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HomeMy WebLinkAboutCT 05-13; LA COSTA RIDGE NEIGH 2.6; GRADING REPORTS;is i• i. PACIFIC SOILS ENGINEERING, INC. 7715 CONVOY COURT, SAN DIEGO, CALIFORNIA 92111 TELEPHONE: (858) 560-1713, FAX: (858) 560-0380 L4 Do- 2-,Lc Or eV' D.R. HORTON, INC. 1021 Costa Pacifica Way 42107 Oceanside, CA 92054 November 30, 2009 Work Order 401036G Attention: Ms. Kim Molina Subject: Project Grading Report, Lots 5 through 53, Melrose 53 Project, Neighborhood 2.6, in the City of Carlsbad, California Reference: See Appendix A Gentlemen: Presented herein are Pacific Soils Engineering, Inc.'s (PSE) geotechnical data and test results pertaining to the completion of grading of Lots 5 through 53 of the Melrose 53 Project, in the City of Carlsbad, California. PSE has provided geotechnical observation and testing services during cut and fill grading operations that occurred in August through September of 2009 for the subject project, and this report pertains to that grading. Data developed during the grading are summarized in the text of this report, on the enclosed 40-scale grading plan (Plate 1) and in Table I. Also presented herein are foundation and slab recommendations based upon field and laboratory testing of as-graded soil conditions. Cuts, fills and processing of original ground covered by this report have been completed under PSE's testing and observation. Based on the testing and observations, the grading summarized herein is considered to be in general conformance with the City of Carlsbad grading code, the 40-scale grading plan, and the referenced geotechnical reports. Slopes are considered grossly stable and should remain so under normal conditions. To reduce exposure to erosion, landscaping of graded slopes should be accomplished as soon as possible. Drainage berms and swales should be established and maintained to aid in long-term slope protection. CORPORATE HEADQUARTERS LOS ANGELES COUNTY RIVERSIDE COUNTY SOUTH ORANGE COUNTY TEL: (714) 220-0770 TEL: (310) 325-7272 or (323) 775-6771 TEL: (951) 582-0170 TEL: (714) 730-2122 FAX: (714) 220-9589 FAX: (714) 220-9589 FAX: (951) 582-0176 FAX: (714) 730-5191 Work Order 401036G Page 2 November 30, 2009 1.0 ENGINEERING GEOLOGY 1.1 Geologic Units The geologic unit encountered during the grading of the subject site included previously placed undocumented artificial fill, topsoil, older alluvium, Santiago Formation and granitic rock. Prior to the placement of compacted fill the existing undocumented fill, topsoil, highly weathered older alluvium, highly weathered Santiago Formation and highly weathered granitic rock were completely removed. The approximate as-graded distribution of older alluvium, Santiago Formation and granitic rock is shown on enclosed Plate 1. 1.2 Structure Based upon review of available literature, maps and aerial photographs and PSE's geologic observation and mapping of project grading, the onsite Santiago Formation is essentially flat-lying and unfaulted. The granitic rock is considered to be unfaulted. 0 Minor fractures were observed. 1.3 Corrective Grading Corrective grading in the form of stabilization fills and/or buttresses was not recommended. 1.4 Groundwater Groundwater was encountered on Lots 13 through 16 and on the Rec. Area pad during grading. 1.5 Subdrains Six-inch diameter subdrains were placed under Lots 14 through 19 and the Rec. Pad. The subdrains outlet in the southeast corner of the site as shown on Plate 1. 1.6 Conclusions From an engineering geologic viewpoint, Lots 5 through 53, located in the City of Carlsbad, California are suitable for their intended residential use. PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 3 November 30, 2009 2.0 PROJECT GRADING 2.1 Compaction Test Results Compaction test results are presented in Table I (Appendix B). Approximate U locations are shown on the enclosed 40-scale grading plan (Plate 1). Compaction testing was conducted utilizing Campbell Pacific Nuclear Test Gauges (ASTM:D 2922 and D 3017). 2.2 Removals 2.2.1 The removal of unsuitable existing artificial fill, topsoil, weathered older alluvium and highly weathered granitic rock was accomplished to competent older alluvium (Qoal), competent Santiago Formation (Tsa) or competent granitic bedrock (Kgr). Prior to the placement of compacted fill, the exposed surface was scarified, moisture conditioned to a minimum of optimum moisture or slightly above, and compacted. 2.2.2 Removals, excavations, cleanouts and processing in preparing fill areas were observed by PSE' s representatives prior to the placement of fill reported herein. 2.3 Overexcavation of Cut and Cut/Fill Transition Lots Cut lots and the cut and shallow fill portions of cut/fill transition lots were overexcavated a minimum of three (3) feet and replaced with compacted fill. 2.4 Compacted Fill Placement Fill consisting of the soil types indicated in Table I was placed in thin lifts (approximately six to eight inches), moisture conditioned to optimum moisture or slightly above and compacted to a minimum of 90 percent relative compaction (ASTM:D 1557). This was accomplished utilizing self-propelled, rubber-tired compactors, along with heavy earth moving equipment. Each succeeding fill lift was treated in a similar manner. 10 PACIFIC SOILS ENGINEERING, INC. S Work Order 401036G Page 4 November 30, 2009 40 2.5 Fill Slope Construction The fill slopes were built to grade and were shaped and compacted by track walking. Finish slope surfaces have been probed and/or tested and are considered to satisfy the F] project requirements and the grading codes of the City of Carlsbad. The soil materials utilized to construct the fill slopes are subject to erosion and creep. As such, landscaping and irrigation management are important elements in the long-term performance of slopes and should be established and maintained as soon as possible and maintained through the life of the project. 2.6 Depth of Fill Compaction testing was performed approximately for each one to two feet of fill placed. The approximate maximum vertical depth of fill placed on individual lots is presented below in Table II in Appendix B. 3.0 PROPOSED DEVELOPMENT The subject site is proposed for single-family residential use. One- and two-story family dwellings will be constructed utilizing wood-frame and post-tensioned, slab-on-grade foundation systems K] 4.0 DESIGN RECOMMENDATIONS 4.1 Expansion Index Materials utilized for compacted fill ranged from "very low" to "high" in expansion potential. Sampling of the post-grading conditions was conducted for Lots 5 through 53 to determine the expansion potential per ASTM:D 4829. That evaluation revealed "medium" expansive materials on the subject lots. Soluble sulfate content was also tested (see Section 4.11). The laboratory test data are presented in Table 4.1. PACIFIC SOILS ENGINEERING, INC. i. I. i0 I* i. Work Order 401036G Page 5 November 30, 2009 TABLE 4.1 Laboratory Test Data and Lot Categories Lut N u.mbers F:p :i i'n 1. iI:. lxpa1mi()I! Potenual Lot - Ue. r. "iLateontent iliR 5-8 59 Medium II 0.014 9-12 53 Medium II 0.010 13-14 68 Medium II 0.050 15-17 68 Medium II 0.044 18-21 88 Medium II 0.076 22-24 69 Medium II 0.003 25-27 74 Medium II 0.003 28-31 72 Medium II 0.030 32-34 73 Medium II 0.013 35-38 68 Medium II 0.010 39-42 56 Medium II 0.017 43-45 52 Medium II 0.005 46-47 59 Medium II 0.003 48-50 80 Medium II 0.035 51-53 78 Medium II 0.012 4.2 Foundation Design Criteria The following foundation design recommendations and the design parameters presented in Table 4.2 may be utilized to design the foundations for the proposed structure. The post-tensioned slab parameters presented herein are based on procedures outlined in the Design of Post-Tensioned Slabs-on-Ground, Third Edition by Post-Tensioning Institute, per the 2007 CBC. PACIFIC SOILS ENGINEERING, INC. is 10 Work Order 401036G Page 6 November 30, 2009 Allowable Bearing: 2000 lbs./sq.ft. (assuming a minimum embedment depth of 12-inches and a minimum width of 12 inches) Lateral Bearing: 250 lbs./sq.ft. per foot plus 125 lbs/ft2 for each additional foot embedment to a maximum of 2000 lbs/ ft2 Sliding Coefficient: 0.35 Total Settlement: 3/4-inch Differential Settlement: 3/8-inch in 20 feet. The above values may be increased as allowed by Code to resist transient loads such as wind or seismic. Building Code and structural design considerations may govern. valuated by the Structural NC. Work Order 401036G Page 7 November 30, 2009 TABLE 4.2 POST-TENSIONED FOUNDATION DESIGN CRITERIA* CENTER LIFT EDGE LIFT MINIMUM All Perimeter Beam SOIL LOT EXPANSION EMBEDMENT Conditions CATEGORY NUMBERS POTENTIAL (INCHES)** Em (ft.) Ym (in.) Em (ft.) I Ym (in.) II 5 through 53 Medium 18 9.0 0.46 5.4 1.10 Footing/Slab Dimensions The footing width, depth and the structural slab-on-grade thickness shall be as specified by the structural engineer based upon the soil parameters, provided by PSE and the requirements of the most current CBC guidelines. Under-Slab Requirements An approved moisture and vapor retarder should be placed below all slabs-on-grade within living and moisture sensitive areas as, discussed in Section 4.4. Stab Subgrade Moisture Requirements Based Upon Expansion Potential I Minimum of 130 percent of optimum moisture at least 24 hours prior to Soil Category H placing concrete to a depth of 12 inches. Footing Embedment If exterior footings adjacent to drainage swales are to exist within five (5) feet horizontally of the swale, the footing should be embedded sufficiently to assure embedment below the swale bottom is maintained. Footings adjacent to slopes should be embedded such that at least seven (7) feet are provided horizontally from edge of the footing to the face of the slope. * The values of predicted lift presented in this table are based on procedures outlines in the Design of Post-Tensioned Slabs-on-Ground, Third Edition. No corrections for vertical barriers at edge of slab or other corrections (such as tree roots under the slab or horizontal barriers) are assumed. The design parameters are based on a Constant Suction Value of 3.9 pF. **Foundations supporting multiple stories may require additional embedment. The foundation designer should verify whether additional embedment is required based on the type of structure being constructed and the requirements of the most current CBC. 0 4.3 Seismic Design Parameters The following seismic design parameters are presented to be code compliant to the California Building Code (2007). The subject site has been identified as "Do site 0 class in accordance with CBC, 2007, Table 1613.5.3 (1). The site is located at Latitude 33.1058'N and Longitude 117.22660 W. Utilizing this information, the computer program USGS Earthquake Ground Motion Parameters Version 5.0.7 and ASCE 7 criterion, the seismic design category for 0.20 seconds (Ss) and 1.0 second (Si) period response accelerations can be determined (CBC, 2007 1613.5.5.1) along with the design spectral response acceleration (CBC, 2007 16 13.5.4). PACIFIC SOILS ENGINEERING, INC. I L4 Work Order 401036G Page 8 November 30, 2009 4.4 Moisture Barrier A moisture and vapor retarding system should be placed below the slabs-on-grade in portions of the structure considered to be moisture sensitive. The retarder should be of suitable composition, thickness and strength, and have low permeability to effectively prevent the migration of water and reduce the transmission of water vapor to acceptable levels. Historically, a I 0-mil plastic membrane, such as Visqueen, placed between one to four inches of clean sand, has been used for this purpose. The use of this system or other systems, materials or techniques can be considered, at the discretion of the designer, provided the system reduces the vapor transmission rates to acceptable levels. S 4.5 Footing Excavation Observations The project soil engineer or his representative should observe footing excavations for the proposed structures prior to the placement of concrete. 4.6 Minimum Depth of Embedment For the subject site, where foundations for structures are to exist in proximity to slopes, the footings should be embedded to satisfy the requirements presented in Figure 1. FIGURE 1 FACE OF I 7 FOOliNG TOP OF SLOPE IT S FACEOF ' STRUCTURE u H - ME OF 3, NEED NOT EXCEED 40 FT SLOPE 1112 BUT NEED NOT EXCEED 15 FT. (4572 MM) MAX. S PACIFIC SOILS ENGINEERING INC. U Work Order 401036G Page 9 November 30, 2009 4.7 Backyard Improvements Future improvements such as patios, slabs, pools, and perimeter screen walls can be constructed within the setback zones; however, the design and siting of all such improvements should be reviewed by a soil engineer who is familiar with the site- specific conditions reported herein. Walls should be structurally separated at appropriate intervals. Wall footing excavations should be observed by the project soils engineer/engineering geologist. 4.8 Retaining Wall Design Retaining walls should be founded on compacted fill or bedrock. Foundations may be designed in accordance with the recommendations presented in Section 4.2. In general, conventional walls can be designed to retain select granular backfill. It should be anticipated that suitable backfill material will have to be imported or selectively produced from onsite sources, and should consist of granular "very low" to "low" expansive materials. Conventional walls constructed with select granular backfill or native soils can be designed to resist lateral pressures that are developed by a fluid as presented on Table 4.3. TABLE 4.3 EARTH PRESSURE COEFFICIENTS SELECT COMPACTED BACKFILL Unit weight = 130 lbs. I cu. ft. Cohesion = 200 lbs. / sq. ft. 0 Friction angle = 32 degrees Rankine Equivalent Fluid Level Backfill Coefficients Pressure (psfllin.ft.) Coefficient of Active Pressure: Ka = 0.31 40 Coefficient of Passive Pressure: K = 3.25 423 Coefficient of At-Rest Pressure: K0 = 0.47 61 2:1Backfihl Coefficient of Active Pressure: Ka = 0.47 61 Coefficient of Passive Pressure: Descending K (-) = 1.23 161 • Coefficient of At-Rest Pressure: K0 = 0.72 94 Per the 2007 CBC, presented below are seismic earth pressure coefficients that may be utilized in the design of retaining walls. 0 PACIFIC SOILS ENGINEERING, INC. [J Work Order 401036G Page 10 November 30, 2009 TABLE 4.4 SEISMIC EARTH PRESSURE COEFFICIENTS Rankine Equivalent Fluid Level Backfill Coefficients Pressure (psf/lin.ft.) Coefficient of Active Pressure: Ka = 0.54 70 Coefficient of Passive Pressure: K = 3.02 393 2:lBackfill Coefficient of Active Pressure: Ka = 0.70 91 Coefficient of Passive Pressure: K (-) = 1.0 130 Restrained retaining walls should be designed for "at-rest conditions, utilizing K0. Retaining walls should be backfilled with a free draining material (SE>20) extending horizontally from the back of the retaining wall a minimum of one-half the height of 40 the retaining wall to within 12 inches of grade (Figure 2). Backfill should be compacted to project specifications. Native soils shall be utilized in the upper 12 inches. Drainage systems including, as a minimum, a 4-inch diameter perforated drain line surrounded by four cubic feet per lineal foot of 3/4-inch to 1-inch crushed rock wrapped with a suitable filter fabric, should be provided to cantilever and restrained retaining walls to relieve hydrostatic pressure i• ie If PACIFIC SOILS ENGINEERING INC. Work Order 401036G Page 11 November 30, 2009 1?IC'TTDt' ) RETAINING WALL BACKFILL N.T.S. PROVIDE DRAINAGE /0 SWALE NATIVE 0A BACKFILL 12 IN. MIN. I NATIVE OR SELECT BACKFILL SELECT - BACKFILL DRAIN LATERALLY, OR PROVIDE WEEP HOLES E.I.K20 11J1 \ AS REQUIRED AND DRAIN - 11111 [I * OR AS MODIFIED BY A SPECIFIC REPORT 4 INCH PERFORATED PVC, SCHEDULE 40, SDR 35 OR APPROVED ALTERNATE, PLACE PERFORATIONS DOWN AND SURROUND WITH 4 CU. FT. PER FT.OF 3 INCH ROCK OR APPROVED ALTERNATE AND MIRAFI 140 FILTER FABRIC OR APPROVED EQUIVALENT 4.8.1 Other Design and Construction Considerations > The design loads presented in Tables 4.3 and 4.4 are to be applied on the retaining wall in a horizontal fashion. Friction between wall and retained soils should not be allowed in the retaining wall analyses. Additional allowances should be made in the retaining wall design to account • for the influence of construction loads, temporary loads and possible nearby structural footing loads. Unit weights of 125 pcf and 130 pcf may be used to model the dry and wet density of onsite compacted fill materials. > Select backfill, imported or native, should be granular, structural quality backfill with a sand equivalent of 20 or better and an ASCE Expansion Index • of 20 or less. The backfill must encompass the full active wedge area. > No backfill should be placed against concrete until minimum design strengths are achieved in compression tests of cylinders. > Footing excavations for retaining walls should be observed by the project soil engineer or his representative. PACIFIC SOILS ENGINEERING, INC. Li U Work Order 401036G Page 12 November 30, 2009 > Backfill should be compacted to a minimum of 90 percent of the laboratory maximum density at or slightly above optimum moisture as per ASTM:D 1557-02. It should be noted that the bearing capacity and passive resistance values presented in Section 4.2 are based on level conditions at the toe. Modified design parameters can be presented for retaining walls with sloped conditions at the toe. 4.9 Utility Trenches 4.9.1 Excavation All utility trenches should be shored or laid back in accordance with applicable OSHA standards. Excavations in bedrock areas should be made in consideration of underlying geologic structure. Pacific Soils Engineering, Inc. should be consulted on these issues during construction. The onsite soils are classified as Soil Type B per OSHA standards. 4.9.2 Backfill Mainline and lateral utility trench backfill should be compacted to at least 90 percent of maximum dry density as determined by ASTM:D-1557-02. Onsite soils will not be suitable for use as bedding material but will be suitable for use in backfill, provided oversized materials are removed. No surcharge loads should be imposed above excavations. This includes spoil piles, lumber, concrete trucks or other construction materials and equipment. Drainage above excavations should be directed away from the banks. Care should be taken to avoid saturation of the soils. Compaction should be accomplished by mechanical means. Jetting of native soils will not be acceptable. Under-slab trenches should also be compacted to project specifications. If native soils are used, mechanical compaction is recommended. If select granular backfill (SE> 30) is used, compaction by flooding will be acceptable. The soil engineer should be notified for inspection prior to placement of the membrane and slab reinforcement. The use of a double layer of mesh across under-slab plumbing trenches is considered an acceptable alternative to compaction of sand backfill. PACIFIC SOILS ENGINEERING, INC. 40 Work Order 401036G Page 13 November 30, 2009 4.10 Exterior Slabs and Walkways 4.10.1 Subgrade Compaction The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be compacted to a minimum of 90 percent relative compaction as determined by ASTM Test Method: D 1557-02. 4.10.2 Subgrade Moisture The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be moisture conditioned to a minimum of 120 percent of optimum moisture content prior to concrete placement. 4.10.3 Slab Thickness Concrete flatwork and driveways should be designed utilizing four-inch minimum thickness. 4.10.4 Control Joints Weakened plane joints should be installed on walkways at intervals of approximately eight feet. Exterior slabs should be designed to withstand shrinkage of the concrete. 4.10.5 Flatwork Reinforcement Consideration should be given to reinforcing any exterior flatwork. 4.10.6 Thickened Edge Consideration should be given to construct a thickened edge (scoop-footing) at the perimeter of slabs and walkways adjacent to landscape areas to minimize moisture variation below these improvements. The thickened edge (scoop-footing) should extend approximately eight inches below concrete slabs and should be a minimum of six inches wide. 4.11 Chemical Tests The results of chemical tests conducted during rough grading indicate that the soluble sulfate concentrations of the majority of the site materials tested are below 0.1. As such, soluble sulfate potential of near surface soils can be classified as "negligible", in accordance with Table 4.3.1 of ACI 318-05. PACIFIC SOILS ENGINEERING, INC. [1 Work Order 401036G Page 14 November 30, 2009 4.12 Concrete Design As stated in Section 4.6, negligible concentrations of sulfates were detected in the onsite soils. Therefore, per ACT 31 8-05, the use of sulfate-resistant concrete is not i0 I* i0 i. i. I . required. 5.0 OTHER DESIGN AND CONSTRUCTION CONSIDERATIONS 5.1 Site Drainage Positive drainage away from structures should be provided and maintained. Roof, pad and slope drainage should be collected and directed away from the proposed structures to approved disposal areas. It is important that drainage be directed away from foundations. This is especially true in patio areas and greenbelt areas. The recommended drainage patterns should be established at the time of fine grading and maintained throughout the life of the structure. 5.2 Service Utility Trench Backfill Service utility trench backfill should be accomplished in accordance with the prevailing criteria of the City of Carlsbad. 5.3 Seismic Design Seismic design should be based on current and applicable building code requirements. 7.0 HOMEOWNER CONSTRUCTION AND MAINTENANCE RESPONSIBILITIES During and upon completion of mass grading of the subject site, representative soil samples were tested for expansive soil characteristics and soluble sulfate concentrations. The results of these tests are presented in Table 4.1 of the text. In addition, certain lots contain manufactured slopes within or adjacent to the building pad area. All of these conditions should be considered in design, construction and maintenance of homeowner improvements. The homeowners should be advised of certain responsibilities they must accept in consideration of these factors. Suggested information to educate the homeowners regarding these responsibilities is presented in Appendix C. We suggest that PACIFIC SOILS ENGINEERING, INC. i* i• BY:SC CE Engineering Consultant HANSON,'CEG 990 1 Work Order 401036G Page 15 November 30, 2009 this information be provided to all homeowners as part of an information packet during the sales process. This report presents information and data relative to the mass grading and/or placement of compacted fill at the subject site. A representative(s) of this firm conducted periodic tests and observations during the progress of the construction in an effort to determine whether compliance with the project drawings, specifications and Building Code were being obtained. The presence of our personnel during the work process did not involve the direction or supervision of the contractor. Technical advice and suggestions were provided to the owner and/or his representative based upon the results of the tests and observations. Completed work under the purview of this report is considered suitable for the intended use. Conditions of the reference reports remain applicable unless specifically superseded herein. Respectfully submitted, PACIFIC S4IILS ENG G, INC. Reviewed by: A. i. i. Dist: (4) Addressee SAGIDAM:401036G, November .2009 f 'No 67391 \ ' -J OFC PACIFIC SOILS ENGINEERING, INC. APPENDIX A . PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 16 November 30, 2009 HS REFERENCES Pacific Soils Engineering, Inc., 2009, Project Grading Report, Model Site, Lots 1 through 4, La Costa Ridge Project, Neighborhood 2.6, in the City of Carlsbad, California, dated September 1, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009a, Observations and Recommendations of Wet Area in Southeast Corner of the La Costa Ridge Project, City of Carlsbad, California, dated August 21, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009b, Supplemental Geotechnical Investigation, La Costa Ridge Project, City of Carlsbad, California, dated July 21, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009c, Foundation Plan Review, La Costa Ridge Project, City of Carlsbad, California, dated June 22, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009d, Updated Foundation Design Recommendations, La Costa Ridge Project, City of Carlsbad, California, dated February 16, 2009 (Work Order 401036). Pacific Soils Engineering, Inc. 2007a, Reinforced 1.5: 1 Fill Slope Recommendations, La Costa Ridge Neighborhood 2.6, Carlsbad, California, dated June 13, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007b, Response to Plan Check Review Comment, La Costa Ridge Project, in the City of Carlsbad, California, dated June 25, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007c, Embankment Constraints, La Costa Ridge Neighborhood 2.6, Carlsbad, California, by Pacific Soils Engineering, Inc., dated February 21, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007d, Updated Preliminary Geotechnical Investigation, La Costa Ridge Project, in the City of Carlsbad, California, by Pacific Soils Engineering, Inc., dated February 15, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2006a, Suitability of Stockpile Material, La Costa Ridge 2.6-Acre Parcel, Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Carlsbad, CA, dated February 15, 2006 (Work Order 401036). Pacific Soils Engineering, Inc., 2006b, Supplemental Geotechnical Recommendations, La Costa Ridge Project, in the City of Carlsbad, CA, dated January 16, 2006 (Work Order 401036). Pacific Soils Engineering, Inc., 2005a, Preliminary Geotechnical Investigation, La Costa Ridge Project (Approximately 7+-Acre Parcel), in the City of Carlsbad, California, dated June 2, 2005 (Work Order 401036). 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 17 November 30, 2009 Pacific Soils Engineering, Inc., 2005b, Geotechnical Summary, La Costa Ridge 2.6-Acre Parcel, Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Carlsbad, CA, dated March 29, 2005 (Work Order 401036). PACIFIC SOILS ENGINEERING, INC. APPENDIX B 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Melrose 53 November 30, 2009 TABLE I Soil Type Laboratory Maximum Density ASTM:D 1557-02 (All Soil Types) Ll Optimum Maximum Moisture Dry Density Soil Type & Description (% dry wt.) (lbs./cu.ft.) • A - Brown Clayey Silt 13.4 118.3 B - Tan Silty Sand 9.3 117.3 C - Tan Clayey Sand 10.9 121.5 C15 - Tan Clayey Sand 15% rock correction 9.4 126.4 C20 - Tan Clayey Sand 20% rock correction 8.9 128.1 C25 - Tan Clayey Sand 25% rock correction 8.4 129.8 D - Tan Clayey Sand 11.1 124.1 D10 - Tan Clayey Sand 10% rock correction 10.1 127.2 D15 - Tan Clayey Sand 15% rock correction 9.6 128.8 • D25 - Tan Clayey Sand 25% rock correction 8.6 132.1 D30 - Tan Clayey Sand 30% rock correction 8.1 133.8 E5 - Gray Brown Silty Sand 5% rock correction 8.6 129.8 E10 - Gray Brown Silty Sand 10% rock correction 8.2 131.2 E15 - Gray Brown Silty Sand 15% rock correction 7.8 132.7 • E20 - Gray Brown Silty Sand 20% rock correction 7.4 134.2 E25 - Gray Brown Silty Sand 25% rock correction 7.0 135.7 F - Black and Tan Sandy Silt 12.3 118.2 LEGEND Non-Designated Test - Indicates test taken in compacted fill. Test Location - Indicated by street and street stationing, by specified utility line number or stationing, or by direction from closest adjacent building, or by lot and unit numbe Elevation - Indicated by approximate field elevation (feet) above mean sea level, or by • Depth (feet) below finished grade. F.G. - Indicates finished grade, (base grade). A - Indicates duplicate test number. R - Indicates retest of previously failing fill. SL - Indicates test taken in sewer lateral trench backfill. • TEST TYPE N - Indicates test by Campbell Pacific Nuclear Test Gauge (per ASTM:D 2922-05 and D 3017-05). PACIFIC SOILS ENGINEERING, INC. S S LA Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test or Moisture Unit Dry Wt. Ret Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 8/6/2009 101 Lot 27 346 15.7 13.4 118.3 108.4 91 A N 90 Pass 8/6/2009 102 Lot 27 347 13.9 13.4 118.3 112.4 95 A N 90 Pass 8/7/2009 103 Lot 22 338 11.9 9.3 117.3 109.2 93 B N 90 Pass 8/7/2009 104 Lot 24 343 12.3 9.3 117.3 105.9 90 B N 90 Pass 8/7/2009 105 Lot 23 343 9.6 9.3 117.3 108.0 92 B N 90 Pass 8/7/2009 106 Lot 26 346 9.5 9.3 117.3 111.2 94 B N 90 Pass 8/7/2009 107 Lot 22 345 10.4 9.3 117.3 108.1 92 B N 90 Pass 8/7/2009 108 Lot 26 341 9.6 9.3 117.3 1066 90 B N 90 Pass 8/7/2009 109 Lot 23 341 13.8 13.4 118.3 113.2 95 A N 90 Pass 8/7/2009 110 Lot 24 345 15.3 13.4 118.3 111.9 94 A N 90 Pass 8/7/2009 111 Lot 25 347 15.8 13.4 118.3 106.7 90 A N 90 Pass 8/10/2009 112 Lot 23 347 12.1 10.9 121.5 117.4 96 C N 90 Pass 8/10/2009 113 Lot 26 348 11.8 9.3 117.3 111.4 94 B N 90 Pass 8/10/2009 114 Lot 25 348 12.4 10.9 121.5 112.5 92 C N 90 Pass 8/10/2009 115 Lot 21 338 11.0 10.9 121.5 111.7 91 C N 90 Pass 8/10/2009 116 Lot 44 340 11.5 9.3 117.3 110.3 94 B N 90 Pass 8/10/2009 117 Lot 42 340 12.8 10.9 121.5 115.4 94 C N 90 Pass 8/10/2009 118 Adj Lot 20 342 13.7 10.9 121.5 112.7 92 C N 90 Pass 8/10/2009 119 Lot 42 342 14.1 10.9 121.5 111.3 91 C N 90 Pass 8/10/2009 120 Lot 21 344 14.8 13.4 118.3 107.8 91 A N 90 Pass 8/10/2009 121 Lot 43 344 13.1 10.9 121.5 110.6 91 C N 90 Pass 8/10/2009 122 Lot 41 344 13.9 13.4 118.3 111.9 94 A N 90 Pass 8/11/2009 123 Lot 26 350 11.8 10.9 121.5 109.6 90 - C N 90 Pass 8/11/2009 124 Lot 24 350 13.5 10.9 121.5 109.9 90 C N 90 Pass 8/11/2009 125 Adj Lot 23 349 14.2 10.9 121.5 111.7 91 C N 90 Pass 8/11/2009 126 Lot 20 346 13.9 11.1 124.1 111.9 90 D N 90 Pass 8/11/2009 127 Adj Lot 44 346 14.0 11.1 124.1 115.8 93 D N 90 Pass 8/11/2009 128 Lot 42 346 14.2 11.1 124.1 113.1 91 D N 90 Pass 8/11/2009 129 Lot 27 351 19.6 11.1 124.1 106.5 85 D N 90 Fail 8/11/2009 130 Lot 23 351 20.4 11.1 124.1 1056 85 D N 90 Fail 8/11/2009 129-R Lot 27 351 13.8 11.1 124.1 114.7 92 D N 90 Pass *Approximate Depth (In Feet) Below Finished Grade Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test or Moisture Unit Dry Wt. Rel Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp., Type Type Spec. Pass/Fail 8/11/2009 130-R Lot 23 351 13.6 11.1 124.1 113.4 91 D N 90 Pass 8/12/2009 131 Lot 12 335 12.6 10.9 121.5 116.7 96 C N 90 Pass 8/12/2009 132 Lot 12 336 13.9 10.9 121.5 115.6 95 C N 90 Pass 8/12/2009 133 Adj Lot ll 338 12.3 10.9 121.5 109.5 90 C N 90 Pass 8/12/2009 134 Lot 10 340 11.7 11.1 124.1 114.8 92 D N 90 Pass 8/12/2009 135 Adj Lot 41 342 13.9 11.1 124.1 117.3 94 D N 90 Pass 8/12/2009 136 Adj Lot 10 344 12.8 10.9 12.1.5 116.7 96 C N 90 Pass 8/12/2009 137 Lot 41 346 10.7 8.6 132.1 120.9 91 D25 N 90 Pass 8/12/2009 138 Lot 42 348 12.7 11.1 124.1 115.8 93 D N 90 Pass 8/12/2009 139 . Lot 21 349 9.2 7.0 135.7 128.6 94 E25 N 90 Pass 8/13/2009 140 Lot 343 9.9 7.0 135.7 127.8 94 E25 N 90 Pass 8/13/2009 141 Lot 342 9.1 10.9 121.5 113.1 93 C N 90 Fail 8/13/2009 141-R Lot 342 13.5 10.9 121.5 114.6 94 C N 90 Pass 8/13/2009 142 Lot 10 339 16.4 11.1 124.1 108.8 87 D N 90 Fail 8/13/2009 143 Lot 11 346 10.0 11.1 124.1 114.9 92 D N 90 Fail 8/13/2009 142-R Lot 10 339 12.7 11.1 124.1 118.1 95 D N 90 Pass 8/13/2009 143-R Lot 11 346 14.3 11.1 124.1 115.1 92 D N 90 Pass 8/14/2009 144 Adj Lot 9 346 11.1 8.6 132.1 125.4 94 D25 N 90 . Pass 8/14/2009 145 Lot 346 10.1 9.3 117.3 112.9 96 B N 90 Pass 8/14/2009 146 Lot 348 12.8 9.4 126.4 118.1 93 C15 N 90 Pass 8/14/2009 147 . Adj Lot 5 352 11.6 10.9 121.5 113.4 93 C N 90 Pass 8/17/2009 150 Lot 12 338 11.2 9.3 117.3 105.8 90 B N 90 Pass 8/17/2009 151 Lot 349 12.1 9.3 117.3 108.5 92 B N 90 Pass 8/17/2009 154 Lot 354 13.7 13.4 118.3 108.4 91 A N 90 Pass 8/17/2009 155 Lot 353 14.4 13.4 118.3 107.8 91 A . N 90 Pass 8/17/2009 156 Adj Lot 38 354 11.9 8.6 129.8 116.9 90 ES N 90 Pass 8/17/2009 157 Adj Lot 8 340 10.7 8.2 131.2 124.0 94 E1O .N 90 Pass 8/17/2009 158 Adj Lot 6 343 11.9 8.6 129.8 118.1 90 E5 N 90 Pass 8/17/2009 159 Adj Lot 53 .341 11.9 8.2 131.2 123.6 94 EIO N 90 Pass 8/18/2009 160 Adj Lot 5 347 9.9 7.4 134.2 124.8 92 E20 N 90 Pass 8/18/2009 161 . AdjLot9 346 10.3 7.4 134.2 122.6 91 E20 N 90 Pass *Approximate Depth (In Feet) Below Finished Grade Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test or Moisture Unit Dry Wt. Rel Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 8/18/2009 162 Adj Lot 38 353 8.7 7.4 134.2 128.5 95 E20 N 90 Pass 8/18/2009 163 Adj Lot 38 349 9.5 7.4 134.2 125.3 93 E20 N 90 Pass 8/18/2009 164 Lot 355 11.1 7.0 135.7 129.4 95 E25 N 90 Pass 8/18/2009 167 Lot 13 335 9.1 7.0 135.7 127.8 94 E25 N 90 Pass 8/18/2009 168 Lot 13 340 8.8 7.0 135.7 130.0 95 E25 N 90 Pass 8/18/2009 169 Lot 11 349 10.3 7.0 135.7 124.8 91 E25 N 90 Pass 8/18/2009 170 Lot 12 348 9.4 7.0 135.7 126.3 93 E25 N 90 Pass 8/19/2009 171 Lot 14 336 14.4 13.4 118.3 107.2 90 A N 90 Pass 8/19/2009 172 Rec Area 333 13.9 13.4 118.3 108.1 91 A N 90 Pass 8/19/2009 173 Rec Area 336 15.7 13.4 118.3 106.9 90 A N 90 Pass 8/19/2009 174 Lot 14 340 14.6 13.4 118.3 108.4 91 A N 90 Pass 8/19/2009 175 Rec Area 338 16.2 13.4 118.3 107.3 90 A N 90 Pass 8/20/2009 176 Lot 17 339 11.8 9.3 117.3 109.3 93 B N 90 Pass 8/20/2009 177 Adj Lot 42 340 10.9 7.8 132.7 123.8 93 E15 N 90 Pass 8/20/2009 178 Lot 19 340 12.1 9.3 117.3 108.6 92 B N 90 Pass 8/20/2009 179 Adj Lot 18 343 11.3 8.2 131.2 118.6 90 E1O N 90 Pass 8/20/2009 180 Adj Lot 14 342 10.7 7.8 132.7 122.4 92 E15 N 90 Pass 8/20/2009 181 Lot 15 340 11.4 7.8 132.7 119.6 90 E15 N 90 Pass 8/20/2009 182 Lot 20 344 9.3 7.8 132.7 124.3 93 E15 N 90 Pass 8/20/2009 183 Lot 18 345 10.7 8.6 132.1 124.1 93 D25 N 90 Pass 8/20/2009 184 Adj Lot 15 334 14 13.4 118.3 108.1 91 A N 90 Pass 8/20/2009 185 Lot 18 336 13.7 11.1 124.1 111.8 90 D N 90 Pass 8/20/2009 186 Lot 16 338 14.4 13.4 118.3 109.5 92 A N 90 Pass 8/20/2009 187 Lot 19 340 15.7 13.4 118.3, 107.6 90 A N 90 Pass 8/21/2009 188 Lot 15 342 11.9 11.1 124.1 112.6 90 D N 90 Pass 8/21/2009 189 Lot 18 342 13.4 11.1 124.1 113.7 91 D N 90 Pass 8/21/2009 190 Lot 17 344 12.6 11.1 124.1 113.9 91 D N 90 Pass 8/21/2009 191 Lot 19 344 14.1 11.1 124.1 113.3 91 D N 90 Pass 8/21/2009 192 Lot 16 346 11.5 11.1 124.1 116.4 93 D N 90 Pass 8/21/2009 193 Lot 18 346 13.4 13.4 118.3 109.5 92 A N 90 Pass 8/21/2009 194 Lot 20 348 11.9 11.1 124.1 111.8 90 D N 90 Pass *Approximate Depth (In Feet) Below Finished Grade Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test or Moisture Unit Dry Wt. Rel Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 8/24/2009 199 Lot 39 342 11.0 9.3 117.3 108.9 92 B N 90 Pass 8/24/2009 200 Lot 41 344 13.1 10.9 121.5 111.8 92 C N 90 Pass 8/24/2009 201 Lot 44 344 12.6 10.9 121.5 111.5 91 C N 90 Pass 8/24/2009 202 Lot 40 346 11.8 9.3 117.3 107.0 91 B N 90 Pass 8/24/2009 203 Lot 45 346 12.1 9.3 117.3 110.0 93 B N 90 Pass 8/24/2009 204 Lot 39 348 10.7 9.3 117.3 106.9 91 B N 90 Pass 8/24/2009 205 Lot 43 348 11.4 9.3 117.3 107.9 91 B N 90 Pass 8/24/2009 206 Lot 45 349 12.3 10.9 121.5 109.9 90 C N 90 Pass 8/24/2009 207 Lot 52 346 14.5 12.3 118.2 108.0 91 F N 90 Pass 8/24/2009 208 Lot 45 344 15.6 12.3 118.2 107.9 91 F N 90 Pass 8/24/2009 209 Lot 50 346. 14.7 12.3 118.2 109.1 92 F N 90 Pass 8/24/2009 210 Lot 46 346 14.1 12.3 118.2 110.4 93 F N 90 Pass '8/24/2009 211 Lot 53 348 13.8 12.3 118.2 110.9 93 F N 90 Pass 8/24/2009 212 Lot 49 348 14.4 12.3 118.2 109.2 92 F N 90 Pass 8/24/2009 213 Lot 51 347 14.0 10.9 121.5 110.9 91 C N 90 Pass 8/24/2009 214 Lot 48 346 13.4 10.9 121.5 114.8 94 C N 90 Pass 8/25/2009 215 Lot 52 349 14.4 12.3 118.2 113.7 96 F N 90 Pass 8/25/2009 216 Lot 47 349 15.1 ' 12.3 118.2 106.5 90 F N 90 Pass 8/25/2009 217 Lot 48 351 13.6 10.9 121.5 112.3 92 C N 90 Pass 8/25/2009 218 Lot 39 351 14.8 12.3 118.2 106.7 90 F N 90 Pass 8/25/2009 219 Lot 50 353 15.1 12.3 118.2 106.8 90 F N 90 Pass 8/26/2009 220FG Lot 355.2 7.4 7.0 135.7 133.0 98 E25 N 90 Pass 8/26/2009 221FG Lot 355.2 11.8 9.6 128.8 120.5 93 D15 N 90 Pass 8/26/2009 222FG Lot 7 354.3 14.9 10.9 121.5 115.1 94 C N 90 Pass 8/26/2009 223FG Lot 8 354.3 13.8 13.4 118.3 110.8 93 A N 90 Pass 8/27/2009 224 Adj Lot 53 344 9.1 7.0 135.7 127.7 94 E25 N 90 Pass 8/27/2009 , 225 Adj Lot 30 344 9.6 7.0 135.7 123.9 91 E25 N 90 Pass 8/27/2009 226 Adj Lot 34 346 9.4 7.0 135.7 124.8 91 E25 N 90 Pass 8/27/2009 227 Adj Lot 47 346 9.7 7.0 135.7 125.8 92 E25 N 90 Pass 8/27/2009 228 Adj Lot 36 348 10.6 7.8 132.7 126.3 95 E15 N 90 Pass 8/27/2009 229 Adj Lot 48 348 10.8 7.8 132.7 123.7 93 E15 N 90 Pass I *Approximate Depth (In Feet) Below Finished Grade Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test Or Moisture Unit Dry Wt. Rel Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 8127/2009 230 Lot 24 352 12.6 10.9 121.5 110.8 91 C N 90 Pass 8/27/2009 231 Lot 47 351 13.4 10.9 121.5 113.0 93 C N 90 Pass 8/27/2009 232 Lot 53 353 11.5 10.9 121.5 109.8 90 C N 90 Pass 8/28/2009 233FG Lot 352.2 11.7 8.9 128.1 118.2 92 C20 N 90 Pass 8/28/2009 234FG Lot 10 352.2 11.3 8.9 128.1 120.9 94 C20 N 90 Pass 8/28/2009 235FG Lot 11 350.5 9.5 8.9 128.1 125.4 97 C20 N 90 Pass 8/28/2009 236FG Lot 12 350.5 9.6 8.4 129.8 122.0 93 C25 N 90 Pass 8/28/2009 237SL Adj Lot 353 13.5 11.1 124.1 112.3 90 D N 90 Pass 8/28/2009 238SL Adj Lot 8 350 12.8 11.1 124.1 114.2 92 D N 90 Pass 8/28/2009 239SL Adj Lot 11 347 9.4 8.1 133.8 126.2 94 D30 N 90 Pass 8/31/2009 240 Lot 38 352 13.9 11.1 124.1 114.6 92 D N 90 Pass 8/31/2009 241 Lot 36 354 12.1 11.1 124.1 114.4 92 D N 90 Pass 8/31/2009 242 Lot 34 352 15.7 13.4 118.3 110.0 92 A N 90 Pass 8/31/2009 243 Lot 32 354 15.2 13.4 118.3 106.9 90 A N 90 Pass 8/31/2009 244 Lot 31 352 15.4 13.4 118.3 106.9 90 A N 90 Pass 8/31/2009 245 Lot 28 350 16.8 13.4 118.3 106.5 90 A N 90 Pass 8/31/2009 246 Lot 29 352 15.8 13.4 118.3 107.9 91 A N 90 Pass 9/1/2009 247FG Lot 53 354.4 12.3 11.1 124.1 111.8 90 D N 90 Pass 9/1/2009 248FG Lot 52 355.1 11.1 11.1 124.1 116.7 94 D N 90 Pass 9/1/2009 249FG Lot 51 355 11.1 11.1 124.1 117.1 94 D N 90 Pass 9/1/2009 250FG Lot 50 354.8 15.8 13.4 118.3 108.9 92 A N 90 Pass 9/1/2009 251FG Lot 49 354.8 13.9 13.4 118.3 106.9 90 A N 90 Pass 9/1/2009 252FG . Lot 48 353.8 10.4 9.3 117.3 109.0 92 B N 90 Pass 9/1/2009 253FG Lot 47 351.2 13.4 13.4 118.3 107.1 90 A N 90 Pass 9/1/2009 254FG Lot 46 351.2 13.8 13.4 118.3 108.9 92 A N 90 Pass 9/1/2009 255FG Lot 45 350.4 12.6 10.9 121.5 113.6 93 C N 90 Pass 9/1/2009 256FG Lot 44 350.4 13.8 11.1 124.1 120.9 97 D N 90 Pass 9/1/2009 257FG - Lot 43 350.2 14.1 11.1 124.1 114.3 92 D N 90 Pass 9/1/2009 258FG Lot 22 351.7 11.7 11.1 124.1 114.4 92 D N 90 Pass 9/1/2009 259FG Lot 23 351.7 12.8 11.1 124.1 112.9 90 D N 90 Pass 9/1/2009 260FG Lot 24 352.5 11.7 11.1 124.1 111.8 90 D N 90 Pass *Approximate Depth (In Feet) Below Finished Grade Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth* Test or Moisture Unit Dry Wt. Ret Soil Test Proj. Date Number Test Location Etev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 9/1/2009 261 F Lot 25 352.5 11.7 11.1 124.1 113.1 91 D N 90 Pass 9/1/2009 262FG Lot 26 353.1 9.6 8.6 132.1 125.8 95 D25 N 90 Pass 9/3/2009 263 Lot 37 354 13.8 11.1 124.1 115.2 92 D N 90 Pass 9/3/2009 264 Lot 35 354 11.7 11.1 124.1 117.6 94 D N 90 Pass 9/3/2009 265 Lot 33 354 12.6 11.1 124.1 113.3 91 D N 90 Pass 9/3/2009 266 Lot 31 352 13.2 11.1 124.1 111.9 90 D N 90 Pass 9/3/2009 267 Lot 30 352 11.9 11.1 124.1 117.0 94 D N 90 Pass 9/3/2009 268 Lot 28 349 14.0 11.1 124.1 112.1 90 D N 90 Pass 9/3/2009 269 Lot 29 352 12.1 11.1 124.1 114.2 92 D N 90 Pass 9/8/2009 270FG Lot 38 355.3 12.8 10.1 127.2 118.3 93 D10 N 90 Pass 9/8/2009 271FG Lot 37 355.3 12.2 10.1 127.2 118.3 93 D1O N 90 Pass 9/8/2009 272FG Lot 36 355.6 12.0 10.1 127.2 119.5 93 D10 N 90 Pass 9/8/2009 273FG Lot 35 355.6 11.7 10.1 127.2 118.6 93 D1O N 90 Pass 9/8/2009 274FG Lot 34 355.6 12.6 10.1 127.2 117.9 92 D1O N 90 Pass 9/8/2009 275FG Lot 33 355.6 10.7 10.1 127.2 120.7 94 D1O N 90 Pass 9/8/2009 276FG Lot 32 355 13.1 10.1 127.2 115.4 90 D1O N 90 Pass 9/8/2009 277FG Lot 31 353.6 14.3 10.9 121.5 109.9 90 C N 90 Pass 9/8/2009 278FG Lot 30 353.6 13.8 10.9 121.5 110.1 90 C N 90 Pass 9/8/2009 279FG Lot 29 352.6 11.3 10.1 127.2 117.0 91 DIO N 90 Pass 9/8/2009 280FG Lot 28 352.6 11.9 10.1 127.2 115.9 91 D1O N 90 Pass 9/9/2009 281FG Lot 42 349.1 8.1 8.1 133.8 127.1 94 D30 N 90 Pass 9/9/2009 282FG Lot 41 350.6 10.8 10.1 127.2 119.0 93 D1O N 90 Pass 9/9/2009 283FG Lot 40 350.6 11.3 10.1 127.2 118.3 93 D1O N 90 Pass 9/9/2009 284FG Lot 39 351.5 11.9 9.6 128.8 119.6 92 D15 N 90 Pass 9/9/2009 285 Rec Area 340 9.1 7.8 132.7 122.4 92 E15 N 90 Pass 9/9/2009 286 Rec Area 342 13.4 11.1 124.1 116.1 93 D N 90 Pass 9/9/2009 287 Adj Lot 14 342 12.6 11.1 124.1 115.2 92 D N 90 Pass 9/9/2009 288 Adj Lot 2 360 12.8 11.1 124.1 114.3 92 D N 90 Pass 9/28/2009 289 Adj Lot 3 358 11.9 11.1 124.1 112.6 90 D N 90 Pass 9/28/2009 290 Adj Lot! 364 12.6 11.1 124.1 113.2 91 D N 90 Pass 9/28/2009 291 Adj Lot 38 361 12.1 11.1 124.1 115.9 93 D N 90 Pass *Approximate Depth (In Feet) Below Finished Grade S Work Order 401036G November 30, 2009 TABLE I (Cont'd) Depth*. Test or Moisture Unit Dry Wt. Rel Soil Test Proj. Date Number Test Location Elev Field Opt. Max. Field Comp. Type Type Spec. Pass/Fail 9/28/2009 292 Adj Lot 38 .359 13.8 11.1 124.1 112.1 90 D N 90 Pass 9/29/2009 293FG Lot 13 348.8 11.3 11.1 124.1 116.5 93 D N 90 Pass 9/29/2009 294FG Lot 14 348.8 12.4 11.1 124.1 114.5 92 D N 90 Pass 9/29/2009 295 Lot 15 346 13.8 11.1 124.1 114.8 92 D N 90 Pass 9/29/2009 296 Lot 17 348 12.9 11.1 124.1 116.2 93 D N 90 Pass 9/29/2009 297FG Rec Area 347.5 14.1 11.1 124.1 113.3 91 D N 90 Pass 9/29/2009 298FG Lot 15 348.7 11.8 11.1 124.1 115.4 92 D N 90 Pass 9/29/2009 299FG Lot 16 348.7 13.9 11.1 124.1 112.1 90 D N 90 Pass 9/29/2009 300FG Lot 17 349 11.7 10.9 121.5 112.0 92 C N 90 Pass 9/29/2009 301FG Lot 18 349.3 12.6 10.9 121.5 113.7 93 C . N 90 Pass 9/29/2009 302FG Lot 19 349.7 13.4 11.1 124.1 118.8 95 D N 90 Pass 9/29/2009 303FG Lot 20 . 350.6 11.8 11.1 124.1 112.5 90 D N 90 Pass 9/29/2009 304FG Lot 21 350.6 13.0 11.1 124.1 114.2 92 D N 90 Pass L] I Work Order 401036G November 30, 2009 TABLE II continued Depth 01 Fill, and Seismic Soil 1'rotile 'lypes : 1)1 1911 of III I. LOT M. Feet P ROF I L i TrY i'i 42 12 D 43 10 D 44 10 D 45 9 46 11 D 47 8 D 48 9 D 49 10 D 50 10 D 51 10 D 52 11 D 53 10 D r S PACIFIC SOILS ENGINEERING, INC. 40 U I* i• i. Work Order 401036G November 30, 2009 TABLE II Depth of Fill, and Seismic Soil Profile Types LOT NO 1LXIMUl DEPTH of FILL SOIL PROFILE TYPE 5 8 D 6 9 7 .6 D 8 16 D 9 14 D 10 17 D 11 17 D 12 17 D 13 16 D. 14 17 D 15 14 D 16 14 D 17 17 D 18 16 D 19 14 D 20 17 D 21 15 D 22 17 D 23 14 D 24 13 D 25 13 D 26 12 D 27 10 D 28 5 D 29 4 D 30 3 31 4 D 32 5 D 33 4 D 34 4 D 35 4 D 36 3 D 37 5 D 38 5 D 39 10 D 40 9 D 41 11 D U PACIFIC SOILS ENGINEERING, INC. APPENDIX C LAM PACIFIC SOILS ENGINEERING, INC. Work Order 401036G November 30, 2009 HOMEOWNER MAINTENANCE AND IMPROVEMENT CONSIDERATIONS General Homeowners and/or residents must assume a certain degree of responsibility for improvements 0 and for maintaining conditions. Maintaining drainage patterns and minimizing the soil moisture variation below all improvements are of primary importance. Such design, construction and maintenance provisions may include: Employing contractors for improvements who design and build in recognition of local building codes and specific site soils conditions. Establishing and maintaining positive drainage away from all foundations, walkways, driveways, patios, and other hardscape improvements. • Avoiding the construction of planters adjacent to structural improvements. Alternatively, planter sides/bottoms can be sealed with an impermeable membrane and drained away from the improvements via subdrains into approved disposal areas. Sealing and maintaining construction/control joints within concrete slabs and walkways to reduce the potential for moisture infiltration into the subgrade soils. Utilizing landscaping schemes with vegetation that requires minimal watering. Watering should be done in a uniform manner, as equally as possible on all sides of the foundation, keeping the soil "moist" but not allowing the soil to become saturated. Maintaining positive drainage away from structures and providing roof gutters or all structures with downspouts that are designed to carry roof runoff directly into area drains or discharged well away from the foundation areas. Avoiding the placement of trees closer to the proposed structures than a distance of one-half the mature height of the tree. Observation of the soil conditions around the perimeter of the structure during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to maintain relatively uniform moisture conditions. Ll Sulfates Homeowners should be cautioned against the import and use of certain inorganic fertilizers, soil amendments, and/or other soils from offsite sources in the absence of specific information relating to their chemical composition. Some fertilizers have been known to leach sulfate- PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 19 November 30, 2009 compounds into soils otherwise containing "negligible" sulfate concentrations and increase the sulfate concentrations to potentially detrimental levels. In some cases, concrete improvements constructed in soils containing high levels of soluble sulfates may be affected by crystalline growth or mineral accumulation, which may, in the long term, result in deterioration and loss of strength. Site Drainage • The owners should be made aware of the potential problems that may develop when drainage is altered through construction of retaining walls, paved walkways, patios or other hardscape improvements. Ponded water, drainage over the slope face, leaking irrigation systems, . overwatering or other conditions which could lead to ground saturation must be avoided. No water should be allowed to flow over the slopes. No alteration of pad gradients should be allowed that would prevent pad and roof runoff from being directed to approved disposal areas. • As part of site maintenance, all roof and pad drainage should be directed away from slopes and around structures to approved disposal areas. All berms were constructed and compacted as part of fine grading and should be maintained by the resident. Drainage patterns have been established at the time of the fine grading should be maintained throughout the life of the structure. No alterations to these drainage patterns should be made unless designed by qualified professionals in compliance with local code requirements and site-specific soils conditions. • Slope Drainage - Homeowners should be made aware of the importance of maintaining and cleaning all interceptor ditches, drainage terraces, downdrains, and any other drainage devices, which have been installed to promote slope stability. Subsurface drainage pipe outlets may protrude through slope surfaces and/or wall faces. These pipes, in conjunction with the graded features, are essential to slope and wall stability and must be protected in-place. They should not be altered or damaged in any way. Planting and Irrigation of Slopes Seeding and planting of the slopes should be planned to achieve, as rapidly as possible, a well-established and deep-rooted vegetal cover requiring minimal watering. PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 20 November 30, 2009 It is the responsibility of the landscape architect to provide such plants initially and of the residents to maintain such planting. Alteration of such a planting scheme is at the resident's risk. • The homeowner is responsible for proper irrigation and for maintenance and repair of properly installed irrigation systems. Leaks should be fixed immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wasteful runoff and serious ground saturation must be avoided If automatic sprinkler systems are installed, their use must be adjustedto account for seasonal and natural rainfall conditions. • Burrowing Animals Homeowners must undertake a program to eliminate burrowing animals. This must be an ongoing program in order to promote slope stability. Owner Improvements Homeowner improvements (patio slabs, retaining walls, planters, etc.) should be designed to account for the terrain of the project, as well as expansive soil conditions and chemical characteristics. Design considerations on any given lot may need to include provisions for differential bearing materials, ascending/descending slope conditions, bedrock structure, perched (irrigation) water, special geologic surcharge loading conditions, expansive soil stresses, and long-term creep/settlement. All owner improvements should be designed and constructed by qualified professionals utilizing appropriate design methodologies, which account for the on-site soils and geologic conditions. • Setback Zones Manufactured slopes may be subject to long-term settlement and creep that can manifest itself in the form of both horizontal and vertical movement. These movements typically are produced as a result of weathering, erosion, gravity forces, and other natural phenomenon. A setback adjacent to slopes is required by most building codes, including the California Building Code. This zone is intended to locate and support the residential structures away from these slopes and • onto soils that are not subject to the potential adverse effects of these natural phenomena. PACIFIC SOILS ENGINEERING, INC. I Work Order 401036G Page 21 November 30, 2009 The homeowner may wish to construct patios, walls, walkways, planters, etc. within this zone. Such facilities may be sensitive to settlement and creep and should not beconstructed within the setback zone unless properly engineered. It is suggested that plans for such improvements be designed by a professional engineer who is familiar with hillside grading ordinances and design and construction requirements associated with hillside conditions In addition, we recommend that the designer and contractor familiarize themselves with the site specific geologic and geotechrncal conditions on the specific lot S S S • S - PACIFIC SOILS ENGINEERING, INC. i9 10 - PACIFIC SOILS ENGINEERING, INC. 7715 CONVOY COURT. SAN DIEGO, CALIFORNIA 92111 TELEPHONE: (858) 560-1713, FAX: (858) 560-0380 D.R. HORTON INC. 1021 Costa Pacifica Way #2107 Oceanside, CA 92054 September 1, 2009 Work Order 401036G Attention: Ms. Kim Molina Subject: Project Grading Report, Model Site, Lots 1 through 4, La Costa Ridge Project, Neighborhood 2.6, in the City of Carlsbad, California Reference: See Appendix A Gentlemen: Presented herein are Pacific Soils Engineering, Inc.'s (PSE) geotechnical data and test results pertaining to the completion of grading for the model site at the La Costa Ridge Project, Lots 1 through 4, in the City of Carlsbad, California. This report pertains to the grading operations that were performed in August of 2009. PSE provided geotechnical observation and testing services during cut and fill grading operations for the subject project. Data developed during the grading are summarized in the text of this report, on the enclosed 40-scale grading plan (Plate 1) and in Table I. Also presented herein are foundation and slab recommendations based upon field and laboratory testing of as-graded soil conditions. Cuts, fills and processing of original ground covered by this report have been completed under PSE's testing and observation. Based on the testing and observations, the grading summarized herein is considered to be in general conformance with the City of Carlsbad grading code, the 40-scale grading plan, and the referenced geotechnical reports. Slopes are considered grossly stable and should remain so under normal conditions. To reduce exposure to erosion, landscaping of graded slopes should be accomplished as soon as possible. Drainage berms and swaies should be established and maintained to aid in long-term slope protection. CORPORATE HEADQUARTERS LOS ANGELES COUNTY RIVERSIDE COUNTY SOUTH ORANGE COUNTY TEL: (714) 220-0770 TEL: (310) 325-7272 or (323) 776-6771 TEL: (951) 582-0170 TEL: (714) 730-2122 FAX: )714) 220-9589 FAX: (714) 220-9589 FAX: (951) 582-0176 FAX: (714) 730-5191 fl . Work Order 4010360 Page 2 September 1, 2009 1.0 ENGINEERING GEOLOGY 1.1 Geologic Units The geologic unit encountered during the grading of the subject site included previously placed undocumented artificial fill, topsoil and granitic rock. Prior to the placement of compacted fill the existing undocumented fill, topsoil and highly weathered granitic rock were completely removed. 1.2 Structure Based upon review of available literature, maps and aerial photographs and PSE's geologic observation and mapping of project grading, the onsite granitic is considered to be unfaulted. Minor fractures were observed. 1.3 Corrective Grading Corrective grading in the form of stabilization fills and/or buttresses was not recommended. 1.4 Groundwater Groundwater was not encountered on Lots I through 4 during grading. 1.5 Conclusions From an engineering geologic viewpoint, the model site, Lots 1 through 4, located in the City of Carlsbad, California are suitable for their intended residential use. 2.0 PROJECT GRADING 2.1 Compaction Test Results Compaction test results are presented in Table I (Appendix B). Approximate locations are shown on the enclosed 40-scale grading plan (Plate 1). Compaction testing was conducted utilizing Campbell Pacific Nuclear Test Gauges (ASTM:D 2922 and 3017). 2.2 Removals 2.2.1 The removal of unsuitable existing artificial fill, topsoil and highly weathered granitic rock was accomplished to competent granitic bedrock (Kgr). Prior to the placement of compacted fill, the exposed surface was scarified, moisture 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page .3 September 1, 2009 40 conditioned to a minimum of optimum moisture or slightly above, and compacted. 2.2.2 Removals, excavations, cleanouts and processing in preparing fill areas were observed by PSE's representatives prior to the placement of fill reported herein. 2.3 Compacted Fill Placement Fill consisting of the soil types indicated in Table I was placed in thin lifts (approximately six to eight inches), moisture conditioned to optimum moisture or slightly above and compacted to a minimum of 90 percent relative compaction (ASTM:D 1557). This was accomplished utilizing self-propelled, rubber-tired compactors, along with heavy earth moving equipment. Each succeeding fill lift was treated in a similar manner. 2.4 Fill Slope Construction - The fill slopes were built to grade and were shaped and compacted by track walking. Finish slope surfaces have been probed and/or tested and are considered to satisfy the project requirements and the grading codes of the City of Carlsbad. The soil - materials utilized to construct the fill slopes are subject to erosion and creep. As such, landscaping and irrigation management are important elements in the long-term performance of slopes and should be established and maintained as soon as possible and maintained through the life of the project. 2.5 Depth of Fill Compaction testing was performed approximately for each one to two feet of fill placed. The approximate maximum vertical depth of fill placed on individual lots is presented below in Table 2.1. PACIFIC SOILS ENGINEERING. INC. S Work Order 401036G Page 4 September 1, 2009 Fr AIainwmDepth:ofFl1 Lot Number Depth of Fill (feet) - 1 - 5 2 5.5 3 8 4 5.5 3.0 PROPOSED DEVELOPMENT The subject site is proposed for single-family residential use. One- and two-story family dwellings will be constructed utilizing wood-frame and post-tensioned, slab-on-grade foundation systems 4.0 DESIGN RECOMMENDATIONS 4.1 Expansion Index Materials utilized for compacted fill ranged from "very low" to "high" in expansion potential. Sampling of the post-grading conditions was conducted for Lots 1 through 4 to determine the expansion potential per ASTM:D 4829. That evaluation revealed "medium" expansive materials on the subject lots. Soluble sulfate content was also tested (see Section 4.11). The laboratory test data are presented in Table 4.1. TABLE 4.1 Laboratory Test Data and Lot Categories F r0t Fxpansi Lot PQIUtJ 1-4 1 61 1 Medium I II I 0.003 4.2 Foundation Design Criteria I. The following foundation design recommendations and the design parameters presented in Table 4.2 may be utilized to design the foundations for the proposed iS PACIFIC SOILS ENGINEERING. INC. Work Order 401036G Page 5 September 1, 2009 structure. The post-tensioned slab parameters presented herein are based on procedures outlined in the Design of Post-Tensioned Slabs-on-Ground, Third Edition by Post-Tensioning Institute, per the 2007 CBC. Allowable Bearing: 2000 lbs./sq.ft. (assuming a minimum embedment depth of 12-inches and a minimum width of 12 inches) Lateral Bearing: 250 lbs./sq.ft. per foot plus 125 lbs/ft2 for each additional foot embedment to a maximum of 2000 lbs/ft2 Sliding Coefficient: 0.35 Total Settlement: 3%-inch Differential Settlement: 3/8-inch in 20 feet. The above values may be increased as allowed by Code to resist transient loads such as wind or seismic. Building Code and structural design considerations may govern. Depth and reinforcement requirements should be evaluated by the Structural I Engineer. I • I 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 6 September 1, 2009 TABLE 4.2 POST-TENSIONED FOUNDATION DESIGN CRITERIA* CENTER LIFT EDGE LIFT MINIMUM A ll Perimeter Beam SOIL LOT EXPANSION EMBEDMENT Conditions CATEGORY NUMBERS POTENTIAL (INCHES)** Em (ft.) I Ym (in.) Em (ft.) Ym (in.) II 1-4 Medium 18 9.0 0.46 5.4 1.10 Footing/Slab Dimensions The footing width, depth and the structural slab-on-grade thickness shall be as specified by the structural engineer based upon the soil parameters provided by PSE and the requirements of the most current CBC guidelines. Under-Slab Requirements An approved moisture and vapor retarder should be placed below all slabs-on-grade within living and moisture sensitive areas as discussed in Section 4.4. Slab Subgrade Moisture Requirements Based Upon Expansion Potential I Minimum of 130 percent of optimum moisture at least 24 hours prior to Soil Category II placing concrete to a depth of 12 inches. Footing Embedment If exterior footings adjacent to drainage swales are to exist within five (5) feet horizontally of the swale, the footing should be embedded sufficiently to assure embedment below the swale bottom is maintained. Footings adjacent to slopes should be embedded such that at least seven (7) feet are provided horizontally from edge of the footing to the face of the slope. * The values of predicted lift presented in this table are based on procedures outlines in the Design of Post-Tensioned Slabs-on-Ground, Third Edition. No corrections for vertical barriers at edge of slab or other corrections (such as tree roots under the slab or horizontal barriers) are assumed. The design parameters are based on a Constant Suction Value of 3.9 pF. **Foundations supporting multiple stories may require additional embedment. The foundation designer should verify whether additional embedment is required based on the type of structure being constructed and the requirements of the most current CBC. 4.3 Seismic Design Parameters The following seismic design parameters are presented to be code compliant to the California Building Code (2007). The subject site has been identified as "D" site . class in accordance with CBC, 2007, Table 1613.5.3 (1). The site is located at Latitude 33.1058'N and Longitude 117.2266' W. Utilizing this information, the computer program USGS Earthquake Ground Motion Parameters Version 5.0.7 and ASCE 7 criterion, the seismic design category for 0.20 seconds (Ss) and 1.0 second (Si) period response accelerations can be determined (CBC, 2007 1613.5.5.1) along with the design spectral response acceleration (CBC, 2007 1613.5.4). 0 PACIFIC SOILS ENGINEERING. INC. . Work Order 401036G Page 7 September 1, 2009 4.4 Moisture Barrier A moisture and vapor retarding system should be placed below the slabs-on-grade in portions of the structure considered to be moisture sensitive. The retarder should be of suitable composition, thickness and strength, and have low permeability to effectively prevent the migration of water and reduce the transmission of water vapor to acceptable levels. Historically, a 10-mil plastic membrane, such as Vis queen, placed between one to four inches of clean sand, has been used for this purpose. The use of this system or other systems, materials or techniques can be considered, at the discretion of the designer, provided the system reduces the vapor transmission rates to acceptable levels 4.5 Footing Excavation Observations The project soil engineer or his representative should observe footing excavations for the proposed structures prior to the placement of concrete. 4.6 Minimum Depth of Embedment For the subject site, where foundations for structures are to exist in proximity to slopes, the footings should be embedded to satisfy the requirements presented in Figure 1. S i. S 5 PACIFIC BOILS ENGINEERING, INC. Work Order 401036G Page 8 September 1, 2009 FIGURE 1 FAcOF FOOTING TOP OF SLX SLOPE Ifr FAOOF DE OF STRUCTURE M, NEED NOT FT. OPE EM rr NOT LESS • HG BUT NEED NOT EXCEED 15 FT. (4.572 nun) MAX 4.7 Backyard Improvements Future improvements such as patios, slabs, pools, and perimeter screen walls can be constructed within the setback zones; however, the design and siting of all such improvements should be reviewed by a soil engineer who is familiar with the site- specific conditions reported herein. Walls should be structurally separated at appropriate intervals. Wall footing excavations should be observed by the project soils engineer/engineering geologist. 4.8 Retaining Wall Design Retaining walls should be founded on compacted fill or bedrock. Foundations may be designed in accordance with the recommendations presented in Section 4.2. In general, conventional walls can be designed to retain select granular backfill. It should be anticipated that suitable backfill material will have to be imported or selectively produced from onsite sources, and should consist of granular "very low" to "low" expansive materials. Conventional walls constructed with select granular backfill or native soils can be designed to resist lateral pressures that are developed by a fluid as presented on Table 4.3. 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 9 September 1, 2009 TABLE 4.3 EARTH PRESSURE COEFFICIENTS SELECT COMPACTED BACKFILL Unit weight = 130 lbs. I Cu. ft. Cohesion = 200 lbs. / sq. ft. . Friction angle = 32 degrees Rankine Equivalent Fluid Level Backfill Coefficients Pressure (psfllin.ft.) Coefficient of Active Pressure: Ka = 0.31 40 Coefficient of Passive Pressure: K = 3.25 423 Coefficient of At-Rest Pressure: K0 = 0.47 61 2:lBackfill Coefficient of Active Pressure: K = 0.47 61 Coefficient of Passive Pressure: Descending K(-)= 1.23 161 Coefficient of At-Rest Pressure: K0 0.72 94 Per the 2007 CBC, presented below are seismic earth pressure coefficients that may be utilized in the design of retaining walls. TABLE 4.4 SEISMIC EARTH PRESSURE COEFFICIENTS Rankine Equivalent Fluid Level Backfill Coefficients Pressure (psfllin.ft.) Coefficient of Active Pressure: Ka = 0.54 70 Coefficient of Passive Pressure: K = 3.02 393 2:lBackfill Coefficient of Active Pressure: K = 0.70 91 Coefficient of Passive Pressure: K, (-) = 1.0 130 Restrained retaining walls should be designed for "at-rest" conditions, utilizing 1(0. Retaining walls should be backfilled with a free draining material (SE>20) extending horizontally from the back of the retaining wall a minimum of one-half the height of the retaining wall to within 12 inches of grade (Figure 2). Backfill should be compacted to project specifications. Native soils shall be utilized in the upper 12 inches. Drainage systems including, as a minimum, a 4-inch diameter perforated drain line surrounded by four cubic feet per lineal foot of 3/4-inch to 1-inch crushed rock wrapped with a suitable filter fabric, should be provided to cantilever and restrained retaining walls to relieve hydrostatic pressure. PACIFIC SOILS ENGINEERING, INC. [] Work Order 401036G Page 10 September 1, 2009 FIGURE 2 RETAINING WALL BACKFILL N.T.S. PROVIDE DRAINAGE / SWALE NATIVE BACKFILL 11/2 MPH. 12 IN, MIN. 1 NATIVE OR SELECT .. ' BACKFILL F SELECT I BACKFILL DRAIN LATERALLY. OR PROVIDE WEEP K ED AND N f.SE~;2O OR AS MODIFIED BY A SPECIFIC REPORT (13 4 INCH PERFORATED PVC, SCHEDULE 40, SDR 35 OR APPROVED ALTERNATE, PLACE PERFORATIONS DOWN AND SURROUND WITH 4 CU. FT. PER FT,OF INCH ROCK OR APPROVED ALTERNATE AND P4IRAFI 140 FILTER FABRIC OR APPROVED EQUIVALENT 4.8.1 Other Design and Construction Considerations The design loads presented in Tables 4.3 and 4.4 are to be applied on the retaining wall in a horizontal fashion. Friction between wall and retained soils should not be allowed in the retaining wall analyses. > Additional allowances should be made in the retaining wall design to account for the influence of construction loads, temporary loads and possible nearby structural footing loads. Unit weights of 125 pcf and 130 pcf may be used to model the dry and wet density of onsite compacted fill materials. > Select backfill, imported or native, should be granular, structural quality backfill with a sand equivalent of 20 or better and an ASCE Expansion Index of 20 or less. The backfill must encompass the full active wedge area. > No backfill should be placed against concrete until minimum design strengths are achieved in compression tests of cylinders. > Footing excavations for retaining walls should be observed by the project soil engineer or his representative. 16 PACIFIC SOILS ENGINEERING, INC. U i• i• S Work Order 401036G Page II September 1, 2009 Backfill should be compacted to a minimum of 90 percent of the laboratory maximum density at or slightly above optimum moisture as per ASTM:D 1557-02. It should be noted that the bearing capacity and passive resistance values presented in Section 4.2 are based on level conditions at the toe. Modified Ll design parameters can be presented for retaining walls with sloped conditions at the toe. 4.9 Utility Trenches 4.9.1 Excavation All utility trenches should be shored or laid back in accordance with applicable OSHA standards. Excavations in bedrock areas should be made in consideration of underlying geologic structure. Pacific Soils Engineering, Inc. should be consulted on these issues during construction. The onsite soils are classified as Soil Type B per OSHA standards. 4.9.2 Backfill 0 Mainline and lateral utility trench backfill should be compacted to at least 90 percent of maximum dry density as determined by ASTM:D-1557-02. Onsite soils will not be suitable for use as bedding material but will be suitable for 0 use in backfill, provided oversized materials are removed. No surcharge loads should be imposed above excavations. This includes spoil piles, lumber, concrete trucks or other construction materials and equipment. Drainage above excavations should be directed away from the banks. Care should be taken to avoid saturation of the soils. Compaction should be accomplished by mechanical means. Jetting of native soils will not be acceptable. Under-slab trenches should also be compacted to project specifications. If native soils are used, mechanical compaction is recommended. If select granular backfill (SE> 30) is used, compaction by flooding will be acceptable. The soil engineer should be notified for inspection prior to placement of the membrane and slab reinforcement. The use of a double layer of mesh across under-slab plumbing trenches is considered an acceptable alternative to compaction of sand backfill. 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 12 September 1, 2009 4.10 Exterior Slabs and Walkways 4.10.1 Subgrade Compaction Thesubgrade below exterior slabs, sidewalks, driveways, patios, etc. should be compacted to a minimum of 90 percent relative compaction as determined by ASTM Test Method: D 1557-02. 4.10.2 Subgrade Moisture The subgrade below exterior slabs, sidewalks, driveways, patios, etc. should be moisture conditioned to a minimum of 120 percent of optimum moisture content prior to concrete placement. 4.10.3 Slab Thickness Concrete flatwork and driveways should be designed utilizing four-inch minimum thickness. 4.10.4 Control Joints Weakened plane joints should be installed on walkways at intervals of approximately eight feet. Exterior slabs should be designed to withstand shrinkage of the concrete, 4.10.5 Flatwork Reinforcement Consideration should be given to reinforcing any exterior flatwork. 4.10.6 Thickened Edge Consideration should be given to construct a thickened edge (scoop-footing) at the perimeter of slabs and walkways adjacent to landscape areas to minimize moisture variation below these improvements. The thickened edge (scoop-footing) should extend approximately eight inches below concrete slabs and should be a minimum of six inches wide. 4.11 Chemical Tests The results of chemical tests conducted during rough grading indicate that the soluble sulfate concentrations of the majority of the site materials tested are below 0.1. As such, soluble sulfate potential of near surface soils can be classified as "negligible", in accordance with Table 4.3.1 of ACI 318-05. 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 13 September 1, 2009 4.12 Concrete Design As stated in Section 4.6, negligible concentrations of sulfates were detected in the onsite soils. Therefore, per AC1 318-05, the use of sulfate-resistant concrete is not required. 5.0 OTHER DESIGN AND CONSTRUCTION CONSIDERATIONS 5.1 Site Drainage Positive drainage away from structures should be provided and maintained. Roof, pad and slope drainage should be collected and directed away from the proposed structures to approved disposal areas. It is important that drainage be directed away from foundations. This is especially true in patio areas and greenbelt areas. The recommended drainage patterns should be established at the time of fine grading and maintained throughout the life of the structure. 5.2 Service Utility Trench Backfill Service utility trench backfill should be accomplished in accordance with the prevailing criteria of the City of Carlsbad. 5.3 Seismic Design Seismic design should be based on current and applicable building code requirements. 7.0 HOMEOWNER CONSTRUCTION AND MAINTENANCE RESPONSIBILITIES During and upon completion of mass grading of the subject site, representative soil samples were tested for expansive soil characteristics and soluble sulfate concentrations. The results of these tests are presented in Table 4.1 of the text. In addition, certain lots contain manufactured slopes within or adjacent to the building pad area. All of these conditions should be considered in design, construction and maintenance of homeowner improvements. The homeowners should be advised of certain responsibilities they must accept in consideration of these factors. Suggested information to educate the homeowners regarding these responsibilities is presented in Appendix C. We suggest that • PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 14 September 1, 2009 this information be provided to all homeowners as part of an information packet during the sales process. This report presents information and data relative to the mass grading and/or placement of compacted fill at the subject site. A representative(s) of this firm conducted periodic tests and observations during the progress of the construction in an effort to determine whether compliance with the project drawings, specifications and Building Code were being obtained. The presence of our personnel during the work process did not involve the direction or supervision of the contractor. Technical advice and suggestions were provided to the owner and/ his representative based upon the results of the tests and observations. Completed work under the purview of this report is considered suitable for the intended use. Conditions of the reference reports remain applicable unless specifically superseded herein. Respectfully submitted PACIFIC S ILS EN CI NEERIN , INC. Reviewed by: SCO~7 A. GRAY, 91 MftPftY, G 18 Manager of Geotechmcal Services Manager of Geologic Se ices Dist: (4) Addressee OESSI0 013/SAG/DAMjz400589AM, January 16,2009 No. 67391 - Exp. I)O PACIFIC SOILS ENGINEERING, INC. APPENDIX A 'i- fl PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 15 September 1, 2009 Pacific Soils Engineering, Inc., 2009a, Observations and Recommendations of Wet Area in Southeast Corner of the La Costa Ridge Project, City of Carlsbad, California, dated August 21, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009b, Supplemental Geotechnical Investigation, La Costa Ridge Project, City of Carlsbad, California, dated July 21, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009c, Foundation Plan Review, La Costa Ridge Project, City of Carlsbad, California, dated June 22, 2009 (Work Order 401036). Pacific Soils Engineering, Inc., 2009d, Updated Foundation Design Recommendations, La Costa Ridge Project, City of Carlsbad, California, dated February 16, 2009 (Work Order 401036). Pacific Soils Engineering, Inc. 2007a, Reinforced 1.5: 1 Fill Slope Recommendations, La Costa Ridge Neighborhood 2.6, Carlsbad, California, dated June 13, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007b, Response to Plan Check Review Comment, La Costa Ridge Project, in the City of Carlsbad, California, dated June 25, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007c, Embankment Constraints, La Costa Ridge Neighborhood 2.6, Carlsbad, California, by Pacific Soils Engineering, Inc., dated February 21, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2007d, Updated Preliminary Geotechnical Investigation, La Costa Ridge Project, in the City of Carlsbad, California, by Pacific Soils Engineering, Inc., dated February 15, 2007 (Work Order 401036). Pacific Soils Engineering, Inc., 2006a, Suitability of Stockpile Material, La Costa Ridge 2.6-Acre Parcel, Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Carlsbad, CA, dated February 15, 2006 (Work Order 401036). • Pacific Soils Engineering, Inc., 2006b, Supplemental Geotechnical Recommendations, La Costa Ridge Project, in the City of Carlsbad, CA, dated January 16, 2006 (Work Order 401036). Pacific Soils Engineering, Inc., 2005a, Preliminary Geotechnical Investigation, La Costa Ridge Project (Approximately 7+-Acre Parcel), in the City of Carlsbad, California, dated June 2, 2005 (Work Order 401036). Pacific Soils Engineering, Inc., 2005b, Geotechnical Summary, La Costa Ridge 2.6-Acre Parcel, Located Southwest of Rancho Santa Fe Road and Melrose Drive, City of Carlsbad, CA, dated March 29, 2005 (Work Order 401036). 0 PACIFIC SOILS ENGINEERING, INC. APPENDIX B 1-1 Ll 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G La Cosa Ridge Models September 1, 2009 TABLE I Laboratory Testing Laboratory Maximum Density ASTM:D 1557-02 (All Soil Types) Rock Corrections were calculated based on ASTM: D 4718 Optimum Maximum Moisture Dry Density Soil Type & Description (% dry wt.) (lbs./cu.ft.) B - Light Brown Sandy Silt 9.3 117.3 C - Brown Silty Sand 10.9 121.5 E - Brown Silty Sand w/Gravel 9.0 128.4 E25 - Brown Silty Sand w/Gravel (25% rock*) - 7.0 135.7 E30 - Brown Silty Sand w/Gravel (30% rock*) 6.6 137.2 • * percent rock was estimated based on field conditions LEGEND Non-Designated Test - Indicates test taken in compacted fill. Test Location - Indicated by street and street stationing, by specified utility line number or stationing, or by direction from closest adjacent building, or by lot and unit number. - Indicates side of center line in direction of ascending stationing. Elevation - Indicated by approximate field elevation (feet) above mean sea level. TEST TYPE N - Indicates test by Campbell Pacific Nuclear Test Gauge (per ASTM:D 2922-05 and D 3017-05). 0 PACIFIC SOILS ENGINEERING. INC. . . Work Order 401036G La Costa Ridge Models September 1, 2009 TABLE I (cont'd) Depth Test or Moisture Unit Dry Density Rel. Soil Test Proj. Date Number Test Location Elev. Opt. Field Max. Field Comp. Type Type Spec. Pass/Fail 8/14/09 148 Lot 358 10.9 113 121.5 116.4 95 C N 90 Pass 8/14/09 149 Lot 355 10.9 11.8 121.5 117.0 96 C N 90 Pass 8/17/09 152 Lot 355 9.3 12.1 117.3 108.5 92 B N 90 Pass 8/17/09 153 Lot 357 9.3 12.8 117.3 108.6 92 13 N 90 Pass 8/18/09 165 Lot 358 7.0 9.8 135.7 129.6 95 E25 N 90 Pass 8/18/09 166 Lot 359 7.0 9.6 135.7 129.9 95 E25 N 90 Pass 8/24/09 195FG Lot 1 360.0 6.6 8.9 137.2 133.5 97 E30 N 90 Pass 8/24/09 196FG Lot 359.0 6.6 6.9 137.2 129.2 94 E30 N 90 Pass 8/24/09 197FG Lot 359.0 6.6 6.8 137.2 133.2 97 £30 N 90 Pass 8,24/09 198FG Lot 358.6 6.6 8.2 137.2 128.9 93 £30 N 90 Pass APPENDIX C 0 0 PACIFIC SOILS ENGINEERING, INC. Work Order 4005 89AM Mr. Jeff O'Connor January 16, 2009 HOMEOWNER MAINTENANCE AND IMPROVEMENT CONSIDERATIONS General Homeowners and/or residents must assume a certain degree of responsibility for improvements and for maintaining conditions. Maintaining drainage patterns and minimizing the soil moisture variation below all improvements are of primary importance. Such design, construction and maintenance provisions may include: s • Employing contractors for impràvements who design and build in recognition of local building codes and specific site soils conditions. Establishing and maintaining positive- diainagë away from all foundafi6'ñãll4s, driveways, patios, and other hardscape improvements. Avoiding the construction of planters adjacent to structural improvements. Alternatively, planter sides/bottoms can be sealed with an impermeable membrane and drained away from the improvements via subdrains into approved disposal areas. Sealing and maintaining construction/control joints within concrete slabs and walkways to reduce the potential for moisture infiltration into the subgrade soils. Utilizing landscaping schemes with vegetation that requires minimal watering. Watering . should be done in a uniform manner, as equally as possible on all sides of the foundation, keeping the soil "moist" but not allowing the soil to become saturated. + Maintaining positive drainage away from structures and providing roof gutters on all structures with downspouts that are designed to carry roof runoff directly into area drains or discharged well away from the foundation areas. Avoiding the placement of trees closer to the proposed structures than a distance of one-half the mature height of the tree. Observation of the soil conditions around the perimeter of the structure during extremely hot/dry or unusually wet weather conditions so that modifications can be made in irrigation programs to maintain relatively uniform moisture conditions. 0 PACIFIC SOILS ENGINEERING, INC. Work Order 401036G Page 17 September 1, 2009 Sulfates Homeowners should be cautioned against the import and use of certain inorganic fertilizers, soil amendments and/or other soils from offsite sources in the absence of specific information relating to their chemical composition. Some fertilizers have been known to leach sulfate- compounds into soils otherwise containing "negligible sulfate concentrations and increase the sulfate concentrations to potentially detrimental levels. In some cases, concrete improvements . constructed in soils containing high levels of soluble sulfates may be affected by crystalline growth or mineral accumulation, which may, in the long term, result in deterioration and loss of strength. Site Drainage The owners should be made aware of the potential problems that may develop when drainage is altered through construction of retaining walls, paved walkways, patios or other hardscape improvements. Ponded water, drainage over the slope face, leaking irrigation systems, overwatering or other conditions which could lead to ground saturation must be avoided. No water should be allowed to flow over the slopes. No alteration of pad gradients should be allowed that would prevent pad and roof runoff from being directed to approved disposal areas. As part of site maintenance, all roof and pad drainage should be directed away from slopes and around structures to approved disposal areas. All berms were constructed and compacted as part of fine grading and should be maintained by the resident. Drainage patterns have been established at the time of the fine grading should be maintained throughout the life of the structure. No alterations to these drainage patterns should be made unless designed by qualified professionals in compliance with local code requirements and site-specific soils conditions. • 0 PACIFIC BOILS ENGINEERING, INC. Work Order 4010360 Page 18 September 1, 2009 Slope Drainage Homeowners should be made aware of the importance of maintaining and cleaning all interceptor ditches, drainage terraces, downdrains, and any other drainage devices, which have been installed to promote slope stability. + Subsurface drainage pipe outlets may protrudethrough slope surfaces and/or wall faces. These pipes, in conjunction with the graded features, are essential to slope and wall stability and must be protected in-place. They should not be altered or damaged in any way. Planting and Irrigation of Slopes 4 Seeding and planting of the slopes should be planned to achieve, as rapidly as possible, a well-established and deep-rooted vegetal cover requiring minimal watering. It is the responsibility of the landscape architect to provide such plants initially and of the residents to maintain such planting. Alteration of such a planting scheme is at the resident's risk. The homeowner is responsible for proper irrigation and for maintenance and repair of properly installed irrigation systems. Leaks should be fixed immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. Overwatering with consequent wasteful runoff and serious ground saturation must be avoided. If automatic sprinkler systems are installed, their use must be adjusted to account for seasonal and natural rainfall conditions. Burrowing Animals Homeowners must undertake a program to eliminate burrowing animals. This must be an ongoing program in order to promote slope stability. Owner Improvements Homeowner improvements (patio slabs, retaining walls, planters, etc.) should be designed to account for the terrain of the project, as well as expansive soil conditions and chemical characteristics. Design considerations on any given lot may need to include provisions for differential bearing materials, ascending/descending slope conditions, bedrock structure, perched (irrigation) water, I. PACIFIC SOILS ENGINEERING, INC. I. is I. i0 i• i. Work Order 401036G Page 19 September 1, 2009 special geologic surcharge loading conditions, expansive soil stresses, and long-term creep/settlement. All owner improvements should be designed and constructed by qualified professionals utilizing appropriate design methodologies, which account for the on-site soils and geologic conditions. Setback Zones Manufactured slopes may be subject to long-term settlement and creep that can manifest itself in the form of both horizontal and vertical movement. These movements typically are produced as a result of weathering, erosion, gravity forces, and other natural phenomenon.. A setback - adjacent to slopes is required by most building codes, including the California Building Code. This zone is intended to locate and support the residential structures away from these slopes and onto soils that are not subject to the potential adverse effects of these natural phenomena. The homeowner may wish to construct patios, walls, walkways, planters, etc. within this zone. Such facilities may be sensitive to settlement and creep and should not be constructed within the setback zone unless properly engineered. It is suggested that plans for such improvements be designed by a professional engineer who is familiar with hillside grading ordinances and design and construction requirements associated with hillside conditions. In addition, we recommend that the designer and contractor familiarize themselves with the site specific geologic and geotechnical conditions on the specific lot. . PACIFIC SOILS ENGINEERING, INC.