site. Colluvium generally consists of dark brown to brown silty sand. These soils were dry to slightly moist, and loose. Based upon observations during the subsurface exploration, these soils were on the order of 4 to 6 feet thick. Colluvium is considered potentially compressible under loading and therefore unsuitable for support of settlement-sensitive improvements in its existing state. Mitigation in the form of removal and recompaction in areas to be developed will be necessary. Quaternary Terrace Deposits (Map Symbol -Qt) Quaternary-age terrace deposits were observed underlying existing fill and/or colluvium, at depths ranging from 4 to 7 feet in all of the borings. These deposits primarily consist of dry to slightly moist, medium dense, light brown to brown, to gray sand with some silt. Cobbles were also noted near the contact with the underlying Santiago Formation. Terrace deposits are considered suitable for the support of engineered fill and/or settlement-sensitive improvements. The basal contact of the terrace deposits, and the underlying Santiago Formation, appears to be a relatively flat lying unconformity, located at an approximate elevation of 8 to 1 O feet above NGVD29. It is our understanding that the basement level for the planned structure is at an elevation of about 25 feet NGVD29, therefore, it is unlikely that this contact will be encountered during construction. Santiago Formation (Not Mapped) Eocene-age sediments directly underlie the Quaternary terrace deposits onsite, and are not exposed onsite. Where encountered at depth, this sedimentary "bedrock" consists of a moist, and very stiff, sandy claystone. • Geologic structure was not observed within bedrock onsite. However, based on a review of regional mapping of the area (Tan and Kennedy, 1996). Sedimentary bedrock in the area is generally flat lying, to gently inclined to the east (i.e., neutral, and/or into the existing slope). R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page6 SLOPE STABILITY Our review of available information, and the findings of this evaluation, does not indicate the presence of deposits formed from mass wasting (landslides, slumps, etc.). Some minor erosion, due to overland flow and local channel incision was observed. "Spring sapping" is a common occurrence in the region, where seepage along the contact between the terrace deposits and the underlying Eocene-age bedrock atthe face of slope, and resulting in erosion of the terrace sand above the contact. This contact is buried in the vicinity, and erosion due to spring sapping is not considered to be significant. As evaluated in this study, and by others (RJSA, 2003), the existing slope between the upper, and lower slope breaks, is at an approximate gradient of 4:1 (horizontal:vertical [h:v]), and appears to have been relatively stable over the past 550 years. Slope retreat, due primarily to marine erosion at the toe of this slope has resulted in the formation of a coastal bluff over the last 4 to 5 ka (RJSA, 2003). In recent times, the placement of a fill embankment across the bluff face, and the construction of a sea wall, appear to have mitigated any further landward migration of the top of bluff. As such, the overall slope configuration appears to be relatively stable. A quantitative slope stability analysis by others (U.S. Army Corps of Engineers, 1996) performed for similar slope conditions in similar soils indicates that the slope is relatively stable, in its current configuration. Surficial soils appear to be relatively low cohesive, and will be subject to erosion, unless stabilized with vegetation, or other suitable method. It is our understanding that the improvement (i.e., minimizing erosion) of existing slopes to remain, in the form of revegetation, is planned, and would result in an improvement in the overall slope stability. Based on our evaluation, planned development should not adversely affect future slope stability. GROUNDWATER Regional groundwater was not encountered within the property during field work performed in preparation of this report and therefore is not anticipated to adversely affect site development, provided that the recommendations contained in this report are incorporated into final design and construction. The water surface elevation of the regional water table is estimated to be about NGVD29, or approximately 25 feet below the basement elevation for the planned structure. A perched water table was observed locally, along the contact between the terrace deposits, and the underlying Eocene bedrock (Santiago Formation). The depth of this contact is on the order of 15 to 17 feet below the planned basement elevation, or about 8 to1 O feet NGVD29. These observations reflect site conditions at the time of our investigation, and do not preclude future changes in local groundwater conditions from excessive irrigation, precipitation, or that were not obvious at the time of our investigation. However, based on the permeability contrasts between any proposed fill and the terrace deposits, perched groundwater conditions may develop R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page? in the future due to excess irrigation, poor drainage, or damaged utilities, and should be anticipated. Should manifestations of this perched condition (i.e., seepage) develop in the future, this office could assess the conditions and provide mitigative recommendations, as necessary. The potential for perched water to occur after development should be disclosed to all interested parties. FAUL TING AND REGIONAL SEISMICITY Regional Faults Active or potentially active faults have not been previously mapped on the subject property, and none were encountered during our field exploration. The site is situated in an area of active, as well as potentially-active, faulting. The nearby Rose Canyon fault zone is considered active and is included within an Alquist-Priolo Earthquake Fault Zone~ Other major active fault zones that may have a significant affect on the site should they experience activity are listed in the following table (modified from Blake, 2000a): , •.· ·APP·Rox:·.0·1srA.r,i6E., • . " • • , . . ... ... · .. · • ·, .. : : APPRO}t o'1sTAN·c1= .. • FROM. SITE' : , • ·.·: • FAGLT zciNi( ·. ,. ·/ ·. ·, . 'FROl'vfs'1TE • . • FAULT i;ONE . , '(l'ifliles ns:no!iiet~i-s])'. . : '•. •, • •, :. • • {ilniiesJkilomete~;j)-'. Newport-Inglewood 4.6 (7.4) Chino-Central Ave. (Elsinore) 47.0 (75.6) (Offshore) Rose Canyon 5.1 (8.2) San Jacinto -Anza 47.0 (75.6) Coronado Bank 20.7 {33.3) San Jacinto -San Jacinto Valley 47.3 (76.2) Elsinore-Temecula 24.5 (39.4) Whittier 50.8 (81.8) Elsinore-Julian 24.9 (40.0) San Jacinto -Coyote Creek 53.2 (95.2) Elsinore-Glen Ivy 33.2 (53.5) Elsinore (Coyote Mountain) 59.2 (95.2) San Joaquin Hills 34.3 (55.2) San Jacinto -San Bernardino 59.5 (95.7) Palos Verdes 34.7 (55.9) Puente Hills Blind Thrust 60.5 (97.4) Newport-Inglewood (L.A. 44.9 (72.3) San Andreas -whole M-1 a 65.7 (105.7) Basin) Earthquake Valley 44.9 (72.3) The relationship of the site to these major mapped faults is indicated on Figure 2 (California Fault Map). Other faults have been mapped in the vicinity; however, these faults are shorter, and hence, are generally considered less likely to produce significant seismic events. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 8 CALIFORNIA FAULT MAP 2497 Ocean Street 1100 .---------------------------~ 1000 900 800 700 600 500 400 300 200 100 0 -100 -+-1_J__L...L--1-L...L......1....J.....l---l-.L...L....L...j.....L......I..J.......l-i-L...L....L..L--!-L..1......l-l-i-1-..L..L...a..+.J......J.....,_'--1-..L..L...L......l.-!-Jc......L...~ -400 -300 -200 -100 0 100 200 300 400 500 600 W .0. 5181-A-SC Figure 2 GeoSoils, Jne. Seismicity The acceleration-attenuation relations of Bozorgnia, Campbell and Niazi (1999), Campbell and Bozorgnia (1997 Rev.), and Sadigh, et al. (1997) have been incorporated into EQFAUL T (Blake, 2000a). For this study, peak horizontal ground accelerations anticipated at the site were assessed based on the random mean plus 1-sigma attenuation curves produced from the relationships noted above. EQFAULT is a computer program by Thomas F. Blake (2000a), which performs deterministic seismic hazard analyses using digitized California faults as earthquake sources. 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) is computed by any of a number of user-selected acceleration-attenuation relations that are contained in EQFAUL T. Based on the EQFAULT program, peak horizontal ground accelerations from an upper bound event at the site may be on the order of 0. 7 g to 0.8 g. The computer printouts of portions of the EQFAUL T program are included within Appendix C. Historical site seismicity was evaluated with the acceleration-attenuation relations of Campbell and Bozorgnia (1997 Rev.) and the computer program EQSEARCH (Blake, 2000b). This program was utilized to perform a search of historical earthquake records for magnitude 5.0 to 9.0 seismic events within a 1 OD-mile radius, between the years 1800 through December 2005. Based on the selected acceleration-attenuation relation, a peak horizontal ground acceleration has been estimated, which may have affected the site during the specific seismic events in the past. Based on the available data and attenuation relationship used, the estimated maximum (peak) site acceleration to affectthe site during the period 1800 through December 2005 was 0.3 g. In addition, a seismic recurrence curve is also estimated/generated from the historical data (see Appendix C). A probabilistic seismic hazards analyses was evaluated with the acceleration-attenuation relations of Campbell and Bozorgnia (1997 Rev.) and the computer program FRISKSP (Blake, 2000c). FRISKSP models earthquake sources as 3-0 planes and evaluates the site specific probabilities of exceedance for given peak acceleration levels or pseudo-relative velocity levels. Based on a review of these data, and considering the relative seismic activity of the southern California region, a probalistic horizontal ground acceleration (PHGA) of 0.37 g was calculated. This PHGA was evaluated in accordance with the Uniform Building Code/California Building Code ([UBC/CBC], International Conference of Building Officials [ICBO], 1997 and 2001), which corresponds to a 1 0 percent probability of exceedance in 50 years (or a 475-year return period). Computer printouts of the FRISKSP program are included in Appendix C. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 10 PRELIMINARY SEISMIC DESIGN PARAMETERS The recommended values related to seismic parameters as indicated in Chapter 16 of the UBC (ICBO, 1997) for the subject tract are shown below. The offshore segment of the Newport-Inglewood fault is the design earthquake fault for the subject site, and is located about 4.6 miles (7.4 kilometers) west of the site. • I CHAPTER 16 OF UBC I SEISMIC PARAMETERS I Seismic zone (per Figure 16-2) 4 Seismic zone factor (per Table 16-1) 0.40 Soil Profile Type (per Table 16-J) SD Seismic Coefficient Ca (per Table 16-Q) 0.44Na Seismic Coefficient Cv (per Table 16-R) 0.64Nv Near Source Factor Nv (per Table 16-T) 1.1 Near Source Factor Na (per Table 16-S) 1.0 Seismic Source Type (per Table 16-U) B Distance to Seismic Source 4.6 mi (7.4 km) Upper Bound Earthquake (Newport-Inglewood [Offshore]) M..,6.9 The following list includes other seismic related hazards that have been considered during our evaluation of the site. The hazards listed are considered negligible and/or completely mitigated as a result of site location, soil characteristics, and typical site development procedures: • Dynamic Settlement • Surface Fault Rupture • Ground Lurching or Shallow Ground Rupture • Mass Wasting • Liquefaction • Tsunami 0 Seiche It is important to keep in perspective that in the event of an upper bound (maximum probable) or 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 listed above. This potential would be no greater than that for other existing structures, and improvements in the immediate vicinity. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 11 Experience has shown that wood-frame structures designed in accordance with the UBC (ICBO, 1997) tend to mitigate earthquake effects. Earthquake effects may include lurching and/or localized ground cracking. This effect is similar to other portions of southern California. Ground lurching, or shallow ground rupture due to shaking, could occur within the project area from an earthquake originating on other nearby faults. Such lurching could possibly cause cracking of hardscape areas, with limited damage to structures. LIQUEFACTION POTENTIAL Seismically-induced liquefaction is a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in soils. The soils may thereby acquire a high degree of mobility, and lead to lateral movement, sliding, sand boils, consolidation and settlement of loose sediments, and other damaging 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. Typically, liquefaction has a relatively low potential at depths greater than 45 feet and is virtually unknown below a depth of 60 feet. Liquefaction susceptibility is related to numerous factors and the following 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 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. The condition of liquefaction has two principal effects. One is the consolidation of loose sediments with a 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 on the site. In the site area, we found there is a potential for seismic activity and a perched water table anticipated to be 26 feet below the site. However, the terrace deposits appear to grade to dense with depth. Inasmuch as at least one or two of these five required concurrent conditions discussed above do not have the potential to affect the site, and considering the generally dense nature of the terrace deposits that underlie the site, and the absence of paleoliquefaction features, our evaluation indicates that the potential for liquefaction and associated adverse effects within the site is very low, even with a future rise in groundwater levels. The site conditions will also be improved by removal and recompaction of low density near-surface soils. If evidence for paleoliquefaction is encountered during grading, additional stronger concrete and/or foundation/slab reinforcement may be subsequently recommended. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 12 Therefore, it is our opinion that the liquefaction potential does not constitute a significant risk to site development, provided that our recommendations are properly implemented. LABORATORY TESTING Laboratory tests were performed on representative samples site earth materials in order to evaluate their physical characteristics. 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 Boring Logs in Appendix B. Moisture-Density Relations The field moisture content and dry unit weight was determined for an undisturbed sample of site soil in the laboratory. The dry unit weight was determined in pounds per cubic foot (pct), and the field moisture content was determined as a percentage of the dry weight. The results of this test are shown on the Boring Logs in Appendix B. Laboratory Standard The maximum density and optimum moisture content was evaluated for the major soil type encountered in the borings. The laboratory standard used was ASTM D-1557. The moisture-density relationship obtained for this soil is shown on the following table: SAMPLE LOCATION MAXIMUM DENSITY OPTIMUM MOISTURE AND DEPTH (Fl) SOIL TYPE (PCF) CONTENT(%) I 8-1 @ 0-3 I SILTY SAND I 126.0 I 10.0 I Expansion Index (E.I.) Testing Expansion Index (E.I.) testing was performed on a representative soil sample, according to UBC (ICBO, 1997) Standard No. 18-2. The test results are presented below as well as the expansion classification according to UBC (ICBO, 1997). R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 13 SAMPLE LOCATION SOIL TYPE EXPANSION EXPANSION AND DEPTH (FT) iNDEX POTENTIAL I 8-1 @ 0-3 I SIL1YSAND I <5 I Very Low I Atterberg Limits Testing (ASTM D 4318) performed on representative soil samples obtained from Boring B-1, at depths of 1 O and 20 feet, indicate that these soils are non-plastic. Shear Testing Shear testing was performed on representative, undisturbed samples of site soil in general accordance with ASTM test method D-3080 in a Direct Shear Machine of the strain control type. Shear test results are presented in Appendix D, and as follows: PRIMARY. RESIDUAL SAMPLE LOCATION AND DEPTH (FT) COHESION F~ICTION ANGLE COHESION FRICTION ANGLE (PSF) (DEGREES) (PSF) (DEGREES) I 8-1@ 10' I 42 I 42 I 225 I 35 I 8-1 @20' 130 40 189 36 Grain Size Distribution The grain size distribution was evaluated for representative soil samples in general accordance with ASTM D422. The results of this evaluation are presented in Appendix D. Consolidation Test Consolidation testing was performed on relatively undisturbed soil sample in general accordance with ASTM test method D-2435-90. pH/Soluble Sulfates/Saturated Resistivity Testing GSI conducted sampling of onsite materials for soil corrosivity on the subject project. Laboratory testing is currently in progress. The testing included an evaluation of pH, soluble sulfates, and saturated resistivity. While test results are pending, our experience in the vicinity indicates that site soils are mildly alkaline with respect to acidity/alkalinity, present a negligible sulfate exposure to concrete, in accordance with Table 19-A-4 of the CBC (ICBO, 2001), and are moderately corrosive to ferrous metals based on saturated R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 14 resistivity. A corrosion specialist should be consulted for the appropriate mitigation recommendations, as needed, regarding foundations, piping, and where metals will come into contact with site soils, etc. PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based on ourfield exploration, laboratory testing, and geotechnical engineering analysis, it is our opinion that the site appears suitable for the proposed residential development from a geotechnical engineering and geologic viewpoint, provided • that the recommendations presented in the following sections are incorporated into the design and construction phases of site development. The primary geotechnical concerns with respect to the proposed development are: • Depth to competent material. • Excavation/shoring. • Expansion and corrosion potential of site soils over the life of the project. • Potential for perched groundwater during excavation/grading, and after development. • 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 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 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 grading to aid the contractor in removing unsuitable soils and in his effort to compact the fill. 2. Geologic observations should be performed during grading to evaluate and/or further evaluate geologic conditions. Although unlikely, if adverse geologic structures are encountered, supplemental recommendations and earthwork may be warranted. 3. As evaluated in this study, and by others (RJSA, 2003), the existing slope between the upper, and lower slope breaks, is at an approximate gradient of 4:1 (h:v), appears to have been relatively stable over the past 550 years. Quantitative slope R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 15 stability analysis by others (U.S. Army Corps of Engineers, 1996) performed for similar slope conditions in similar soils indicates that the slope is relatively stable, in its current configuration. Slope retreat, due primarily to marine erosion at the toe of this slope has resulted in the formation of a coastal bluff over the last 4 to 5 ka (RJSA, 2003). In recent times, the placement of a fill embankment across the bluff face, and the construction of a sea wall, appear to have mitigated any further landward migration of the top of bluff. As such, the overall slope configuration appears to be relatively stable, and planned development should not adversely affect future slope stability. 4. Existing artificial fill (on the order of 2½ to 7 feet thick), and colluvium (approximately 4 to 6 feet thick) are considered unsuitable for the support of settlement-sensitive structures in their present condition, based on current industry standards. These materials are potentially compressible in their present condition, and may be subject to differential settlement. Mitigation in the form of removal and recompaction is recommended. Preliminary removal depths are anticipated to range between approximately 2½ to 7 feet below the existing grade. Localized deeper removals cannot be precluded. Alternatively, foundation systems may penetrate these soils and be founded into the underlying terrace deposits. 5. Plans indicate proposed excavation depths up to 15 feet below existing grades. Based on the planned excavation depths, suitable terrace deposits will likely be exposed near proposed foundation grades within a majority of the building footprint (eastern portion), while the westernmost ±20 feet is anticipated to be underlain with surficial fills and/or colluvium (see Plate 2). In order to provide uniform foundation support, the foundation system may be deepened into the underlying terrace deposits. 6. Surficial improvements within the development envelope, i.e., flatwork, driveways, perimeter walls, etc., will require the removal/recompaction of any underlying and unsuitable soil deposits (existing fill and colluvium). 7. The existing "fieldstone" garden wall is located beyond the limits of the planned development, and should not significantly affect new construction. However, the wall appears to be distressed, and the potential for this structure to eventually topple seaward, should not be precluded. The observed distress to the wall appears to be related to its location along a former coastal bluff (RJSA, 2003), and the placement of existing fill, which forms the existing graded slope descending from the fieldstone wall, to the beach. Differential settlement of the fill and/or a potentially under-designed foundation, appears to have resulted in the wall rotating seaward. An existing system of wooden buttresses was observed; however, these structures were highly decomposed, and not performing as intended. 8. Our laboratory test results indicate that soils with very low E.I. (0 to 20) underlie the site. This should be considered during project design. Conventional foundations R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 16 may be utilized for very low expansion potentials, with a plasticity index (P.I.) of less than 15. Although not anticipated, if finish grade soils exhibit a low expansion potential or a P .I. of 15, or greater, additional concrete strength and foundation/slab reinforcement may be necessary per code. 9. Laboratory testing regarding soil pH, soluble sulfates, and saturated resistivity indicate that site soils are mildly alkaline, present negligible sulfate exposure to concrete, and are moderately corrosive to ferrous metals when saturated. Additional comments and/or recommendations should be provided by a qualified corrosion specialist regarding foundations, piping, reinforcement, etc. 10. In general and based upon the available data to date, regional groundwater is not expected to be a major factor in development of the site. However, due to the nature of the site materials, seepage may be encountered throughout the site along with seasonal perched water within any drainage areas. Perched water will likely occur after development, which warrants more onerous concrete slab design and construction. This potential should be disclosed to all interested parties. 11 . Due to the relatively low cohesion of some ofthe onsite materials, some caving and sloughing may be anticipated to be a factor in subsurface excavations and trenching. Therefore, current local and state/federal safety ordinances for subsurface trenching should be enforced. 12. The seismicity-acceleration values provided herein should be considered during the design of the proposed development. 13. General Earthwork and Grading Guidelines are provided at the end of this report as Appendix E. Specific recommendations are provided below. EARTHWORK CONSTRUCTION RECOMMENDATIONS General Grading All grading should conform to the guidelines presented in the UBC (ICBO, 1997), the City (i.e., grading, water quality protection, etc.), and Appendix E (this report), except where specifically superceded in the text of this report. When code references are not equivalent, the more stringent code should be followed. 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. R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 17 Demolition/Grubbing 1. Existing structures, vegetation, and any miscellaneous debris should be removed from the areas of proposed grading. 2. Any previous debris from, foundations, irrigation lines, cesspools, septic tanks, leach fields, or other subsurface structures uncovered during the recommended removals should be removed from the existing soils, stockpiled, and removed from the site. 3. Cavities or loose soils remaining after demolition and site clearance should be cleaned out and observed by the soil engineer. 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. Treatment of Existing Ground 1. All existing fill and colluvium should be removed, cleaned of deleterious materials, as recommended, moisturized, and recompacted. Preliminary estimates of removal depths range between 2½ and 7 feet. Variations from these estimated depths should be anticipated and deeper removals cannot be precluded. Actual depths of removals will be evaluated in the field during grading by the soil engineer. Removals should be completed below a 1: 1 projection from the bottom outside edge of any proposed footing and not be advanced below a 1: 1 projection from the bottom outside edge of any existing footing that is to remain without shoring. Alternatively, foundations may be deepened through any unsuitable surficial soil, and be embedded into the underlying terrace deposits. 2. Subsequent to the above removals, the upper 12 inches of the exposed terrace deposits should be scarified, brought to at least optimum moisture content, and recompacted to a minimum relative compaction of 90 percent of the laboratory standard prior to placing any fill (if necessary). 3. Existing artificial fill and colluvium may be reused as compacted fill provided that major concentrations of vegetation and miscellaneous debris are removed prior to or during fill placement. 4. Localized deeper removals may be recommended due to buried drainage channel meanders or dry porous materials. The project soils engineer/geologist should observe all removal areas during the grading. It should be noted that the use of deep foundations would preclude removals. 5. Soils generated during excavation operations will likely consist of fine to medium grained sand, with some silt (USCS designations SP and SM-SP). These soils are R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 18 considered to be similar to the existing beach deposits within, and west of, the western portion of the site, and could be used to supplement the existing beach deposits. It should be noted that erosional processes along this section of coast, naturally incorporate these materials into the active beach system. Overexcavation In order to provide uniform foundation support, any cut portion of a cut/fill transition within the building pad area should be over excavated a minimum of 3 feet below finish grade to provide for a 3-foot thick compacted fill blanket. Areas where planned fill thickness are less than 3 feet E!.nd/or areas where removal excavations are less than 3 feet below finish grade should also be over excavated to provide for a 3-foot thick compa_cted fill blanket. The maximum to minimum fill thickness across the building pad should not exceed a ratio of 3:1 (maximum: minimum). Overexcavation of the building pad will not be necessary if homogenous terrace deposits are exposetj at finish grade for a lateral distance of 5 feet outside any proposed footing. Due to property line restrictions, the lateral limits of over excavation will likely be limited. Alternatively, foundations may be deepened through any unsuitable surficial soil, and be embedded into the underlying terrace deposits. Fill Placement 1. Subsequent to ground preparation, fill materials should be brought to at least optimum moisture content, placed in thin 6-to 8-inch lifts, and mechanically compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. 2. Fill materials should be cleansed of major vegetation and debris prior to placement. PRELIMINARY RECOMMENDATIONS -FOUNDATIONS The foundation design and construction recommendations are based on laboratory testing and engineering analysis of onsite earth materials by GSI. Recommendations for foundation systems are provided in the following sections. The recommended foundation systems may be used to support the proposed structure, provided they are founded in competent bearing material. The proposed foundation systems should be designed and constructed in accordance with the guidelines contained in the UBC (ICBO, 1997). The following foundation construction recommendations are presented as minimum criteria from a soils engineering viewpoint. The onsite soils expansion potentials are generally in the very low range (E.I. = 0 to 20 range). Soils in the low expansion range (E.I. = 21 to 50) and/or soils with a P.I. of 15 or greater may also be present onsite, and foundations underlain by these soils should be designed in accordance with the UBC (ICBO, 1997), Section 1815 and/or 1816 and CBC (ICBO, 2001). R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 19 Conventional Foundations -Very Low (E.1. o to 20) to Low (E.1. 21 to 50) Expansion Potentials With a P.I. Less Than 15 The following foundation construction recommendations assume that the soils in the top 7 feet from finish grade will have a very low to low expansion potential (and a P .I. of less than 15), and that paleoliquefaction features are not encountered during grading. Although not anticipated, if finish grade soils exhibit a P.I. of 15, or greater, and/or if paleoliquefaction features are encountered during grading, additional concrete and foundation/slab reinforcement will be necessary. Recommendations by the project1s design-structural engineer or architect, which may exceed the soils engineer1s recommendations, should take precedence over the following minimum requirements. Final foundation design will be provided at the conclusion of grading. Foundation Design 1. Conventional spread and continuous footings may be used to support the proposed commercial structure, provided they are founded entirely in properly compacted fill or competent (unweathered), homogenous terrace deposits. The foundation should not simultaneously bear on compacted fill and terrace deposits. 2. An allowable bearing value of 2,000 pounds per square foot (psf) may be used for design of footings which maintain a minimum width of 12 inches and a minimum depth of at least 12 inches below the lowest adjacent grade (continuous) and 24 inches square (isolated) The bearing value may be increased by one-third for seismic or other temporary loads. This value may be increased by 20 percent for each additional 12 inches in depth to a maximum of 3,000 psf. No increase in bearing value for increased footing width is recommended. 3. 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. 4. Passive earth pressure may be computed as an equivalent fluid having a density of 325 pct with a maximum earth pressure of 3,000 psf. 5. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. 6. All footings should maintain a minimum ?-foot horizontal distance between the base of the footing and any adjacent descending slope, and minimally comply with the guidelines depicted on Figure No. 18-1-1 of the UBC (ICBO, 1997). Construction 1. Conventional continuous footings should be founded at a minimum depth of 12 inches below the lowest adjacent ground surface for one-story floor loads, R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 20 18 inches below the lowest adjacent ground surface for two-story floor loads, and 24 inches below the lowest adjacent grade for three-story floor loads. Interior footings may be founded at a depth of 12 inches below the lowest adjacent ground surface. All footings should bear on properly compacted fill or competent (unweathered), homogenous terrace deposits. Footings for one-, two-, and three-story floor loads should have a minimum width of 12, 15, and 24 inches, respectively. All footings should minimally have one No. 4 reinforcing bar placed at the top and one No. 4 reinforcing bar placed at the bottom of the footing. Isolated interior or exterior piers and columns should be founded at a minimum depth of 24 inches below the lowest adjacent ground· surface. If low expansive soils are present within the top 7 feet, these elements should be tied together with a grade beam. 2. A grade beam, reinforced as above and at least 12 inches square, should be provided across the garage entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 3. Concrete slabs should be constructed in accordance with the recommendations provided in the "Floor Slab Design Recommendations" section of this report. Although concrete floor slabs are not anticipated to receive heavy loads as conveyed to GSI by the project architect, floor slab recommendations to accommodate heavy loading conditions have been provided. 4. Garage slabs (if any) should be poured separately from the building footings and be quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 5. Concrete and concrete slab underlayment should be utilize the recommendations provided in the "Soil Moisture Considerations" section of this report. 6. Presaturation is not necessary for these soil conditions; however, the moisture content of the subgrade soils should be equal to or slightly greater than optimum moisture to a depth of 12 inches below the adjacent ground grade in the slab areas. 7. Soils generated from footing excavations to be used onsite should be compacted to a minimum relative compaction 90 percent of the laboratory standard, whether it is 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. 8. Foundations near the top of slope should be deepened to conform to the latest edition of the UBC (ICBO, 1997) and provide a minimum of 7 feet horizontal R & M Enterprises 2497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 21 distance from the slope face. Rigid block wall designs located along the top of slope should be reviewed by a soils engineer. PIER FOUNDATIONS Foundations Design Criteria -Drilled Piers The proposed structure may be supported in whole (or in combination with conventional spread footings), by drilled, cast-in-place, concrete piers which penetrate existing fill and colluvium, and are embedded into the underlying terrace deposits. We anticipate that the wall loads of 1.5 kips/foot, and column loads of 5 to 20 kips will be utilized. The drilled pier founqation for the building should gain vertical support from friction and end bearing in the native bedrock underlying the site. The drilled piers should be at least 12 inches in diameter and should extend at least 7 feet into suitable terrace deposits. Based on site geology, piers should be anticipated up to approximately 15 feet in depth, along the western edge of the building footprint. Drilled piers should be spaced a minimum of 3 pier diameters apart (center to center). The effects of pier groups should be evaluated when the preliminary foundation drawings are made available. Soil parameters to be used in pier and grade beam design are provided below. All the parameters provided are computed based on soil strength only, structural strength of the piers should be checked by the structural engineer or civil engineer specializing in structural analysis. 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: ?-foot vertical zone below the slope face and projected upward parallel to the slope face. Creep Load: The creep load projected on the area of the grade beam should be taken as an equivalent fluid approach, having a density of 60 pct. For the caisson, it should be taken as a uniform 900 pounds per linear foot of caisson's depth, located above the creep zone. Point of Fixity: Located a distance of 1.5 times the caisson's diameter, below the creep zone. R & M Enterprises W.O. 5181-A-SC 12497 Ocean Street, Carlsbad June 27, 2006 File:e:\wp9\5100\5181 a.upg Page 22 GeoSoils, lne. Passive Resistance: Allowable Axial Capacity: Shaft capacity: Tip capacity: Pier Construction Passive earth pressure of 325 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. 325 psf applied below the point of fixity over the surface area of the shaft. 4,500 psf. Pier holes should be drilled straight and plumb. Locations (both plan and elevation) and plumbness should be the contractors responsibility. All loose materials should be removed from the bottom of each pier hole. Concrete and steel reinforcement should be placed in each pier hole on the same day that the hole is drilled. If a caving sand condition occurs, during or after drilling, the pier hole should be cased. The bottom of the casing should be at least 4 feet below the top of the concrete as the concrete is poured and the casing is withdrawn. Dewatering would be required for concrete placement if seepage or groundwater is encountered during construction. Alternately, tremie concrete placement should be considered. The tops of the drilled piers should be interconnected with grade beams which will aid in resisting differential foundation movement and lateral drift. In general the minimum grade beam size should be 18 inches in width and 12 inches below the finished soil subgrade. The actual design of the grade beams and reinforcement should be performed by the Structural Engineer or civil engineer specializing in structural analysis. Based on the allowable foundation pressures recommended above, and assuming uniformity of the bedrock surface slope and consistent composition of the bedrock, we estimate that the total foundation settlement will be less than ½ inch and the differential settlement will be less than ¼ inch between adjacent piers. Prior to construction, we should review the construction procedure proposed by the contractor. Pier excavations should be observed and approved by us prior to concrete and steel placement. Observations during pier excavations will allow us to correlate the subsurface conditions exposed during construction with that obtained from our borings and make necessary changes in the foundation support and other geotechnical design criteria, if necessary. R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 23 Drilled pier steel reinforcement cages should have spacers to allow for a minimum spacing of steel from the side of the pier excavation. During pier placement, concrete should not be allowed to free fall more than 5 feet. Concrete used in the foundation should be tested by a qualified materials testing consultant for proper slump strength and mix design. All footing trench excavations and/or pier excavations should be observed by a representative of this office prior to placing reinforcement. Footing trench or pier soil 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. FLOOR SLAB DESIGN RECOMMENDATIONS Concrete slab-on-grade floor construction is anticipated. The following are presented as minimum design parameters for the slab, they are in no way intended to supersede design by the structural engineer. Floor slabs should be a minimum of 5 inches thick and be reinforced with No. 3 reinforcing bar on 18 inches centers in two horizontally perpendicular directions. Reinforcing should be properly supported to ensure placement near the vertical midpoint of the slab. "Hooking" of the reinforcement is not considered an acceptable method of positioning the steel. For areas using a pier and grade beam system, and underlain with existing fill and/or colluvium, slabs should be designed as a structural slab able to span an unsupported distance of at least 6 feet. The project structural engineer should consider the use of transverse and longitudinal control joints to help control slab cracking due to concrete shrinkage or expansion. Two of the best ways to control this movement are: 1) add a sufficient amount of reinforcing steel to increase the tensile strength of the slab; and 2) provide an adequate amount of control and/or expansion joints to accommodate anticipated concrete shrinkage and expansion. 1ransverse and longitudinal crack control joints should be spaced no more than 12 feet on center and constructed to a minimum depth of T /4, where "T" equals the slab thickness in inches. These recommendations are meant as minimums. The project architect and/or structural engineer should review and verify that the minimum recommendations presented herein are considered adequate with respect to anticipated uses. SOIL MOISTURE CONSIDERATIONS Per Table 19-A-2 of the UBC/CBC (ICBO, 1997 and 2001 ), concrete ("intended to have a low permeability when exposed to water") should have a maximum water/cement ratio of 0.50, and a minimum strength of 2,500 pounds per square inch (psi). Concrete slab R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 24 underlayment should consist of a 10-mil to 15-mil vapor retarder, or equivalent, with all laps sealed per the UBC/CBC (ICBO, 1997 and 2001) and the manufacturer's recommendation). The vapor retarder should comply with the ASTM E-17 45 Class A or B criteria and be installed per the recommendations of the manufacturer, 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 of specify suitable products for lap sealing (ASTM E-1745). In order to break the capillary rise of soil moisture, the vapor retarder should be underlain by 4 inches of pea gravel and/or fine to coarse, washed, clean gravel (80 to 100 percent greater than #4 sieve) and be overlain by at least 2 inches of clean, washed sand (SE >30). Where slab concrete compressive strength is increased, admixtures used and water/cement ratios are adjusted herein, the structural consultant should also make changes to the concrete in the grade 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 use of a penetrating slab surface sealer may be considered in rooms where permeable floor tile or wood will be used. In all planned floorings, the waterproofing specialist should review the manufacturer's recommendations and adjust installation as needed. All interested parties should be advised which areas are suitable for tile or wood floors. Additional recommendations regarding water or vapor transmission should be provided by the architect/structural engineer/slab or foundation designer. SHORING DESIGN Shoring of Excavations Based on present design excavations for the proposed structures, excavations on the order of up to 15 foot are anticipated. Accordingly, and because of limited space, temporary shoring of vertical excavations may be required. We recommended that slopes be retained either by a cantilever shoring system deriving passive support from cast-in place soldier piers (lagging-shoring system) or a restrained tie-back and pile system. Based on our experience with similar projects in the County of San Diego area, if lateral movement of the shoring system on the order of 1 to 2 inches cannot be designed for or tolerated, we recommend the utilization of an internal bracing/raked shoring system. Shoring of excavations of this size is typically performed by specialty contractors with knowledge of the County of San Diego area soil conditions. We recommend that shoring contractors provide the excavation shoring design. However, for the design parameters, we provide the following. Lateral earth pressures for lagging design of shoring are presented in Figure 3. The use of anchors may not be feasible on this site due to the location of adjacent buildings and utilities north and east of the site. If desired, additional anchor recommendations will be provided. Since design of retaining systems is sensitive to surcharge pressures behind the excavation, we recommend that this office be consulted if unusual load conditions are anticipated. Care should be exercised when excavating into the on-site soils since caving or sloughing of these materials is possible. Field testing of R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 25 Cantilever Shorina Svste~ r---xH --~Lline Load QL (pounds) urcharge Pressure P (psf) H (feet) ID :tl_....--~,,,.,._., ---~ f--4000(psf)---~ H 0.35 (psf) Tie-Back Shoring System H (feet) 35H ( psf) (1) ( QL (pounds) istance ind'thi line Tie ,.._'"'"-.....____, Back= 1200 psf Bond Stress (2) '· (3) R ID ( fees)""""'"~-• ~ 400D (psf) NOTES Minimum 7' depth for supporting piersH I I . a.3s(psf) ••21H tpsfj(2) 1. Include ground water effects below ground water level. 2. Include water effects below ground water level. X < 0. 4, > (J. 4 X l'. C .1 0.6H G.3 0.6H 0.5 0.56H 0.7 0.48H R 0.55 QL 0.64QL x2 + 1 • (feet) LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. • SAN DIEGO CO. 3. Grouted length greater than 7 feet; field test anchor strength. 4. Neglect passive pressure bel~w base of excavation to a depth of one pier diameter. • LATERAL EARTH PRESSURES FO.R SHORING SYSTEMS • • Fi ure 3 w.o. 5181-A~C_, s1oe , scALE Noraif· tie-backs and observation of soldier pile excavations should be performed during construction. Shoring of the excavation is the responsibility of the contractor. Extreme caution should be used to minimize damage to existing pavement, utilities, and/or structures caused by settlement or reduction of lateral support. Accordingly, we recommend that the foundations of adjacent structures be surveyed prior to and during construction to evaluate the effects of shoring on these structures. Photo documentation is also advisable. Underpinning (If Necessary) Based on the proximity of the proposed excavation to the existing structures, underpinning may be necessary, as determined by the structural engineer. The results of our analyses for piers to be used in underpinning are provided in Fig.ure 4. The allowable capacities presented in the figure are based on ¼ inch of settlement. Please note that the purpose of our analysis was to provide preliminary design for rough estimates only. We recommend thatfinal project drawings be provided by a qualified underpinning contractor and reviewed by this office prior to construction, if underpinning is necessary. Settlement monitoring of adjacent flatwork and structures should be considered to evaluate the performance of the underpinning. Shoring of the excavation and underpinning of the existing structures is the responsibility of the contractor. Extreme caution should be used to minimize damage to existing pavement and/or structures caused by settlement or reduction of lateral support. Accordingly, we recommend that the foundations of adjacent structures be surveyed prior to and during construction to evaluate the effects of shoring and underpinning on these structures. Photo documentation is also advisable. Open Excavations Construction materials and/or stockpiled soil should not be stored within 5 feet of the top of any temporary slope or trench wall. Temporary/permanent provisions should be made to direct any potential runoff away from the top of temporary excavations. Excavations constructed deeper than 4 feet may be constructed in accordance with guidelines presented in Title 8 of the California Code of Regulations for Excavation, Trenches and Earthwork for Type "C" soil material. Lateral Pressure 1. The active pressure to be utilized for trench wall shoring design may be computed by the rectangular active pressure (psf) as shown in the following table. R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Inc. W.O. 5181-A-SC June 27, 2006 Page 27 -.;J QJ QJ 4- C: 0 .,... ~ 11' > 11' u X LU 4- 0 5 1 0 1 5 ~ 20 11' co :;:: 0 ~ <lJ· co s.. (1J -a.. 4- 0 ..c ~ Cl. ciJ Cl 25 30 35 40 a 10 ~ ' 12-ir ch di amE Allowable Pier Capacity (kips) 20 30 40 50 60 70 BG so . '~ /24 inch di ameter c :rncrete pier ... ~ ~ " "\ " "" ~ ' ' ~ ~ ~ ter COii rete pi er _..., ~' - ~ " "' ~ 1. Miniraum pier lengths should be 5 feet. 2. Capacities are allowable capacities (based an F.S. = 2) and may be increased by one-third for short-tern wind or seismic loads. 3. Far uplift use 75 percent of these capacities far single piers and 50 percent for piers in clusters. LOS ANGELES CO. RIVERSIDE CO. ORANGE CO. SAN D)EGO CO. PIER CAPACITY CHART Figure 4 w.o. 5181-A-SC , DATE 6/06 SCALE None Earth Pressure for Shoring (Level Ground Surface) SOIL TYPE RECTANGULAR EQUIVALENT FLUID WEIGHT FOR ACTIVE PRESSURE (PSF) PASSIVE PRESSURE (PCF) I Terr.ace Deposits I 40H I 325 I 2. Passive pressure may be computed as an equivalent fluid having a given density shown in the table above (pcf per depth). 3. The above criteria assumes that hydrostatic pressure is not allowed to build up behind excavation walls. 4. These recommendations are for excavation walls up to 15 feet high. Active earth pressure may be used for trench wall design, provided t,he wall is not restrained from minor deflections. An empirical equivalent fluid pressure approach may be used to compute the horizontal pressure against the wall. Appropriate fluid unit weights are provided for specific slope gradients of the retained material: these do not include other superimposed loading conditions such as traffic, structures, seismic events, expansive soils or adverse geologic conditions. For excavation walls greater than 7 feet in height, a seismic increment of 1 OH (uniform pressure) may be considered for level excavation. For walls, these seismic loads should be applied at 0.6H up from the bottom of the wall to the height of retained earth materials. Excavation Observation (All Excavations) When excavations are made adjacent to an existing structure (i.e., utility, road or building) there is a risk of some damage to that structure even if a well designed system of excavation and/or shoring, is planned and installed. We recommend, therefore, that a systematic program of observations be made before, during, and after construction to determine the effects (if any) of construction on the existing structures. We believe that this is necessary for two reasons: first, if excessive movements (i.e., more than½ inch) are detected early enough, remedial measures can be taken which could possibly prevent serious damage to the existing structure; and, second, the responsibility for damage to the existing structure can be determined more equitably if the cause and extent of the damage can be determined more precisely. Monitoring should include the measurement of any horizontal and vertical movements of both the existing structures and the shoring and/or bracing. Locations and type of the monitoring devices should be selected as soon as the total shoring system is designed R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, 'Jne. W.O. 5181-A-SC June 27, 2006 Page 29 and approved. The program of monitoring should be agreed upon between the project team, the site surveyor and the Geotechnical Engineer of Record, prior to excavation. Reference points on the existing structures should be placed as low as possible on the exterior walls of buildings adjacent to the excavation. Exact locations may be dictated by critical points within the structure, such as bearing walls or columns for buildings; and surface points on roadways and sidewalks near the top of the excavation. The points on the shoring should be placed under or very near the points on the structures. For a survey monitoring system, an accuracy of a least 0.01 foot should be required. Reference points should be installed and read initially prior to excavation. The readings should continue until all construction below ground has been completed and the backfill has been brought up to final grade. The frequency of readings will depend upon the results of previous readings and the rate of construction. Weekly readings could be assumed throughout the duration of construction with daily readings during rapid excavation near the bottom and at critical times during the installation of shoring or support. The reading should be plotted by the Surveyor and then reviewed by the Geotechnical Engineer. In addition to the monitoring system, it would be prudent for the Geotechnical Engineer and the Contractor to make a complete inspection of the existing structures both before and after construction. The inspection should be directed toward detecting any signs of damage, particularly those caused by settlement. Notes should be made and pictures should be taken where necessary. Observation It is recommended that all excavations be observed by the Geologist or Geotechnical Engineer. Any fill which is placed should be approved, tested, and verified if used for engineered purposes. Cut slopes and temporary trench excavations should be observed by the Geologist or Geotechnical Engineer. Should the observation reveal any unforseen hazard, the Geologist or Geotechnical Engineer will recommend treatment. Please inform us at least 24 hours prior to any required site observation. WALL DESIGN PARAMETERS Conventional Retaining Walls The design parameters provided below assume that either non expansive soils (typically Class 2 permeable filter material or Class 3 aggregate base) or native onsite materials (up to and including an E.1. of 65) are used·to backfill any retaining walls. The type of backfill (i.e., select or native), should be specified by the wall designer, and clearly shown on the R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 30 plans. Below grade walls 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 adjacent grade (excluding top landscape layer, 6 inches) and should be 24 inches in width. There should be no increase in bearing for footing width. 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 pressure (EFP) of 65 pcf, plus 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 and/or County 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. SURFACE SLOPE OF EQU_IVALENT FLUID EQUIVALENT FLUID. RETAINED MATERIAL WEIGHT P.C.F. WEIGHT P.C.F. {Horizontal:Vertical) {Select Backfill) {Native Backfill) I Level* I 35 I 45 I 2 to 1 50 60 * 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. 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 back drainage options R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 31 Provide Surface Drainage <Dwaterproofing Membrane (optional) @ Weep Hole Finished Surface ,:t12" DETAILS N . T . S . 2 Native Backfill Slope or Level Native Backfill Native Backfill (!) WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. @ ROCK: 3/4 to 1-1/2" (inches) rock. @ FILTER FABRIC: Mirafi 140N or approved equivalent; place fabric flap behind core. @ PIPE: 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1 % gradient to proper outlet point (Perforations down). @WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface (No weep holes for basement walls.). • TYPICAL RETAINING WALL BACKFILL AND DRAINAGE DETAIL DETAIL 1 . Geotechnical • Coastal • Geologic.• Environmental DETAILS N . T . S . 2 Native Backfill Native Backfill ®waterproofing Membrane (optional) ® Weep Hole @ Filter Fabric Finished Surface @ Pipe (!) WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. @ DRAIN: Miradrain 6000 or ]-drain 200 or equivalent for non-waterproofed walls. Miradrain 6200 or ]-drain 200 or equivalent for waterproofed walls (All Perforations down). @ FILTER FABRIC: @ PIPE: Mirafi 140N or approved equivalent; place fabric flap behind core. 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1 % gradient to proper outlet point. @ WEEP HOLE: Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) RETAINING WALL BACKFILL AND SUBDRAIN DETAIL GEOTEXTILE DRAIN DETAIL 2 Geotechnical o Coastal • Geologic • Environmental DETAILS N . T . S . 2 Native Backfill Provide Surface Drainage H/2 min. (!) Waterproofing Membrane ( optional) Slope or Level ► H • @ Weep Hole Jf--_--~------'-1'"---------@ Clean ® Filter Fabric : Finished Surface ® Roe ► Heel Width ◄ (!) WATERPROOFING MEMBRANE (optional): Liquid boot or approved equivalent. @ CLEAN SAND BACKFILL: Must have sand equivalent value of 30 or greater; can be densified by water jetting. @ FILTER FABRIC: Mirafi 140N or approved equivalent. @ ROCK: 1 cubic foot per linear feet of pipe or 3/4 to 1-1/2" (inches) rock. @ PIPE: Sand Backfill 4" (inches) diameter perforated PVC. schedule 40 or approved alternative with minimum of 1 % gradient to proper outlet point (Perforations down). @ WEEP HOLE: . Minimum 2" (inches) diameter placed at 20' (feet) on centers along the wall, and 3" (inches) above finished surface. (No weep holes for basement walls.) • RETAINING WALL AND SUBDRAIN DETAIL CLEAN SAND BACKFILL DETAIL 3 Geotechnical • Coastal • Geologic • Environmental discussed below. Backdrains should consist of a 4-inch diameter perforated PVC or ABS pipe encased in either Class 2 permeable filter material or ¾-inch to 1 ½-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 medium expansion potential, 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 E.I. potential of greater than 65 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. <90). 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 engineer's/wall designer's recommendations, regardless of whether or not transition 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). R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 35 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. DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS The soil materials on site may 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 any homeowners or homeowners association of this long-term potential for distress. To reduce the likelihood of distress, the following recommendations are presented for all exterior flatwork: 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. If very low expansive soils are present, only optimum moisture content, or greater, is required and specific presoaking is not warranted. 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 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. If very low expansive soils are present, the rock or gravel or sand may be deleted. The layer or subgrade should be 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 R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Ine. W.O. 5181-A-SC June 27, 2006 Page 36 direction. If subgrade soils within the top 7 feet from finish grade are very low expansive soils (i.e., E.I. =20), then 6x6-W1 .4xW1 .4 welded-wire mesh may be substituted for the rebar, provided the reinforcement is placed on chairs, at slab mid-height. The exterior slabs should be scored or saw cut,½ 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. 8. Overhang structures should be supported on the slabs, or structurally designed with continuous footings tied in at least two directions. If very low expansion soils are present, footings need only be tied in one direction. 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. 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 R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 37 curing for climate and time of year, sulfate content of soils, corrosion potential of soils, and fertilizers used on site. DEVELOPMENT CRITERIA Drainage Adequate lot surface drainage is a very important factor in reducing the likelihood of adverse performance of foundations, hardscape, etc. Surface drainage should be sufficient to prevent ponding of water anywhere on the lot, and especially near structures. Lot 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 lot should be provided and maintained at all times. Water should be directed away from foundations and not allowed to pond and/or seep into the ground. In general, the area within 5 feet around a structure should slope away from the structure. We recommend that unpaved lawn and landscape areas have a minimum gradient of 1 percent sloping away from the structure, and whenever possible, should be above adjacent paved areas. Consideration should be given to avoiding construction of planters adjacent to the structure. 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 the structure 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 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. 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 R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 38 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 retarder 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. 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. Site Improvements If in the future, any additional improvements are planned for the site, recommendations concerning the geological or geotechnical aspects of design and construction of said improvements could be provided upon request. 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. R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 39 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 [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. R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, Inc. W.O. 5181-A-SC June 27, 2006 Page 40 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. • 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.). R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 41 • During retaining wall subdrain installation, prior to backfill placement. • During placement of backfill for area drain, interior plumbing, utility line trenches, and retaining wall backfill. • When any unusual soil conditions are encountered during any construction operations, subsequent to the issuance of this report. • When any developer improvements, such as flatwork, walls, etc., are constructed, prior to construction. GSI should review and approve such plans prior to construction. " A report of geotechnical observation and testing should be provided at the conclusion of each of the above stages, in o~der to provide conci~e and clear documentation of site work, and/or to comply with code requirements. • GSI should review project sales documents to all interested parties for geotechnical aspects, including irrigation practices, the conditions outlined above, etc., prior to any sales. At that stage, GSI will provide the interested parties maintenance guidelines which should be incorporated into such documents. 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 entirely 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 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 structur~I engineer/designer result in less critical details than are provided herein as R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 42 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. R & M Enterprises 12497 Ocean Street, Carlsbad File:e:\wp9\5100\5181 a.upg GeoSoils, lne. W.O. 5181-A-SC June 27, 2006 Page 43 .APPEND.IX A: REFERENCEs·· ,' I, APPENDIX A REFERENCES ASTM E 1745-97, 2004, Standard specification for water vapor retarders used in contact with soil or granular fill under concrete slabs. Blake, T.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 through December, 2005, Windows 95/98 version. __ , 2000c, FRISKSP, A computer program for the probabilistic estimation of peak acceleration and uniform hazard spectra using 3-D faults as earthquake sources; 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. California, State of, 2001, Senate Bill 800, Burton. Liability: construction defects, February 23; approved by Governor September 20, 2002; filed with Secretary September 20, 2002; effective January 1, 2003. Campbell, K.W. and Bozorgnia, Y., 1997, Attenuation relations for soft rock conditions; in EQFAULT, A computer program for the estimation of peak horizontal acceleration from 3-D fault sources; Windows 95/98 version, Blake, 2000. C.W. La Monte Company, Inc., 2004, Report of limited geotechnical investigation, proposed residential project, 2497 Ocean Street, Carlsbad, California, Job No. 04-4412, dated February 4. Dall & Associates, 2006, Aerial Photographs dated 1949 and 1960, No Job No. GeoSoils, Inc., 2006, Coastal hazard & wave runup study, 2497 Ocean Street, Carlsbbad, Ca., W.O. 5181-A-SC, June 13. International Conference of Building Officials, 2001, California building code, California code of regulations title 24, part 2, volume 1 and 2. --, 1997, Uniform building code: Whittier, California, vol. 1, 2, and 3. Lintvedt, McColl & Associates, 2006, Topographic survey of 2497 Ocean Street, Sheet 1, W.O. 12295, dated June 6. GeoSoils, lne. Roy J. Shlemon & Associates, Inc., 2003, Peer review, geotechnical and geomorphic investigations, 2649 Ocean Street, Carlsbad, California, no job No., dated November 23. Sadigh, K., Chang, C.-Y., Egan, J.A., Makdisi, F., and Youngs, R.R., 1997, Attenuation relations for shallow crustal earthquakes based on California strong motion data, Seismological Research Letters, Vol. 68, No. 1, pp. 180-189. Sowers and Sowers, 1979, Unified soil classification system (After U. S. Waterways Experiment Station and ASTM 02487-667) in Introductory Soil Mechanics, New York. Tan, S.S. and Kennedy, M.P., 1996, Geologic maps of the northwestern part of San Diego County, California, DMG Open-File Report 96-02. U.S. Army Corps of Engineers, 1996, Encinitas shoreline, San Diego County, California, dated March. R & M Enterprises File:e:\wp9\5100\5181 a.upg GeoSoils, lne. Appendix A Page2 ,APPEN·DIX :a. TEST/ PIT AND· BORING LOGS·. UNIFIED SOIL CLASSIFICATION SYSTEM CONSISTENCY OR RELATIVE DENSITY Major Divisions Group Typical Names CRITERIA Symbols GW Well-graded gravels and gravel- (I) C .!fl. sand mixtures, little or no fines Standard Penetration Test > Ill (I) (I) ~ ~ ....,. C "ii) Poorly graded gravels and Penetration (I) CO'S!" () .... > (/) ~ ~ ci C} GP gravel-sand mixtures, little or no Resistance N Relative (I) iii a> 0 lllz fines (blows/ft) Density >E-l= 0 ~ 0 8l § 0 C\J e}o'--a Silty gravels gravel-sand-silt 0-4 Very loose 1/) • cl'( Ill (I) ID .c GM =D 0 0 c mixtures oz lO O "iii ~ .'!: en C -& :j:: 4-10 Loose "C 0 ~ ~"C Clayey gravels, gravel-sand-clay ·-(I) GC ~-£: mixtures 10.-30 Medium C} .!!1 ' (I) (I) ... Well-graded sands and gravelly 30-50 Dense ;~ SW oo ..... (I) C rn sands, little or no fines () lO O C ii, Ill "C Ql C > 50 Very dense C :,!;! 0 ·--Ill Ill o ·-en 0 Cl) Poorly graded sands and :G rn55'g~ SP (I) -gc.:=o gravelly sands, little or no fines 0 Ill jg ID Z ~ cn ...... ~UJ SM Silty sands, sand-silt mixtures (I) Ill (I) .__ o rn ~ :G gJ ~ 0 gj C--C Clayey sands, sand-clay C. ~ ~ u: SC mixtures Inorganic silts, very fine sands, Standard Penetration Test ML rock flour, silty or clayey fine sands rn (I) ~~ ~ Unconfined > o.s~ Inorganic clays of low to Penetration Compressive (I) ~ :Q 0 medium plasticity, gravelly clays, "iii CL Resistance N Strength 0 «J ~~ sandy clays, silty clays, lean 0 (blows/ft} Consistency {tons/If) 1/) C\J ~Jg clays 'o . Cl) en~ Organic silts and organic silty <2 Very Soft <0.25 "C 1/) (I) (I) OL clays of low plasticity C 1/) -~ rn 2-4 Soft 0.25-.050 Ill C} C. (I) (I) Inorganic silts, micaceous or C 0 MH diatomaceous fine sands or silts, 4-8 Medium 0.50-1.00 u:: E rn ~ elastic silts 0 >, 0 CU =! lO 8-15 Stiff 1.00-2.00 ';]!. 0~ /ij Inorganic clays of high plasticity, 0 -0 -0 .c c--_. CH lO Ill :::, ._ fat clays 15-30 Very Stiff 2.00-4.00 {T Ql ~::im Cl) ... >30 Hard >4.00 Cl Organic clays of medium to high OH plasticity Highly Organic Soils PT Peat, mucic, and other highly organic soils 3" 3/4" #4 #10 #40 #200 U.S. Standard Sieve Unified Soil Gravel Sand Silt or Clay Classification Cobbles I I I coarse fine coarse medium fine MOISTURE CONDITIONS MATERIAL QUANTITY OTHER SYMBOLS Dry Absence of moisture: dusty, dry to the touch trace 0-5% C Core Sample Slightly Moist Below optimum moisture content for compaction few 5-10 % s SPTSample Moist Near optimum moisture content little 10-25 % B Bulk Sample Very Moist Above optimum moisture content some 25-45% T Groundwater Wet Visible free water; below water table Qp Pocket Penetrometer BASIC LOG FORMAT: 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 TEST DEPTH GROUP SAMPLE DEPTH PITNO. . (ft.) SYMBOL (ft.) TP-1 0-1 1-2½ SM 2-3 SP 3-4 GP-SP W.O. 5181-A-SC R & M Enterprises 2497 Ocean Street, Carlsbad June 9, 2006 LOG OF EXPLORATORY TEST PITS MOISTURE FIELD DRY DENSITY DESCRIPTION (%) (p-cf) Organics. FILL: SIL TY SAND, brown, dry, loose; some debris (broken plates, tile, etc.) BEACH DEPOSITS: SAND, brown, slightly moist, loose. Rounded cobbles and fine to medium grained SAND, light to medium gray, moist, loose. Total Depth= 4' Test Pit Elevation Approximately 12' NGVD29 No Groundwater Encountered Backfilled 6-9-2006 PLATE B-2 GeoSoils, Inc. PROJECT: RAND M ENTERPRISES 2497 Ocean Street - - - 5- - - - 10- - - - 15- - - - Sample u Ql -e .3 ti) -" =a :l C Ill ::::> ~ 36 ~ 31 0 .c E ~ (/) 0 Cl) ::::> SM SM-SF 108.0 100.4 5.4 4.1 ~ C 0 e .3 ta (/) 27 17 BORING LOG BORING 8-1 DATE EXCAVATED w.o. __ 5_1_81_-A_-_s_c_----1 SHEET_1_ OF _3_ 6-9-06 SAMPLE METHOD: Hollow Stem Auger Drill Rig -..r. :....,:... ·:,,.:,:-· '-"',' • ·-· ... Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 40' NGVD29 "5l-Groundwater Description of Material COLLUVIUM: @ 0' SIL TY SAND, dark brown, slightly moist, loose; many roots. TERRACE DEPOSITS: @ 4' SAND w/SIL T, brown, slightly moist, medium dense; fine grained. @ 10' Becomes gray brown, dry. @ 15' Becomes light yellowish brown. ', 20-1---11,-,-,..,+---f---,-,,--+----,--,---l---+---:-----IP.--4--4----=,....-.,,.---:--:::--,--=,...--:-:-:--:------:---:-----:::----:-----:-:------:---:-------i ~ 65 SP 98.8 4.3 17 .. · :. @ 20' SAND, light gray, dry, dense; fine to medium grained. - @ 23' Few cobbles. 2497 Ocean Street GeoSoils, Inc. PLATE B-3 GeoSoils, Inc. PROJECT: RAND M ENTERPRISES 2497 Ocean Street Sample 0 "O .c ~ ID E ~ -e >, ::, !!:! C/J t 1ii "' C/J ..le:: =c 3: (.) ID "5 C: 0 C/J 0 ID ::J iii ::J GP - - - '7 - 30-~ 62 I.Jo Recover CL - - - 35-~ 50-4" - - - 40- - - - - 45- - - - - 2497 Ocean Street ~ ~ ~ 0 C: ~ I!! 0 :;:; ~ ~ .a ·5 <ll ~ C/J iO iO iO iO iO iO iO iO iO .ie BORING LOG BORING B-1 DATE EXCAVATED W.O. 5181-A-SC SHEET _3_ OF _3_ 6-9-06 SAMPLE METHOD: Hollow Stem Auger Drill Rig m ~ • • • • • • • • • • • • • • • • • • • • Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 40' NGVD29 ¥ Groundwater Description of Material @ 26' Many cobbles. @ 29' Perched groundwater. Basal Contact Elevation = 9' NGVD29. I SANTIAGO FORMATION: @ 31' SANDY CLAYSTONE, light gray, wet, dense. Total Depth = 36' Perched Groundwater from 29' to 31' Bottom of Hole Elevation = 4' NGVD29 Backfilled w/Bentonite Chips 6-9-2006 GeoSoils, Inc. PLATE B-4 GeoSoils, Inc. PROJECT: RAND M ENTERPRISES 2497 Ocean Street Sample '6 0 .3: "O .a ;;: Q) E ~ -e >, !E en -~ ·c: :5 en en :J a. ..><: '5 ;;: 0 c'.:' Q) ::i C 0 en 0 []) :J ffi :J 0 SP - - - - 5- - SM-SP - - 10- - - - - 15- SP - - - 20- - - - - 2497 Ocean Street ~ ~ 0 ~ ~ ·o ~ ~ ~ 0 C 0 :;:, e! ~ en BORING LOG BORING B-2 DATE EXCAVATED W.O. 5181-A-SC SHEET_1_ OF_1_ 6-9-06 SAMPLE METHOD: Solid Flight Auger -Beaver Drill m ~ .. .. •. .. •' Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 27½' NGVD29 ¥ Groundwater Description of Material FILL: @ O' SAND w/SIL T, brown, slightly moist, loose; poorly sorted, fine grained. TERRACE DEPOSITS: @ 7' SAND w/SIL T, light brown, slightly moist, medium dense; fine to medium grained. @ 16' SAND, light brownish gray, dry, medium dense. ~@:::.:....,..:1:.::c9c.,,' ::....:Rc::cef!,::u'-=s=a:...;I o,:,:n~co~b::.:b::..:,le:;.:s::..:·-c-=c--:--..,,..--------------'/ Total Depth = 19' (Practical Refusal) No Groundwater/Caving Encountered Bottom of Hole Elevation = 8½' NGVD29 Backfilled w/Bentonite Chips 6-9-2006 GeoSoils, Inc. PLATE B-5 GeoSoils, Inc. PROJECT: RAND M ENTERPRISES 2497 Ocean Street Sample '§' 0 .e, "C .c i OJ E ~ -e >. ~ CJ) -::, ·2 :5 . iii en CJ) ::::> C. .Y. =a ;;:: () c:-OJ "5 C 0 CJ) 0 [O ::::> in ::::> 0 SM - - - - 5- SM-SF - - - 10- - - - 15- - - - 20- - - 2497 Ocean Street BORING LOG BORING 8-3 DATE EXCAVATED W.O. 5181-A-SC SHEET_1_ OF_!__ 6-9-06 SAMPLE METHOD: Solid Flight Auger -Beaver Drill m ~ . '-'; .. ,:....,-., ~...:r,.·. .·· .. Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 22½' NGVD29 'Sl Groundwater Description of Material COLLUVIUM: @ O' SIL TY SAND, brown, dry, loose. TERRACE DEPOSITS: @ 6' SAND w/SIL T, brown to light brown, dry, medium dense; fine to medium grained. Contact Elevation = 1 O' NGVD29. \ SANTIAGO FORMATION: (8) 13' Dense soil· no recoverv. Total Depth= 13' (Practical Refusal) No Groundwater/Caving Encountered Bottom of Hole Elevation = 9½' NGVD29 Backfilled w/Bentonite Chips 6-9-2006 GeoSoils, Inc. PLATE 8-6 GeoSoils, Inc. PROJECT: RAND M ENTERPRISES 2497 Ocean Street Sample 0 "C .0 Q) E ~ -e >, ::, ~ en :5 1n "' en a. ~ =a 3: t) Q) :'i C: 0 en 0 ID :::> m :::> SM - - - $M-SF 5- - SP - 10- - 15- - - 20- - - 2497 Ocean Street ~ ~ ::R ~ 0 C: ~ e! 0 ~ ~ ·o ~ ~ en BORING LOG BORING B-4 DATE EXCAVATED W.O. __ 5_1_8_1-_A-_S_C_---1 SHEET_1_ OF_!__ 6-9-06 SAMPLE METHOD: Solid Flight Auger -Beaver Drill ~- Standard Penetration Test Undisturbed, Ring Sample Approx. Elevation: 17' NGVD29 'Sl-Groundwater Description of Material COLLUVIUM: @ 0' SIL TY SAND, brown, slightly moist, loose. TERRACE DEPOSITS: @ 4' SAND w/SIL T, brown, slightly moist, loose to medium dense. ® 6½' COBBLES and SAND. Total Depth= 7' (Practical Refusal) No Groundwater/Caving Encountered Bottom of Boring Elevation = 1 0½' NGVD29 Backfilled w/Bentonite Chips 6-9-2006 GeoSoils, Inc. PLATE B-7 > E-< -r:r., ~ A > 0::: Q 2 0 Log of Test Boring No. 1 ~ <~ uu Surface Elevation:± 23' Date: J/23/04 Logged By: JBR -. ta;. rF,) -....: rF,)..., rF,) < d Drilling Method: 4" Dia. Hand Auger Sampling Methods: 2.5" I.D. Sampler Drive Weight: 35# DESCRIPTION OF SUBSURFACE CONDITIONS SM TOPSOIL Dark red brown, slightly moist, loose to medium dense, silty sand. SM TERRACE DEPOSITS Drop: 30" 5 Red brown, very moisl medium dense, silty sand. -------- -- ---------- SP Light brown-tan, very moist, medium dense to dense, slightly silty sand SM and fine to medium sand. IS--1--l----l---l'----+-----1---1--------------------------------- EXCAVATION BOTTOM 20 25-l..-L-~----1----1----4--.......I'---------------------------------- PROJECT: JOB NO. 04-4412 Proposed Residential Project 2497 Ocean Street Carlsbad, California FIGUEX NO. 3a GSI Plate B-8 • rn ~ r"'1 ,..._ u ,..J f-< ::R ~ 0. 0 0 ._, c--~ ~ 0 r"'1 >-~ <I'. la:. ~ ~ .._, rn ._ ::i rn ::i: rn f-< z ~ z ~ rn ~ o--( ~ ~ r"'1 0 0 Q r.;i ,..J > ...::i ~ >-Q ::i c2 l:Q Q:; l:Q Q Q 7.5 108 5 15 20 25 Log of Test Boring No. 2 :z: 0 C < 1:12 Surface Elevation:± 28' Date: 1/23/04 Logged By: JBR uu ~ uj ..... Drilling Method: 4" Dia. Hand Auger Drive Weight: 35# Drop: 30" rn ;:, rr.i Sampling Methods: 2.5" l.D. Sampler < ...l u DESCRIPTION OF SUBSURFACE CONDITIONS SM TOPSOIL Dark red brown, slightly moist, loose to medium dense, silty sand. SM TERRACEDEPOSITS SP SM Red brown to light brown, slightly moist to moist, medium dense, slightly silty sand with occasional small "pockets" of clayey sand. ---------- --------- ----- Light brown to tan, very moist, medium dense to dense, slightly silty sand and sand. EXCA VA TYON BOTTOM PROJECT: JOB NO. 04-4412 Proposed Residential Project 2497 Ocean Street Carlsbad, California FIGURE NO. 3b GSI Plate B-9 ,...., [F) µ;, Log of Test Boring No. 3 ~ ,...., u ,_;J E-~ e::, 5 i::,., 0 e..... ,z-. ~ 0 -Q) """ > ..... Surface Elevation:± 37' ~ -<!! r.. 0:: E-<C'.l Date: 1/23/04 Logged By: JBR -rr.i ---;::, -uu [F) rZ ~ Drilling Method: 4" Dia. Hand Auger :r: rr.i E-:z; Drive Weight: 35# Drop: 30" E-:z; ~ rr.i fail ~;::i -Q., ~ ~ 0 0 A < Sampling Methods: 2.5" LD. Sampler ~ ,_;J > ,_;J ~ > ..J 0 ;::i PE CQ 0:: u CQ A Ci DESCRIPTION OF SUBSURFACE CONDITIONS SM TOPSOIL Dark red bro-wn, slightly moist, loose to medium dense, silty sand. SM TERRACE DEPOSITS 8.0 107.7 Red brown, very moist, medium dense, silty sand. -----------------------5 SP Light brown to tan, very moist. medium dense to dense, slightly silty sand and sand and SM fine to medium sand. 10 -4--1---+-----,l----+----+---i-------------------------------- 15 20 25 EXCA VA TJON BOTTOM PROJECT: JOB NO. 04-4412 Proposed Residential Project 2497 Ocean Street Carlsbad, California FIGURE NO. 3c GSI Plate B-10 .--. rJ) r.. Log of Test Boring No. 4 i-J ,--, u ,..;i E-< :::.-e ~ z c.. 0 ~ 0 :;:-~ 0 i-J ;;... ~ ~ Cl.I < Surface Elevation:± 37.5' Date: Logged By: .TBR ~ r., 0::: E-< 1/23/04 '-' rJ) ::::> -uu --rn ~ rli Drilling Method: 4" Dia Hand Auger ::i:: rn E-< ;z Drive Weight: 35# Drop: 30" ~ ;z :::: ~ i-J en ::5 0.. ::t: ""1 0 0 Q VJ Sampling Methods: 2.5" I.D. Sampler < l;,;"l ,..;i > ,..;i ~ ;;... ...;i Q ::::> -~ ~ 0::: u CQ Q p DESCRIPTION OF SUBSURFACE CONDITIONS SM TOPSOIL Dark red brown, slightly moist, loose to medium dense, silty sand. 6.9 109 SM TERRACE DEPOSITS Red brov.111, very moist, medium dense, silty sand. 5 SP Light brown to tan, very moisl medium dense to dense, slightly silty sand and sand and SM fine to medium sand. 10 EXCAVATION BOTTOM 15 20 2s~---'~-f.------J-------+----'----------------------------------i PROJECT: JOB NO. 04-4412 Proposed Residential Project 2497 Ocean Street Carlsbad, California FIGURE NO. 3d GSI Plate B-11 .ISAMPLE TEST EXCAVATION NOo 1 ,.__ t::; TYPE 0 ('j~ "'1 l:"'l ~ C: ,.__ tzj t::i oo = E '"C z ,.__ '.2 -i'n ~ i::, 0 -0 z ~ ., ""3 rn <::: ;;; (j 00~ ;;,::: • >-3 ~ = t"' ..., ',z,j-__, i:,;, c r' Elevation:::: l0.5' Date: 1/22/04 Excavation Method : Manual ~ C: '-' >-3 :::s ~ '.2 :::0 = >-3 tzj t=l SOIL DESCRIPTION 0 BEACH SAND 1 -Light gray, moist, medium dense, fine to medium sand. 2 - 3 -@ 3 -3.5' Abundant gravel and cobble. 4 - 5 -@ 5 -6' Abundant gravel and cobble. 6 EXCAVATION BOTTOM 7 •Groundwater level @ 5 feet. -• Excavation Terminated along side of field stone retaining wall. • Caving 5 - 61 do to ground water. SAMPLE TEST EXCAVATION NO. 2 ,.__ ~ TYPE 0 ('j~ ~ ~ C: ..-._ tzj t;1 Oo = l_'rj '"C z ----z-i'n _j ~ co 0 ~ '.2 ~ :::;:'. >-3 00 ~ c:: iii (j 00 1-('. 0 tzj >-3 = ..., >,:j-__, c (;) r-C: '-' >-3 Elevation: -:. 10.5' Date: 1/22/04 Excavation Method : Manual -'.2:-:, .,., "' ..,:: ::, >-3 tzj t,,:! SOIL DESCRIPTION 0 BEACH SAND 1 -Light gray, moist, medium, fine to medium sand. 2 - 3 4 -EXCAVATION BOTTOM 5 - 6 - 7 - PROJECT: Proposed Residential Project C.W. LA MONTE COMPANY INC. 2497 Ocean Street Carlsbad, California Soil and Foundation Engineers PROJECT NO. 04-4412 FIGURE NO. 3e GSI Plate B-12 ·APPENDIXC • EQFAUL T EQSEARCH' A.ND FRISKSP ' . ., • ' . ' ' . . ' '.: ' , ,, I-ro Cl) >--............ z .__, Cl) ..... C Cl) > w 4-0 I- Cl) ..0 E :J z Cl) > :.:; ro :J E E :J () EARTHQUAKE RECURRENCE CURVE 100 10 1 .1 .01 .001 2497 Ocean Street ' ' ~ --. -----......... l~ """' ~ 4 --I I -.... ' 0 •II' I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ,~,,--,, :1'," ,, -· /'.' // ,,, , ,.+ ' ~,' , ,n, -q, 't'!I' ~, ,,, ~,---,-, '&•<t' .. ,?..,;-:.·-~·-o1e, _,,.,1-; --., "':'I! x' -y ,"''('/~ ,,,, M ,'!,, /f ,.-..~-r~~.-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 .0. 5181-A-SC Plate C-1 EARTHQUAKE EPICENTER MAP 2497 Ocean Street 1100 ......---------------------------, 1000 800 700 600 500 400 300 200 100 LEGEND X M=4 0 M=5 0 M=6 L~ M=7 0 ◊M=8 -1 00 ~....1.....J..-'-+-L...I.-L...l.-j-L....1..-L---'-¼---'-'-'--''-f--J'--'-'--'-+--'--""-'--'--+---.,__,_............_+-=.,_,.,_--'--+-...L......L....L......L.-f-'-............ -L-f -400 -300 -200 -1 00 0 100 200 300 400 500 600 W .O. 5181-A-SC Plate C-2 RETURN PERIOD vs. ACCELERATION ~ 100000 (J1 ..... 0) ..... I )> I en 0 ...--.... en s.... ~ ....__, -0 0 ·-s.... (1) a. :!? Q) .... CD 0 I (,) C: s.... ::::J +-' (1) 0::: 10000 1000 100 BOZ. ET AL.(1999)HOR PS UNC 1 ---~ ./ .,,,,,,- ¥ ✓ / V -., ., _/' / / / / / ~ ,, -,, / / /' V ✓ I . I I _I - I I I I I I I I I I I I I I I I I I I I I I I I I 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Acceleration (Q) .--... ~ 0 ,._.. ~ +-' ·- .c co .c 0 s.... a.. (1) (.) C co "O (1) (1) (.) X w PROBABILITY OF EXCEEDANCE BOZ. ET AL.(1999)HOR PS UNC 1 I • I I • I 25yra 50yra I ■ I I TI 100 75 rs 100 rs 90 80 70 60 50 40 30 20 10 -+--~~~---+---1----+----t-i 0 _fu_uJu}:~~~ ....... 4....uJ_.J..LL,4JJ 0.00 0.25 0.50 0. 75 1.00 1.25 1.50 Acceleration (g) W.O. 5181-A-SC Plate C-4 ~ p ~ t I en 0 ....--.... en 5->. ....._... "'C 0 ·-5- Q) Cl. C 5- ::J ......, Q) 0::: RETURN PERIOD vs. ACCELERATION BOZ. ET AL.(1999)HOR PS UNC 2 / 100000 / ,, -~ ~ ~ / / 10000 / ,, ,_ ,, -~ / ,IT / 1000 /' I I , .r / )' , 100 I I I "" I I I I I I I I I I I I I I I I I I I I I I I I I 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Acceleration (Q) ...-.. ~ ..._... ~ ....., ·--·-..c rn ..c 0 s... a.. Cl) (.) C rn -0 Cl) Cl) (.) X w PROBABILITY OF EXCEEDANCE BOZ. ET AL.(l 999)HOR PS UNC 2 I • I I ... I 25 yrs 50 yrs I ■I I T I 100 75 rs 100 rs 90 80 70 60 50 40 30 20 10 0.00 0.25 0.50 0. 75 1.00 1.25 1.50 Acceleration (g) W.O. 5181-A-SC Plate C-6 MAXIMUM EARTHQUAKES 2497 Ocean Street 1 ' ', -.-.. 0) T T T ...__,,,, C .1 f -~ --0 , 1 +-' co s... (]) -(]) _Ir I ,. llil , ·-= (.) ■ (.) <( .01 .001 .1 1 10 100 Distance (mi) W .0. 5181.-A-SC , Plate C.-'7i .A.PPENDIX D, LABOBATORY DATA ~ :c en t; w a: i5 en ::::, e • 3,000 0 2,500 / 1/' 2,000 / 1/ .... /). en a. :r: I-C) I z w 1,500 oc V I-(/J oc .. / <{ w :c (/J 1,000 / V 500 / 1/ 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> B-1 10.0 SIL TY SAND{SM) Primary Shear Undisturbed 110.3 5.4 130 40 B-1 10.0 Residual Shear Undisturbed 110.3 5.4 189 36 Note: Sample Innundated prior to testing GeoSoils, Inc. DIRECT SHEAR TEST ~ 57 41 Palmer Way Project: R & M ENTERPRISES ff . Carlsbad, CA 92008 ~ Telephone: {760) 438-3155 Number: 51~1-A-SC Fax: (760) 931-0915 Date: June 2006 Plate: D-1 .., a. (!) .; .:; 0: ifj :r: {/) t; w 0: i5 {/) ::, • • 3,000 2,500 /' v· 2,000 / 1/ ' .... ./) 1.11 a. :r: I-C) z w 1,500 0:: V I-Cl) 0:: / <( w :c Cl) 1,000 / 500 / V // 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 Y.i MC% C <I> 8-1 20.0 POORLY GRADED Primary Shear Undisturbed 99.1 4.3 42 42 SAND with SILT(SP-SM) B-1 20.0 Residual Shear Undisturbed 99.1 4.3 225 35 Note: Sample Jnnundated prior to testing GeoSoils, Inc. DIRECT SHEAR TEST f· 57 41 Palmer Way Project: R & M ENTERPRISES Carlsbad, CA 92008 Number: 5181-A-SC Telephone: (760) 438-3155 Fax: (760) 931-0915 Date: June 2006 Plate: D-2 ~ ~ 5 (!) ~ rn :;, ii: C? 0. 0 0. 2 0. 4 0. 6 0. 8 1.0 1.6 1.8 2.0 2.2 2.4 2.6 100 Sample --r-- Depth/El. ~ ~ r----... 1-....... ,._,. 4~ \ \ \ j~-f--.._ ---I---.. :---......._ ~ 1,000 STRESS, psf Visual Classification e B-1 10.0 SILTY SAND(SM) Stress at which water was added: 1000 psf Strain Difference: 0.53% • \ \ \ \ \ \ \ \ ~ \ r-----.._ \ ~ \ I'--. I'---~~ 10,000 % MC MC H20 Initial Initial Final 110.1 5.4 16.3 1000 ;;;:1---------------------,.--------------------;;; GeoSoils, Inc. iira 5741 PalmerWay 1i{:. Carlsbad, CA 92008 ~ Telephone: (760) 438-3155 Fax: (760) 931-0915 CONSOLIDATION TEST Project: R & M ENTERPRISES Number: 5181-A-SC Date: June 2006 Plate: D-3 (0 !2 "' ;ii l:i Cl m 5 .., 0.. Cl 1o in w t:::! "' z ~ Cl 3 U.S. SIEVE OPENING IN INCHES I U.S. SIEVE NUMBERS I HYDROMETER 6 4 3 2 1.5 1 3/4 1/23/8 3 i 6 810 1410 20 3o 40 so so 100140200 100 I II I I II I : I } ·~ I I I 95 l\k\ 90 I\\ 85 ~I\ 80 : -: 75 : : \ : \ : 70 \ 1-65 :c ~ C) [i]60 "' s ! \ 6)55 ! \ • oc LU50 z ~45 z : ~40 0:: \ : ~35 i, 30 : I: 25 ,\ 20 \""-: 15 \ ~ 10 ' 5 : • 0 : 100 10 1 0.1 O.Q1 0.001 GRAIN SIZE IN MILLIMETERS I GRAVEL SAND I GOBBLES I fine coarse I medium fine I SILT OR CLAY coarse Sample Depth Visual Classification/USCS CLASSIFICATION LL PL Pl Cc Cu • B-1 10.0 SIL TY SANO(SM) NP NP NP • B-1 20.0 POORLY GRADED SAND with SILT(SP-SM) NP NP NP 0.93 2.47 .... B-1 35.0 Sandy Clay Sample Depth 0100 060 D30 D10 %Gravel %Sand %Silt I %Clay • B-1 10.0 4.75 0.368 0.211 0.0 85.5 14.5 • B-1 20.0 2 0.375 0.23 0.152 0.0 93.8 6.2 .... B-1 35.0 4.75 0.14 0.0 45.5 54.5 GeoSoils, Inc. GRAIN SIZE DISTRIBUTION i,ie 57 41 Palmer Way Proje~t: R & M ENTERPRISES ~-Carlsbad, CA 92008 . Telephone: (760) 438-3155 Number: 5181-A-SC Fax: (760) 931-0915 Date: Jun·e20D6 Plate: D-4 APPEN-DIXE GENERAL EARTHWORK AND GRADING -GUIDELINES GENERAL EARTHWORK AND GRADING GUIDELINES General These guidelines present general procedures and requirements for earthwork and grading as shown on the approved grading plans, including preparation of areas to filled, placement of fill, installation of subdrains, and excavations. The recommendations contained in the geotechnical report are part of the 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. The contractor is responsible for the satisfactory completion of all earthwork in accordance with provisions of the project plans and specifications. The project soil engineer and engineering geologist (geotechnical consultant), 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, the approved grading plans, and applicable grading codes and ordinances. The geotechnical consultant should provide testing and observation so tbat determination 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 project engineering geologist and/or soil engineer prior to placing and fill. It is the contractor's responsibility to notify the engineering geologist and soil engineer 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, GeoSoils, Jne. 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 contractor1s responsibility to prepare the ground surface to receive the fill, to the satisfaction of the soil engineer, and to place, spread, moisture condition, mix, and compact the fill in accordance with the recommendations of the soil engineer. The contractor should also remove all non-earth material considered unsatisfactory by the soil engineer. It is the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the earthwork in accordance with applicable grading guidelines, codes or agency ordinances, 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, determined by the soil engineer or engineering geologist 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 soil engineer. 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 soil engineer. Soft, dry, spongy, highly R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, lne. Appendix E Page2 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 soil engineer 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 to a minimum depth of 6 to 8 inches, or as directed by the soil engineer. 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 soils engineer and/or engineering geologist. 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, 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 soil engineer and/or engineering geologist. 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 soil engineer, the minimum width of fill keys should be approximately equal to½ 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 soil engineer and/or engineering geologist prior to placement of fill. Fills may then be properly placed and compacted until design grades (elevations) are attained. R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, 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 determined to be suitable by the soil engineer. These materials should be free of roots, tree branches, other organic matter, or other deleterious materials. All unsuitable materials should be removed from the fill as directed by the soil engineer. 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 soil engineer. Oversized material should be taken offsite, or placed in accordance with recommendations of the soil engineer in areas designated as suitable for rock disposal. Per the UBC/CBC, oversized material should not be placed within 1 O feet vertically of finish grade ( elevation) or within 20 feet horizontally of slope faces (any variation will require prior approval from the governing agency). To facilitate future trenching, rock (or oversized material) should not be placed within 1 O feet from finish grade, the range of foundation excavations, future utilities, or underground construction unless specifically approved by the soil engineer 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 soil engineer to determine it's physical properties and suitability for use onsite. If any material other than that previously tested is encountered during grading, an appropriate analysis of this material should be conducted by the soil engineer 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 soil engineer 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. R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, lne. Appendix E Page4 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 determined by ASTM test designation D-1557, or as otherwise recommended by the soil engineer. 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 offill has been tested and found to meet the density and moisture requirements, and is approved by the soil engineer. In general, per the UBC/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 determination 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. 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 subject 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 R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, Inc. Appendix E Pages 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. 6. Erosion control and drainage devices should be designed by the project civil engineer in compliance with ordinances of the controlling governmental agencies, and/or in accordance with the recommendation of the soil engineer or engineering geologist. 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 soil engineer and/or engineering geologist may recommend and direct changes in subdrain line, grade, and drain material in the field, pending exposed conditions. The location of constructed subdrains, especially the outlets, should be recorded by the project civil engineer. EXCAVATIONS Excavations and cut slopes should be examined during grading by the engineering geologist. If directed by the engineering geologist, further excavations or overexcavation and refilling of cut areas should be performed, and/or remedial grading of 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 engineering geologist prior to placement of materials for construction of the fill portion of the slope. The engineering geologist 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 engineering geologist and soil engineer 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 engineering geologist, whether anticipated or not. R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, Ine. Appendix E Page6 Unless otherwise specified in soil and geological reports, 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 soil engineer or engineering geologist. 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 soil engineer and engineering geologist have finished their observations of the work, final reports should be submitted subject to review by the controlling governmental agencies. No further excavation or filling should be undertaken without prior notification of the soil engineer and/or engineering geologist. 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. 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: R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, Inc. Appendix E Page? 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. Test Pits Location, 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. R & M Enterprises File: e:\wp9\5100\5181a.upg GeoSoils, Ine. Appendix E Page 8 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 UJe 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. 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. R & M Enterprises File: e:\wp9\5100\5181 a.upg GeoSoils, lne. Appendix E Page9 CANYON SUBDR·AIN DETAIL TYPE A TYPE B _____________________ ...,. _________________ ._ SEE ALTERNATIVES NOTE: ALTERNATIVES, LOCATION ANO EXTENT OF SUBDRAINS SHOULD BE DETERMINED • BY THE SOILS ENGINEER ANO/OR ENGINEERING GEOLOGIST-DURING GRADING. PLATE EG-1 CANYON SUBDRAIN ALTERNATE DETAILS ALTERNATE t PERFORATED PIPE AND FILTER MATERIAL A-1 1i9 MINIMUM FILTER MATERIAL: MINIMUM VOLUME OF 9 FT.3 ~-;.·. ·.:; 'I /LINEAR FT. s· j ABS OR PVC PIPE OR APPROVED •::. ·:.:. SUBSTITUTE WITH MINIMUM 8 11/4 • e'I PERFS ::.· • •• ,, LINEAR FT. lN BOTTOM HALF OF. PIPE. -••• ;. ·.-; '' ASTM 02751, SOR 35 OR ASTM D1527, SCHD.-40 ASTM D3034, SOR 35 OR ASTM D1785b SCHD. 40 FOR CONTINUOUS RUN IN EXCESS OF 5 0 FT. USE s• J! PIPE · FILTER MATERIAL. . SIEVE SIZE PERCENT PASSING 1 INCH , 100 ° ·3/4 INCH 90-:-:100 3/8 INCH 40-100 NO. 4 25-40. NO. 8 18-33 .NO. 30 :5-15. -N.0. 50 .0-7. No.·200 0-3 ALTERNATE 2: PERFORATED PIPE, GRAVEL AND.FILTER FABRIC ~Hl~UM OVERLAP 5· MINIMUM OVER~~, 6. MINIMUM -COVER •• 4·• MINIMUM BEDDING L. MINIMUM BEDDING .,. ...... ,,.. s....;..........-::::'-'_"d'.t A-2 • GRAVEL.MATERIAL 9 FT3/LINEAR FT. 8-2 PERFORA1EO PIPE: SEE ALTERNATE 1 GRAVEL: CLEAN 3/ 4 IND-I ROCK OR APPROVED SUBSTITUTE FILTER FABRIC: MIRAFI 11+0 OR APPROVED SUBSTITUTE PLATE EG-2 DETAIL FOR FILL SLOPE TOEING OUT ON FLA·T ALLU.VIA TED CANYON TOE OF SLOPE AS SHOWN ON GRADING PLAN ORIGINAL GROUND SURFACE TO BE RESTORED WITH COMPACTED FILL -L~Gl:L..:~~U=A~ BACKcu-0 VARIES. FOR DEEP REMOVALS, /.....~'3 r BACKCUT :\~SHOULD BE MADE NO <_,$-~ STEEPER·THA~:1 OR AS NECESSAR~~'> ANTICIPATED ALLUVIAL REMOVAL FOR SAFETY ....._ ~CONSIDERATIONS-:, l ~ , DEPTH PER SOIL ENGaNEER. ~/~ // - \'l(k'-..,/\ ~\\vj,~1~ PR«rn"~ei.. ;-; MiN"1MuM ~o~cnoN7R'™ ;OE;;- SLOPE AS SHOWN ON GRADING PLAN TO THE RECOMMENDED REMOVAL DEPTH. SLOPE HEIGHT, SITE CONDITIONS AND/OR LOCAL CONDITIONS COULD DICTATE FLATTER PROJECTIONS. REMOVAL ADJACENT TO EXISTING FILL ADJOINING CANYON FILL ----------------------- PROPOSED ADDITIONAL COMPACTED F.ILL COMPACTED FlLL LIM.ITS LIN!;\ , TEMPORARY COMPACTED FILL----~ -- . ).,FOR DRAINAGE ONLY --.--- Oaf ..,-&<o, Qaf /~ (TO BE REMOVED) IEXISTING,COMPACTED FlLU "'.;:.',,, ;.,., ❖~ ... ~zylf'y,.\ ~\ ;/\\ ~ ~fWP" LEGEND TO BE REMOVED BEFORE PLACING ADDITIONAL COMPACTED FILL Oaf Qal ARTIFICIAL FILL ALLUVIUM PLATE EG-3 -0 r )> -, rn rn G) I +- TYPICAL STABILIZATION / BUTTRESS-_FILL □ET AIL 15' TYPICAL OUTLETS TO BE SPACED AT 100' MAXIMUM "INTERVALS, AND SHALL EXTEND 12· BEYOND THE FACE ,OF SLOPE AT TIME OF. ROUGH GRADING COMPLETION. 1◄ 15' MINIMUM ~1 BLANKET FILL IF RECOMMENDED BY THE SOIL ENGINEER DESIGN FINISH SLOPE ~ 1/1 \ 3' MINIMUM KEY DEPTH TYPICAL STABILIZATION / BUTTRESS SU BO RAIN □ET AIL t... MINIMUM 2. MINIMUM PIPE I.. MINIMUM -0 r )> --f m rn G) I 01 r MINtMUM FILTER ~ATERIAL: MINIMUM OF FIVE FP/LINEAR Fl OF PIPF OR FOUR FP/LINEAR Ft OF PIPE WHEN PLACED IN SQUARE CUT TRENCH, .AJ..T'ERNATIVE IN LIEU OF FILTER MATERIAL: GRAVEL MAY B ENCA~ED IN APPROVED FILTER FABRIC, FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT, FILTER FABRIC Sh1ALL BE LAPPED A MINIMUM OF 12• ON ALL JOINTS. MIN!MUM 4• DIAMETER PIPE: ABS-ASTM D-2751, SOR 35 OR ASTM D-1527 SCHEDULE 40 PVC-ASTM D-3034, SPR _35 OR ASTM D-1785 SCHEDULE 40 WI.TH A CRUSHING STRE~GTH OF 1,000 POUNDS MINIMUM, AND A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS OF BOTTOM ·oF PIPE . . PROVIDE CAf AT UPSTREAM END OF PIPE_. SLOPE AT 2% TO OUTLET PIPE, OUTLET PIPE TO BE CONNECTED TO SUBDRAIN PIPE WITH TEE OR ELBOW. t-PTE:: 1. TRENCH FOR OUTLET PIPES TO BE BACKFILLED I. WITH ON-SITE SOIL. i. 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 SOILS ENGINEER AND/OR ENGINEERING ~EOLOGIST. FILTER MATERIAL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED EQUIVALENT: SIEVE SIZE PERCENT PASSING 1 INCH 100 3/ 4 INCH 90-100 3/B INCH 40-100 NO. 4 25-40 N0.8 18-33 NO, 30 5-15 NO. 50 0-7 N0.200 0-3 GRAVEL SHALL BE OF THE FOLLOWING SPECIFICATION OR AN APPROVED E,OUIVALENT: ' SIEVE SIZE PERCENT PASSING 1 1/2 INCH.. 100 NO. 4 50 N0.200 8 SAND EQUIVALENT: MINIMUM OF 51 FILL OVER NATURAL DETAIL SIDEHILL FILL COMPACTED FILL TOE OF SLOPE AS SHOWN ON GRADING PLAN PROVIDE A 1:1 MINIMUM PROJECTION FROM DESIGN TOE OF SLOP_E TO TOE OF= KEY AS SHOWN ON AS BUILT NATURAL SLOPE TO BE RESTORED WITH II ~ BENCH WIDTH MAY VARY ''t'----_-_-_-_-_J 'E• MINIM~M -u r )> -f rn rn G> I en NOTE: 1. WHERE THE NATURAL SLOPE APPROACHES OR EXCEE-DS THE I 1 'MINIMUM KEY WIDT 2'X 3' MINIMUM KEY DEPTH 2' MINIMUM IN BEDROCK OR APPROVED MATERIAL. I DESIGN SLOPE RATIO, SPECIAL RECOMMENDATIONS WOULD BE PROVIDE □ BY THE SOILS ENGINEER. 2, THE NEED FOR AND DISPOSl:TION OF DRAINS WOULD BE DETERMINED BY THE SOILS ENGINEER BASED UPON EXPOSED CONDITIONS. FILL OVER CUT □ET AIL . . CUT/FILL CONTACT 1. AS SHOWN ON GRADING PLAN MAINTAIN MINIMUM .15' FILL SECTION FROM BACK CUT TO FACE OF FINISH SLOPE H 2. AS SHOWN ON AS-BUILT ORIGINAL TOPOGRAPHY \ '/'-~ 1\~ BEDROCK OR APPROVED MATERIAL -0 r )> -I rn rn G) I ~ LOWEST BENCH WIDTH • 15'MINIMUM OR H/2 _,,,,...----~--- COMPACTED FILL ~ 1/'~' '.'.~ 4' MINIMUM NOTE: THE CUT PORTION OF THE SLOPE SHOULD BE EXCAVATED AND EVALUATED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST PRIOR TO CONSTRUCTING THE FILL PORTION. lJ r )> -I rn rn G) I 00 ST AB.I LIZA TION FILL FOR UNSTABLE MATERIAL NOTE: 1. 2. EXPOSED IN PORTION OF CUT .SLOPE NATURAL SLOPE REMOVE: UNSTABLE MATERIAL REMOVE: UNSTABLE MATEijlAL r8 15' MINIMUM ~ "-----~~JW:l~.-.:s...i..w;LK.1.L-.a=...¥1.1.AOE UNWEATHERED BEDROCK OR APPROVED MATERIAL SUBDRAINS ARE NOT REQUIRED UNLESS SPECIFIED BY SOILS ENOINEER AND/OR ENGINEERING GEOLOGIST, ·wr SHALL ei;: I;:OUIPMliNT WIDTH (15'} FOR SLOPE HEIGHTS LESS THAN 25 FEET. FOR SLOPES GREATER· THAN 25 FEET ·w· SHALL BE DETERMINED BY THE PROJECT SOILS ENGINEER AND /OR ENGINEERING GEOLOGIST. AT NO TIME SHALL •w• BE LESS THAN H/2. -0 £: -t rn m· G) I lO SKIN FILL OF NATURAL GROUND ORIGINAL SLOPE 15' MINIMUM TO BE MAINTAINED FROM PROPOSED FINISH SLOPE FACE TO BACKCUr'-- I MINIMUM __ .....,._.......,_~, ----~,~ BEDROGK OR APPROVED MATERIAL 3' Ml~IMUM KEY DEPTH NOTE: 1. THE NEED AND DISPOSITION OF DRAINS WILL BE DETERMINED! BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST BASED ON FIELD CONDITIONS. 2. PAD OVEREXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED TO BE NECESSARY BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. I . -0 r :t>- -J m m G) I --0 DAYLIGHT CUT LOT DETAIL RECONSTRUCT COMPACTED FILL SLOPE AT 2:1 OR FLATTER NATURAL GRADE~ ,,-/"" _,,,-/ / -----{MAY INCREASE OR DECREASE· PAD AREAL OVEREXCAVATE AND RECOMPACT -- REPLACEMENT FILL AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE \;.~,~ :__,, ~~~ / OPOSED FINISH GRADE ,-uV--• O INIMUM BLANKET FILL 1/ o\.\.u-.\ ----n '-~\~'-'M\W\\YF - ~~/ so" ~ q_</.;o/ .. ~o'? __ ,...... BEDROCK OR APPROVED MATERIAL •"/ .. l0~ \; a~'" ~I -P NOTE: 1. 2. MINIMUM KEY DEPTH YPICAL BENCHING SUBDRAIN AND KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKN~SS OF OVERBURDEN. PAD OVER EXCAVATION AND RECOMPACTION SHOULD BE PERFORMED IF DETERMINED NECESSARY BY THEi. SOILS ENGINEER AND/OR THE ENGINEERING GEOLOGIST. TRANSITION LOT DETAIL CUT LOT (MATERIAL TYPE TRANSITION) - --------.----------------- PAD GRADE COMPACTED FILL 1/\\\~ 3" MINIMUM* ~ ~ UNWEATHERED BEDROCK OR APPROVED M~TERIAL 1// TYPICAL BENCH ING CUT-FILL LOT (DAYLIGHT TRANSITION) NATURAL GRADE~ MUM PAD GRADE ~~~ • _____ ....._ _____ ..:....-...,....~.,~ OVEREX-CAVATE··· -=·. · ~ · · ~v . . COMPACTED FILL ~ AND RECOMPACT ____.-, co'--'--u~\: ~\\1//(\V-'l 3• MINIMUM* ~· •. ,o~ A'F-.~~-~~ ~ £-"'o--t~-...._,\;~\, ~ ~~v~ . ~ NWEATHERED BEDROCK OR APPROVED MATERIAL YPICAL BENCH ING NOTE: * DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST IN STEEP CUT-FILL TRANSITION AREAS. PLATE EG-11" SETTLEMENT PLATE AND RISER □ET AIL 2•x 2'X 111.· STEE-L PLATE STANDARD 3/4· PIPE NIPPLE WELDED TO TOP OF PLATE. ~----i--314· X s• GALVANIZED PIPE. STANDARD PIPE TH READS TOP ANO BOTTOM. EXTENSIONS THREADED ON BOTH ENDS AND ADDED IN s• INCREMENTS. 3 INCH SCHEDULE 40 PVC PIPE SLEEVE. ADD IN s• INCREMENTS WITH GLU~ JOINTS. FINAL GRADE r s· / / / I I I . I' ~ -,+ : MAINTAIN 5' CLEARANCE OF HEAVY EQUIPMENT. --L.1\-MECHANICALLY HANO COMPACT IN 2" VERTICAL -r'\r LIFTS OR ALTERNATIVE SUITABLE TO AND • I ~ 1---M .,._----ilil>ol' ACCEPTED BY THE SOILS ENGINEER. I 5• I I I I / / s· I I I MECHANICALLY HAND COMPACT THE INITIAL s• VERTICA~ WITHIN As• RADIUS OF PLATE BASE. ' ' ' ' ' :•: : • •• :. ·.--:•. •. • •. •. • .• • • BOTTOM OF CLEANOUT .......... -....... - PROVIDE A MINIMUM 1· BEDDING OF COMPACTED SAND NOTE: 1. LOCATIONS OF SETTLEMENT PLATES SHOULD BE CLEARLY MARKED AND READILY VISIBLE {RED FLAGGED) TO EQUIPMENT OPERATORS. 2. CONTRACTOR SHOULD MAINTAIN CLEARANCE OF A s· RADIUS OF PLATE BASE AND WITHIN 5' (VERTICAL) FOR HEAVY EQUIPME·NT. FILL WITHIN CLEARANCE AREA SHOULD BE HANO'COMPACTED TO PROJECT SPECIFICATIONS OR COMPACTED BY ALTERNATIVE APPROVED BY THE SOILS ENGINEER. 3. AFTER S"(YERTICAU OF FILL IS IN PLACE, CONTRACTOR SHOULD MAINTAIN A 5.:...RADIUS EQUIPMENT CLEARANCE FROM RISER. I... PLACE AND MECHANICALLY HAND COMPACT INITIAL 2' OF FILL PRIOR TO ESTABLISHING THE INITIAL READING. 5. IN THE EVENT OF DAMAGE TO THE SETTLEMENT PLATE OR EXTENSION RESULTING FROM EQUIPMENT OPERATING WITH IN THE SPECIFIED CLEARANCE AREA, CONTRI\CTOR SHOULD IMMEDIATELY NOTIFY THE SOILS ENGINEER 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 SOILS ENGINEER. PLATE EG-14 TYPICAL SURFACE SETTLEMENT MONUMENT FlNISH GRADE _....,_,,_.;.;..;....;:;,;.;;;.;,:;;.;;__ _____ ---------,------------ ...__i:-3/B• DIAMETER X s• LENGTH CARRIAGE BOLT OR EQUIVALENT • DIAMETER X 3 1/2" LENGTH HOLE ..,.._+-CONCRETE BACKFILL PLATE EG-15 TEST PIT SAFETY DIAGRAM SIDE VIEW ( NOT TO SCALE ) TOP VIEW r----_.:..,_ ___ ____:,:100=-:...::FEE:::.!T ________ --l~~ so FEET SPOIL APPROXIMATE CENTER / CF TEST PlT f-Hi u. 0 u, t- ttl u.. 0 in FLAG ! NOT TO SCALE } 50 FEET PLATE EG-16 OVERSIZE ROCK DISPOSAL VIEW NORMAL TO SLOPE FACE PROPOSED FINISH GRADE r:::,:::, ($:J o::> 00 20° MINIMUM ~ (B) oo 15" MINIMUM (A) ~ 00 00 OCl~~~'M.;..U_M_,.~ co 0:, CX) 0 (G) co oO colF) BEDROCK OR APPROVED MATERIAL . ViEW PARALLEL TO SLOPE FACE PROPOSED FINISH GRADE 10"MINIMUM (E) JJOO"MAXIMUM(B • ~ 15" MINIMUM c;.x -Ot,. ~ ~ 3• MINIMUM C::) o1filo 15" MINIMUM 1/ BEDROCK. OR APPROVED MATERIAL NOTE: !Al ONE EQUIPMENT WIDTH OR A MINIMUM OF 15 FEET. (B) HEIGHT AND WIDTH MAY VARY DEPENDING ON ROCK SIZE AND TYPE OF EQUIPMENT, LENGTH OF WINDROW SHALL BE NO GREATER THAN 100· MAXIMUM. IC) IF APPROVED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST, WINDROWS MAY BE PLACED DIRECTLY ON COMPETENT MATERIAL OR BEDROCK PROVIDED ADEQUATE SPACE IS AVAILABLE FOR COMPACTION. . ID) ORIENTATION OF WINDROWS MAY VARY BUT SHOULD BE AS RECOMMENDED BY THE SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST. STAGGERING OF WINDROWS IS NOT NECESSARY UNLESS RECOMMENDED. IE) CLEAR AREA FOR UTILITY TRENCHES. FOUNDATIONS AND SWIMMING POOLS. (Fl ALL FILL OVER AND AROUND ROCK WINDROW SHALL BE COMPACTED TO 90% RELATIVE COMPACTION OR AS RECOMMENDED. IG) AFTER FILL BETWEEN WINDROWS IS PLACED AND COMPACTED WITH THE LIFT OF FILL COVERING WINDROW, WINDROW SHOULD BE PROOF ROLLED WITH A 0-9 DOZER OR EQUIVALENT. VIEWS ARE DIAGRAMMATIC ONLY. ROCK SHOULD NOT TOUQ-i AND VOIDS SHOULD BE COMPLETELY FILLED IN. PLATE RD-1 ROCK DISPOSAL PITS VIEWS ARE DIAGRAMMATIC ONLY. ROa< SHOULD NOT TOUCH AND VOIDS SHOULD BE COMPLETELY FILLED IN. ALL LIFTS COMPACTED OVER ROCK AFTER EMBEDMENT ,---------1 GRANULAR MATERIAL I I ------1 RGE RO ------, I 1 COMPACTED FILL I I I I SIZE OF EXCAVATION TO BE COMMENSURATE WITH ROCK SIZE I I I I I I ROCK DISPOSAL LAYERS GRANULAR SOIL TO FILL VOIDS .. ~ • FCOMPACTED All DENSIFIED BY FLOODING --;;--------._ LAYER ONE ROCK HIGH O□IT:U.D\ -• ...__, ----------........ --------- PROPOSED FINISH GRADE I□• MINIMUM OR BELOW LOWEST UTILI ---------------~ 20· PROFILE ALONG LAYER FILL SLOPE ICLEAR ZONE 20· MINIMUM LAYER ONE ROCK HIGH PLATE RD-2 Af Col Ob at Tsa ----- BOH 10' 2 ~ 0 R1 0 {5 z p w w lL ......, z 0 ~ w _J w LEGEND Artificial fill Colluvium Quaternary beach deposits Quaternary terrace deposits Tertiary Santiago Formation A Boring B-2 Projected 32' NW I Boring B-3 I Projected 14' SE I Boring B-4 Projected 5' NW I 40 20 Fieldstone wall and approximate top of former7 natural bluff I I Test Pit TP-1 \ I Projected 17' SE J Lower \ \ seawal'7 \ \Af (buried) I \ Ob 0 Tsa Ob_J I I I IAf I Approximate location of geologic contact, queried where uncertain Approximate elevation (in feel) NGVD29 Datum of bottom of hole Existing --Building-- Wine Cellar at Tsa N57E Existing Grad\ Boring B-1 Projected 10' SE I I I I Col j ?- at Ocean Str et BOH4' Tsa A' 40 20 0 ALL LOCATIONS ARE APPROXIMATE RIVERSIDE CO. ORANGECO. SAN DIEGO CO. CROSS SECTION A-A' Plate 2 of 2 W.O. 5181-A-SC DATE 06/06 SCALE 1 "=20'