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PD 2022-0007; HAGUE RESIDENCE; PRELIMINARY GEOTECHNICAL INVESTIGATION AND RECOMMENDATIONS; 2021-10-18
PRELIMINARY GEOTECHNICAL INVESTIGATION AND RECOMMENDATIONS PROPOSED NEW, SINGLE-FAMILY RESIDENCE TO BE LOCATED AT CYNTHIA LANE (APN: 156-231-70) CARLSBAD, CALIFORNIA EDG Project No. 216614-1 October 18th, 2021 PREPARED FOR: Jeff Hague 6244 Dartington Way Carlsbad, California ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 Date: October 18th, 2021 To: Jeff Hague 6244 Dartington Way Carlsbad, California Re: Proposed new, single-family residence to be located at Cynthia Lane (APN: 156-231-70), Carlsbad, California Subject: Geotechnical Investigation and Recommendations Report In accordance with your request and our signed proposal we have provided this preliminary geotechnical investigation and recommendations report of the subject site for the proposed new, single-family residence. The findings of the investigation, earthwork recommendations and foundation design parameters are presented in this report. In general, it is our opinion that the proposed construction, as described herein, is feasible from a geotechnical standpoint, provided the recommendations of this report and generally accepted construction practices are followed. If you have any questions regarding the following report, please do not hesitate to contact our office. Sincerely, ENGINEERING DESIGN GROUP Steven Norris Erin E. Rist California GE#2590 California RCE #65122 ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 Table of Contents 1.0 SCOPE ................................................................................................................................................ 1 2.0 SITE AND PROJECT DESCRIPTION ...................................................................................................... 1 3.0 FIELD INVESTIGATION ....................................................................................................................... 1 4.0 SUBSURFACE CONDITIONS ............................................................................................................... 1 5.0 GEOLOGIC HAZARDS ......................................................................................................................... 2 6.0 GROUND WATER ............................................................................................................................... 3 7.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS ................................................................ 3 8.0 GRADING AND EARTHWORK............................................................................................................. 4 9.0 SEISMIC DESIGN PARAMETERS ......................................................................................................... 6 10.0 SHALLOW FOUNDATIONS ................................................................................................................. 7 11.0 CORROSION AND VAPOR EMISSION ................................................................................................. 8 12.0 CONCRETE SLAB-ON-GRADE ........................................................................................................... 10 13.0 RETAINING WALLS........................................................................................................................... 11 14.0 POOL ............................................................................................................................................... 13 15.0 INFILTRATION .................................................................................................................................. 14 16.0 SURFACE DRAINAGE ........................................................................................................................ 15 17.0 LABORATORY TESTING .................................................................................................................... 15 18.0 CONSTRUCTION OBSERVATION AND TESTING ............................................................................... 16 19.0 MISCELLANEOUS ............................................................................................................................. 17 FIGURES Site Vicinity Map .......................................................................................................................... Figure No. 1 Site Location Map ........................................................................................................................ Figure No. 2 Site Plan ....................................................................................................................................... Figure No. 3 Test Pit Logs ....................................................................................................................... Test Pit Logs 1 – 2 APPENDICES References .................................................................................................................................... Appendix A General Earthwork and Grading Specifications ............................................................................ Appendix B Laboratory Results ........................................................................................................................ Appendix C Retaining Wall Drainage and Slab Underdrain Detail ...................................................................Appendix D Hague Residence Page No. 1 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 1.0 SCOPE This report gives our geotechnical recommendations for the proposed new, single-family residence to be located at Cynthia Lane (APN: 156-231-70), Carlsbad, California. (See Figure No. 1, "Site Vicinity Map", and Figure No. 2, "Site Location Map"). The scope of our work conducted onsite to date has included a visual reconnaissance of the property and surrounding areas, review of geologic maps, a limited subsurface investigation of the subject property, review of preliminary project plans, laboratory tests and preparation of this report presenting our findings, conclusions, and recommendations. 2.0 SITE AND PROJECT DESCRIPTION The subject property is located at Cynthia Lane (APN: 156-231-70), in the City of Carlsbad, California. For the purposes of this report the lot is assumed to face north. The property is bordered to the west, east and south, by single-family homes, and to the north by Cynthia Lane. The site area topography generally consists of rolling foothill terrain. At the time of this report the lot is undeveloped, except for a shed, a small hardscape area and vegetation. The site generally consists of a relatively flat pad, which gently slopes, descending to the north and west. Based on our review of preliminary project plans, we understand the proposed development will consist of the construction of a new, two-story, single-family residence, and associated hardscape and landscape improvements. 3.0 FIELD INVESTIGATION Our field investigation of the property consisted of a site reconnaissance, site field measurements, observation of existing conditions on-site and on adjacent sites and a limited subsurface investigation of soil conditions. Our subsurface investigation consisted of the visual observation of two exploratory test pits in the general areas of proposed construction, logging of soil types encountered, and sampling of soils for laboratory testing. The approximate location of the test pits is given in Figure No. 3, "Site and Approximate Location of Test Pits". 4.0 SUBSURFACE CONDITIONS Topsoil, fill, and weathered profiles were encountered to approximate depths of between 2 and 3 feet below adjacent grade in our exploratory test pits. Soil types encountered within our exploratory test pits are described as follows: Hague Residence Page No. 2 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 4.1 Topsoil / Fill / Weathered Topsoil, fill and weathered unsuitable materials were encountered to depths of between 2 and 3 feet below adjacent grade in our exploratory test pits. These materials consist of light brownish gray to light brown, dry, loose to medium dense, silty sands and sandy silts. Organic material was encountered within our test pits. In general, these materials are not considered suitable for the support of structures and structural improvements in their present state but may be utilized as re-compacted fill, if necessary, provided the recommendations of this report are followed. Unsuitable soil materials classify as SW - SM per the Unified Soil Classification System, and based on our observation and our experience, are considered to possess low to medium potential for expansion. 4.2 Qvop13 – Very Old Paralic Deposits (as mapped per Kennedy, P., et. al., 2007) Paralic deposit material was found to underlie the topsoil/fill/weathered profiles material within the exploratory test pit excavations. The encountered paralic deposit material consists of light brown with reddish staining, dry to moist, dense, silty sands and sandy silts. These materials are considered suitable for the support of structures and structural improvements, provided the recommendations of this report are followed. These materials classify as SW - SM per the Unified Soil Classification System, and based on visual observation, are considered to possess a low to medium potential for expansion. Detailed logs of our exploratory test pits, as well as a depiction of their locations, please see the Figures section attached herein. 5.0 GEOLOGIC HAZARDS 5.1 FAULTS Our review of geologic literature pertaining to the general site area indicates the subject site is not within a mapped Alquist-Priolo fault zone. It is our opinion that the site could be subjected to moderate to severe ground shaking in the event of a major earthquake along any of the faults in the Southern California region. The seismic risk at this site is similar to that of the surrounding developed area. 5.2 LIQUEFACTION, LATERAL SETTLEMENT, SUBSIDENCE Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose, granular soils underlain by a near-surface ground water table are Hague Residence Page No. 3 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and the lack of near surface water, the potential for lateral spreading, liquefaction, subsidence or seismically induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced by adhering to the most recent edition of the California Building Code and current design parameters of the Structural Engineers Association of California. 5.3 TSUNAMI Tsunami are sea waves generated by submarine earthquakes, landslides, or volcanic activity. Submarine earthquakes are common along the edge of the Pacific Ocean and coastal areas are subject to potential inundation by tsunami. Most of the tsunamis recorded on the San Diego Bay tidal gauge have only been a few tenths of a meter in height. The possibility of a destructive tsunami along the San Diego coastline is considered low. Tsunami or storm waves (associated with winter storms), even in conjunction with high tides, do not have the potential for inundations of the site. 5.4 SLOPE STABILITY As part of the preparation of this report we have reviewed geologic maps of the subject area. Our review of geologic maps does not indicate landslide deposits at the area in and around the subject site. 6.0 GROUND WATER Static ground water was not encountered during our limited subsurface investigation. However, perched groundwater conditions can develop and change over time, where no such condition previously existed and can have a significant impact. Waterproofing membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are encountered during site excavations, a slab underdrain system may be required. Trenches below slab should be detailed with perimeter and trench cut-off walls keyed into competent material. 7.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Based upon our review of preliminary project plans, we understand the proposed improvements will include a new, two-story, single-family residence, and associated hardscape & landscape improvements. In general, it is our opinion that the proposed new structure and improvements, as discussed and described herein, are feasible from a geotechnical standpoint, provided the recommendations of this report and all applicable codes are followed. Hague Residence Page No. 4 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS • Based upon our subsurface investigation, competent material is anticipated at approximate depths of 2 to 3 feet below existing grades. • We anticipate new shallow foundations and new slab-on-grade floors for the proposed improvements. New shallow foundations and new slab-on-grade floors shall be founded in competent re-compacted material. • Based upon our review of the preliminary grading plans we anticipate a new graded building pad which will include new fill slopes/site retaining walls to the west and south of the proposed residence. • We recommend the removal and re-compaction of the upper 3 feet of material in the area of the proposed improvements. We anticipate a portion of the graded pad will require localized undercutting. • Any changes in the proposed design should be reviewed by this office for any revisions to the recommendations herein. 8.0 GRADING AND EARTHWORK We anticipate grading and earthwork operations for the proposed residence will include the removal and re-compaction of the upper 3 feet of material in the area of new improvements, and the creation of a new fill slope and/or site retaining walls to the west and south, as part of the creation of the building pad. As part of pad preparation, we anticipate the removal of all unsuitable material in the area of the proposed improvements. All grading shall be done in accordance with the recommendations below as well as Appendix B of this report and the standards of county and state agencies, as applicable. 8.1 Site Preparation Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly disposed of off-site prior to the commencement of any fill operations. Construction debris should not generally be mixed with fill soils. Holes resulting from the removal of debris, existing structures, or other improvements, should be filled, and compacted. Hague Residence Page No. 5 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 8.2 Removals In areas of new proposed structures, topsoil/fill/weathered profiles found to mantle the site, are not suitable for the structural support of buildings or structural improvements in their present state. We anticipate grading will consist of the removal of all unsuitable fill and weathered soil, approximately the upper 3 feet of material, scarification of bottom, moisture conditioning, the placement and re-compaction of fill material. New fills should be re-compacted to a minimum of 90 percent relative compaction (ASTM D1557 – latest edition). Grading operations may include the creation of new, limited, fill slopes. New fill slopes should include the creation of a keyway at the toe of all new fill slopes, canting and scarification of keyway bottom, benching, placement, and re-compaction of fill material per Appendix B. Where new retaining walls are constructed in lieu of fill slopes, footings shall extend through weathered & fill profiles. 8.3 Transitions All settlement sensitive improvements (including but not limited to building structures, site walls, etc.), should be constructed on a uniform building pad. We anticipate all improvements to be placed on competent re-compacted material. We do not anticipate undercuts. We anticipate undercuts at portions of the residence and garage; undercuts should extend a minimum of 5 feet (or to a distance at least equal to depth of fill) beyond the footprint of the proposed structures (including exterior columns) and settlement sensitive improvements. Undercuts shall be made a minimum of 3 feet, or to a minimum depth of half the depth of deepest fill. Undercut bottoms may require sloping at a minimum 1% to daylight and construction of a subdrain (reference Appendix B). We anticipate building foundations will be founded on competent re-compacted material or competent material. This condition needs to be verified in the field by a representative of our firm prior to placement of fill or improvements during site grading operations. 8.4 Fills/Backfill All fill/backfill material should be cleaned of loose debris and oversize material (material more than 6 inches in diameter), be brought to approximately +2% of optimum moisture content, and re-compacted to at least 90 percent relative compaction (based on ASTM D1557 – latest edition). Fills should generally be placed in lifts not exceeding 6 - 8 inches in thickness. Hague Residence Page No. 6 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Imported soils should have a low potential for expansion (E.I. < 50), free of debris and organic matter. Prior to importing soils, they should be visually observed, sampled, and tested at the borrow pit area to evaluate soil suitability as fill. Onsite materials are suitable for re-use as fill material during grading operations provided, they are free of contamination (construction debris and organics) and oversize material in excess of 6 inches in diameter. Utility trenches should be properly backfilled in accordance with the latest edition of Green Book standards. 8.5 Slopes Where new slopes are constructed, permanent slopes may be cut to a face ratio of 2:1 (horizontal to vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes shall be excavated in accordance with OSHA requirements and OSHA Alternative Sloping Plans and shall not undermine adjacent properties, public improvements, or any structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or other acceptable cover should be provided to increase the stability of slopes, especially during the rainy season (October thru April). 8.6 Driveways and Flatwork In the areas of proposed new, rigid (i.e., concrete), driveways and exterior flatwork we recommend, the upper 12 inches of subgrade or finish grade shall be ripped a minimum of 12 inches, moisture conditioned to near optimum moisture content and compacted to 90% minimum relative compaction (ASTM D1557 – latest edition). Where flexible pavements are proposed, Engineering Design Group should be contacted for additional recommendations. (Please see our CONCRETE SLAB-ON-GRADE section for additional flatwork recommendations, and our INFILTRATION section for additional paver recommendations). 9.0 SEISMIC DESIGN PARAMETERS 9.1 2019 CBC Seismic Design Parameters Site Class D Seismic Design Category D Hague Residence Page No. 7 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Spectral Response Coefficients SS (g) 1.048 S1 (g) 0.381 SMS (g) 1.258 SDS (g) 0.839 10.0 SHALLOW FOUNDATIONS The following design parameters may be utilized for new foundations founded on competent re- compacted material. 10.1 Footings bearing uniformly in competent material may be designed utilizing maximum allowable soils pressure of 2,000 psf. 10.2 Bearing values may be increased by 33% when considering wind, seismic, or other short duration loadings. 10.3 The parameters in the table below should be used as a minimum for designing new footing width and depth below lowest adjacent grade into competent material. Footing depths are to be confirmed in the field by a representative of Engineering Design Group prior to the placement of form boards, steel, and removal of excavation equipment. No. of Floors Supported Minimum Footing Width *Minimum Footing Depth Below Lowest Adjacent Grade 1 15 inches 18 inches 2 15 inches 18 inches 3 18 inches 24 inches *Footings are anticipated to be founded in competent material. 10.4 All footings founded into competent material should be reinforced with a minimum of two #4 bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30 inches in depth, additional reinforcement, and possibly a stemwall system will be necessary, and should be reviewed by project structural engineer prior to construction. Hague Residence Page No. 8 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 10.5 All isolated spread footings should be designed utilizing the above given bearing values and footing depths and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction (3 inches above the ground). Isolated spread footings should have a minimum width and depth of 24 inches. 10.6 For footings adjacent to slopes a minimum of 10 feet horizontal setback in competent material or properly compacted fill should be maintained. A setback measurement should be taken at the horizontal distance from the bottom of the footing to slope daylight. Where this condition cannot be met, it should be brought to the attention of the Engineering Design Group for review. 10.7 All excavations should be performed in general accordance with the contents of this report, applicable codes, OSHA requirements and applicable city and/or county standards. 10.8 All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a minimum of 18 inches in depth prior to the pouring of concrete. 11.0 CORROSION AND VAPOR EMISSION 11.1 Resistivity and chloride testing of onsite samples from our subsurface investigation was conducted to evaluate corrosion potential to proposed improvements. Tests performed indicate that soils classify, according to ACI 318 standard, as category C1, and based upon laboratory results are considered mild to moderately corrosive to buried metals. Test results are included in Appendix C of this report. The project structural engineer to note increased concreted protection requirements for corrosive environments, as applicable. 11.2 Laboratory testing of onsite samples for water soluble sulfates, indicate soils classify, according to ACI 318 standard, as category S0, mildly to moderately corrosive due to sulfate attack to concrete structures. 11.3 In consideration of ACI standards and the corrosion potential of the onsite soils as indicated above, we recommend for moisture sensitive slabs, retaining walls and foundations (i.e., below grade walls/spaces, built interior environments, floor finishes) a concrete with a maximum water to cement ratio of 0.45 resulting in a compressive strength of 4,500 psi minimum (no special inspection required for water to cement ratio purposes, unless otherwise specified by structural engineer). Hague Residence Page No. 9 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 11.4 For non-moisture sensitive areas, we recommend concrete with a minimum compressive strength of 2,500 psi minimum. 11.5 Buried metals shall be protected, and a corrosion engineer should be consulted for appropriate mitigation recommendations. EDG is not an expert in corrosion protection. Design recommendations for the protection of improvements from corrosive environment shall be provided by the corrosion consultant. 11.6 Where onsite improvements propose the use of reclaimed water, onsite soils are to be considered highly corrosive to buried metals. Precautions should be taken to protect all buried metals. 11.7 Slab Underlayment: We recommend the following beneath proposed slab-on-grade floors. 11.7.a. For moisture-sensitive areas, we recommend a vapor barrier. 11.7.b. The slab underlayment for moisture-sensitive areas consists of a vapor barrier layer (15 mil) placed below the upper one-inch of sand. The vapor barrier shall meet the following minimum requirements: Permeance of less than 0.01 perm [grains/(ft²hr in/Hg)] as tested in accordance with ASTM E 1745 Section 7.1 and strength per ASTM 1745 Class A. 11.7.c. In areas of level slab on grade floors, we recommend a one-inch layer of coarse sand material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials, should be placed beneath the slab in moisture-sensitive areas, above the vapor barrier. There shall be not greater than a 2-inch difference across the sand layer. 11.7.d. The vapor barrier should extend down the interior edge of the footing excavations a minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed along all laps with the manufacturer’s recommended adhesive. Beneath the vapor barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in order to more uniformly support the slab, help distribute loads to the soils beneath the slab, and act as a capillary break. 11.8 The project waterproofing consultant should provide all slab underdrain, slab sealers and various other details, specifications and recommendations (i.e. Moiststop and Linkseal) at areas of potential moisture intrusion. Engineering Design Group accepts no responsibility for design or quality control of waterproofing elements of the building. Hague Residence Page No. 10 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 12.0 CONCRETE SLAB-ON-GRADE We anticipate new concrete slab-on-grade floors for the new structure will be placed on competent material. Where new slabs are proposed, we recommend the following as the minimum design parameters. 12.1 Interior concrete slab-on-grade: Minimum thickness of 5 inches and reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. Driveways: Minimum thickness of 5 inches and reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab. Exterior Flatwork: Minimum thickness of 4 inches and should be reinforced with #3 bars at 18 inches o.c. at the midpoint of the slab. 12.1.a. Slump: Between 3 and 4 inches maximum. 12.1.b. Aggregate Size: ¾ - 1 inch. 12.2 Adequate control joints should be installed to control the unavoidable cracking of concrete that takes place when undergoing its natural shrinkage during curing. The control joints should be well located to direct unavoidable slab cracking to areas that are desirable by the designer. 12.3 All required fills used to support slabs, should be placed in accordance with the GRADING AND EARTHWORK section of this report and the attached Appendix B, and compacted to 90 percent relative compaction (Modified Proctor Density, ASTM D-1557 – Latest Edition). 12.4 All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over optimum moisture content, to a minimum depth of 18 inches. 12.5 Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil movement, are subject to normal minor concrete cracking. To minimize expected concrete cracking, the following may be implemented: 12.5.a. Concrete may be poured with a 10-inch-deep thickened edge. Flatwork adjacent to top of a slope should be constructed with an outside footing to attain a minimum of 7 feet distance to daylight. 12.5.b. Concrete should be poured during cool (40 - 65 degrees) weather if possible. If concrete is poured in hotter weather, a set retarding additive should be included in the mix, and Hague Residence Page No. 11 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS the slump kept to a minimum. 12.5.c. Concrete should be constructed with tooled joints creating concrete sections no larger than 225 square feet. For sidewalks, the maximum run between joints should not exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected points of concrete shrinkage (such as male corners), with diagonal reinforcement placed in accordance with industry standards. 12.5.d. Isolation joints should be installed at exterior concrete where exterior concrete is poured adjacent to existing foundations. 12.5.e. Drainage adjacent to concrete flatwork should direct water away from the improvements. Concrete subgrade should be sloped and directed to the collective subdrain system, such that water is not trapped below the flatwork. 12.6 The recommendations set forth herein are intended to reduce cosmetic nuisance cracking. The project concrete contractor is ultimately responsible for concrete quality and performance and should pursue a cost-benefit analysis of these recommendations, and other options available in the industry, prior to the pouring of concrete. 13.0 RETAINING WALLS We anticipate new site retaining walls up to 5 feet may be utilized as part of the proposed graded pad construction. New retaining walls up to 5 feet may de designed and constructed in accordance with the following recommendations and minimum design parameters. 13.1 Retaining wall footings should be designed in accordance with the allowable bearing criteria given in the Foundations section of this report and should maintain minimum footing depths outlined in the Foundations section of this report. Any retaining wall footings are to be placed on competent material. Where cut-fill transitions may occur, alternative detailing may be provided by the Engineering Design Group on a case-by-case basis. 13.2 Unrestrained cantilever retaining walls should be designed using an active equivalent fluid pressure of 40 pcf. This assumes that granular, free draining material with low potential for expansion (E.I. <50) will be used for backfilling, and that the backfill surface will be level. Where soil with potential for expansion is not low (E.I. > 50) a new active fluid pressure will be provided Hague Residence Page No. 12 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS by the project soils engineer. Backfill materials should be considered prior to the design of the retaining walls to ensure accurate detailing. We anticipate onsite material may be utilized as retaining wall backfill, additional Expansion Index Testing may be conducted during site grading to confirm. 13.3 Where the backfill behind the wall is sloped at a maximum slope of 2:1 (H:V) an active equivalent fluid pressure of 55 pcf, shall be utilized. 13.4 Any other surcharge loadings shall be analyzed in addition to the above values. These surcharge loads shall include foundations, construction equipment, vehicular traffic, etc. 13.5 If the tops of retaining walls are restrained from movement, they should be designed for a uniform at-rest soil pressure of 60 psf. 13.6 Retaining walls shall be designed for additional lateral forces due to earthquake, where required by code, utilizing the following design parameters. 13.6.a. For unrestrained, retaining walls with level backfill, we recommend an additional seismic load of 15H applied as a uniform load. The resultant load should be applied a distance of 0.5H from the bottom of the footing. 13.6.b. For unrestrained, retaining walls with sloped backfill up to 2:1 slope, we recommend an additional seismic load of 18H applied as a uniform load. The resultant load should be applied a distance of 0.5H from the bottom of the footing. 13.6.c. The unit weight of 125 pcf for the onsite soils may be utilized. 13.6.d. The above design parameters assume unsaturated conditions. Retaining wall designs for sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall or waterfront conditions) will require special design considerations and should be brought to the attention of Engineering Design Group. 13.7 Passive soil resistance may be calculated using an equivalent fluid pressure of 325 pcf. This value assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the height of the passive pressure wedge of the soil. Where the horizontal distance of the available passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value must be reduced by the percent reduction in available horizontal length. Hague Residence Page No. 13 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 13.8 A coefficient of friction of 0.32 between the soil and concrete footings may be utilized to resist lateral loads in addition to the passive earth pressures above. 13.9 All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be designed in accordance with the minimum standards contained in the "Retaining Wall Drainage Detail", Appendix D. The waterproofing elements shown on our details are minimums and are intended to be supplemented by the waterproofing consultant and/or architect. The recommendations should be reviewed in consideration of proposed finishes and usage, especially at the proposed basement levels, performance expectations and budget. 13.10 If deemed necessary by the project owner, based on the above analysis, and waterproofing systems can be upgraded to include slab under drains and enhanced waterproofing elements. 13.11 In moisture sensitive areas (i.e., interior living space where vapor emission is a concern), in our experience poured-in-place concrete provides a surface with higher performance-repairability of below grade waterproofing systems. The developer should consider the cost-benefit of utilizing cast in place building retaining walls in lieu of masonry as part of the overall construction of the commercial structure. Waterproofing at any basement floors is recommended in areas of moisture sensitive floor finishes. 14.0 POOL No new pool is proposed as part of the proposed development; however, in the case of a future pool, Engineering Design Group shall provide additional and specific pool recommendations. The following general pool design parameters are provided below. • Future pool and/or spa should be founded on a uniform building pad as outlined in the Earthworks / Transitions and the Foundations section of this report. • Depending upon future pool location, future pool excavations shall not undermine residence footings, slopes, or adjacent properties. Temporary shoring or other construction means may be necessary to accommodate future pool excavations. • Vanishing edge type pools or other pool designs that do not allow for ½”-1” differential, should be designed on a deepened/specialty foundation system. Hague Residence Page No. 14 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS • Flatwork around the proposed pool should be designed to be impervious and slope away from the pool to an area drain system. Additional recommendations may be necessary upon review of specific future pool plans. 15.0 INFILTRATION We understand that bioretention/infiltration facilities are not proposed at the time of this report. If bioretention/infiltration facilities are proposed, they be designed to maintain sufficient horizontal and vertical offset to the future structures to not create a groundwater condition. Infiltration facilities proposed within a 10-foot horizontal distance to a moisture sensitive structure should be lined with an impervious barrier, within the 10-foot zone. In cases where there is a vertical offset, wherein the bottom of the infiltration basin is detailed above the finish floor of the building, the impervious barrier should line the bottom of the basin or paver subgrade, such that the cumulative distance of the horizontal and vertical offset equal at a minimum the depth of the subterranean finish pad. Infiltration facilities should be offset from the top and toes of any slopes steeper than a 3:1 or lined with an impervious barrier. At tops of slopes minimum horizontal distance of 10 feet or a horizontal distance equal to the height of the slope, measured from the edge of infiltration basin to slope, up to a maximum of 40 horizontal feet. At the toe of new fill slopes infiltration facilities shall maintain a minimum 10 feet horizontal offset to not undermine the stability of the slope. New retaining walls to support proposed slope might be necessary where infiltration/retention basins are located at toes of slopes. Where pervious paver subgrade is located adjacent to the building, paver subgrade shall be sloped away at 2% should be lined with an impervious liner a minimum horizontal distance of 5 feet from building. Permeable paver subgrade shall be sloped 2% minimum to a perforated subdrain, gravel filled (1cf/ft), wrapped in a filter fabric, permeable pavers shall be detailed with reinforced concrete edge restraints and horizontal restraints. Where permeable paver driveways are utilized in sloped conditions, cut-off wall detailing should also be anticipated. In addition to the above details, specific paver detailing should be detailed and constructed per the minimum recommendations of the specific paver manufacturer as well as the Interlocking Concrete Paver Institute including minimum bedding specifications, base and subgrade requirements, installation tolerances, and drainage, etc. Where runoff and storm water is directed over permeable pavements and water is anticipated to flow through pavers into an aggregate base near and adjacent to foundations, basements or other structures, additional detailing shall include systems to control and to prevent subsurface flow beneath the building. Generally, these systems, detailed as part of the specific building construction plans, may include the cut-off walls and underdrains. Hague Residence Page No. 15 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS Proper surface drainage and irrigation practices will play a significant role in the future performance of the project. Please note in the Corrosion and Vapor Emission section of this report for specific recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The project architect and/or waterproofing consultant shall specifically address waterproofing details. 16.0 SURFACE DRAINAGE Adequate drainage precautions at this site are imperative and will play a critical role on the future performance of the proposed improvements. Under no circumstances should water be allowed to pond against or adjacent to tops of slopes and/or foundation walls. The ground surface surrounding proposed improvements should be relatively impervious in nature, and slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal distance of 10 feet (where possible). Area drains or surface swales should then be provided in low spots to accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed on the new and existing structures and tightlined to the area drain system. All drains should be kept clean and unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for proper drainage. Over watering can adversely affect site improvements and cause perched groundwater conditions. Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices and maintenance of irrigation and drainage systems are an important component to the performance of onsite improvements. During periods of heavy rain, the performance of all drainage systems should be inspected. Problems such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly controlled or avoided. 17.0 LABORATORY TESTING Laboratory tests were performed on samples of onsite material collected during our subsurface investigation. Test results are attached as Appendix C. Hague Residence Page No. 16 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 18.0 CONSTRUCTION OBSERVATION AND TESTING The recommendations provided in this report are based on subsurface conditions disclosed by the investigation and our general experience in the project area. Interpolated subsurface conditions should be verified in the field during construction. The following items shall be conducted prior/during construction by a representative of Engineering Design Group in order to verify compliance with the geotechnical and civil engineering recommendations provided herein, as applicable. The project structural and geotechnical engineers may upgrade any condition as deemed necessary during the development of the proposed improvement(s). 18.1 Review of final approved grading and structural plans prior to the start of work for compliance with geotechnical recommendations. 18.2 Attendance of a pre-grade/construction meeting prior to the start of work. 18.3 Observation of keyways, subgrade, and excavation bottoms. 18.4 Testing of any fill placed, including retaining wall backfill and utility trenches. 18.5 Observation of footing excavations prior to steel placement and removal of excavation equipment. 18.6 Field observation of any "field change" condition involving soils. 18.7 Walk through of final drainage detailing prior to final approval. The project soils engineer may at their discretion deepen footings or locally recommend additional steel reinforcement to upgrade any condition as deemed necessary during site observations. Engineering Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above inspections have been conducted by a representative of their firm, and the design considerations of the project soils report have been met. The field inspection protocol specified herein is considered the minimum necessary for Engineering Design Group to have exercised due diligence in the soils engineering design aspect of this building. Engineering Design Group assumes no liability for structures constructed utilizing this report not meeting this protocol. Before commencement of grading the Engineering Design Group will require a separate contract for quality control observation and testing. Engineering Design Group requires a minimum of 48 hours’ notice to mobilize onsite for field observation and testing. Hague Residence Page No. 17 Cynthia Lane (APN: 156-231-70), Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS 19.0 MISCELLANEOUS It must be noted that no structure or slab should be expected to remain totally free of cracks and minor signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils, or the motions induced from seismic activity. All of the above can induce movement that frequently results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab finishes. Data for this report was derived from surface and subsurface observations at the site and knowledge of local conditions. The recommendations in this report are based on our experience in conjunction with the limited soils exposed at this site. We believe that this information gives an acceptable degree of reliability for anticipating the behavior of the proposed improvement; however, our recommendations are professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits of the obtained data, is herein expressed or implied. This report is based on the investigation at the described site and on the specific anticipated construction as stated herein. If either of these conditions is changed, the results would also most likely change. Man-made or natural changes in the conditions of a property can occur over a period. In addition, changes in requirements due to state-of-the-art knowledge and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to these changes. Therefore, this report for the specific site, is subject to review and not considered valid after a period of one year, or if conditions as stated above are altered. It is the responsibility of the owner or his/her representative to ensure that the information in this report be incorporated into the plans and/or specifications and construction of the project. It is advisable that a contractor familiar with construction details typically used to deal with the local subsoil and seismic conditions be retained to build the structure. If you have any questions regarding this report, or if we can be of further service, please do not hesitate to contact us. We hope the report provides you with necessary information to continue with the development of the project. FIGURES FIGURE 1 Vicinity Map Site Location Project: Hague Residence Address: Cynthia Lane (APN:156-231-70), Carlsbad, California EDG Project No:216614-1 ENGINEERING DESIGN GROUP 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 FIGURE 2 Site Map Site Location Project: Hague Residence Address: Cynthia Lane (APN:156-231-70), Carlsbad, California EDG Project No:216614-1 ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 FIGURE 3 Site and Approximate Location of Exploratory Test Pits Test Pits Not to Scale TP1 TP2 Project: Hague Residence Address: Cynthia Lane (APN:156-231-70), Carlsbad, California EDG Project No:216614-1 ENGINEERING DESIGN GROUP www.designgroupca.com ]'• ) -· -o- 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 ~ (") l'T1 r ~-- -- ..... ,, ? _,,., '! 6 ' :~ . I =· ; l'l j t J 'l'l I . '' ~:1 I i I ' I ):,.. - 15 ~ Project Name: Hague Residence TEST PIT LOG N O. 1 EDG Project 216614-1 Number: Location: See Figure 3 -Location of Test Pits Sheet 1 of 1 Date(s) Total Depth: Groundwater Excavated: 8/27/2021 3.5' Level: Not encountered Logged By: ER/RM Approx. Surface Backfilled Elev. Finished Grade (date) Same Day Excavation Method: Hand Dug Soil Type Depth Material Description and Notes ucsc Sample TOPSOIL, FILL, WEATHERED A 0-2.0' Brownish gray to light brown, dry, loose to dense, silty sands and sandy silts SW-SM Bulk with roots/organics VERY OLD PARALIC DEPOSITS B 2.0' -3.5' Light brown with reddish staining, dry to slightly moist, dense to very dense, SW-SM -- silty sand and sandy silt GRAPHIC REPRESENTATION FT. B.A.G. I FG 1 - 2 - 3 - 4 - 5 - 6 Project Name: Hague Residence TEST PIT LOG N O. 2 EDG Project 216614-1 Number: Location: See Figure 3 -Location of Test Pits Sheet 1 of 1 Date(s) Total Depth: Groundwater Excavated: 8/27/2021 5.5' Level: Not encountered Logged By: ER/RM Approx. Surface Backfilled Elev. Finished Grade (date) Same Day Excavation Method: Hand Dug Soil Type Depth Material Description and Notes ucsc Sample TOPSOIL, FILL, WEATHERED A 0-3.0' Brownish gray to light brown, dry, loose to dense, silty sands and sandy silts SW-SM Bulk with roots/organics in upper two feet. VERY OLD PARALIC DEPOSITS B 3.0' -5.5' Light brown with reddish staining, dry to slightly moist, dense to very dense, SW-SM -- silty sand and sandy silt GRAPHIC REPRESENTATION -, ~ FT. B.A.G. FG ii © ..,_y y . ~" +_~ '\ ~ 1 , r _.) ) .,_ . . .,,,., 2 \>. "/\ ' ~--_,~-/-- \' '·.· ' 3 .. J',~,;. ... #"r~, ~ "'--:-'✓"~.,\ ··'"~(#.r I;.~'· ... ~ "" " .. ........ , ·( • '-. 1-\ 4 \ ; . \ ---, ~. '' \, ,. ,\ ' ' ~' - ' ' , r ..... ~:v.:g,··-----~---- ' ' ,.... r.. ' .. ... \ \ ' ... ' ' .. , ' ' 5 -• ; "' \ . .. ,.. r ~ 11-· ' \ '.... ' . -. \... ., ) -, ... ~····,; _ ..... • ... ··,,,. ' ... ;., ... \ C' .... T .. ~ '\ t3 '-_' h ' • / ' ,.,. ~'!:t. .. "' 6 APPENDIX A REFERENCES 1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page. 2. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special Publication 42, Revised 1990. 3. California Department of Conservation, Division of Mines and Geology, DMG Open-File Report 95-04, Landslide Hazards in the Northern Part of the San Diego County Metropolitan Area, San Diego County, California – Landslide Hazard Identification Map No. 35 – Encinitas Quadrangle (Plate D), dated 1995. 4. Ciremele Surveying Inc., Topographic Survey for Parcel 3, PM 19753 – Cynthia Lane, Carlsbad CA 92008. 5. Day, Robert W. 1999. Geotechnical and Foundation Engineering Design and Construction. McGraw Hill. 6. Engineering Design Group, Preliminary Grading Plans, dated 10-18-2021. 7. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines and Geology, Map Sheet 23. 8. Kennedy, Michael P., Geologic Map of the Oceanside 30x60 Minute Quadrangle, California, dated 2007. 9. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of Natural History John Porter Dexter Memorial Publication. 10. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California Geology, Vol. 27, No. 9, P. 195-199. 11. State of California, Fault Map of California, Map No. 1, Dated 1975. 12. State of California, Geologic Map of California, Map No. 1, Dated 1977. 13. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar Presentation on Seismically Induced Earth Pressure, June 8, 2006. 14. Unnamed, Preliminary concept plans, undated. 15. U.S. Army Corps of Engineers, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data Report, Portuguese Point to Mexican Border, dated December 1985. 16. U.S. Army Corps of Engineers, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments, San Diego Region (CCSTWS 87-2), dated June 1985. 17. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott, W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook. 18. Various Aerial Photographs. APPENDIX B General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with the applicable grading codes and agency ordinances, recommendations in the geotechnical report and the approved grading plans not withstanding the testing and observation of the geotechnical consultant If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction shouls be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparations of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor / civil engineer should be utilized. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back, blended and / or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material and moisture-conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. 4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension of greater than 6 inches, should not be buried or placed in fills, unless the location, materials and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as necessary to attain a uniform moisture content near optimum. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of fill out to the slope face would be at least 90 percent. 5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed at the consultant’s discretion based on file dconditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces, as a guideline approximately one test should be taken for every 5,000 square feet of slope face and /or each 10 feet of vertical height of slope. 6.0 Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall be allowed for the survey, prior to commencement of filling over the subdrains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized. SIDE HILL STABILITY FILL DETAIL FINISHED SLOPE FACE PROJECT 1 TO 1 LINE FROM TOP OF SLOPE TO OUTSIDE EDGE OF I< EY OVERBURDEN OR UNSUITABLE MATERIAL EXISTING GROUND -- SURFACE~ -------- ,,,...---.,,,,,. / ,.,,.,... / .,,...,,.. / .,,...,,.. / __ ,.,,.,... / ..,,,-- ,,,,,., ✓ / / FINISHED CUT PAO / / -------MP_A_CTeo-:-= _-:f:f:§:j:j f !J....L_p::-- ~ ·-----------I -------------------------PAO OVEREXCAVATION DEPTH ANO RECOMPACTION MAY BE RECOMMENDED BY THE GEOTECHNICAL CONSUL TANT BASED ON ACTUAL FIELD CONOIT-IONS-.ENCOUNTERED. ( COMPETENT BEDROCK OR MATERIAL AS EVALU~TEO BY THE GEOTECHNICAL CONSULTANT NOTE: Subdrain details and key width recommendations to be provided based on exposed subsurface conditions STABILITY FILL / BUTTRESS DETAIL OUTLET PIPES ,4• ~ NONPERFORATEO PIPE, 100' MAX. O.C. HORIZONTALLY, 30' MAX. O.C. VERTICALLY -~-=-~ KEY DEPTH --::COl,il'A-CI::J --=---==~~~~==~~~:-~:~~::~=~~=.-.... -. ..---- 2 ~\\I MIN. f ---------_21'-~~-====~~~~~- ll~I I KEY WIDTH j AS NOTED ON .GRADING PLANS 15' MIN. e• MIN. 31,4•-1-112· CLEAN GRAVEL (3ft~/ft. MIN. ... 9J NON-PERFORAT OVERLAP PIP~::-==--:~~=!ijii~;;,,:Jj --FIL TEA FABRIC ENVELOPE (MIRAFI 140N OR APPROVED EQUIVALENT)* . see T-CONNECTION DETAIL 4• ~ PERFORATED PIPE 4• MIN. BEDDING SUBDRAIN TRENCH DETAIL NOTES: SEE SUBDRAIN TRENCH DETAIL LOWEST SUBDAAIN SHOULD BE SITUATED AS LOW AS POSSIBLE TO ALLOW SUITABLE OUTLET r-----,. 1 O' MIN. PERFORATED I t · I EACH SIDE PIPE~• CAP NON-PER FORA OUTLET PIP T-CO.NNECTION DETAIL * IF CAL TRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 314•-1-112• GRAVEL, FILTER FABRIC MAY BE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size l" 3/4" 3/8" No. 4 No. 8 No. 30 No. SO No. 200 % Passing 100 90-100 40-100 25-40 18-33 5-15 0-7 0-3 Sand Equiva1ent>7S For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and aubdrain may be changed by the geotechnical consultant based on field conditions. SUBDAAIN INSTALLATION-Subdraln pipe should be Installed with perforations down as depicted. At locatlon, recommended by the geotechnical consultant, nonperforated pipe should be Installed SUBORAIN TYPE-Subdraln type should be Acrylon trlle Butadlene Styrene (A.B.S.), Polyvinyl Chloride (PVC) or approved equivalent. Class 125,SDR 32.5 should be used for maximum fill depths of 35 feet. Claaa 200, SOR 21 1hould be used for maximum fill depth• of 100 feet. KEY AND BENCHING DETAILS FILL SLOPE ~':.~~~~~ 6~ ~L~:: \\\~~!!! TO COMPl!TENT MATERI ~:;!.l.~~~::- EXIST1NG GROUND SURFAC 2' MIN.L15' MIN~ KEY ILOWEST--7 OEPTH BENCH (KEY) BENCH ACTEO=-:~ FILL-OVER-CUT SLOPE ILL~-----=- EXISTING ~ GROUND SURF ACE ) --------- --LO-WEST ...--MIN. BENCH D~~fH (KEY) CUT SLOPE (TO BE EXCAVATEO PRIOR TO FILL PLACEMENT) //~ CUT-OVER-FILL SLOPE PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING / / GROUND / / SURFACE~// K // ~l~.?' / I,, 1.,, ..... / -::,JI CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) NOTE: Back drain may be recommended by the geotechnical consultant based on actual field conditions encountered. Bench dimension recommendations may also be altered based on field conditions encountered. ROCK DISPOSAL DETAIL PIN&aH GRADE GRANULAR SOIL (S.E.~ 30) TO BE 0ENSIFIED IN PLACE BY FLOODING _ _;;:,,,.-c:::::..._ ___ __ DETAIL -------------------------------------------- -------------------------------------------- TYPICAL PROFILE ALONG WINDROW 1) Rock with maximum dimensions greater than 6 inches should not be used within 10 feet vertically of finish grade (or 2 feet below depth of lowest utility whichever is greater), and 15 feet horizontally of slope faces. 2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills. 3) Rock placement, flooding of granular soil, and fill placement should be observed by the geotechnical consultant. 4) Maximum size and spacing of windrows should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrows should be staggered vertically (as depicted). 5) Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. APPENDIX C Hague Residence Cynthia Lane, Carlsbad, California Job No. 216614-1 ENGINEERING DESIGN GROUP GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS LABORATORY RESULTS Method Cal-Trans Analyte Result Reporting Limit Units Dilution Method SULFATE 28.1 n/a ppm 1 CT 417 CHLORIDE 10.8 n/a ppm 1 CT 422 p.H. 6.90 n/a pH units 1 CT 643 RESISTIVITY 12900 n/a ohms.com 1 CT 643 ND=None detected – us/cm = micro-Siemens per centimeter - ppm-parts per million (10,000ppm=1% by weight) ENGINEERING DESIGN GROUP www.designgroupca.com 2121 Montiel Road, San Marcos, CA 92069 760.839.7302 APPENDIX D llll ENGINEERING DESIGN GROUP 2121 MONTIEL ROAD PHONE: {760) 839-7302 SAN MARCOS, CALIFORNIA 92069 FAX: {760) 480-74n CONC OR CMU----,__,.'----+-....,,__ RET WALL FER FLAN l DETAILS I-IYOROTITE WATER- STOFS AT COLO- JOINTS FER f"FR INSTALLATION INSTFi!LICTIONS SL.Al3 l VAPOR 1!3ARRIER FER FLAN l DETAILS MINIMUM WATEREfsQOFING SPECIFICATIONS (NOT TO SCALE) r.i\ FOAM UV PROTECTION BOARD FER \.V MANI.FACTURER'S SPECIFICATION GRACE FROCOR FLUID-APPLIED WATERFROCf=ING INSTALLED FER MANI.FACTURER'S SPECIFICATIONS l EXTEND E3EI-IINO CEMENTITOUS BACl<ER BOARD. f"i\ GRACE I-IYOROOUCT 22,J 0 INSTALLED FER MANI.FACTURER'S SFECIFICA TIONS OYER FLUID-APPLIED WA TERFROCf=ING (l) TEFNINATION f3AR FER MANLFACTURER'S SFECIFICA TIONS FILTER FAl3RIC WI 6" MIN LAP 314" GRA\iEL (I SF I FT) 4" DIA t=EFiFORATED DRAIN LINE (SCI-I 4,; OR EQJIVJ t=EFiFORATIONS ORIENTED DOILN IS MINIMUM GRADIENT TO SUITABLE OUTLET - EXACT PIPE LOCATION TO E3E OETEFiHINED er SITE CONSTRAINTS ® 4" TALL CONCRETE CANT • FTG I WALL CONNECTION (IK)ER WATERFROCf=INGJ. SLOPE TO 13ACI<. EDGE C1= FOOTING. ® ca-tPACTEO l3ACl<FILL ~ MIN RELATl\iE ca-tPACTION IN ALL OTI-IER AREAS U.O.N. 6 11 MAX LIFTS. ONLY LIGI-ITUEIGI-IT I-IANO-OFERA TED EQJIFMENT SI-IALL E3E USED WITI-IIN 3 FEET C1= Tl-IE 13ACI<. FACE C1= WALL.