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Home My WebLink AboutCDP 2020-0026; BEGONIA COURT RETAINING WALL; GEOTECHNICAL EVALUATION OF EXISTING MECHANICALLY STABILIZED EARTH WALLS; 2019-10-09FUSION ENGINEERING & TECHNOLOGY 4231 Balboa A venue, Suite 619 San Diego, CA 92117 Attention: John Rivera, PE .ADVANCED C?EOTECHNI CPJ... SOLLJTI ONS, I NC. '1' orporate Drive, Suite B Escondido, California 92029 Telephone: (6 I 9) 867-0487 Fax: (714) 409-3287 October 9, 2019 P/W 1907-03 Report No. 1907-03-B-3 Subject: Geotechnical Evaluation of Existing Mechanically Stabilized Earth Walls, 939 Begonia Court, City of Carlsbad, California References: See Appendix Gentlemen, Pursuant to your request, Geotechnical Solutions, Inc., (AGS) has prepared this letter summarizing the results of our geotechnical evaluation of the existing mechanically stabilized earth (MSE) walls located in the rear yard of the existing single-family residence located at 939 Begonia Court, City of Carlsbad, California. Also provided are recommendations for remediating the current conditions. AGS appreciates the opportunity to provide you with geotechnical consulting services on this project. If you have questions concerning this report, please do not hesitate to contact the undersigned at (619) 867- 0487. Respectfully Subm~tted, Advanced Geotechnical Solutions, Inc. £/v--- v AN, Geotechnical Engineer E 2790, Reg. Exp. 6-30-21 Distribution: (I) Addressee (pdf) MAR 2 3 2020 CITY er= CARLSBAD PLAN1 . 2 C.,'. PS.-1. ORANGE AND L.A. COUNTIES (714) 786-5661 INLAND EMPIRE (619) 867-0487 ~ J:J[J;2~ m\ULJ. DERISI, Vice President CEG 2536, Reg. Exp. 5-31-21 SAN DIEGO AND IMPERIAL COUNTIES (619) 867-0487 October 9, 2019 • P/W 1907-03 TABLE OF CONTENTS Page ii Report No~ 07-0 ,Jl- Page 1.0 INTRODUCTION .............................................................................................................. 1 1.1. Scope of Study ................................................................................................................ 1 1.2. Geotechnical Study Limitations ...................................................................................... l 2.0 SITE LOCATION AND DESCRIPTION .......................................................................... 2 3.0 SUBSURFACE INVESTIGATION ................................................................................... 2 4.0 ENGINEERING GEOLOGY ............................................................................................. 2 4.1. SiteGeology .................................................................................................................... 2 4.1.1. Undocumented Artificial Fill .................................................................................. 2 4.1.2. Very Old Paralic Deposits ...................................................................................... 3 4.2. Groundwater ................................................................................................................... 3 5.0 GEOTECHNICAL ENGINEERING .................................................................................. 3 5.1. Expansion Potential ........................................................................................................ 3 5.2. Shear Strength ............... : ................................................................................................. 3 5.3. Earthwork Adjustments .................................................................................................. 4 5.4. Relative Compaction of Artificial Fill Materials ............................................................ 4 5.5. Slope Stability ................................................................................................................. 4 6.0 CONCLUSIONS ................................................................................................................. 5 7 .0 Earthwork Recommendations ............................................................................................. 5 7.1. Site Preparation and Removals ....................................................................................... 6 7.2. Remediation Option Recommendations ......................................................................... 6 7.2.1. OPTION 1-MSE Wall System ............................................................................... 7 7.2.2. OPTION 2-Restore Slope with Reinforced Soil Slope .......................................... 7 7.2.3. Temporary Backcut Stability .................................................................................. 8 7.3. Geologic Observation During Grading ........................................................................... 9 7.4. Seepage ........................................................................................................................... 9 7.5. Earthwork Considerations ............................................................................................... 9 7.5.1. Compaction Standards ............................................................................................ 9 7.5.2. Benching ................................................................................................................. 9 7.5.3. Mixing and Moisture Control ............................................................................... 10 7.5.4. Haul Roads ............................................................................................................ 10 7.5.5. Import Soils ........................................................................................................... 10 7 .5.6. Fill Slope Construction ......................................................................................... 10 7.5.6.1. Overbuilding Fill Slopes ................................................................................... 10 7.5.6.2. Compacting the Slope Face .............................................................................. 11 7.5.6.3. Reinforced Soil Slopes ...................................................................................... 11 8.0 DESIGN RECOMMENDATIONS .................................................................................. I I 8.1. Mechanically Stabilized Earthen Wall Recommendations ........................................... I I , 8. I .1. Observation During Construction ......................................................................... 11 8.2. Civil Design Recommendations ................................................................................... I 2 9.0 SLOPE AND LOT MAINTENANCE .............................................................................. 12 9.1. SlopePlanting ............................................................................................................... 12 9 .2. Lot Drainage ................................................................................................................. 12 9.3. Slope Irrigation ............................................................................................................. 12 9.4. Burrowing Animals ....................................................................................................... 13 ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page iii Rep n.N ~ 07--- 10.0 CLOSURE ........................................................................................................................ 13 ATTACHMENTS: Figure 1 -Site Location Map Plate 1 -Boring Location Map Plate 2 -Geologic Cross Sections Appendix A -References Appendix B -Boring Logs Appendix C -Laboratory Test Results Appendix D -Slope Stability Analysis Appendix E-Earthwork Specifications and Grading Details ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Rep rtN . 1.0 INTRODUCTION Advanced Geotechnical Solutions, Inc., (AGS) has prepared this report which presents the results of our subsurface exploration and geotechnical evaluation of existing mechanically stabilized earth (MSE) walls located in the rear yard of the existing single-family residence located at 939 Begonia Court, City of Carlsbad, California. 1.1. Scope of Study The scope of this study included the following tasks: ► Review of pertinent published and unpublished geologic and geotechnical literature, maps, and aerial photographs (Appendix A, References). ► Geotechnical site reconnaissance to observe site conditions and select exploratory locations. ► Subsurface exploration consisting of four soil borings excavated with a tripod mounted limited access drill rig (Appendix B). ► Geotechnical laboratory testing on selected soil samples (Appendix C). ► Preparation of a plan (utilizing the 10-scale site plan as a base) showing the approximate locations of borings and geologic cross sections (Plate 1 ); ► Prepare geologic cross sections depicting the existing site conditions and anticipated geologic contacts (Plate 2). The proposed design is also shown; ► Compile and analyze data collected from our site reconnaissance, subsurface evaluation, and laboratory testing. Specifically, our analyses included the following: o Evaluation of general subsurface conditions and description of types, distribution, and engineering characteristics of subsurface materials; o Perform slope stability analyses of the existing as-graded/as-built condition. ► Provide recommendations on remediating the current conditions. ► Prepare this report describing the work performed, data acquired and our conclusions regarding the global stability of the existing tiered MSE wall system as well as providing recommendations on the repair of the existing slope and wall. 1.2. Geotechnical Study Limitations The conclusions and recommendations in this report are professional opm10ns based on information provided by involved parties and the data developed during this investigation. The conclusions presented herein are based on a limited geotechnical investigation. AGS did not provide geotechnical testing or observation services during site grading and wall construction. The materials immediately adjacent to or beneath those observed may have different characteristics than those observed. No representations are made as the quality or extent of material not observed. Any evaluation regarding the presence or absence of hazardous material is beyond the scope of this firm's services. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 2 Report No. l 9Q'.Z-Q.3-B-3 2.0 SITE LOCATION AND DESCRIPTION The subject site is located at 939 Begonia Court, City of Carlsbad, California and currently supports one single-family residence and associated improvements including an in-ground pool and Jacuzzi in the rear yard. The property is bounded on the west by Begonia Court and on the north, south, and east by existing single-family residences. Site topography ranges from flat to very gently sloping to the west in the lower building pad area and moderately sloping up to the east in the rear portion of the property. Elevations across the site range from approximately 165 feet above mean sea level (amsl) at the westerly property boundary to 200 feet amsl at the easterly property boundary. A majority of the rear slope has been graded to support the subject multi-tiered MSE wall system. Based on available information and review of historic satellite imagery, construction of the subject retaining walls began in 2016 and continued until recent months. The subject MSE walls were constructed with Keystone® Country Manor retaining wall blocks in a tiered manner with a maximum overall height of approximately 21 feet. Individual wall sections are approximately 5 feet in height and are horizontally separated by approximately 1 to 10 feet. Geogrid reinforcement (Miragrid® 2XT) appears to have been placed at 1-foot vertical increments. Length of the geogrid reinforcement is reported to be 4 feet. The walls appear to be generally founded in formational materials with the exception of a portion of the lowest wall adjacent to the pool which is founded upon a pre-existing masonry wall. At the time of our site exploration, the uppermost wall was partially constructed. Groundwater seepage was observed coming through the southerly portion of the uppermost wall. 3.0 SUBSURFACE INVESTIGATION On July 18, 2019, AGS conducted subsurface exploration at the subject site. Four (4) exploratory borings (B-1 through B-4) were excavated with a tripod drill rig to depths ranging from 5.5 to 16.5 feet below ground surface (bgs). The materials encountered in the borings were logged by our field personnel. The boring logs are presented in Appendix B. Upon COf.Rl~ion, the borings were backfilled with soil cuttings. The approximate boring locations are shown on ~ 11, Boring Location Map. Bulk and relatively undisturbed ring samples of the soils were obtained from the borings at various depths in an effort to evaluate lithologic changes and onsite geology at the study site. Soil samples were transported to AGS ' laboratory and tested for in-situ unit weight and moisture content, shear strength, and maximum density and optimum moisture content. Laboratory results are presented in Appendix C. 4.0 4.1. ENGINEERING GEOLOGY Site Geology Current published regional geologic maps indicate the site is underlain by Very Old Paralic Deposits (Kennedy, M.P., and Tan, S.S., 2007). The following is a brief description of the geologic units encountered during our geotechnical exploration. A geologic cross section showing approximate distribution of geologic units encountered onsite is presented on Plate 2. 4.1.1. Undocumented Artificial Fill Undocumented artificial fill materials were encountered extending to depths ranging from 3 feet to 7 feet onsite. These soils appear to be locally derived and generally consist of ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 3 Repmt No. l 901-03-B-3 light yellow brown, silty sand with gravel and cobbles. The artificial fill is generally in a dry to slightly moist and loose to moderately dense condition. 4.1.2. Very Old Paralic Deposits Very old paralic deposits were encountered beneath fill soils to the maximum depth explored. As encountered, these soils generally consist of dark yellow brown to orange brown, silty sand with trace clay in a slightly moist to moist and moderately dense to dense condition. 4.2. Groundwater 5.0 Groundwater was not encountered during our subsurface investigation. No natural groundwater condition is known to exist at the site. However, seepage was observed coming through the uppermost wall near the southerly property boundary. Based on our observations, the seepage does not appear to be naturally occurring and is most likely related to drainage and/or irrigation water from the easterly superjacent residence. It should be noted that localized perched groundwater may develop at a later date, most likely at or near fill/bedrock contacts, due to fluctuations in precipitation, irrigation practices, or factors not evident at the time of our field explorations. GEOTECHNICAL ENGINEERING Presented herein is a general discussion of the geotechnical properties of the various soil types and the analytic methods used in this report. 5.1. 5.2. Expansion Potential Expansive soils are characterized by their ability to undergo significant volume changes (shrink or swell) due to variations in moisture content. Changes in soil moisture content can result from precipitation, landscape irrigation, utility leakage, roof drainage, perched groundwater, drought, or other factors and may result in unacceptable settlement or heave of structures or concrete slabs supported on grade. Based on our laboratory testing, it is anticipated that the expansion potential of the onsite materials will be "Very Low" to "Low". Shear Strength Based on our laboratory test results and previous experience in the area with similar soils, the following shear strengths for undocumented artificial fill, engineered artificial fill, and very old paralic deposits are presented on Table 5.2. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Re Page 4 N . 1 .07-02~-3 TABLE 5.2 RECOMMENDED SHEAR STRENGTHS FOR DESIGN Cohesion Friction Angle Total Unit Material Weight (psf) (degrees) (pcf) Artificial Fill, Undocumented (Existing) 50 27 120 Artificial Fill, Engineered (Proposed) 50 30 125 Very Old Paralic Deposits 150 31 125 5.3. Earthwork Adjustments The following average earthwork adjustment factors are presented for use in evaluating earthwork quantities. These numbers are considered approximate and should be refined during grading when actual conditions are better defined. Contingencies should be made to adjust the earthwork balance during grading if these numbers are adjusted. TABLE 5.3 Earthwork Adjustments Geologic Unit Approximate Range Existing Fill 15 to 25 percent shrinkage Very Old Paralic Deposits 0 to 10 percent bulk 5.4. Relative Compaction of Artificial Fill Materials 5.5. Some of the fill materials were observed to be loose and dry to slightly moist. Test results indicated that some of the artificial fill materials have relative compactions that are less than 90 percent when compared to the maximum dry density (ASTM D 1557). Slope Stability Slope stability analyses were performed on representative cross-sections and considered both static and pseudo-static conditions to evaluate global stability. AGS evaluated the global stability of the tiered MSE retaining walls using GSTABL 7. Geogrid reinforcement was added at a spacing schedule that the owner provided AGS. Per the owner, Mirafi Miragrid 2XT was placed every 12 inches vertically and extended 48 inches beyond the wall. The Long Term Design Strength was used as provided by the geogrid manufacturer. Searches were conducted in GST ABL 7 to find the critical failure surface with the lowest factor of safety. The factor of safety was calculated using the Bishop method (circular failures). A pseudo-static analysis was used to evaluate the stability of slopes under seismic loading. A horizontal destabilizing seismic coefficient (kh) of 0. 15 was selected for the site. The critical failure surface that was determined for the static analysis was also selected for the pseudo-static analysis, and the factor of safety was calculated using the Bishop method (circular failures). ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 5 . 19Q7-Jl3-R-3 6.0 The results of the global stability analyses are presented in Appendix C. Based on the results of the analysis, the existing MSE retaining wall system has a slope stability Factor of Safety of less than 1.5 for static conditions and less than 1.0 for seismic conditions. The failure surfaces were shallow and indicate a potential for shallow or localized failures. Typically, the standard of practice in southern California, and has been adopted by most agencies, is to show that slopes have a slope stability factor of safety of 1.5 or greater for static conditions and 1.1 or greater for seismic conditions. AGS also conducted a stability analysis using a proposed design profile consisting of a new toe- of-slope MSE wall, ascending slope and mid-slope MSE wall. This design profile is considered preliminary since the civil engineer has not yet prepared grading plans for the site remediation. The proposed design has factor of safety is greater than 1.5 for static conditions and 1.1 for seismic conditions, which both meet the minimum recommended factors of safety. CONCLUSIONS Based on the information gathered and the analyses performed, it is our professional opinion that the existing tiered MSE wall system will not meet current code standards as adopted by the City of Carlsbad. The following two items will need to be mitigated in order to meet the current standards. 7.0 ► The fill has not been compacted to a minimum of 90 percent of the relative compaction. Typically, fill should be compacted to a minimum of90 percent of the relative compaction as determined by ASTM Dl557, or as recommended by the geotechnical consultants. If settlement and material strength is not a concern, then perhaps a lesser relative compaction may be permissible. However, the shear strength of fill would expected to improve with increased compaction. ► The tiered wall system does not possess an adequate factor of safety for long term global stability. Typically, a minimum factor of safety of 1.5 is needed for long term stability and 1.1 for seismic stability. Mitigation may be needed to improve the stability of the system and demonstrate that the slope and wall system has an adequate factor of safety. The existing geogrid lengths are not adequate for the overall height of the system. EARTHWORK RECOMMENDATIONS It is recommended that the existing MSE wall system be remediated to meet current code standards. AGS considered three options of remediation, described below. I. NEW MSE WALL SYSTEM: Remove the existing MSE walls and undocumented fill. Replace with a new MSE wall system and slope. A five-foot wall can be constructed at the toe of the slope, with a proposed ascending fill slope located above the wall and a new MSE wall constructed near the top of the fill slope. Detailed recommendations are provided herein on constructing this option. 2. RESTORE SLOPE WITH REINFORCED SOIL SLOPE: Remove the existing MSE walls and undocumented fill. Restore the existing slope by constructing a keyway at the bottom and fill slope. Portions of the new slope will need to be steeper than 2: 1 (H: V), which is typically the steepest that is recommended without reinforcement. For the portions that are steeper than 2: 1, ADVANCED GEOTECHNICAL SOLUTIONS. INC. r • October 9, 20 I 9 P/W 1907-03 Page 6 ReprutNo. 1907-03-B-3. reinforcement should be added consisting of primary and secondary geogrid layers. Reinforced soil slopes are typically more difficult to construct than unreinforced slopes and are typically much more expensive. Due to the limited space for stockpiling, the reinforced soil slope will need to be constructed in sections. Difficulty should be expected when tying each section together, which will increase construction costs. They reinforced soil slopes should be constructed by an experienced contractor. Repair recommendations are provided herein. 3. REINFORCEMENT OF EXISTING SYSTEM: The existing tiered system can be left-in-place with a considerable reinforcement effort. AGS has met with a specialty geotechnical contractor to discuss possible repair options. Such an effort is expected to consist of building a reinforced shotcrete wall in front of each MSE wall. The MSE wall will be cored and a tight spacing of anchors will be drilled through the walls into the formational materials. The MSE walls will need to be cored at each anchor location. The anchor will be connected to the shotcrete wall. The MSE walls will essentially be used as form work for the shotcrete and anchor wall system. Due to the limited access, constructing the shotcrete wall and drilling will be completed with small equipment and is expected to take a considerable amount of time to complete. This system would need to be designed by a licensed engineer familiar with these systems. It is our understanding that additional information is being gathered by homeowner in regard to this remediation option. If the homeowner opts to remediate the as-built/as-graded condition through reinforcement of the existing wall system, additional geotechnical analyses should be performed and repair recommendations provided in a supplemental report. A possible configuration of repair option I is shown on the attached geologic cross-sections. The civil engineer will need to provide a grading plan if this option is selected. An MSE wall plan with supporting calculations may need to be prepared by a licensed engineer. It is possible that Keystone may have standard wall plans that can be used in lieu of a site-specific design. 7.1. 7.2. Site Preparation and Removals All grading shall be accomplished under the observation and testing of the project Geotechnical Consultant in accordance with the recommendations contained herein, the current codes practiced by the City of Carlsbad and this firm's Earthwork Specifications (Appendix E). Existing vegetation, trash, debris, and other deleterious materials should be removed and wasted from the site prior to commencing removal of unsuitable soils and placement of compacted fill materials. The existing retaining walls on the slope should be removed. Within the limits of grading, existing undocumented fill materials and highly weathered Very Old Paralic Deposits should be removed until competent Very Old Paralic Deposits are encountered. In general, the removed materials are suitable to be reused as compacted fill provided deleterious materials are removed. Remediation Option Recommendations The following sections provide preliminary recommendations for Options I and 2, as discussed in Section 7.0 above, to remediate the existing as-graded/as-built condition. Recommendations for Option 3, if requested, can be provided in a supplemental geotechnical report. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 7 ReportN . 907--- 7.2.1. OPTION 1-MSE Wall System MSE walls can be constructed near the toe of the slope. The wall should not be constructed atop or near the influence of the existing cantilever retaining walls. The lower MSE wall should have geogrid lengths of not less than 8 feet. The limits of the geogrid should be extended to the backcut, even if shorter geogrid lengths are shown on the wall plans. A minimum horizontal fill width of 8 feet should be maintained on the slope. The fill slope can be constructed as described in Section 7.5 .6. A minimum of 1 subdrain should be installed at the toe of the slope. A second drain may also be needed behind the upper MSE retaining wall. The MSE retaining walls should be embedded as recommended by the designer, but no less than 12 inches at the toe of the slope. MSE walls installed above descending slope should be embedded so that the daylight distance from the bottom of the wall to the slope face is at least 5 feet. 7.2.2. OPTION 2-Restore Slope with Reinforced Soil Slope A stabilization keyway should be constructed at the toe of the proposed slope. The limits of this keyway should be based on the final slope design, but should be no less than 12 feet wide. Reinforced soil slopes (RSS) should be constructed on fill slopes steeper than 2: 1. The grading contractor should have experience in the construction of a RSS. There are several methods on constructing a RSS, such as using temporary wooden formwork or permanent wire mesh forms (See Figure 7.2.2, below), and the grading contractor should select the most economical method of construction. The construction method should allow for the fill to be compacted out to the slope face without damaging the reinforcement. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 20 I 9 P/W 1907-03 WIRE MESI-I FACING OR TEMPORARY FORMWORK VEGETATION WIRE MESH FACING-c-'·-···-··-- OR TEMPORARY FORMWOR K "' Page 8 ort.l\Jo. 190-7-01-B-3 ···-·--·,...---SECONDARY REINFORCEMENT WRAP ·-PRIMARY REINFORCEMENT ---· ---GEOTEXTI LE WRAP AT FACE Figure 7.2.2 Alternative Methods ofRSS Construction (from TenCate™ 2010a) The primary reinforcement can include placing layers of Mirafi Miragrid 3XT ( or approved equivalent) every 4 feet vertically starting from the bottom of the keyway. The primary geogrid layers should extend from the slope face to the backcut. The primary geogrid should be oriented so that the primary strength is perpendicular to the slope face. Splices in the primary direction should be avoided. A secondary layer of reinforcement consisting of Mirafi Miramesh TR (or approved equivalent) should be wrapped around the slope face and embedded a minimum of 5 feet with a maximum vertical spacing of 18 inches. The Miramesh vertical spacing can be reduced to every 2 to 4 feet if the primary geogrid layer is wrapped on the outside of the Miramesh and the primary geogrid is embedded a minimum of 8 feet as measured from the slope face. Geogrid reinforced slopes are expected to be globally and surficially stable to inclinations up to 1:1 (H:V). Splicing of the secondary layer shall not be conducted. 7.2.3. Temporary Backcut Stability During grading operations, temporary backcuts will be required to accomplish removals and provide room to place geogrid. Care should be taken during backcut construction and backfill should be placed expeditiously in order to minimize risk of failure. Complete removal of the failed materials will be required should failure occur. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 9 Re.12ort No. 1907-03-B-3 7.3. Backcuts exposing competent Very Old Paralic Deposits should be made no steeper than 1 : 1 to heights of up to 20 feet. Steeper backcuts may be possible for small sections but should be evaluated by AGS. Shallower backcuts are recommended below existing walls or within undocumented fill. Close geologic mapping of the stabilization and buttress key backcuts should be provided to document the exposed conditions. Revised recommendations may be necessary should areas of instability be encountered. In consideration of the inherent instability created by temporary construction of backcuts, it is imperative that grading schedules be coordinated to minimize the unsupported exposure time of these excavations. Once started these excavations and subsequent fill operations should be maintained to completion without intervening delays imposed by avoidable circumstances. In cases where five-day workweeks comprise a normal schedule, grading should be planned to avoid exposing at-grade or near-grade excavations through a non-work weekend. Where improvements may be affected by temporary instability, either on or offsite, further restrictions such as slot cutting, extending work days, implementing weekend schedules, and/or other requirements considered critical to serving specific circumstances may be imposed. Geologic Observation During Grading All temporary slope excavations, including front, side and backcuts, and all cut slopes should be mapped to verify the geologic conditions that were modeled prior to grading. 7 .4. Seepage Seepage, if encountered during grading, should be evaluated by the Geotechnical Consultant. If seepage is excessive, remedial measures such as horizontal drains or under drains may need to be installed. 7.5. Earthwork Considerations 7.5.1. Compaction Standards All fills should be compacted at least 90 percent of the maximum dry density as determined by ASTM DJ 557. All loose and or deleterious soils should be removed to expose firm native soils or bedrock. Prior to the placement of fill, the upper 6 to 8 inches of suitable material should be ripped, moisture conditioned to optimum moisture or slightly above optimum, and compacted to a minimum of90 percent of the maximum dry density (ASTM DJ 557). Fill should be placed in thin (6 to 8-inch) lifts, moisture conditioned to optimum moisture or slightly above, and compacted to at least 90 percent of the maximum dry density (ASTM D 1557) until the desired grade is achieved. 7.5.2. Benching Where the natural slope is steeper than 5-horizontal to ] -vertical and where determined by the Geotechnical Consultant, compacted fill material shall be keyed and benched into competent materials. ADVANCED GEOTECHNICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 10 o. 19il7-03-B~3 7.5.3. Mixing and Moisture Control In order to prevent layering of different soil types and/or different moisture contents, mixing and moisture control of materials will be necessary. The preparation of the earth materials through mixing and moisture control should be accomplished prior to and as part of the compaction of each fill lift. Water trucks or other.water delivery means may be necessary for moisture control. Discing may be required when either excessively dry or wet materials are encountered. 7.5.4. Haul Roads All haul roads, ramp fills, and tailing areas shall be removed prior to engineered fill placement. 7.5.5. Import Soils Import soils, if required, should consist of clean, structural quality, compactable materials similar to the on-site soils and should be free of trash, debris or other objectionable materials. Import soils should be tested and approved by the Geotechnical Consultant prior to importing. At least three working days should be allowed in order for the geotechnical consultant to sample and test the potential import material. 7.5.6. Fill Slope Construction Fill slopes may be constructed by preferably overbuilding and cutting back to the compacted core or by back-rolling and compacting the slope face. The following recommendations should be incorporated into construction of the proposed fill slopes. Care should be taken to avoid spillage of loose materials down the face of any slopes during grading. Spill fill will require complete removal before compaction, shaping and grid rolling. Seeding and planting of the slopes should follow as soon as practical to inhibit erosion and deterioration of the slope surfaces. Proper moisture control will enhance the long- term stability of the finish slope surface. 7 .5 .6.1. Overbuilding Fill Slopes Fill slopes should be overfilled to an extent determined by the contractor, but not less than 2 feet measured perpendicular to the slope face, so that when trimmed back to the compacted core, the compaction of the slope face meets the minimum project requirements for compaction. Compaction of each lift should extend out to the temporary slope face. The sloped should be back-rolled at fill intervals not exceeding 4 feet in height unless a more extensive overfilling is undertaken. ADVANCED GEOTECHNICAL SOLUTIONS, INC. October 9, 2019 P/W 1907-03 Page 11 p.rutNo. 19-07--03-B-3 8.0 8.1. 7.5.6.2. Compacting the Slope Face As an alternative to overbuilding the fill slopes, the slope faces may be back- rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 2-foot fill height intervals. Back-rolling at more frequent intervals may be required. Compaction of each fill should extend to the face of the slope. 7.5.6.3. Reinforced Soil Slopes Reinforced soil slopes should be constructed by an experienced contractor. Compaction of the slope face is often achieved through the use of temporary or permanent forms. DESIGN RECOMMENDATIONS Mechanically Stabilized Earthen Wall Recommendations The base of the proposed MSE wall should be founded on compacted fill or on competent formational materials. The wall designer should provide specifications on the materials placed in the retained and reinforced zones. Assuming materials derived from onsite sources are used to backfill the MSE wall, the wall may be designed using the parameters presented in Table 8. 1. More stringent criteria may be required by the wall designer. Testing should be conducted during grading to verify that the backfill materials meet the design criteria shown on the retaining wall plans. TABLE 8.1 MSE WALL DESIGN PARAMETERS1 Moist Unit Shear Strength Zone Weight Cohesion Friction Angle (pcf) Ultimate Ultimate (psf) (dee:rees) Reinforced and Retained Soil Zones 125 50 30 Foundation Zone 125 50 30 Notes: 1 Assuming fill is derived from onsite sources 8.1.1. Observation During Construction During construction of the MSE walls, the geotechnical consultants should observe the following operations: ► Grading to create wall foundation support and to verify competency of foundation materials; ► Block type and size; ► Reinforcement type; ► Placement of geogrid at design elevation, strength direction, and embedment; ► Drain placement; ADVANCED GEOTECH NICAL SO LUT IO NS. INC. October 9, 2019 P/W 1907-03 Page 12 Jl rt No. 1907-93 B-3 ► Gradation and placement of drainage rock; ► Gradation, shear strength, compaction, and moisture content of reinforced soils. ► Observations of operations not included above (including wall batter, connections, and block placement) are the responsibility of the wall designer and the contractor. The geotechnical consultant's observation of these operations in no way relieves the contractor of his obligation to construct the wall system in accordance with approved plans and specifications. 8.2. Civil Design Recommendations 9.0 Final site grading should assure positive drainage away from structures. A concrete swale should be constructed at the top of the slope to capture offsite irrigation and rainfall runoff. Planter areas should be provided with area drains to transmit irrigation and rain water away from structures. The use of gutters and down spouts to carry roof drainage well away from structures is recommended. Raised planters should be provided with a positive means to remove water through the face of the containment wall. SLOPE AND LOT MAINTENANCE Maintenance of improvements is essential to the long-term performance of structures and slopes. Although the design and construction during mass grading created slopes that are considered both grossly and surficially stable, certain factors are beyond the control of the soil engineer and geologist. The homeowners must implement certain maintenance procedures. The following recommendations should be implemented. 9.1. Slope Planting Slope planting should consist of ground cover, shrubs and trees that possess deep, dense root structures and require a minimum of irrigation. The resident should be advised of their responsibility to maintain such planting. 9.2. Lot Drainage 9.3. Roof, pad and lot drainage should be collected and directed away from structures and slopes and toward approved disposal areas. Design fine-grade elevations should be maintained through the life of the structure, or if design fine grade elevations are altered, adequate area drains should be installed in order to provide rapid discharge of water away from structures and slopes. Residents should be made aware that they are responsible for maintenance and cleaning of all drainage terraces, downdrains, and other devices that have been installed to promote structure and slope stability. Slope Irrigation The resident, homeowner and Homeowner Association should be advised of their responsibility to maintain irrigation systems. Leaks should be repaired immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wasteful run-off and ground saturation should be avoided. If ADVANCED GEOTECH NICAL SOLUTIONS. INC. October 9, 2019 P/W 1907-03 Page 13 R port N 907-Q -B -J automatic sprinkler systems are installed, their use must be adjusted to account for natural rainfall conditions. 9.4. Burrowing Animals 10.0 Residents or homeowners should undertake a program for the elimination of burrowing animals. This should be an ongoing program in order to maintain slope stability. CLOSURE The findings and recommendations in this report are based on the specific excavations, observations, and tests results as noted herein. The findings are based on the review of the field and laboratory data combined with an interpolation and extrapolation of conditions between and beyond the exploratory excavations. The results reflect an interpretation of the direct evidence obtained. Services performed by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same locality under similar conditions. No other representation, either expressed or implied, and no warranty or guarantee is included or intended. The recommendations presented in this report are based on the assumption that an appropriate level of field review will be provided by geotechnical engineers and engineering geologists who are familiar with the design and site geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and corresponding recommendations presented in this report. If the project description varies from what is described in this report, AGS must be consulted regarding the applicability of, and the necessity for, any revisions to the recommendations presented herein. AGS should review structural plans to verify whether the recommendations presented herein are incorporated into the design. AGS accepts no liability for any use of its recommendations if the project description or final design varies and AGS is not consulted regarding the changes. The data, opinions, and recommendations of this report are applicable to the specific design of this project as discussed in this report. They have no applicability to any other project or to any other location, and any and all subsequent users accept any and all liability resulting from any use or reuse of the data, opinions, and recommendations without the prior written consent of AGS. AGS has no responsibility for construction means, methods, techniques, sequences, or procedures, or for safety precautions or programs in connection with the construction, for the acts or omissions of the CONTRACTOR, or any other person performing any of the construction, or for failure of any of them to carry out the construction in accordance with the final design drawings and specifications. ADVANCED GEOTECHNICAL SOLUTIONS. INC. APPENDIX A REFERENCES ADVANCED GEOTECHNICAL SOLUTIONS, INC. October 9, 2019 P/W 1907-03 REFERENCES Page A-1 Report No. 199'.7-93-3 Fusion Engineering and Technology, Preliminary Site Plan for Lichtman Residence, 939 Begonia Court, City of Carlsbad, California, Map 1 of 1, 10-Scale, undated. Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California Geological Survey: Scale I: I 00,000. ADVANCED GEOTECHNICAL SOLUTIONS. INC. APPENDIXB BORING LOGS ADVANCED GEOTECHNICAL SOLUTIONS, INC. ~ (!) ti (!) 0 BORING NUMBER B-1 PAGE 1 OF 1 ~O\IANCED GEOTECHNICAL SOLIJJIONS, INC CLIENT ___________________ _ PROJECTNUMBER_1'-"9~0~7-;0~3 ____________ _ PROJECT NAME...,Be:c,e::.::g,.,,o"-'n,.,,iac.,C~o""u"-'rt~------------- PROJECT LOCATION 939 Begonia Ct., Carlsbad DATESTARTED_7~/~18~/~19=----------COMPLETED ....:7:..:../1~8"-/1'""9'-----GROUND ELEVATION 186 ft HOLE SIZE _,6'------- DRILLING CONTRACTOR_,N~a,,_,t'--'iv~e-=D"-'ri""lli""'n.,,_g _________ _ GROUND WATER LEVELS: DRILLING METHOD. ___,_,Tn'-'--·-.:....p~od,,__ ____________ _ AT TIME OF DRILLING_-_____________ _ LOGGED BY SS CHECKED BY _,P'--"Jce::D ___ _ AT END OF DRILLING._-_____________ _ NOTES ___________________ _ AFTER DRILLING_-_______________ _ J: (.) :i:0 1--a..= c..o w-r?_..J 0 (.'J 0 .. .. •.· (f) (.) (f) ::> SM MATERIAL DESCRIPTION Artificial Fill -Undocumented, lafu) SIL TY SAND, fine-to coarse-grained , light yellow brown, dry to slightly moist, medium dense; with some sub-rounded gravel to cobble -@ 1.5 ft., Poorly graded SAND with trace CLAY, fine-to medium-grained, slightly moist, medium dense SM ,__ @ 3.0 ft., SIL TY SAND, fine-to coarse-grained, slightly moist to moist @6.0 ft., CLAYEY SAND, fine-to coarse-grained, yellow brown to orange brown, moist, medium dense Very Old Paralic Deposits, (Qvop) SIL TY SAND with trace CLAY, fine-to coarse-grained, red brown to orange brown, moist to very moist, medium dense; micaceous w a.. >-a:: I-UJ woo ..J~ C..::> ~z <!'. (f) BU MC SPT SPT (f)W 3;: I-::> 0Z..J ..J::><!'. ooo> (.) ~ 4-8-10 (18) 6-8-9 (17) 4-8-7 (15) SPT 12-11-12 (23) ~ MC 14-14-12 (26) ~ ATTERBERG I-g w~ e..., (f) LIMITS z z I-w a:: -(f) /'.: I-t:::c;:-::> I-0 w z 1-Z ~ I-(.) 8l zu Q1-i= t::: ~ [';'.) ::>S (/)w a:: ::,--1-w a~ (f)~ 1-0 ~ Oz ::> J: :'.):::i (f)z (f) ~o ~ I-:::i..J :'.5-w 0 (.) 0 a.. z (f) a.. u::: Max lshea1 104 7.5 32 I--- 94 9.6 33 ~ ._1L .-:· ::. :.:. @ 15.0 ft., dense (/) :, 0 ,... (/) \; c3 ~ (!) 0 ...J (!) z ii': 0 m en (!) <( -.. Total Depth= 16.5 feet No groundwater encountered Backfilled with soil cuttings ~ MC 11-16-17 (33) 0 0 I .tJ.d~J BORING NUMBER B-2 PAGE 1 OF 1 - CLIENT PROJECT NAME Begonia Court PROJECT NUMBER 1907-03 PROJECT LOCATION 939 Begonia Ct., Carlsbad DATE STARTED 7/18/19 COMPLETED 7/18/19 GROUND ELEVATION 182 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS: DRILLING METHOD Tri-Pod AT TIME OF DRILLING - LOGGED BY ss CHECKED BY PJD AT END OF DRILLING - NOTES AFTER DRILLING -- :,!;! ATTERBERG I-LJ.J ~ UJl 0 Cl) LIMITS z 0.. -I-LJ.J (.) ~ffi Cl)UJ z Cl) I-I :i:c, Cl) s: I-::, !:::13 Cl:'. I-0 LJ.J ~ z I-~ (.) LJ.Ja'.l 0Z...J ::, z l= I-91- (.) 0~ o..~ o..o MATERIAL DESCRIPTION I-w Q~ w-~...J Cl) ...J~ ...J ::, <( z a. ~I-c2 Cl:'. l= !::: (.) e..., 0 ::, o..::, a:io> ::>-w ::,-Cl)~ 1-0 Oz a~ Cl) (9 ~z (.) e. >-~o ::, I 5::J C/lz LJ.J <( Cl:'. I-I-::J...J 5-Cl) 0 (.) <( 0 a.. z 0 Cl) 0.. u:: ... · SM Artificial Fill -Undocumented, (afu) ·. ... SIL TY SAND, fine-to medium-grained, light yellow brown, dry to slightly moist, medium dense; with some sub-rounded •. ·.· gravel to cobble ... · ... .. -. . . : . · .. ~ MC 3-3-3 Shear ~ -· . : . (6) 81 4.1 10 .. •. -. ••, •.· .. - • .. .. ·. _L . :. SPT 4-5-8 •, .. (13) ·. SM Ve!:J! Old Paralic De12osits1 (Qvop) :::.:· SIL TY SAND with trace CLAY, fine-to coarse-grained, dark .. ' yellow brown to orange brown, slightly moist to moist, -.. .. medium dense, micaceous ;, ·.· @ 6.0 ft., dense M MC 11-16-33 $hear •,•• (49) 97 8.8 32 .. .. . . Total Deoth = 7.5 feet No groundwater encountered Backfilled with soil cuttings ii'. C) (/) I- §1- ~ 0 0 BORING NUMBER 8-3 PAGE 1 OF 1 CLIENT ___________________ _ PROJECT NAME--=Be""g""o"'n""ia:...;C,:.;o::..:u::..rl,__ ____________ _ PROJECTNUMBER,_:_:19~0~7--=0~3 ____________ _ PROJECT LOCATION 939 Begonia Ct., Carlsbad DATESTARTED_7~/~18~/~19~---COMPLETED _7~/~18~/1~9~--GROUND ELEVATION 178 ft HOLE SIZE _6=-------- DRILLING CONTRACTOR.~N~a=t~iv~e~D~r=ill=in=g _________ _ GROUND WATER LEVELS: DRILLING METHOD_T'--'n'--'·_p'--'o""'d~-------------AT TIME OF DRILLING_-_____________ _ LOGGED BY SS CHECKED BY-'P-=J=D ___ _ AT END OF DRILLING_-_-_____________ _ NOTES ___________________ _ AFTER DRILLING - ::c (..) I c, en t-~ (..) 0..¢< o..o w~ ~.....I en 0 ::, Cl 0 MATERIAL DESCRIPTION w ~ ATTERBERG I-~ ~ ~ en LIMITS z 0.. enw w~ I-w ~ffi 0:: ~ z en ~ I-s: I-::, t::c;::-::, I-0 w z wai 0Z....J 1-Z i== I-91-(..) 0 ~ zu i== t:: Qrz'.i .....1:::E .....I ::, <( ::, .9, enW <( 0:: (..)~ 0..::, aio> -I-0:: w ::,-en::E t-o Oz a~ en :::Ez (..)6 fr :::EO ::, ::c ::J.....I ::i::J enz w <( I-I-::s-en 0 (..) <( 0 0.. z en 0.. u::: .. SM ·. Artificial Fill -Undocumented. lafu) : .. .. SIL TY SAND with trace CLAY, fine-to medium-grained, light yellow brown, dry to slightly moist, medium dense; with some sub-rounded gravel to cobble ···:•.·. (ii . :. ~ ·-:· ~----------------------M MC ~ -:·. •. • • SM Very Old Paralic Deposits. (Qvopl 5-8-8 (16) § ·. · SIL TY SAND with trace CLAY, fine-to coarse-grained , __L_ :_:_ :..: ·:·: orange brown, slightly moist to moist, medium dense; ~ micaceous o, .. • :. @ 4.5 ft., dense MMC 7-20-20 (40) - 101 8.0 32 lshea1 ~ ot---"-.....,,_...__......_ ____ ,.....,...._,_...___,,.....,...-------------...L......L..-....1...---1.....-L-..---..JL-----..J-......1--.1._---.1._--1-_--1 ~ Total Depth = 6.0 feet ::) No groundwater encountered ~ Backfilled with soil cuttings ::J ~ t; < z 8 w IIl ~ iii w ....I LC t; w ~ !l, N ~ 9 C) z ~ (/) ~'--------------------------------------------------.1.-......1 ti ,:,, ~ en :::, 0 t; !z c3 0 0 U2~~..J BORING NUMBER 8-4 PAGE 1 OF 1 . . CLIENT PROJECT NAME Begonia Court PROJECT NUMBER 1907-03 PROJECT LOCATION 939 Begonia Ct., Carlsbad DATE STARTED 7/18/19 COMPLETED 7/18/19 GROUND ELEVATION 174 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS: DRILLING METHOD Tri-Pod AT TIME OF DRILLING -- LOGGEDBY SS CHECKED BY PJD AT END OF DRILLING - NOTES AFTER DRILLING - ~ ATTERBERG I-lJ.J ~ ~ 0 en LIMITS z a. w~ I-lJ.J :r: t) ~ffi enw o:::~ z en ~ I-:i: c, en 3: I-:::> !:::~ :::> I-0 lJ.J z I-~ I-t) 0.¢: a.o t) MATERIAL DESCRIPTION LI.Jill 0Z.J 1--Z ~ Q1--Q1';5 8l w~ ~__J en .J'.2 __J :::> <(> z C. en w 0::: i= !::: :::>-:::,-0 :::> a.:::> lllO -1--UJ a~ en'.2 1--o C, '.2z u~ 1'i Oz :::> :r: :s :J enz en <( '.20 I-I-:J __J :s-UJ en 0 t) <( 0 a. z 0 en a. u::: .• SM Artificial Fill • Undocumented, {afu) ·::•.·. SIL TY SAND, fine-to coarse-grained, gray brown, dry to • ... slightly moist, loose; with some sub-rounded gravel ·. •. ·.· .. ,· .. · .. . .. -• .... :· . .. .. M 3-5-6 ·. MC ~ -· ... (11) 10.5 .. SM Ve!)l Old Paralic De(!osits, {Qvop) •, .. .. SIL TY SAND with trace CLAY, fine-to coarse-grained, · . -· • ·:::.:· orange brown, moist, medium dense: micaceous . , .. @ 4.0 ft., dense :,1·:·. M 12-20-25 ~ .. MC .• (45) •. ·.· .. . . Total Depth= 5.5 feet No groundwater encountered Backfilled with soil cuttings APPENDIXC LABO RA TORY TEST RESULTS ADVANCED GEOTECHNICAL SOLUTIONS, INC. October 9, 2019 P/W 1907-03 Classification APPENDIXC LABORATORY TESTING Page C-1 Report No. 1907 3 -J- Soils were visually and texturally classified in accordance with the Unified Soil Classification System (USCS) in general accordance with ASTM D2488. Soil classifications are indicated on the boring logs in Appendix B. Modified Proctor Density The maximum dry density and optimum moisture content of a selected representative soil sample was evaluated using the Modified Proctor method in general accordance with ASTM D1557. The results of these tests are summarized herein. Direct Shear Direct shear tests were performed on relatively undisturbed samples in general accordance with ASTM D3080 to evaluate the shear strength characteristics of selected materials. The samples were inundated during shearing to represent adverse field conditions. The results are shown herein. ADVANCED GEOTECHNICAL SOLUTIONS, INC. ADVANCED GEOTECHNICAL SOLUTIONS, INC. MAXIMUM DENSITY -ASTM D1557 Project Name: 939 Begonia Ct. Location: Carlsbad P/W No.: 1907-03 Date: 7/2/2019 Method: A Point No. 1 Dry Density (pcf) 113.2 Moisture Content %) 8.2 Excavation: 8-1 Depth: 0-3 ft Soil Type: afu Tested by: FV Checked by: PJ Oversize Retained: 5.3 % 2 3 4 116.5 118.2 115.6 10.2 12.3 14.3 MAXIMUM DENSITY CURVE MOISTURE(%) Corrected Max. Dry Density 120.1 pcf Max. Dry Density 118.2 pcf Corrected Moisture __ 1;...;1~.6;:___ % Optimum Moisture 12.3 % AGS FORM E-8 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM 03080 Project Name: _9_3_9_B_e_,g,._o_n_ia_C_t._ Location: Carlsbad --------Project No.: 1907-03 --------Date: 7/23/2019 Samples Tested 1 lntial Moisture (%) 7.5 Initial Dry Density (pcf) 104.0 Normal Stress (psf) 500 Peak Shear Stress (psf) 456 Ult. Shear Stress (psf) 456 2 3 7.5 7.5 105.7 105.9 1000 2000 816 1740 744 1596 Strength Parameters 2500 2000 i;:-! 1500 "' "' ~ .. tii .. : 1000 ~ <ll 500 0 Friction Angle, phi (deg) Cohesion (psf) 0 500 1000 1500 Excavation: B-1 Depth: 2.5-3 ft Tested by: FV Reviewed by: ---- Soil Type: Yellow SC-SM Test Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (in/min): 0.01 Peak 41 0 2000 Ultimate 39 0 2500 o Peak --Peak o Ultimate ---Ultimate 3000 3500 Normal Stress (psf) 2000 1800 1600 ~ 1400 Q. ";" 1200 f 1000 "' ... 800 "' ., .t:. 600 "' 400 200 0 Shear Stress v. Displacement ................... "••·········· , ---... ~------, , t, r----li«-----l-----1----il ~·~~··~·~· ~~: 1 --500 0.00 0.10 0.20 Displacement (In) 0.30 0.05 ;[ 0.04 C 0.03 ~ "' 0.02 § 2 ., O.Ql 0 ;;; u 0.00 "€ QI > -0.01 -0.02 Vertical Deformation v. Displacement 1-------,1------1----11 •••••••••••••••••• 2000 1-----1000 --500 0.00 0.10 0.20 0.30 Displacement (in) ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM D3080 Project Name: 939 Begonia Ct. Location: Carlsbad --------Project No.: _1_9_0_7_-0_3 ___ _ Date: 7/23/2019 -------- Samples Tested 1 2 3 lntial Moisture (%) 4.1 4.1 4.1 Initial Dry Density (pct) 80.6 81 .7 83.8 Normal Stress (psf) 500 1000 2000 Peak Shear Stress (psf) 432 828 1368 Ult. Shear Stress (psf) 408 816 1308 Strength Parameters 2500 2000 c.=-! 1500 ~ f! t;; ... i 1000 .c VI 500 0 Friction Angle, phi (deg) Cohesion (psf) 0 500 1000 1500 Excavation: B-2 Depth: 3-3.5 ft Tested by: FV ----Reviewed by: ---- Soil Type: Light Brn SC Test: Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (;"/min): 0.01 Peak 32 125 2000 Ultimate 32 75 2500 o Peak --Peak o Ultimate ---Ultimate 3000 3500 Normal Stress (psf) 1600 1400 _ 1200 'ti °-:' 1000 .. ~ 800 ti; 5 600 ..c .,, 400 200 0 f , , • I Shear Stress v. Displacement .............................. .. •······ .... IV 1 ·············2000 l>l"-----+-----+---11 _ ----1000 --soo 0.00 0.10 0.20 0.30 Displacement (in) 0.05 ]: 0.04 C O.o3 -~ .. 0.02 e ~ ., 0.01 0 ii u 0.00 f ., > -0.01 -0.02 Vertical Deformation v. Displacement i...-.. --------- ......__._ .... _ •••• _ •••• __, ••• _····_·· .. __ ··_····➔•• ·_····_····__,···, .................. 2000 I -----1000 --500 0.00 0.10 0.20 0.30 Displacement (In) ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM D3080 Project Name: _9_3_9_B_e __ g..__o_n_ia_C_t._ Location: Carlsbad Excavation: 8-2 Depth: 7-7.5 ft Tested by: FV Reviewed by: AB --------Project No.: _1_9_0_7_-0_3 ___ _ 1600 1400 _ 1200 ':;; .!!: 1000 ::: ~ 800 t;; 2 600 .I: "' 400 200 0 Date: 7/25/2019 Samples Tested lntial Moisture(%) Initial Dry Density (pcf) Normal Stress (psf) Peak Shear Stress (psf) Ult. Shear Stress (psf) 2500 2000 ~ .,2: 1500 "' "' CII ... .. VI ... i 1000 ~ VI 500 0 0 500 1 2 3 8.8 8.8 8.8 99.4 102.0 100.5 500 1000 2000 432 708 1428 408 684 1404 Stren th Parameters Friction Angle, phi (deg) Cohesion s 1000 1500 ---- Soil Type: Reddish Brn. SC-SM Test: Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate e"/min): 0.01 Peak 2000 34 75 Ultimate 34 25 2500 o Peak --Peak a Ultimate ---Ultimate 3000 3500 Normal Stress (psf) Shear Stress v. Displacement i ," !, ,/:---!,1/ 1 .................. 2000 ,,,_---+-----+----<I _ ----1000 --500 0.05 I 0.04 C 0.03 :3 "' E 0.02 0 li 0.01 C ;; 'f 0.00 GI > -0.01 ·0.02 Vertical o'etormation v. Displacement '·, ... __ -•_··-~-~~-·-···+· ·_····_····...;· .. 1r"··.-.... -..... -.... -'-.... ~2~000~ I -----1000 --500 0.00 0.10 0.20 0.30 0.00 0.10 0.20 0.30 Displacement (in) Displacement (in) ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR -ASTM D3080 Project Name: _9_3_9_B_e_.g._o_n_ia_C_t._ Location: Carlsbad --------Project No.: _1_9_07_-_0_3 ___ _ Date: 7/25/2019 -------- Samples Tested 1 lntial Moisture(%) 8.0 Initial Dry Density (pcf) 103.9 Normal Stress (psf) 500 Peak Shear Stress (psf) 456 Ult. Shear Stress (psf) 444 2 3 8.0 8.0 98.0 98.4 1000 2000 780 1416 732 1344 Strength Parameters 2500 2000 I;' .S 1500 ~ ~ ... .. VI ... : 1000 .c VI 500 0 Friction Angle, phi (deg) Cohesion (psf) D 500 1000 1500 Excavation: B-3 Depth: 5-5.6 ft Tested by: FV Reviewed by: ---- Soil Type: Reddish Brn. SC-SM Test: Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (;"/min): 0.01 Peak Ultimate 32 31 160 150 o Peak --Peak □ Ultimate ---Ultimate 2000 2500 3000 3500 Normal Stress (psf) 1600 Shear Stress v. Displacement 0.05 Vertical Deformation v. Displacement 1400 0.04 .... · .. ··• ...... _ 1200 ......... •••• ~ C 0.03 't; .S: 1000 "' "' ~ 800 ~ .. 600 .. ., .I: .,, 400 200 0 .g ,,,,_,... ...... .. 0.02 E 0 ... ., 0.01 0 --------iii ' ' ... 0.00 ~ ., ""··':':.-............................... . f' > ty -0.Ql -0.02 1 .................. 2000 j ................ 2000 ..,._--------t------<I -----1000 I -----1000 --500 --500 L_ __ __,JL,__ __ __J_--===== 0.00 0.10 0.20 Displacement (in) 0.30 0.00 0.10 0.20 0.30 Displacement (in) APPENDIXD SLOPE STABILITY ANALYSIS ADVANCED GEOTECHNICAL SOLUTIONS, INC. 70 # FS a 1.474 b 1.492 C 1.550 d 1.553 60 H-e. 1.573. f 1.584 g 1.614 h 1.623 i 1.623 ,, ......... 0 I t'!.t .. } I 50 40 30 1907-03 Section Ae-Ae' -Static -Existing z:\project files\1907-03 begonia ct wall evaluatio.n\calcs & analysis\1907-03 section ae static.pl2 Run By: AGS 10/8/2019 05:20PM Soil Soil Total Saturated· Cohesion Friction Pore Pressure Piez., Desc. Type Unit 'M. Unit 'M. Intercept Angle Pressure Constant Surfa~ No. (pcf} (pcf) (psf} (deg) Param. (psf} No. ' afu 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Qvop 2 125.0 125.0 150.0 31 .0 0.00 0.0 0 : i . 9 R!i~"""'-""'109, ~ 2 5 ()9----- H5.dl-l"0'1 x / ,✓-/ 2 /2 14. ~----··_.-0 ~------ ~-----------2 20 i I .. /IA~ 2 • ft 10 o ~---~---~---~---~---~---~---~---~----~---~--~ 160 110 1so 190 200 210 220 230 240 250 260 21b GSTABL7 v.2 FSmin=1.474 Safety Factors Are Calculated By The Modified Bishop Method 1907-03 Section Ae-Ae' -Pseudostatic -Existing z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section ae static surface #1.plt Run By: AGS 10/8/2019 05:22PM 70 r.=====:i======i~====i~====i~=====i=:;-;::::====i======i::::;-----,-----,---~-----, 60 50 40 30 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Desc. Type Unit Wt.. Unit wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) {deg) Param. (psf) No. afu 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Qvop 2 125.0 125.0 150.0 31 .0 0.00 0.0 0 Load ' Peak(A) kh Coef. Value 0.470(9) 0.150(9)< 9 RIJ~"t)96J7 I 7 Rlfl:~.,/0.Y(; 2 R.9 r,:'B:P.l:"-B:-l-'4fJ9f,---,r,_-1_8"'_-.,., R.~•-13-;0 J 9 • 2 R'~I~ 2 O 5 R§. :cu,J,f,,.-,r,·,;, //5_,,_ I • / 1<4 ;urr,a3. 20 ¢ 1 ~1;_ 2 ~ 10 0 160 170 180 190 200 210 220 230 GSTABL7 v.2 FSmin=1.134 14 ____________ ...o • - 0-------·--··----2··- Y;/ ' ,fa_,/ 2 12/ 2 240 250 260 270 Factor Of Safety Is Calculated By The Modified Bishop Method 1907-03 Section Be-Be' -Static -Existing z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section 3-3' stalic.pl2 Run By: AGS 10/8/2019 05:05PM 70 r.===::;;:::::i=====i=====i=====+=====i====::i:::;---------i,----,----r---,-------, # FS a 1.107 b 1.111 C 1.112 d 1.117 60 H e 1.11s f 1.126 g 1.128 h 1.129 1.133 ·l 1313 I 50 40 30 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez., Desc. Type Unit Wt.. Unit Wt.. Intercept Angle Pressure Constant Surfac~ No. (pcf) (pcf) (psf) (deg) Param. , (psf) No. ' afu 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Qvop 2 1~5.0 125.0 150.0 31.0 0.00 0.0 0 a 1 ....... 11 2-.~ 0 .......... , ~i<JY6 ."9~~/Jtt;:J'·'""J/J109,. _ u,'4 11~1, 2 R6'.r,,--;;:/-&:~ R54:, , JU , R3Ji'ii R. J ......,._ 6 20 9 2 10 ~ 13~ . 2 19 2 15,,....-/--- ///2 iv /2 --·· ,!9,------__.. 0 '-------'-----'-----'------'--------'-----'-----'---------'-----'-----'----~ 0 10 20 30 40 50 60 70 80 90 100 110 GSTABL7 v.2 FSmin=1.107 Safety Factors Are Calculated By The Modified Bishop Method 1907-03 Section Be-Be' -Pseudostatic -Existing z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section be-be' static surface #1 .plt Run By: AGS 10/8/2019 05:09PM 70 r;:======i====+====:::::+=====i=====i==::::;-;===:i======i;::::;-----r------r---,------, 60 50 40 30 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Desc. Type Unit Wt.. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. afu 1 125.0 125.0 50.0 27.0 0.00 0.0 b Qvop 2 125.0 125.p 150.0 31 .0 0.00 0.0 0 Load , Peak(A) kh Coef. Value 0.470(g) 0.150(g)< . . I'} _ _!)_ ~ I It ·····jg 11' 9 1 ••••• 111~-& ' 1 19. 2 2 0·-·-7 ... RlJ).iJ,;,: ~/J/u96 RY~/;:,, • • ,.__ w,; 2 _ ~-• ~.1,/fz 2 ,16'?·····?····B.,."'..,,,~(J..,.,.,j 2 ;llia:«u+.'Oi•IY 2 ,-"' -~>-U'/ 1/ 11.ol:.:..ti'•-,u,,1, ;2/ , i"'t''.9n'.•'_15'-i4 !~A~~"'~-f~ 20 9 /. IU 2 6--~ 10 16 __ • .-0 ____ ._. .. --- ~----------· 2 /5 /,/" / __ ,,,.-·-; /4 ,/1:)" / 2 o ~--~---~---~---~---~---~--~---~---~---~--~ 0 10 20 30 40 50 60 70 80 90 100 11 b GSTABL7 v.2 FSmin=0.895 Factor Of Safety Is Calculated By The Modified Bishop Method 70 # FS a 1.543 b 1.576 C 1.581 d 1.602 60 H e. 1.603 f 1.605 g 1.611 h 1.618 1.620 I . ·; 828 50 40 30 1907-03 Section Ap-Ap' -Static 8 ft. Key -Proposed z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section ap 8ft key and grid.pl2 Run By: AGS 10/8/2019 04:47PM Soil Soil Total Saturated· Cohesion Friction Pore Pressure Piez., Desc. Type Untt Wt.. Unit Wt.. Intercept Angle Pressure Constant Surfa~ No. (pcf) (pcf) (psf) (deg) Param. (psf) No. ' afe 1 120.0 125.0 50.0 30.0 0.00 0.0 0 : Qvop 2 125.0 125.0 150.0 31 .0 0.00 0.0 0 5 /.--- ,,,_,.,,,... . ..-"' ~ -, ----,.----)2/ :'f1 ,_,.,,. Lo/?/J,:, ,12 ~,Y 2 IO _,...,/_.o--· ----,o-----2 I 1 _.---··_........-----e ________ .,........-2 20 ?= i ~--~i ' ; 10 o ~--~---~---~--~---~---~---~--~---~---~--~ 160 170 180 190 200 210 220 230 240 250 260 270 GSTABL7 v.2 FSmin=1.543 Safety Factors Are Calculated By The Modified Bishop Method 1907-03 Section Ap-Ap' -Pseudostatic 8 ft. Key -Proposed z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section ap 8ft key and grid surface #1 .plt Run By: AGS 10/8/2019 04:48PM 70 r.=:===i=======i======i======i======i=:;;:::::::====i======i:::::;------,-----,----,---7 60 50 40 30 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Desc. Type Unit Wt.. Unit VIit. Intercept Angle Pressure Constant Surface No. (pcf) (pcf} (psf) (deg) Param. (psf) No. afe 1 120.0 125.0 50.0 30.0 0.00 0.0 0 Qvop 2 125.0 125.0 150.0 31.0 0.00 0.0 0 Load ' Peak(A) kh Coef. Value 0.470(9) 0.150(9)< ~/ . . . .. s✓,,-2 7 I ,fr ' 1,77°2 i(O M ·~--····1. 0/9[.P,:;' ;~:..o :sv l8 ,3P9J.y 2 -••• ,./✓-/7/ J /.,.r I , .... ,, ___ ,./1 /17 Rif~:~:~:~·~::~!m ' . / 2 11."fl ·_,_..,,. ·•>i,i},lj./, j J Rl ,1, ......... _,.,,._~:;:;o,-49iS 20 ?= 2 ,-2cr~~rfi;... -cJ 8 i,b-Ji 2 10 ,,..,o ,,,.· IO _ _.,.-- ...--...--~ _.,,... . .0-.. --·-·· 1 I __ ,_.------------o ---------2 o ~--~---~---~--~---~---~---~--~---~---~--~ 160 170 180 190 200 210 220 230 240 250 260 270 GSTABL7 v.2 FSmin=1.166 Factor Of Safety Is Calculated By The Modified Bishop Method 1907-03 Section Bp-Bp' -Static 8 ft. Key -Proposed z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section bp 8ft key and grid.pl2 Run By: AGS 10/8/2019 04:46PM 80 rr===:::;;=======i==========F=======,--,-----------,-------~ 60 40 # FS a 1.569 b 1.572 C 1.594 d 1.613 e 1.623 f 1.658 g 1.662 h 1.664 1.670 ·,.673 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Desc. Type Unit IM.. Unit IM.. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. afe 1 125.0 125.0 50.0 30.0 0.00 0.0 0 Qvop 2 125.0 125.0 150.0 31.0 0.00 0.0 0 7 • a tf eR;;itF -·•,awli; f RJ.~----.<;1 _____ ..... --· g \i i-:1,::f- ~/···-rl}jifL -•····•'···· 1 /.. , • 2 0 1 .er-o-.......! 2 -~t----··/ -,·· 2 I .Q.-·· ____ o / ;:·-··--···· 2 o ~-------~-------~--------~-------~-------~ 160 180 200 220 240 26Q GSTABL7 v.2 FSmin=1.569 Safety Factors Are Calculated By The Modified Bishop Method 1907-03 Section Bp-Bp' -Pseudostatic 8 ft. Key -Proposed z:\project files\1907-03 begonia ct wall evaluation\calcs & analysis\1907-03 section bp 8ft key and grid surface #1 .plt Run By: AGS 10/8/2019 04:44PM 80 r;::=========i==========i====:::;-;=:====:i:===::::;------,-------------; 60 40 Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Desc. Type Unit wt. Unit Wt.. Intercept Angle Pressure Cor;istant Surface No. (pcf) (pcf} (psf) (deg) Param. (psf) No. afe 1 125.0 125.0 50.0 30.0 0.00 0.0 0 Qvop 2 125.0 125.0 150.0 31 .0 0.00 0.0 0 Load Peak(A) kh Coef. Value 0.470(g) 0.150(_g_)< 11 _ _,,,,--· _ _J__0....---------0-------/' _________ 2 9_?_________ 2 7 8 ./2 . --~ 0/, R6 ,+c ... ,~,---'c:jiM l\>~~efJ.: 5 ,,-</,/ •• , -------;--· / /4 l'J_ 2 -------------------------/ 2 -,,_,.,.-·" / ~ ::;I-=::----<>/91". )§_ 20 :n -········••0"'~-1/, 1 ,1. 0>------~·-;:;:::""1(!(~ 2 ~ijfilh.ft o ~-------~-------~--------~-------~-------~ 160 180 200 220 240 26b GSTABL7 v.2 FSmin=1.210 Factor Of Safety Is Calculated By The Modified Bishop Method APPENDIXE GENERAL EARTHWORK SPECIFICATIONS AND GRADING DETAILS ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 1 GENERAL EARTHWORK SPECIFICATIONS I. General A. General procedures and requirements for earthwork and grading are presented herein. The earthwork and grading recommendations provided in the geotechnical report are considered part of these specifications, and where the general specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the geotechnical report shall govern. Recommendations provided herein and in the geotechnical report may need to be modified depending on the conditions encountered during grading. B. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans, specifications, applicable building codes, and local governing agency requirements. Where these requirements conflict, the stricter requirements shall govern. C. It is the contractor's responsibility to read and understand the guidelines presented herein and in the geotechnical report as well as the project plans and specifications. Information presented in the geotechnical report is subject to verification during grading. The information presented on the exploration logs depict conditions at the particular time of excavation and at the location of the excavation. Subsurface conditions present at other locations may differ, and the passage of time may result in different subsurface conditions being encountered at the locations of the exploratory excavations. The contractor shall perform an independent investigation and evaluate the nature of the surface and subsurface conditions to be encountered and the procedures and equipment to be used in performing his work. D. The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the earthwork in accordance with applicable requirements. When the quality of work is less than that required, the Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions are corrected. E. Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading procedures and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines presented herein. All clearing and grubbing, remedial removals, clean-outs, removal bottoms, keyways, and subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill. It is the contractor's responsibility to apprise the Geotechnical Consultant of their schedules and notify the Geotechnical Consultant when those areas are ready for observation. F. The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading and conduct tests. II. Site Preparation A. Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as required by the Geotechnical Consultant, and such materials shall be ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 2 properly disposed of offsite in a method acceptable to the owner and governing agencies. Where applicable, the contractor may obtain permission from the Geotechnical Consultant, owner, and governing agencies to dispose of vegetation and other deleterious materials in designated areas onsite. B. Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as necessary to the satisfaction of the Geotechnical Consultant. C. Any underground structures such as cesspoles, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, other utilities, or other structures located within the limits of grading shall be removed and/or abandoned in accordance with the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant. Environmental -evaluation of existing conditions is not the responsibility of the Geotechnical Consultant. D. Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be processed or scarified to a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform moisture content that is at or near optimum moisture content. The scarified materials shall then be compacted to the project requirements and tested as specified. E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill. A licensed surveyor shall provide survey control for determining elevations of processed areas and keyways. III. Placement of Fill A. Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion potential, and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved prior to being imported. B. Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials and prevent abrupt changes in material type. Fill materials derived from benching should be dispersed throughout the fill area instead of placing the materials within only an equipment-width from the cut/fill contact. C. Oversize Materials: Rocks greater than 12 inches in largest dimension shall be disposed of offsite or be placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for oversize rock placement. Rocks that are smaller than 8 inches in largest dimension may be utilized in the fill provided that they are not nested and are their quantity and distribution are acceptable to the Geotechnical Consultant and do not inhibit the ability to properly compact fill materials. ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 3 D. The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain a near uniform moisture content and uniform blend of materials. E. Moisture Content: Fill materials shall be placed at or above the optimum moisture content or as recommended by the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water shall be added, and the fill materials shall be blended so that a near uniform moisture content is achieved. If the moisture content is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by discing, blading, or other methods until the moisture content is acceptable. F. Each layer of fill shall be compacted to the project standards in accordance to the project specifications and recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical Consultant, the fill shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM Test Method: D1557. G. Benching: Where placing fill on a slope exceeding a ratio of 5 to 1 (horizontal to vertical), the ground should be keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable materials such as firm materials or sound bedrock or as recommended by the Geotechnical Consultant. The minimum keyway width shall be 15 feet and extend into suitable materials, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. The minimum keyway width for fill over cut slopes is also 15 feet, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. As a general rule, unless otherwise recommended by the Geotechnical Consultant, the minimum width of the keyway shall be equal to ½ the height of the fill slope. H. Slope Face: The specified minimum relative compaction shall be maintained out to the finish face of fill and stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the compacted core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may be achieved by backrolling the slope face with suitable equipment or other methods that produce the designated result. Loose soil should not be allowed to build up on the slope face. If present, loose soils shall be trimmed to expose the compacted slope face. I. Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and governing agencies, permanent fill slopes shall be designed and constructed no steeper than 2 to I (horizontal to vertical). J. Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation is needed. K. Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When grading is interrupted by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture and density of the previously placed compacted fill. ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 4 IV. Cut Slopes A. The Geotechnical Consultant shall observe all cut slopes, including fill over cut slopes, and shall be notified by the contractor when cut slopes are started. B. If adverse or potentially adverse conditions are encountered during grading, the Geotechnical Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions. C. Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the requirements of the local governing agencies. Short-term stability of the cut slopes and other excavations is the contractor's responsibility. V. Drainage A. Backdrains and Subdrains: Backdrains and subdrains shall be provided in fill as recommended by the Geotechnical Consultant and shall be constructed in accordance with the governing agency and/or recommendations of the Geotechnical Consultant. The location of subdrains, especially outlets, shall be surveyed and recorded by the Civil Engineer. B. Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage shall not be permitted to flow over the tops of slopes. C. Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in accordance with the recommendations of the Civil Engineer. D. Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the prevailing drainage. VI. Erosion Control A. All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the project specifications and/or landscape architect's recommendations. Such measures to protect the slope face shall be undertaken as soon as practical after completion of grading. B. During construction, the contractor shall maintain proper drainage and prevent the ponding of water. The contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control measures have been installed. VII. Trench Excavation and Backfill A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavations. Knowing and following these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of 5 feet in depth shall be shored or laid back. Trench excavations and open cuts exposing adverse geologic conditions may require further evaluation ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 5 by the Geotechnical Consultant. If a contractor fails to provide safe access for compaction testing, backfill not tested due to safety concerns may be subject to removal. B. Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting. C. Backfill: Jetting of backfill materials to achieve compaction is generally not acceptable. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a Sand Equivalent greater than 30. VIII. Geotechnical Observation and Testing During Grading A. Compaction Testing: Fill will be tested and evaluated by the Geotechnical Consultant for evaluation of general compliance with the recommended compaction and moisture conditions. The tests shall be taken in the compacted soils beneath the surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant by excavating suitable test pits for testing of compacted fill. B. Where tests indicate that the density of a layer of fill is less than required, or the moisture content is not within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the fill. The portions of the fill that are not within specifications shall be reworked until the required density and/or moisture content has been attained. No additional fill shall be placed until the last lift of fill is tested and found to meet the project specifications and approved by the Geotechnical Consultant. C. If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill placement, results in a quality of work that is unacceptable, the consultant shall notify the contractor, and the contractor shall rectify the conditions, and if necessary, stop work until conditions are satisfactory. D. Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's discretion. Generally, compaction tests shall be taken at intervals approximately two feet in fill height. E. Compaction Test Locations: The Geotechnical-.Consultant shall document the approximate elevation and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations. Alternately, the test locations can be surveyed and the results provided to the Geotechnical Consultant. F. Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be removed and recompacted at the contractor's expense. The depth and extent ofremovals will be determined by the Geotechnical Consultant. ADVANCED GEOTECHNICAL SOLUTIONS, INC. General Earthwork Specifications Page 6 G. Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the Geotechnical Consultant to state that, in his opinion, grading has been completed in accordance with the approved geotechnical report and project specifications. H. Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit reports documenting their observations during construction and test results. These reports may be subject to review by the local governing agencies. 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