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Home My WebLink AboutMS 07-05; JONES MINOR SUBDIVISION; PRELIMINARY GEOTECHNICAL INVESTIGATION; 2007-05-03CONSTRUCTION TESTING & ENGINEERING. INC. SAN DIEGO, CA RIVERSIDE, CA VENTURA, CA TRACY, CA SACRAMENTO, CA N. PALM SPRINGS, CA 1441 Montiel Road 12155 Magnolia Ave. 1645 Pacific Ave. 242W. Larch 3628 Madison Ave. 19020 N. Indian Ave. Suite 115 Suite 6C Suite 107 Suite F Suite 22 Suite 2-K Escondido, CA 92025 Riverside, CA 92503 Oxnard, CA 93033 Tracy, CA 95376 N. Highlands, CA 95660 N. Palm Springs, CA 92258 (760) 746-4955 (951) 352-6701 (805) 486-6475 (209) 839-2890 (916) 331-6030 (760) 329-4677 (760) 746-9806 FAX (951) 352-6705 FAX (805) 486-9016 FAX (209) 839-2895 FAX (916)331-6037 FAX (760) 328-4896- FAX PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED THREE LOT RESIDENTIAL DEVELOPMENT 1369 MAGNOLIA AVENUE CARLSBAD, CALIFORNIA PREPARED FOR: TONY CASSOLATO 576 CAMINO ELDORADO ENCINITAS, CALIFORNIA 92024 CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CA 92026 CTE JOB NO. 10-8791G APRIL 3, 2007 \\Cte_server\projects\] 0-8791G\Rpt_Geotech. Invest..doc GEOTECHNICAL I ENVIRONMENTAL I CONSTRUCTION INSPECTION AND TESTING I CIVIL ENGINEERING I SURVEYING TABLE OF CONTENTS Section Page INVESTIGATIONSUMMARY .....................................................................................................1 1.0 INTRODUCTION AND SCOPE OF SERVICES ....................................................................1 1.1 Introduction ........................................................... ..........................................................1 1.2 Scope of Services...........................................................................................................2 2.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ................................................... 2 2.1 Site Description ....... ....................................................................................................... 2 2.2 Proposed Development ........................................................................... . ....................... 3 3.0 FIELD AND LABORATORY INVESTIGATIONS.................................................................3 3.1 Field Investigations........................................................................................................3 3.2 Laboratory Investigation ................................................................................................4 4.0 GEOLOGY .................................................................................................................................4 4.1 General Setting ............................................................................................................... 4 4.2 Site Geologic Conditions .............................. . ................................................................ 4 4.2.1 Quaternary Undocumented Fill (unmapped) ........................................................5 4.2.2 Topsoil and Residual Soil (unmapped).................................................................5 4.2.3 Quaternary Terrace Deposits (Qt).........................................................................5 4.3 Groundwater Conditions ................................................................................................. 6 4.4 Geologic Hazards...........................................................................................................6 4.4.1 Local and Regional Faulting .............................................................. . ................... 6 4.4.2 Liquefaction and Seismic Settlement Evaluation .................................................8 4.4.3 Tsunamis and Seiche Evaluation ..........................................................................8 4.4.4 Landsiiding or Rocksliding .................... . ............................................... . ............... 8 4.4.5 Compressible and Expansive Soils ............................................... ........................ 9 4.4.6 Corrosive Soils......................................................................................................9 5.0 CONCLUSIONS AND RECOMMENDATIONS ..................................................................10 5.1 General.........................................................................................................................10 5.2 Grading and Earthwork ................................................................................................ 10 5.3 Site Preparation............................................................................................................11 5.4 Excavations..................................................................................................................12 5.5 Fill Placement and Compaction...................................................................................12 5.6 Fill Materials ................................................................................................................ 13 5.7 Temporary Construction Slopes .................... ................................................................ 13 5.8 Foundations and Slab Preliminary Recommendations ................................................14 5.8.1 Foundations.........................................................................................................14 5.8.2 Foundation Setback.............................................................................................15 5.8.3 Concrete Floor Slabs...........................................................................................15 5.9 Seismic Design Criteria ...............................................................................................16 5.10 Lateral Resistance and Earth Pressures .............................................. . ........................ 16 \\Ctesei vet \project\! fl- 879 1 C\Rpt Geotech, Invest .doc 5. 10 Lateral Resistance and Earth Pressures ..................................................................... 16 5.11 Exterior Concrete Flatwork ....................................................................................... 18 5.12 Vehicular Pavements ................................................................................................. 18 5.13 Drainage.....................................................................................................................19 5.14 Slopes ........................................................................................................................ 20 5.15 Construction Observation .........................................................................................20 5.16 Plan Review .............................................................................................................. 20 5.17 Addendum Geotechnical Report and Plan Review...................................................21 6.0 LIMITATIONS OF INVESTIGATION .................................................................................. 21 FIGURES FIGURE 1 FIGURE 2 FIGURE 3 APPENDICES APPENDIX A APPENDIX B APPENDIX C APPENDIX D INDEX MAP EXPLORATION LOCATION / GEOLOGIC MAP REGIONAL FAULT AND SEISMICITY MAP GENERAL REFERENCES FIELD METHODS AND EXPLORATION LOGS LABORATORY METHODS AND RESULTS STANDARD GRADING SPECIFICATIONS \\Cteserver\project') 0-879 G\RptGeotech Invest. doc Preliminary Geotechnical Investigation Page 1 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G INVESTIGATION SUMMARY This report provides geotechnical information for the proposed three lot residential development located at 1369 Magnolia Avenue in Carlsbad, California. Our geotechnical investigation found that Quaternary terrace deposit bedrock overlain by residual silty sand soils are in the proposed imprcvement areas at the site. The bedrock materials were generally found to be dense to very dense and suitable for support of the planned improvements, as recommended herein. Active faults or other geologic hazards are not considered to present a significant impact to the site. The site is located in the San Diego area, which has a relatively high risk for ground shaking associated with seismic activity. However, the risk to this site is typical of the Carlsbad/San Diego area. In general, the results of our investigations indicate that from a geotechnical perspective the proposed project can be constructed as planned provided the recommendations presented in this report are followed. 1.0 INTRODUCTION AND SCOPE OF SERVICES 1.1 Introduction This report presents the results of our preliminary geotechnical investigation and provides conclusions and geotechnical engineering criteria for the proposed residential improvements to be constructed at the referenced site. Our investigation included field exploration, laboratory testing, \\Cte_server\projects\10-879 lG\Rpt_0eotech. Invest. .doc Preliminary Geotechnical Investigation Page 2 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Sob No. 10-8791G geologic hazard evaluation, and engineering analysis. Preliminary geotechnical recommendations for site grading and foundations, pavements, and concrete slabs and flatwork are presented in this report. Cited references are presented in Appendix A. Work was authorized via CTE Proposal Number G-1347, dated September 29, 2006. 1.2 Scope of Services The scope of services provided included: Review of available geologic and soils reports pertinent to the site and adjacent areas. Exploration of subsurface conditions by six test pits excavated with a CAT 420 rubber tire backhoe. Laboratory testing of representative soil samples to provide data for evaluation of geotechnical characteristics of the site soils. Evaluation of potential geologic hazards at the site. Development of soil engineering design criteria for the proposed improvements. Preparation of this summary report. 2.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT 2.1 Site Description The site address is 1369 Magnolia Road, in Carlsbad, California. Existing residences surround the proposed improvement areas of the site. At the time of our explorations, an abandoned house and shed was along the northern portion of the site, adjacent to Magnolia Avenue. The remaining site area is covered by grass. A stockpile of soil is at the southeast .corner of the site. The site surface elevations are approximately 150 to 160 feet above mean sea level (msl), and surface drainage sheet flows to the west, towards Yvette Way. Figures 1 and 2 are drawings showing the approximate location and configuration of the site. \\Ctc_seiver\piojects\ 10-8791 GRptGeotech. Invest. .doc Preliminary Geotechnical Investigation Page 3 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 GTE Job No. 10-8791G 2.2 Proposed Development Planned site improvements are to consist of three, one'- to two-story wood framed residential structures and associated minor improvements. Anticipated construction is shallow strip footings and isolated pad footings for the lightly-loaded one- to two-story structures. Basements or other subsurface structures are not anticipated at this site. In addition, an approximate nine foot high fill slope is proposed along the west margin of the property. Detailed locations of the proposed structures at the site is unknown and therefore not shown on Figure 2 3.0 FIELD AND LABORATORY INVESTIGATIONS 3.1 Field Investigations Field explorations, conducted on February 16, 2007, included site reconnaissance and the excavation of six exploratory test pits to assess the condition of the subsurface soil materials. Test pits were excavated using a CAT 420 rubber tire backhoe to the maximum explored depth of six feet. Soils were logged in the field by a CTE geologist and visually classified using the Unified Soil Classification System. The field descriptions have been modified, where appropriate, to reflect laboratory test results. Exploration logs including descriptions of the soil are included in Appendix B. Approximate exploration locations are shown on Figure 2. Bulk soil samples were collected from the explorations for geotechnical laboratory testing. Samples collected in this manner were placed in sealed plastic bags and bulk bags, and transported to the CTE geotechnical laboratory for testing. \\Cte_server\projects\1 0-879 G\Rpt_Geotech. hwest..doc I Preliminary Geotechnical Investigation I Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 3.2 Laboratory Investigation Page 4 CTE Job No. 10-87 Laboratory tests were conducted on representative soil samples for classification purposes and to evaluate physical properties and engineering characteristics. Tests conducted on select soil samples include: particle-size analysis, maximum dry density and optimum moisture content (Modified Proctor test), chemical analysis (sulfate, chloride, pH, conductivity, and resistivity), and R-Value. Test method descriptions and laboratory results are included in Appendix C. 4.0 GEOLOGY 4.1 General Setting San Diego is located with the Peninsular Ranges physiographic province which is characterized by northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending regional faults. The San Diego region can be further subdivided into the coastal plain area, central mountain—valley area and the eastern mountain valley area. The project site is located along the western margin of the coastal plain area. The coastal plain subprovince ranges in elevation from approximately sea level to 1200 feet above mean sea level and is characterized by Cretaceous and Tertiary sedimentary deposits that onlap an eroded basement surface consisting of Jurassic and Cretaceous crystalline rocks. 4.2 Site Geologic Conditions Regional geologic mapping by Tan and Kennedy (1996) indicates site bedrock is Quaternary-age terrace deposits. According to our explorations, topsoil and residual soil overlie the bedrock at the site. In addition, small amounts of fill, as well as a stockpile of soil materials, were locally \\Cte_server\piojects\ I 0-8791 O\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 5 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G encountered. Following is a description of the soil and bedrock based upon our site explorations. A general assessment of these materials is also provided. 4.2.1 Quaternary Undocumented Fill (unmapped) Undocumented Fill soil was found stockpiled in the southeast corner of th site. The material appeared to consist of light brown, silty sands. In addition, a small amount of fill material was encountered in TP-2, which is located in a previous garden area. These materials contained small amounts of rubbish. These materials will require overexcavation and compaction to produce an engineered fill. 4.2.2 Topsoil and Residual Soil (unmapped) Topsoil and residual soil was encountered in each of the test pit explorations. These surficial soils generally consist of slightly moist, loose to medium dense, dark brown to brown, silty, fine sand with organic materials. These materials will require overexcavation and compaction to produce an engineered fill. 4.2.3 Quaternary Terrace Deposits (Qt) Quaternary-age terrace deposit bedrock was encountered below the surfIcial soil in each of the test pit explorations. The bedrock generally consists of slightly moist, dense to very dense, mottled brown to orange brown, silty fine sandstone. According to Tan and Kennedy (1996), this unit has been regionally correlated with the Quaternary Bay Point Formation. These materials are suitable for support of engineered fills and improvement, as recommended herein. \\Cteserver\projects\!0-879I G\.RptGeotech. Invest. .doc I Preliminary Geotechnical Investigation Page 6 I Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California I April 3, 2007 CTE Job No. 10-8791G 4.3 Groundwater Conditions I Groundwater was not encountered to a maximum explored depth of six feet. Surface seepage or springs were not observed at the time of our explorations. I 4.4 Geologic Hazards Geologic hazards at the site are primarily limited to shaking from earthquake generated ground I motion waves. The potential for surface damage from displacement or fault movement beneath the I proposed structure is considered to be very low. Following is a presentation of possible geologic hazards as they may impact the site. A general assessment of these possible geologic hazards as they I apply o the site is also presented. I 4.4.1 Local and Regional Faulting I Based on our site reconnaissance, evidence from the site subsurface explorations, and review of the referenced literature, no known active fault traces underlie or project toward the site. I According to the California Division of Mines and Geology, a fault is active if it displays evidence of activity in the last 11,000 years (Hart and Bryant, 1997). I The California Geological Survey broadly groups faults as "Class A" or "Class B" (CDMG, I 1996). Class A faults are identified based upon relatively well constrained paleoseismic activity, and a fault slip rate of more than 5 millimeters per year (mmlyr). In contrast Class B I faults have comparatively less defined paleoseismic activity and are considered to have a I fault slip rate less than 5 mm/yr. The nearest known Class A fault to the site is the Temecula I segment of the Elsinore Fault, which is approximately 38.3 kilometers west of the site. The \\Cteserver\projects\ 0-879 1 G\RpLGeotech. Invest. .doc Preliminary Geotechnical Investigation Page 7 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G following Table 1 presents the six nearest faults to the site, including magnitude and fault classification. The attached Figure 3 shows regional faults and seismicity with respect to the site. TABLE 1 NEAR SITE FAULT PARAMETERS FAULT NAME DISTANCEFROM 0 SITE (km) MAXIMUM EARTHQUAKE MAGNITUDE CLASSIFICATION Rose Canyon 8.9 7.2 B Newport-Inglewood (offshore) 9.5 7.1 B Coronado Bank 34.6 7.6 B Elsinore- Temecula 38.3 6.8 A Elsinore-Julian 38.6 7.1 A Elsinore-Glen Ivy 54.1 . 6.8 A California Geologic Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page (on line pshamap.asp) indicates ground motions with 10% probability of exceedance in 50 years for the site as underlain by firm bedrock are shown on Table 2. TABLE2 - SITE GROUND MOTION WITH io PROBABIIJTY OF EXCEEDANCE IN 50 YEARS PARAMETER UNIT GRAVITY (soft rock) Ground Acceleration 0.294 Spectra! Acceleration at Short (0.2 second) Duration 0.703 Spectra! Acceleration at Long (1.0 second) Duration 0.319 \\Cte_server\projects\ 0-8791 G\Rpt_Geotech. Invest. .doc I Preliminary Geotechnical Investigation Page 8 I Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 GTE Job No. 10-8791G The site could be subjected to significant shaking in the event of a major earthquake on any of the faults listed in Table 1 or other regional faults in the southern California or northern Baja California area. However, the seismicity of the site is similar to conditions in the San Diego area. 4.4.2 Liquefaction and Seismic Settlement Evaluation Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths during earthquake induced shaking and behave as a liquid. This is due to loss of point-to--point grain contact and transfer of normal stress to the pore water. Liquefaction potential varies with water level, soil type, material gradation, relative density, and probable intensity and duration of ground shaking. The site is underlain by dense to very dense, silty sandstone bedrock. Therefore, it is Our opinion that the potential for damage resulting at the site due to liquefaction or seismic settlement is negligible. 4.4.3 Tsunamis and Seiche Evaluation The site is not near any significant bodies of water that could induce seiche damage. Potential tsunami damage is not considered to present a significant adverse geologic factor to the site due to distance from the ocean (approximately one mile) and elevation (approximately 150 feet above mean sea level). 4.4.4 Landsliding or Rocksliding According to Tan and Giffen (1995) the site lies within an area considered generally susceptible to landsliding. However, active landslides were not encountered by our field exploration and have not been regionally mapped near the site. Therefore, landsliding is not \\Cte_server\projccts\ 10-8791 O\Rpt Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 9 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G considered a significant geologic hazard within or immediately adjacent to the proposed structures. 4.4.5 Compressible and Expansive Soils Based on site observations, in-situ testing, and our general knowledge of geologic conditions in the vicinity of the site, it is our opinion that onsite formational bedrock is not compressible. However, near surface unconsolidated soils are considered to be compressible and should be removed and placed as compacted engineered fill in accordance with the recommendations of this report. Based on geologic observation, review of regional geologic documents, and laboratory testing of near site materials, the underlying terrace deposit bedrock at the site exhibits very low to low expansion characteristics. 4.4.6 Corrosive Soils Analytical test results indicate that site earth materials have a low potential to corrode Portland cement concrete. It also appears that, according to electrical resistivity testing, site soil materials have a mild potential to corrode buried ferrous metals. CTE does not practice corrosion engineering. Therefore, a corrosion consultant shall be retained for additional information or recommendations, if necessary. \\Cte_server\piojects\ 0-8791 0\Rpt_Geotech. Invest. doc Preliminary Geotechnical Investigation Page 10 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General The site can be developed from a geotechnical perspective provided the recommendations of this report are followed. Topsoils and residual soils are unsuitable for support of structures or structural fill in their present condition. Therefore, in areas to receive structures or structural fill these soils should be excavated, objectionable materials removed, and processed as a compacted engineered fill placed under observation and testing of a CTE representative. Compacted fill should be placed on competent bedrock in structural areas. Prior to placement of compacted fill, a suitable surface should be exposed under the observation and testing of a CTE representative. Recommendations for the proposed earthworks and improvements are included in the following sections and Appendix D. However, recommendations in the text of this report supersede those presented in Appendix D. The recommendations may require modifications based on the conditions encountered during grading or as presented in addendums prepared prior to grading as proposed property use and plans become available. 5.2 Grading and Earthwork Upon commencement of work for the demolition of the existing structure or site grading, whichever occurs first, CTE personnel should continuously observe the grading and earthwork operations for this project. CTE personnel should perform observation and testing of soil removal, processing, and placement during grading as they pertain to the Geotechnical Consultants professional opinions and recommendations contained herein. \\Cte_server\projects\10-879 I G\Rpt_Geotech. Investdoc Preliminary Geotechnical Investigation Page 11 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G 5.3 Site Preparation The site should be cleared of any existing debris and other deleterious materials including the previously placed fills, topsoil, and residual soil. Objectionable materials such as demolition debris and vegetation should be removed from the materials prior to placement as compacted fill. In areas to receive structures or distress-sensitive improvements, expansive, surficial eroded, desiccated, burrowed, or otherwise loose or disturbed soils should be removed to the depth of competent bedrock or 18-inches below the bottom of foundations, whichever depth is greater. Flatwork and pavement area removals and scarification should extend at least 12 inches beyond the edge of the concrete. Where such improvements are planned, subgrades should be overexcavated at least 12 inches, prior to scarification of 12 inches, moisture conditioning, and compaction. These preparations should be the minimum anticipated. Deeper removals, based on the conditions encountered, may be necessary. Removals should extend a minimum five feet laterally beyond the perimeter of proposed structures or at a 1:1 plane downward from the footing bottom edge, whichever is greater. Based on our investigation we anticipate removal depths on the order of three feet will be necessary; however. locally deeper removals may be required. An engineer or geologist from CTE should observe the exposed ground surface prior to placement of compacted fill. Removals should continue until suitable materials are encountered. Organic and other deleterious materials not suitable for structural backfill should be disposed of offsite at a regulated disposal site. Select grading to reduce expansion \\Cte_server\projects\ I 0-879! G\Rpt_Geotech. lnvest..doc Preliminary Geotechnical Investigation Page 12 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G qualities of the site soils may also be necessary depending upon materials encountered. If groundwater conditions are encountered, installation of subdrains along the bottom of the overexcavations may also be required. 5.4 Excavations Excavation of surficial soils to a bedrock surface observed by a CTE representative is recommended in area; to receive structures or structural fill. Excavations in site materials are considered feasible with standard heavy-duty grading equipment under normal conditions. Irreducible materials generally greater than three inches in diameter should not be used in shallow fills on the site. However, such materials may be place at depth as per the recommendations in Appendix D or as recommended by CTE during construction. The Geotechnical Consultant should evaluate the exposed surface prior to placement of compacted fill. 5.5 Fill. Placement and Compaction The Geotechnical Consultant should observe that site preparation has occurred before placement of compacted fill. Subsequent to removal of loose, disturbed, or vegetation containing soils, areas to receive fills should be scarified, moisture conditioned, and compacted fill placed. Fill should be compacted to a minimum relative compaction of 90 percent as evaluated by ASTM D1557 at moisture contents a minimum of two percent above optimum. Fill lift thickness depends on the type of compaction equipment used. Generally, fill should be placed in uniform lifts not exceeding eight inches in loose thickness. Fill placement and compaction should be done in overall conformance with geotechnical recommendations of this report and local ordinances. \\Cte_server\projects\ 10-8791 G\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 13 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G 5.6 Fill Materials Very low to low expansion potential soils derived from the onsite materials are generally considered suitablefor reuse on the site as compacted fill. If used, these materials should be screened of significant construction debris, vegetation matter and materials greater than three inches in diameter. Adverse effects of moderately to highly expansive clay soils, if encountered, should be mitigated by blending these soils with granular materials and compacting at moisture contents of at least two percent above optimum, or by placing all medium to highly expansive clays as a compacted fill at a minimum depth of four feet below proposed site grades. Imported fill beneath structures, pavements and walks should have an expansion index 30 or less with less than 35 percent passing the no. 200 sieve. Imported fill soils for use in structural or slope areas should be evaluated by the Geotechnical Consultant before placement on the site. 5.7 Temporary Construction Slopes Sloping recommendations for unshored temporary excavations are provided herein. The recommended slopes should be relatively stable against deep-seated failure, but may experience localized sloughing. Recommended slope ratios are set forth in Table 3 TABLE 3 ' RECOMMENDED TEMPORARY SLOPE RATIOS SLOPE RATIO SOILS TYPE MAXIMUM HEIGHT (Horizontal: Vertical) B (Bedrock) 1:1 (MAXIMUM) 10 FEET C (Topsoil/Residual Soil) 1.5:1 (MAXIMUM) 10 FEET \\Cte_server\pi'ojects\ 10-879 G\Rpt_Geotech, Invest. .doc Preliminary Geotechnical Investigation Page 14 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G Actual field conditions and soil type designations must be verified by a "competent person' while excavations exist according to Cal-OSHA regulations. In addition, the above sloping recommendations do not allow for potential water seepage or surcharge loading at the top of slopes by vehicular traffic, equipment or materials. Appropriate surcharge setbacks must be maintained from :he top of all unshored slopes and slope repair areas. We do not anticipate temporary construction shoring will be necessary for this project. However, should shoring become necessary, CTE will provide additional design and construction recommendations, upon request. 5.8 Foundations and Slab Preliminary Recommendations o The following recommendations are for preliminary planning purposes. It is assumed that foundations will be underlain by at least 18 inches of compacted fill. The project engineer should evaluate all footing trenches before reinforcing steel placement. Upon completion of rough grading, Expansion Index testing should be performed and the recommendations herein modified, if necessary, in the Building Pad As-Graded Report. 5.8.1 Foundations Continuous and isolated spread footings underlain by at least 18 inches of compacted fills should be designed based on an allowable bearing capacity of 2,000 psf. The bearing value may be increased by 1/3 for short duration loadings. Following are foundation minimum recommendations for one- to two-story structures. The recommendations are dependent upon \\Cte_sei'ver\projects\10-8791 O\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 15 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G depth and geometry of underlying fill and Expansion Index. Additional foundation recommendations can be provided should fill parameters change or Expansion Index exceed 50. Foundations designed and constructed as outlined below are expected to have maximum total and differential settlements less than 1.0 and 0.5 inches, respectively. Moisture in foundation excavations and slab-on-grade areas should be maintained until overlying improvements are placed. Single-story structures underlain by less than 10 feet of compacted fill and with Expansion Index less than or equal to 50 can be constructed with a 12-inch wide and 12-inch deep (below lowest adjacent rough grade) continuous perimeter footing reinforced with four number 4 bars, two at the top and two at the bottom. Two-story structures underlain by soils described above, should utilize a minimum 15-inch wide by 18-inch deep continuous perimeter foundation. Isolated pad footings should be at least 24 inches wide and extend 12 inches below lowest adjacent rough grade. The structural engineer should provide recommendations for isolated footing reinforcement. 5.8:2 Foundation Setback If applicable, footings for structures should be designed such that the horizontal distance from the face of nearby slopes to the outer edge of the footing is at least 10 feet. 5,8.3 Concrete Floor Slabs Lightly loaded concrete slabs should be designed for the anticipated loading, but measure a minimum of 4.5 inches thick. If elastic design is used, a 150 psi/inch modulus of subgrade \\Cte_server\projects\ 10-879 1 G\Rpt_Geotech. livest. .doc Preliminary Geotechnical Investigation Page 16 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G reaction is considered appropriate. Minimum slab reinforcement should consist of #3 reinforcing bars placed on 18-inch centers, each way, at mid-slab height. In moisture sensitive floor areas, a vapor barrier of ten-mil visqueen overlying a niaximum two-inch layer of consolidated aggregate base (SE greater than 30) should b installed. At a maximum, a two-inch layer of similar material may be placed above the visqueen to protect the membrane during steel and concrete placement 5.9 Seismic Design Criteria The following table summarizes seismic design parameters from the California Building Code (CBC, I 2001). The values listed in Table 4 are applicable to faults listed in Table 1. TABLE 4 SEISMIC DESIGN PARAMETERS PARAMETER VALUE CBC REFERENCE Seismic Zone Factor 0.4 Figure 16-2 Soil Profile Type SD Table 16-J Seismic Coefficient, C, 0.44 Table 16-Q Seismic Coefficient, C. 0.67 Table 16-R Near-Source Factor, N, 1.0 Tajle 16-S Near Source Factor, N., 1.04 TaDle 16-T Seismic Source B Table 16-U 5.10 Lateral Resistance and Earth Pressures The following recommendations may be used for shallow footings on the site. Foundations may be designed using a coefficient of friction of 0.30 (total frictional resistance equals the coefficient of \\Cte_server\projects\ 0-879: G\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 17 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G friction times the dead load). A design passive resistance value of 250 pounds per square foot per foot of depth (with a maximum value of 1250 pounds per square foot) may be used. The allowable lateral resistance can be taken as the sum of the frictional resistance and the passive resistance, provided the passive resistance does not exceed two-thirds of the total allowable resistance. Retaining walls up to twelve feet high and backfilled using granular soils (Expansion Index less than 20) may be designed using the equivalent fluid weights given in the following Table 5. TABLE EQUIV \LENI FLUID UNIT WEIGHTS (pounds per cubic toot) WALL TYPE LEVEL BACKFILL SLOPE BACKFILL 2:1 (HORIZONTAL: VERTICAL) CANTILEVER WALL 35 55 (YIELDING) RESTRAINED WALL . 55 85 We recommend that all walls be backfilled with soil having an expansion index of 20 or less. Importing wall backfill soils may be necessary should on-site soils not meet the Expansion Index recommendations. The backfill area should include the zone defined by a 1:1 sloping plane, extended back from the base of the wall. Retaining wall backfill should be compacted to at least 90 percent relative compaction, based on ASTM D1557. Backfill should not be placed until walls have achieved adequate structural strength. Heavy compaction equipment, which could cause distress to walls, should not be used. \\Cte_server\projects\10-879 I G\RptGeotech. Invest. .doc I Preliminary Geotechnical Investigation Page 18 I Propcsed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 GTE Job No. 10-8791G The above values assume non-expansive backfill and free draining conditions. Measures should be taken to prevent a moisture buildup behind all walls below grade. Drainage measures should include free draining backfill materials and perforated drains. Drains should discharge to an appropriate offsite location. The project architect or structural engineer should determine the necessity of waterproofing the subterranean walls to reduce moisture infiltration. 5.11 Exterior Concrete Flatwork Exterior concrete flatwork for pedestrian loads should measure a minimum 4.5 inches thick and have minimal reinforcement of #3 bars on 18-inch centers (both ways). Reinforcement should be placed in the upper one-third of the slab and with appropriate minimum cover. Flatwork should be installed with reinforcement and crack control joints. All subgrade should be prepared according to recommendations provided in Section 5.3 "Site Preparation" of this report. However, subgrade for exterior concrete slabs should be pre-soaked and tested to be at a minimum 130% of optimum moisture content just prior to concrete placement. Positive drainage to convey water away from all flatwork should be established and maintained. Minimizing landscape areas adjacent to critical flatwork areas is also recommended. 5.12 Vehicular Pavements The upper foot of subgrade beneath proposed pavements and all aggregate base materials should be moisture conditioned and compacted to at least 95% of the laboratory maximum density. Additionally, subgrade should be overexcavated at least 12 inches, prior to scarification of 12 inches, 1 These 1 h 4 ,,,-,-, ,, 1 ms L. conditioning, compaction. i ii_s_ preparations SliOulLi uie miflirnuiji LnLilalc, Deeper removal, based on the conditions encountered, may be necessary. \\Cte_servei\projects\ 10-879 0\RptGeotech. Invest..doc Preliminary Geotechnical Investigation Page 19 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G Preliminary pavement sections presented below are based on a laboratory determined Resistance "R' Value of a near surface soil sample collected at the site. The asphalt pavement design is based on California Department of Transportation Highway Manual, and estimated traffic as indicated in Table 3 below. If these assumptions are incorrect, this office should be contacted to obtain further pavement recommendations. .TABLE3 PAVEMENT RECOMMENDATIONS Class II PCC AC Traffic Area Assumed Subgrade R- Thickness Thickness Aggregate Base Traffic Index Value Thickness (inches) (inches) (inches) 5.5 - - Auto Parking and 45 50+ Drive Areas 4.0 3.0 Alter rough grading, we recommend testing finish subgrade soils to determine their Resistance "R"- value. This testing may enable us to provide modified pavement recommendations. Either the project civil, structural engineer or architect should specify joint layout and detailing, and concrete specifications. The City of Carlsbad should be contacted to ascertain their involvement regarding their review and approval of the exposed subgrade R-Value soil sampling plan and recommended I section. I 5.13 Drainage Surface runoff should be collected and directed away from improvements by means of appropriate erosion reducing devices and positive drainage should be established around the proposed improvements. Positive drainage should be directed away from improvements at a gradient of at \\Cte_server\projects\1 0-8791 G\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 20 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 •CTE Job No. 10-8791G least 2 percent for a distance of at least five feet. The project civil engineer should evaluate the on- site drainage and make necessary provisions to keep surface water from affecting the site. 5.14 Slopes Slopes at this site should be constructed at 2:1 (horizontal: vertical) or flatter surface ratio. Surface water should not be permitted to drain over the edges of slopes unless that water is confined to properly designed and constructed drainage facilities. Erosion resistant vegetation should be maintained on the face of all 2:1 slopes. 5.15 Construction Observation The recommendations provided in this report are based on preliminary design information for the proposed construction and the subsurface conditions found in our exploratory test pit locations. The interpolated subsurface conditions should be checked in the field during construction. Recommendations provided in this report are based on the understanding and assumption that CTE will provide the observation and testing services for the project. All geotechnical related work should be observed and tested as they pertain to recommendations contained within this report. All foundation excavations should be evaluated by a CTE representative. 5.16 Plan Review CTE should review the project grading and foundation plans before the start of earthworks. Depending upon the review, an addendum report may be necessary depending upon development specifc conditions. \\Cteserver\projects\10-879 1 G\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 21 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 CTE Job No. 10-8791G 5.17 Addendum Geotechnical Report and Plan Review An addendum report should be prepared as project use and plans are more defined and available. The addendum report would provide additional geotechnical recommendations, as necessary, for the development-specific project proposed. This addendum report may also incorporate a review of the project grading/improvement, and/or foundation plans. 6.0 LIMITATIONS OF INVESTIGATION The recommendations provided in this report are based on the anticipated construction and the subsurface conditions found in our explorations. The interpolated subsurface conditions should be checked in the field during construction. Recommendations provided in this report are based on the understanding and assumption that CTE will provide the observation and testing services for the project. All earthworks should be observed and tested in accordance with the recommendations of contained within this report. The Geotechnical Consultant should evaluate all footing trenches before reinforcing steel placement. The field evaluation, laboratory testing and geotechnical analysis presented in this report have been conducted according to current geotechnical engineering practice and the standard of care exercised by reputable geotechnical consultants performing similar tasks in this area. No other warranty, expressed or implied, is made regarding the conclusions, recommendations and opinions expressed in this report. Variations may exist and conditions not observed or described in this report may be \\Cte..server\projects\ I 0-8791 G\Rpt_Geotech. Invest. .doc Preliminary Geotechnical Investigation Page 22 Proposed Three Lot Residential Development 1369 Magnolia Avenue, Carlsbad, California April 3, 2007 . CTE Job No. 10-8791G encountered during construction. The scope of this report does not include an evaluation of environmental conditions at the site. The recommendations herein have been developed to minimize the expansion potential of the onsite materials. However, even with the design and construction precautions herein, some post- construction heave of the onsite materials may occur. Our conclusions and recommendations are based on the observed conditions. if conditions different from those described in this report are encountered, our office should be notified and additional recommendations, if required, will be provided upon request. We appreciate this opportunity to be of service on this project. If you have any questions regarding this report, please do not hesitate to contact the undersigned. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. Dan T. Math, GE# 2665 Geotechnical Engineer 1/08 C'ni /(vrcLtorv cLDen Kilian Proj ect Geologist DAK!GFR/DTM:nri Dist: (4) Addressee Rzonca, CEG #1191 ineering Geologist \\Cte_servcr\projects\ I O879] GRpt_Geotech. Invest. .doc OF ,2%Orn \•:i \ : I Ile- If APPROXIMATE I \ \ I SITE LOCATION I \ \ / ' \ 1 \ \ ;• A I \ \1,Fd \\' \\ • Ire I' I' ' \ 1 ' \ \ ( & kin raa,Iia Ave - I, ) ay oce A 74 - CONSTRUCTION TESTING & ENGINEERING, INC. GEOTECHNICAL AND CONSTRUCTION ENGINEERING TESTING AND INSPECTION - 1441 MONTIEL ROAD. STE lIT ESCONDIDO CA 9202612601 7464950 CIE JOB NO: SITE INDEX MAP 10-8791G PROPOSED THREE LOT DEVELOPMENT SCALE: 1369 MAGNOLIA ROAD DATE: AS SHOWN CARLSBAD, CALIFORNIA 03/07 U LEGEND I U 0 HISTORIC FAULT MOVEMENT 01 2 - HOLOCENE (ACTIVE) FAULT MOVEMENT - / - SCALE 1" = 12 MILES - _____ LINEAR ALIGNED EARTHQUAKE EPICENTERS I 47 '~Mz QUATERNARY FAULT (YOUNGER THAN 1.6 MILLION YEARS) DISPLACEMENT AGE UNDIFFERENTIATED IIA PRE-QUATERNARY (OLDER THAN 1.6 MILLION YEARS) DISPLACEMENT FAULT r 1800- 1869 1932 0 ' ' PERIOD 1868 1931 1999 I I - fl 7.0 ", I I , 000 G• ••.. 6.5-6.9 0 ______ 67 5.5- 5.9 CII) U [:54 0 LAST TWO DIGITS OF M> 65 EARTHQUAKE YEAR 'IN C7 I i '_ - •\\I \\ I APPROXIMATE . I .. '. ••\ \. - SflELOCATION ~o (92 01 Ilk ZI 7 I EII --ij t1 4,1 )I/..\1" _.i. •I-3I - : 4• 10) t'__ / •. -t / - 0 NOTES: FAULT MAP ADAPTED AFTER JENNINGS, 1994, CDMG MAP NO. 6; REGIONAL FAULT REFERENCE FOR ADDITIONAL EXPLANATION CONSTRUCTION TESTING & ENGINEERING INC. THREE L EPICENTERS OF AND AREAS DAMAGED BY M>5 CALIFORNIA EARTHQUAKES, 1600-1999 ADAPTED PLANNING -CIVIL ENGINEERING - LAND SURVEYING - GEOTECHNICAL 1369 ! CDMG MAP SHEET 49 q !~s AFTER TOPPOZADA, BRANIJM, PETERSEN, HAILSTORM, CRAMER, AND REICULE, 2000, 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO CA. 92026, PH:(760) 746-4955 CARTS} u....rsI. T MAflttb, fl#d...-. JI1/24WI7 1.1-AS DQT AND SEISMICITY MAP CALIFORNIA _______ 10-8791G 1 inch = 12 miles 03/07 I APPENDIX A GENERAL REFERENCES \\CTE_SERVER\PROIECTS\J 0-879! G\RPT GEOTECH. INVEST. .DOC I GENERAL REFERENCES I 1. 2001 California Building Code, "California Code of Regulations, Title 24 Part 2, Volume I I", California Building Standards Commission, published by ICBO, 2002. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using I Modified Effort", Volume 04.08. Blake, T.F., 1996, "EQFAULT," Version 2.20, Thomas F. Blake Computer Services and I Software. California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by I Martin and Ross. I 5. Hart, Earl W. and Bryant, W.A., 1997, "Fault-Rupture Hazard Zones in California, Alquist- Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps," California Division of Mines and Geology, Special Publication 42. I 6. Tan, S. S. and Kennedy, M., 1996, "Geologic Map of the Oceanside, San Luis Rey, and San Marcos 7.5' Quadrangles, San Diego County, California", in: Geologic Maps of the I Northwestern Part of San Diego County, California, California Division of Mines and Geology, Open File Report 96-02. I 7. Tan, S.S. and Giffen, D.G., 1995, "Landslide Hazards in the Northern Part of the San Diego Metropolitan Area, San Diego County, California, Oceanside and San Luis Rey I Quadrangles," California Division of Mines and Geology. 8. TOPO!, 2000, "Seamless USGS Topographic Maps on CD-ROM", California, Disc ii of 11: San Diego, Wildflower Productions. I \\CTE_SERVER\PROJECTS\ I 0-1179! G\RPT GEOTECH. INVEST,.DOC I I APPENDIX B FIELD EXPLORATION LOGS \\CTE_SERVER\PROJECTS\I 0-879 G\Rvr GEOTECH. INVEST..DOC A ' CONSTRUCTION TESTING & ENGINEERING, INC. S•' 600TECHNICAL I CONSTRUCTION ENGIEERING TESTING AND INSPECTION 1441 Mo NI IEL ROAD, SUITE 115 I IS C ONDI 0 0. CA 92055 I 760746.4605 DEFINITION OF TERMS PRIMARY DIVISIONS SYMBOLS SECONDARY DIVISIONS GRAVELS CLEAN WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES MORE THAN GRAVELS ________ LITTLE OR NO FINES -. GP POORLY GRADED GRAVELS OR GRAVEL SAND MIXTURES, z HALF OF <5% FINES I COARSE LITTLE OF NO FINES CF) L1 N FRACTION IS GRAVELS GM SILTY r N_ GRAVELS, GRAVEL-SAND-SILT MIXTURES, - X LARGER THAN WITH FINES ___1. NON-PLASTIC CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES, NO.4 SIEVE GC PLASTIC FINES SANDS CLEAN WELL GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO MORE THAN SANDS _________ FINES sr POORLY GRADED SANDS, GRAVELLY SANDS, LITTLE OR b HALF OF <5% FINES COARSE _________ __________ NO FINES ___________________________________ SANDS J ~ M SILTY SANDS, SAND-SILT MIXTURES, NON-PLASTIC FINES L) FRACTION IS SMALLER THAN WITH FINES ''E CLAYEY SANDS, SAND-CLAY MIXTURES, PLASTIC FINES NO.4 SIEVE I I I I ML 11 INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY C#S LL u N SILTS AND CLAYS J, >J CLAYEY FINE SANDS, SLIGHTLY PLASTIC CLAYEY SILTS CL IN CLAYS OF LOW TO MEDIUM PLASTICITY, LIQUID LIMIT IS LESS THAN 50 GRAVELLY, SANDY, SILTS OR LEAN CLAYS 1 iui,1 ORGANIC SILTS AND ORGANIC CLAYS OF LOW PLASTICITY 1 j IOL M14 SANDY INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SILTS AND CLAYS OR SILTY SOILS, ELASTIC SILTS // ' // INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS LIQUID LIMIT IS GREATER THAN 50 OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTY CLAYS HIGHLY ORGANIC SOILS PEAT AND OTHER HIGHLY ORGANIC SOILS GRAIN SIZES BOULDERS COBBLES GRAVEL I SAND I I SILTS AND CLAYS COARSE I FINE COARSE I MEDIUM I FINE I 12" 3" 3/4" 4 10 40 200 CLEAR SQUARE SIEVE OPENING U.S. STANDARD SIEVE SIZE ADDITIONAL TESTS (OTHER THAN TEST PIT AND BORING LOG COLUMN HEADINGS) MAX- Maximurr. Dry Density PM- Permeability PP- Pocket Penetrometer GS- Grain Size Distribution SG- Specific Gravity WA- Wash Analysis SE- Sand Equivalent HA- Hydrometer Analysis . DS- Direct Shear El- Expansion Index AL- Atterberg Limits UC- Unconfined Compression CHivI- Sulfate and Chloride RV- R-Value MD- Moisture/Density Content , pH, Resistivity . CN- Consolidation M- Moisture COR - Corrosivity CP- Collapse Potential SC- Swell Compression SD- Sample Disturbed . HC- Hydrocollapse 01- Organic Impurities REM- Remolded FIGURE:l BL1 : CONSTRUCTION TESTING & ENGINEERING, INC. c G007ECUNICAL CONSTRUCTION ENGINEERING TESTING AGO INSPECTION 1441 MaNuEL 4040, SUITE 115 5000710100. CE 62526 I 740.044.4624 PROJECT: DRILLER: SHEET: of CTE JOB NO: DRILL METHOD: DRILLING DATE: LOGGED BY: . SAMPLE METHOD: ELEVATION: 15 .3 C/) BORING LEGEND Laboratory Tests DESCPJPTION - . - Block or Chunk Sample - - - X __ - Bulk Sample - - 5- - .- - - - Standard Penetration Test 10— - - / - - Modified Split-Barrel Drive Sampler (Cal Sampler) - - - I - - Thin Walled Army Corp. of Engineers Sample - - 15- - Groundwater Table - - _ Soil Type or Classification Change - - - Formation Change [(Approximate boundaries queried (?)1 - "SM" . Quotes are placed around classifications where the soils 25 exist in situ as bedrock FIGURE: I BL2 CONSTRUCTION TESTING & ENGINEERING, INC. GEOTECHNICAL I CONSTRUCTION ENGINEERING TESTING AND INSPECTION 144 MONTIEI. ROAD. SUITE 5 I A SCONOIDO, CA 02010 I 760, 044.4005 PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CTE JOB NO: 10-8791G - EXCAVATION METHOD: BACKHOE . EXCAVATION DATE: 2/16/2007 LOGGED BY: DK . SAMPLING METHOD: BULK . ELEVATION: —155' TEST PIT LOG: TP- 1 Laboratory Tests a y 0 T C, DESCRIPTION ,L, . ,L. ,k J 0-1' TOPSOIL; Loose to medium dense, slightly moist, - - / dark brown, silty SAND (SM) with roots/organics. WA, RV, CHEM 1-3 RESIDUAL SOIL Medium dense, slightly moist, light brown - - Qt / to tan, silty fine SAND (SM). 5 / 3-6' QUATERNARY TERRACE DEPOSITS (ot); Dense, slightly moist, light brown - - to tan, silty fine SAND (SM). - - - Total depth 6' fbg No groundwater - - Backfilled with spoils 0- -15— FIGURE:I 'IF-I CONSTRUCTION TESTING & ENGINEERING, INC. 6001ECHNICAL I CONSTRUCTION ENGINEERING TESTING AND INSPECTION 144 Mo 41151 6 SAD. SUITE lIE I E500NOIDS. Cl 90026 I 752.744.4655 PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CILJOB NO: 10-8791G EXCAVATION METHOD: BACKHOE EXCAVATION DATE: 2/1 6/2007 LOGGED BY - DK SAMPLING METHOD: BULK ELEVATION: l52.5' - G) oo TEST PIT LOG: TP-2 Laboratory Tests ' 6 DESCRIPTION - -- -0- - - 1 0-1.5 TOPSOIL; - - / Loose to medium dense, dry to slightly moist. brown, silty fine grained SAND (SM) with debris - and organic materials (roots, logs). 1.5-3 RESIDUAL SOIL - - - -- / . Qt . . . Medium dense, slightly moist, light brown to tan, silty fine SAND (SM). WA -5- - 3-5.5' QUATERNARY TERRACE DEPOSITS (Ot); - - Total depth 5.5' tbg Dense, slightly moist, mottled orange brown - - No groundwater to tan, silty fine SAND (SM). — — - - -ie — — Bàckfilled with spoils — FIGURE:I 1P-2 CONSTRUCTION TESTING & ENGINEERING, INC. GEOTECANIcAt. I CONSTRUCTION ENGINEERING TESTING AND INSPECTION 4 411 Mo FATIEL ROAD, SOlID 115 1 ESCONDIDo, CA 92024 I 760.145.4555 PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CTE JOB NO: W-87916 EXCAVATION METHOD: BACKHOE EXCAVATION DATE: 2/1 6/2007 LOGGED BY: DK - - SAMPLING METHOD: BULK ELEVATION: .. —1575 .3 TEST PIT LOG: TP-3 Laboratory Tests T2W-L) DESCRIPTION 0-1.5' TOPSOIL: Loose to medium dense, slightly moist, dark brown, silty SAND (SM) with roots/organic MAX materials. 1.5-3' RESIDUAL SOIL Medium dense, slightly moist, light brown to tan, silty fine SAND (SM). - - Qt 35' QUATERNARY TERRACE DEPOSITS (00: Dense, slightly moist, mottled orange brown - - Total depth 5' tbg to tan, silty fine SAND (SM). No groundwater - - lB -15 - -- I Backfilled with spoils FIGURE:I I'P-3 CONSTRUCTION TESTING & ENGINEERING, INC. ______ T1— 0 0010CHNICAL CONSTRUCTION ENGINEERING TESTING AND INSPECTION 7-::= 44 MO NI EL 9000, 20110 115 I ESCGRO 100. CA STOOD I 260.746.4954 - PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CTE JOB NO: 10-8791 G EXCAVATION METHOD: BACKHOE EXCAVATION DATE: 2/16/2007 LOGGED BY: DK — — SAMPLING METHOD: BULK ELEVATION: -152.5' I GA) TEST PIT LOG: TP-4 Laboratory Tests a '3 L) Lei M DESCRIPTION 0-.75 TOPSOIL; Loose to medium dense, slightly moist, - - dark brown silty SAND (SM) with roots/organic / materials. .753' RESIDUAL SOIL, - \ / Medium dense to dense, slightly moist, light brown - - and dark brown, silty SAND (SM). 0 3-6' QUATERNARY TERRACE DEPOSITS (Ot); WA -/ Dense to very dense, slightly moist, light brown and dark brown, silty SAND (SM).with small - - (-.25) weathered quartz nodules. Total depth 6 fbg No groundwater - -- — - - -18 -15- — — Backfilled with cuttings — FIGURE:I 'I 'P-4 SLt-\ CONSTRUCTION TESTING & ENGINEERING, INC. GEOTECHNICAL I CONSTRUCTION ENGINEERING TESTING AND INSPECTION 1441 MG 40141 4040, SUITE 115 I ESCONOIDO CA 55024 I I60046.4955 PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CTE JOB NO: lo-8791G EXCAVATION METHOD: BACKHOE EXCAVATION DATE: 2/1 6/2007 LOGGED BY: DK - SAMPLING METHOD: BULK ELEVATION: —156 TEST PIT LOG: TP-5 Laboratory Tests e DESCRIPTION TOPSOIL. - - 0.8' Medium dense, slightly moist, mottled light brown - \ / to brown, silty fine SAND (SM) with roots MAX / and organic material. RESIDUAL SOIL~ Qt .83 Medium dense to dense, slightly moist, light brown and dark brown, silty SAND (SM). Total depth 4.5 thg 1.5 Loose, dry, pale gray, fine to coarse sand (SP-SW). - --- / No groundwater Backfilled with spoils 3-6 QUATERNARY TERRACE DEPOSITS (Qt): - - Dense to very dense, slightly moist, light brown - - and dark brown, silty SAND (SM) with small -ie -15 (.25) weathered quartz nodules. FIGURE:I 'IP-5 - - - - - - - - - - - - - - - - - - - CONSTRUCTION TESTING & ENGINEERING, INC. ETEOTECHNICAI I CONSTRUCTION ENGINEERING TESTING AND INSPECTION ORTIEL ROAD, SUITE Ill I S SCONDID 0. CE 01026 I 100.14 0,4955 PROJECT: Three Lot Development EXCAVATOR: D. Higgenbotham CTE JOB NO: 10-8791G EXCAVATION METHOD: BACKHOE EXCAVATION DATE: 2/16/2007 LOGGED BY: DK SAMPLING METHOD: BULK ELEVATION: 152' - -a U C/) - TEST PIT LOG TP-6 Laboratory Tests Lei DESCRIPTION 0-1 TOPSOIL; - slightly moist, mottled light brown \ / to brown, silty fine SAND (SM) with roots and - - \ organic materials. - Mediumdense, 1-3' RESIDUAL SOIL; \ Qt / Medium dense to dense, slightly moist, brown to - - - light brown, silty fine SAND (SM). 5 3' QUATERNARY TERRACE DEPOSITS (Q); Dense, slightly moist, brown to - - Total depth 5.5' fbg . light brown, silty fine SAND (SM). - - No groundwater - - - l -15 Backfilled with spoils FIGURE:! '1P-6 APPENDIX C LABORATORY METHODS AND RESULTS \\CTE_SERVER\PROJECTS\I0-8791G\RPT_GEOTECH. INVEST.DOC I APPENDIX C LABORATORY METHODS AND RESULTS I Laboratory tests were performed on representative soil samples to detect their relative engineering properties. Tests were performed following test methods of the American Society for Testing I Materials or other accepted standards. The following presents a brief description of the various test methods used. Laboratory results are presented in the following section of this Appendix. I Classification I Soils were classified visually according to the Unified Soil Classification System. Visual classifications were supplemented by laboratory testing of selected samples according to ASTM I D2487. Particle-Size Analysis I Particle-size analyses were performed on selected representative samples according to ASTM D422. Modified Proctor To determine the maximum dry density and optimum moisture content, a soil sample was tested in accordance with ASTM D-1557. - Resistance "R"-Value I The resistance "R"-value was determined by the California Materials Method No. 301 for representative subbase soils. Samples were prepared and exudation pressure and "R"-value determined. The graphically determined "R"- value at exudation pressure of 300 psi is the value I used for pavement section calculation. Chemical Analysis 1 Soil materials were collected with sterile sampling equipment and tested for Sulfite and Chloride content, pH, Corrosivity, and Resistivity. I \\CTE_SERVER\PROJECTS\ O-H79 I G\RPT_GEOTECH. INVESTDOC ! CONSTRUCTION TESTING & ENGINEERING, INC. I . \92 1 7 54 200 WASH ANALYSIS I LOCATION DEPTH PERCENT PASSING CLASSIFICATION (feet) #200 SIEVE I TP-1 1-3 20.3 SM TP-2 4-5 25.6 SM TP-4 4-6 24.1 SM I TP-5 1.5 6.3 SP-SM RESISTANCE 'R"-VALUE CALTEST 301 I LOCATION DEPTH R-VALUE (feet) TP-i 1-3 74 I SULFATE LOCATION DEPTH RESULTS I (feet) ppm TP-1 1-3 45.9 I . CHLORIDE LOCATION DEPTH RESULTS (feet) ppm I TP-I 1-3 8.5 CONDUCTIVITY I CALIFORNIA TEST 424 LOCATION DEPT . . H RESULTS (feet) us/cm I TP-1 1-3 . 86.2 RESISTIVITY CALIFORNIA TEST 424 I LOCATION DEPTH RESULTS (feet) ohms/cm TP-I 1-3 10400 I MAXIMUM DRY DENSITY & OPTIMUM MOISTURE CONTENT (MODIFIED PROCTOR) LOCATION • DEPTH OPTIMUM MOISTURE DRY DENSITY I (feet) (%) (pci) TP-3 .5-1 9.5 124.5 I LABORATORY SUMMARY CTE JOB NO, I0-8791G 145 140 135 130 25 100 95 90 85 •....... • ---H cTh\ J 5 1 0 15 20 25 30 35 PERCENT MOISTURE (%) ASTM D1557 METHOD. 91 A 0 B. Q C MODIFIED PROCTOR RESULTS I I LAB I SAMPLE DEPTH MAXIMUM OPTIMUM SOIL DESCRIPTION J DRY DENSITY I MOISTURE NUMBER I NUMBER I (FEET) I I (PCF) CONTENT (%) 17078 TP-3 0.5-1 BROWN SILTY SAND 124.5 9.5 CTE JOB NO: T CONS RUCTION TESTING & ENGINEERING, INC. DATE: 03/07 10-8791G GEOTECHNICAL AND CONSTRUCTION ENGINEERING TESTING AND INSPECTION I 1441 MONTIEL ROAD. STE 115 ESCONDIDO CA. 92026 1760) 746.4955 I FIGURE: C-i APPENDIX D STANDARD SPECIFICATIONS FOR GRADING Appendix D Page D-1 Standard Specifications for Grading Section 1 - General I The guidelines contained herein represent Construction Testing & Engineering's standard recommendations for grading and other associated operations on construction projects,. These I guidelines should be considered a.portion of the project specifications. Recommendations contained in the body of the previously pr esented soils report shall supersede the recommendations and or requirements as specified herein. The project geotechn:cal consultant I shall interpret disputes arising out of interpretation of the recommendations contained in the soils report or specifications contained herein. Section 2 - Responsibilities of Proiect Personnel - The geotechnical consultant should provide observation and testing services sufficient to assure I that geotechnical construction is performed in general conformance with project specifications and standard grading practices. The geotechnical consultant should report any deviations to the client or his authorized representative. The Client should be chiefly, responsible for all aspects of the project. He or his authorized representative has the responsibility of reviewing the findi ngs and recommendations of the I geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or other consultants to perform work and/or provide services. During grading the Client or his I authorized representative should remain on-site or should remain reasonably accessible to all concerned parties in order to make decisions necessary to maintain the flow of the Droject. I The Contractor should be responsible for the safety of the project and satisfactory completion of all grading and other associated operations on construction projects, including, but not limited to, earth work in accordance with the project plan s, specifications and contrc lling agency I requirements. I Section 3 - Preconstruction Meeting A preconstruction site meeting shall be arranged by the owner and/or client and shall include the I grading contractor, the design engineer, the geotechnical consultant, owner's representative and representatives of the appropriate governing authorities. I Section 4 - Site Preparation The client or contractor should obtain the required approvals from the controlling authorities for I the project prior , during and/or after demoliti on, site preparation and removals, etc. The appropriate approvals should be obtained prior to proceeding with grading operations. STANDARD SPECIFICATIONS FOR GRADING Page 1 of 23 I Appendix D Page D-2 Standard Specifications for Grading - Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods, stumps, trees, root of trees and otherwise dele terious natural m aterials from the areas to be graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill areas. Demolition should include removal of buildings, structures, foundations, reservoirs, utilities (including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts, tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the project perimeter and cutoff and capping of wells in accordance with the requirements of the governing authorities and the recommendations of the geotechnical consultant at the time of demolition. Trees, plants or man-made improvements not planned to be removed or demolished should be protected by the contractor from damage or injury. Debris generated during clearing, grubbing and/or demolition operations should be wasted from areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be performed under the observation of the geotechnical consultant. Section 5 - Site Protection Protection of the site during the period of grading should be the responsibility of the contractor. Unless other provisions are made in writing and agreed upon among the concerned parties, completion of a portion of the project should not be considered to preclude that portion or adjacent areas from the requirements for site protection until such time as the entire project is complete as identified by the geotechnical consultant, the client and the regulating agencies. Precautions should be taken during the performance of site clearing, excavations and grading to protect the work site from flooding, ponding or inundation by poor or improper surface drainage. Temporary provisions should be made during the rainy season to adequately direct surface drainage away from and off the work site. Where low areas cannot be avoided, pumps should be kept on hand to continually remove water during periods of rainfall. Rain related damage should be considered to include, but may not be limited to, erosion, silting, saturation, swelling, structural distress and ot her adverse conditions as determined by the geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and should be subject to overexcavation and replacement with compacted fill or other remedial grading as recommended by the geotechnical consultant. STANDARD SPECIFICATIONS FOR GRADING Page 2 of 23 I Appendix D Page D-3 Standard Specifications for Grading The contractor should be responsible for the stability of all temporary excavations. Recommendations by the geotechnical consultant pertaining to temporary excavations (e.g., backcuts) are made in consideration of stability of the completed project and, therefore, should not be considered to preclude the responsibilities of the contractor. Recommendations by the geotechnical consultant should not be consider ed to preclude requirements that ar e more restrictive by the regulating agencies. The contractor should provide during periods of extensive rainfall plastic sheeting to pr event unprotected slopes from beco ming saturated and unstable. When deemed appropriate by the geotechnical consultant or governing agencies the contractor shall install checkdams, desilting basins, sand bags or other drainage control measures. In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies ,exist to depths of greater than 1.0 foot; they should be overexcavated and replaced as compacted fill in accordance with the applicable specifications. Where affected materials exist to depths of 1.0 foot or less below proposed finished grade, remedial grading by moisture conditioning in-place, followed by thorough recompaction in accordance with the applicable grading guidelines herein may be attempted. If the desired results are not ach ieved, all affected materials should be overexcavated and replaced as compacted fill in accordance with the slope repair recommendations herein. If field condition s dictate, the geotechnical consultant may recommend other slope repair procedures. Section 6 - Excavations 6.1 Unsuitable Materials Materials that are unsuitable should be excavated under observation and recommendations of the geotechnical consultant. Unsuitable materials include, but may not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured, weathered, soft bedrock and nonengineered or otherwise deleterious fill materials. Material identified by the geotechnical consultant as unsatisfactory due to its moisture I conditions should be overexcavated; moisture conditioned as needed, to a uniform at or above optimum moisture condition before placement as compacted fill. I If during the course of grading adverse geotechnical conditions are exposed which were not anticipated in the preliminary soil report as determined by the geotechnical consultant I additional exploration, analysis, and treatment of these problems may be recommended. 6.2 Cut Slopes I Unless otherwise recommended by the geotec hnical consultant and approved by the regulating agencies, permanent cut slopes should not be steeper than 2:1 (horizontal: vertical). I STANDARD SPECIFICATIONS FOR GRADING Page 3of23 I I Appendix D Page D-4 Standard Specifications for Grading The geotechnical consultant should observe cut slope excavation and if these excavations expose loose cohesionless, significantly fractured or otherwise unsuitable material, the I materials should be overexcavated and replaced with a compacted stabilization fill. If encountered specific cross section details should be obtained from the Geotechnical i Consultant. When extensive cut slopes are excavated or these cut slopes are made in the direction of I the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided at the top of the slope. 6.3 Pad Areas All lot pad areas, including side yard terrace containing both cut and fill materials, transitions, located less than 3 feet deep should be overexcavated to a depth of 3 feet and replaced with a uniform compacted fill blanket of 3 feet. Actual depth of ovérexcavation may vary and should be delineated by the geotechnical consultant during grading, especially where deep or drastic transitions are present. For pad areas created above cut or natural slopes, positive drainage should be established away from the top-of-slope. This may be accomplished utilizing a berm drainage swale and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes of 2 percent or greater is recommended. Section 7 - Compacted Fill All fill materials should have fill quality, placement, conditioning and compaction as specified below or as approved by the geotechnical consultant. 7.1 Fill Material Quality Excavated on-site or import materials which are acceptable to the geotechnical consultant may be u tilized as compacted fill, provided trash, vegetation and other deleterious materials are removed prior to placement. All import materials anticipated for use on-site should be sampled tested and approved prior to and placement is in conformance with the requirements outlined. Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided I sufficient fill material is placed and thoroughly compacted over and around all rock to effectively fill rock voids. The amount of rock should not exceed 40 percent by dry I weight passing the 3/4-inch sieve. The geotechnical consultant. may vary those requirements as field conditions dictate. STANDARD SPECIFICATIONS FOR GRADING Page 4 of 23 I I Appendix D Page D-5 Standard Specifications for Grading I Where rocks greater than 12 inches but less than four feet of maximum dimension are generated during grading, or otherwise desired to be placed within an engineered fill, I special handling in accordance with the recommendations below. Rocks greater than four feet should be broken down or disposed off-site. 1 7.2 Placement of Fill Prior to placement of fill material, the ge otechnical consultant should observe and approve the area to receive fill. A fter obs ervation and approval, the exposed ground I surface should be scarified to a depth of 6 to 8 inches. The scarified material should be conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture I content at or slightly above optimum moisture conditions and compacted to a minimum of 90percent of the maximum density or as otherwise recommended in the soils report or I by appropriate government agencies. Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in I loose thickness prior to compaction. Each lift should be moisture conditioned as needed, thoroughly blended to achieve a consistent moisture content at or slightly above optimum and thoroughly compacted by mechanical me thods to a minimum of 90 percent of I laboratory maximum dry density. Each lift should be treated in a like manner until the desired finished grades are achieved. The contractor should have suitable and sufficient mechanical compaction equipment and watering apparatus on the job site to handle the amount of fill being placed in consideration of moisture retention properties of the materials and weather conditions. When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:1 (horizontal: I vertical), horizontal keys and vertical benches should be excavated into the adjacent slope area. Keying and benching should be sufficient to provide at least six-foot wide benches and a minimum of four feet of vertical bench height within the firm natural ground, firm I bedrock or engineered compacted fill. No compacted fill should be placed in an area after keying and benching until the geotechnical consultant has reviewed the area. Material generated by the benching operation should be moved sufficiently away from I the bench area to allow for the recommended review of the horizontal bench prior to placement of fill. Within a single fill area where grading procedures dictate two or more separate fills, temporary slopes (false slopes) may be created. When placing fill adjacent to a false I slope, benching should be conducted in the same manner as above described. At least a 3-foot vertical bench should be established within the firm core of adjacent approved I STANDARD SPECIFICATIONS FOR GRADING Page 5 of 23 I I Appendix D Page D-6 Standard Specifications for Grading compacted fill prior to placement of additional fill. Benching should proceed in at least 3-foot vertical increments until the desired finished grades are achieved. Prior to placement of additional compacted fill following an overnight or other grading delay, the exposed surface Or previously compacted fill should be processed by scarification, moisture conditioning as needed to at or slightly above optimum moisture content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory maximum dry density. Where unsuitable materials exist to depths of greater than one foot, the unsuitable materials should be over-excavated. Following a period of flooding, rainfall or overwatering by other means, no additional fill should be placed until damage assessments have been made and remedial grading performed as described herein. Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill provided the fill is placed and thoroughly co mpacted over and around all rock. No oversize material should be used within 3 feet of finished pad grade and within 1 foot of other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any slope face. These recommendations could vary as locations of improvements dictate. Where practical, oversized material should not be placed below areas where structures or deep utilities are proposed. Oversized material should be placed in windrcws on a clean, overexcavated or unyielding compacted fill or firm natural ground surface. Select native or imported granular soil (S.E. 30 or higher) shouldbe placed and thoroughly flooded over and around all windrowed rock, such that voids are filled. Windrows of oversized material should be staggered so those successive strata of oversized material are not in the same vertical plane. It may be possible to dispose of individual larger rock as field conditions dictate and as recommended by the geotechnical consultant at the time of placement. The contractor should assist the geotechnical consultant and/or his representative by digging test pits for removal determinations and/or for testing compacted fill. The contractor shbuld provide this work at no ad ditional cost to the owner or contractor's client. Fill should be tested by the geotechnical consultant for compliance with the recommended relative compaction and moisture conditions. Field density testing should conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at STANDARD SPECIFICATIONS FOR GRADING Page 6 of 23 Appendix D Page D-7 Standard Specifications for Grading a m inimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found not to be in conformance with the grading recommendations should be removed or otherwise handled as recommended by the geotechnical consultant. 7.3 Fill Slopes Unless otherwise recommended by the geotec finical consultant and approved by the regulating agencies, permanent fill slopes should not be steeper than 2:1 (horizontal: vertical). Except as specifically recommended in these grading guidelines compacted fill slopes should be over-built two to five feet and cut back to grade, exposing the firm, compacted fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If the desired results are not achieved, the existing slopes should be overexcavated and reconstructed under the guidelines of the geotechnical consultant. The degree of overbuilding shall be increased until the desired compacted slope surface condition is achieved. Care should be taken by the cont ractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. At the discretion of the geotechnical consultant, slope face compaction may be attempted by conventional construction' procedures in eluding backrolling. The procedure must create a firmly compacted material throughout the entire depth of the slope face to the surface of the previously compacted firm fill intercore. During grading operations, care should be taken to extend compactive effort to the outer edge of the slope. Each lift should extend horizontally to the desired finished slope surface or mor e as needed to ultimately est ablished desired grades. Grade during construction should not be allowed to roll off at the edge of the slope. It may be helpful to elevate slightly the outer edge of the slope. Slough resulting from the placement of individual lifts should not be allowed to drift down over previous lifts. At intervals not exceeding four feet in vertical slope height or the capability of available equipment, whichever is less, fill slopes should be thoroughly dozer trackrolled. For pad areas above fill slopes, positive drainage should be established away from the top-of-slope. This may be accomplished using a berm and pad gradient of at least two percent. STANDARD SPECIFICATIONS FOR GRADING Page 7of23 Appendix D Page D-8 Standard Specifications for Grading Section 8 - Trench Backfill Utility and/or other excavati on of trench backfill should, uni ess otherwise recommended, be compacted by mechanical means. Unless otherwise recommended, the degree of compaction should be a minimum of 90 percent of the laboratory maximum density. Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical means. If on-site materials are utilized, th ey should be wheel-rolled, tamped or otherwise compacted to a firm condition. For minor interior trenches, density testing may be deleted or spot testing may be elected if deemed necessary, based on review of backfill operations during construction. If utility contractors indicate that it is unde sirable to use compaction equipment in close proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical compaction equipment and/or shading of the conduit with clean, granular material, which should be thoroughly jetted in-place a bove the conduit, prior to in itiating mechanical compaction procedures. Other methods of utility trench compaction may also be appropriate, upon review of the geotechnical consultant at the time of construction. In cases where clean granular materials are proposed for use in lieu of native materials or where I flooding or jetting is proposed, the procedures should be considered subject to review by the geotechnical consultant. Clean granular backfill and/or bedding are not recommended in slope I . areas. Section 9 - Drainage I Where deemed appropriate by the geotechnical consultant, canyon subdrain systems should be installed in accordance with CTE's recommendations during grading. I Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be installed in accordance with the specifications. - I Roof, pad and slope drainage should be directed away from slopes and areas of structures to I suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swales). For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum I of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2 percent should be maintained over the remainder of the site. I STANDARD SPECIFICATIONS FOR GRADING Page 8 of 23 I I Appendix D Page D-9 Standard Specifications for Grading Drainage patterns established at the time of fine grading should be maintained throughout the life of the project. Property owners should be made aware that altering drainage patterns could be detrimental to slope stability and foundation performance. Section 10 - Slope Maintenance 10.1 - Landscape Plants To enhance surficial slope stability, slope planting should be accomplished at the completion of grading. Slope planting should consist of deep-rooting vegetation requiring little watering. Plants native to the southern California area and plants relative to native plants are generally desirable. Plants native to other semi-arid and arid areas may also be appropriate. A Landscape Archit ect should be the best party to consult regarding actual types of plants and planting configuration. 10.2 - Irrigation Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into slope faces. Slope irrigation should be minimized. If automatic timing devices are utilized on irrigation systems, provisions should be made for interrupting normal irrigation during periods of rainfall 10.3 - Repair As a precautionary measure, plastic sheeting should be readily available, or kept on hand, to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This measure is strongly recommended, beginning with the period prior to landscape planting. If slope failures occur, the geotechnic al consultant should be contacted for a field review of site conditions and development of recommendations for evaluation and repair. If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas and currently unaffected areas should be covered with plastic sheeting to protect against additional saturation. In the accompanying Standard Details, appropriate repair procedures are illustrated for superficial slope failures (i.e., occurring typically within the outer one foot to three feet of a slope face). STANDARD SPECIFICATIONS FOR GRADING Page 9 of 23 BENCHING FILL OVER NATURAL SURFACE OF FIRM EARTH MATERIAL FILL SLOPE 15' MIN. (INCLINED 2% MIN. INTO SLOPE) BENCHING FILL OVER CUT SURFACE OF FIRM EARTH MATERIAL FINISH FILL SLOPE FINISH CUT SLOPE -L 4' TYPICAL t 10, TYPICAL 15' MIN OR STABILITY EQUIVALENT PER SOIL ENGINEERING (INCLINED 2% MIN. INTO SLOPE) NOT TO SCALE BENCHING FOR COMPACTED FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 10 of 23 TOE OF SLOPE SHOWN ON GRADING PLAN FILL Al / MINIMUM _J ' 15'MINIMUM BASE KEY WIDTH DO WN S LO P E KEY DEPTH TYPICAL BENCH HEIGHT PROVIDE BACKDRAIN AS REQUIRED PER RECOMMENDATIONS OF SOILS ENGINEER DURING GRADING WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS, BENCHING IS NOT NECESSARY. FILL IS NOT TO BE PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL. NOT TO SCALE - I I I I • IILL LUIt ABOVE NATURAL GROUND DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 11of 23 10' TYPICAL BENCH WIDTH VARIES COMPETENT EARTH MATERIAL REMOVE ALL TOPSOIL, COLLUVIUM, AND CREEP MATERIAL FROM TRANSITION CUT/FILL CONTACT SHOWN ON GRADING PLAN CUT/FILL CONTACT SHOWN ON "AS-BUILT" NATURAL TOPOGRAPHY\ - - - - - - CUT SLOPE* FILL - - - J4'TYPICAL MEN PICAL - - - - - 15' MINIMUM BEDROCK OR APPROVED FOUNDATION MATERIAL *NOTE: CUT SLOPE PORTION SHOULD BE MADE PRIOR TO PLACEMENT OF FILL NOT TO SCALE FILL SLOPE ABOVE CUT SLOPE DETAIL SURFACE OF I COMPETENT ----------------- C -- MATERIAL - - OM loe \ \ COMPACTED /1 TYPICAL BENCHING REMOVE UNSUITABLE MATERIAL SEE DETAIL BELOW 0 INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM MINIMUM 9 FT PER LINEAR FOOT MINIMUM 4" DIAMETER APPROVED OF APPROVED FILTER MATERIAL PERFORATED PIPE (PERFORATIONS DOWN) 6' FILTER MATERIAL BEDDING 14" MINIMUM FILTER MATERIAL TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUAL: SIEVE SIZE PERCENTAGE PASSING 10 100 3/40 90-100 40-100 NO. 4 25-40 NO. '30 18-33 NO.8 5-15 NO. 50 0-7 APPROVED PIPE TO BE SCHEDULE 40 POLY-VINYL-CHLORIDE (P.V.C.) OR APPROVED EQUAL. MINIMUM CRUSH STRENGTH 1000 psi PIPE DIAMETER TO MEET THE FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING LENGTH OF RUN PIPE DIAMETER INITIAL 500' 4" 500' TO 1500' 6" > 1500' 8' NO. 200 0-3 NOT TO SCALE TYPICALCANYONSUBDRAINDETAIL r STANDARD SPECIFICATIONS FOR GRADING CANYON SUBDRAIN DETAILS SURFACE OF COMPETENT MATERIAL C ell OMPACTED FILL 4, ii TYPICAL BENCHING BELOW REMOVE UNSUITABLE MATERIAL SEE DETAILS INCLINE TOWARD DRAIN AT 2% GRADIENT MINIMUM TRENCH DETAILS 6" MINIMUM OVERLAP OPTIONAL V-DITCH DETAIL MINIMUM 9 FT PER LINEAR FOOT OR APPROVED EQUAL - - f/_OF APPROVED DRAIN MATERIAL MIRAFI 140N FABRIC MIRAFI 140N FABRIC 10/ OR APPROVED EQUAL 6° MINIMUM OVERLAP APPROVED PIPE TO BE 24 SCHEDULE 40 POLY- 7:2 k VINYLCHLORIDE (P.V.C.) TFT MINIMUM OR APPROVED EQUAL. 24"3 MI U MINIMUM CRUSH STRENGTH PER LINEA R FOOT 1000 PSI. MINIMUM \ OF APPROVED DRAIN MATERIAL 60° TO 90° DRAIN MATERIAL TO MEET FOLLOWING PIPE DIAMETER TO MEET THE SPECIFICATION OR APPROVED EQUAL: FOLLOWING CRITERIA, SUBJECT TO FIELD REVIEW BASED ON ACTUAL SIEVE SIZE PERCENTAGE PASSING GEOTECHNICAL CONDITIONS ENCOUNTERED DURING GRADING 88-100 LENGTH OF RUN PIPE DIAMETER 1° 5-40 INITIAL 500' 4" 3/4 0-17 500' TO 1500' 6" 0-7 > 1500' 8" NO. 200 0-3 NOT TO SCALE GEOFABRIC SUBDRAIN STANDARD SPECIFICATIONS FOR GRADING Page 14 of 23 2 ENCHING 4" DIAMETER PERFORATED PIPE BACKDRAIN 4" DIAMETER NON-PERFORATED PIPE LATERAL DRAIN SLOPE PER PLAN -s FILTER MATERIAL 15' MINIMUM AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR SLOPE IN EXCESS OF 40 FEET HIGH. KEY-DIMENSION PER SOILS ENGINEER (GENERALLY 1/2 SLOPE HEIGHT, 15' MINIMUM) DIMENSIONS ARE MINIMUM RECOMMENDED NOT TO SCALE TYPICAL SLOPE STABILIZATION FILL DETAIL I STANDARD SPECIFICATIONS FOR GRADING Page 15 of 23 I I L#IIVIII fljfl.fll I I..I. L_I'%JII1L.I...I DIMENSIONS ARE MINIMUM RECOMMENDED NOT TO SCALE TYPICAL BUTTRESS FILL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 16 of 23 FINAL LIMIT OF DAYLIGHT EXCAVATION LINE FINISH PAD OVEREXCAVATE 3' AND REPLACE WITH COMPACTED FILL OVEREXCAVATE 20' MAXIMUM COMPETENT BEDROCK 2' MINIMU TYPICAL BENCHING OVERBURDEN \ \ LOCATION OF BACKDRAIN AND (CREEP-PRONE) \ OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST \ DURING GRADING. MINIMUM 2% \ FLOW GRADIENT TO DISCHARGE LOCATION. EQUIPMENT WIDTH (MINIMUM 15') NOT TO SCALE DAYLIGHT SHEAR KEY DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 17 of 23 NATURAL GROUND PROPOSED GRADING / 7 1.5/ -- -- -- BASE WIDTH 'W' DETERMINED BY SOILS ENGINEER COMPACTED FILL PROVIDE BACKDRAIN, BACKDRAIN, PER BACKDRAIN DETAIL. AN ADDITIONAL BACKDRAIN AT MID-SLOPE WILL BE REQUIRED FOR BACK SLOPES IN EXCESS OF 40 FEET HIGH. LOCATIONS OF BACKDRAINS AND OUTLETS PER SOILS ENGINEER AND/OR ENGINEERING GEOLOGIST DURING GRADING. MINIMUM 2% FLOW GRADIENT TO DISCHARGE LOCATION. NOT TO SCALE TYPCALSHEARKEYDETAiL I STANDARD SPECIFICATIONS FOR GRADING L Page 18of23 FINISH SURFACE SLOPE 3 FT MINIMUM PER LINEAR FOOT APPROVED FILTER ROCK* CONCRETE COLLAR PLACED NEAT COMPACTED FILL 4 MINIMUM DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS DURING GRADING TYPICAL BENCHING - 4 MINIMUM APPROVED PERFORATED PIPE** (PERFORATIONS DOWN) MINIMUM 2% GRADIENT TO OUTLET BENCH INCLINED TOWARD DRAIN DETAIL A-A TEMPORARY FILL LEVEL MINIMUM 12" COVER OM PACTE BACKFILL MINIMUM 4'DIAMETER APPROVED SOLID OUTLET PIPE 12" MINIMUM *FILTER ROCK TO MEET FOLLOWING "APPROVED PIPE TYPE: SPECIFICATIONS OR APPROVED EQUAL: SCHEDULE 40 POLYVINYL CHLORIDE SIEVE SIZE PERCENTAGE PASSING (P.V.C.) OR APPROVED EQUAL. 1" 100 MINIMUM CRUSH STRENGTH 1000 PSI 3/.. 74 3U-1UU 40-100 NO.4 25-40 NO. 30 5-15 NO. 50 0-7 NO. 200 0-3 NOT TO SCALE TYPICAL BACKDRAIN DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 19 of 23 FINISH SURFACE SLOPE MINIMUM 3 FT PER LINEAR FOOT OPEN GRADED AGGREGATE* TAPE AND SEAL AT COVER CONCRETE COLLAR PLACED NEAT -... COMPACTED FILL MIRAFI 140N FABRIC OR APPROVED EQUAL 4" MINIMUM APPROVED PERFORATED PIPE \ (PERFORATIONS DOWN) MINIMUM 2% GRADIENT \ TO OUTLET TYPICAL "- BENCH INCLINED BENCHING TOWARD DRAIN A MINIMUM 4" DIAMETER SOLID OUTLET PIPE SPACED PER SOIL ENGINEER REQUIREMENTS DETAIL A-A TEMPORARY FILL LEVEL MINIMUM M PACTE rOBACKFILL 12' COVER I MINIMUM 4" DIAMETER APPROVED SOLID OUTLET PIPE L 12" MINIMUM *NOTE: AGGREGATE TO MEET FOLLOWING SPECIFICATIONS OR APPROVED EQUAL: SIEVE SIZE PERCENTAGE PASSING lao 1" 5-40 0-17 0-7 NOT TO SCALE NO. 200 0-3 A I . •. A P uiuwm DETAIL (GEOFRABIC) I STANDARD SPECIFICATIONS FOR GRADING Page 20 of 23 I FILL SLOPE CLEAR ZONE SOIL SHALL BE PUSHED OVER EQUIPMENT WIDTH ROCKS AND FLOODED INTO VOIDS. COMPACT AROUND AND OVER EACH WINDROW. STACK BOULDERS END TO END. DO NOT PILE UPON EACH OTHER. FILL SLOPE 10, 10'MIN STAGGER 0 ROWS -7777- 777~7 NOT TO SCALE ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 21 of 23 FINISHED GRADE BUILDING I STREET 15 16 41 0 TYPICAL WINDROW DETAIL (EDGE VIEW) - GRANULAR SOIL FLOODED TO FILL VOIDS HORIZONTALLY PLACED COMPACTION FILL •i•i•i PROFILE VIEW NOT TO SCALE ROCK DISPOSAL DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 22 of 23 10' SLOPE FACE __ AND SWIMMING POOLS c - NO OVERSIZE, AREA FOR I J 0 WINDROW I FOUNDATION, UTILITIES 5' MINIMUM OR BELOW DEPTH OF DEEPEST UTILITY TRENCH (WHICHEVER GREATER) GENERAL GRADING RECOMMENDATIONS CUT LOT —ORIGINAL GROUND - - - - - TOPSOIL, COLLUVIUM AND - - WEATHERED BEDROCK . 5' 5'MIN FT-MIN OVEREXCAVATE - UNWEATHERED BEDROCK AND REGRADE CUT/FILL LOT (TRANSITION) COMPACTED FILL hi I jij'9 njr-i: :1 u I UNV ORIGINAL GROUND - 'MIN ol 10 10 V/// 7//7j Tl 3' MIN OVEREXCAVATE AND REGRADE /EATHERED BEDROCK NOT TO SCALE TRANSITION LOT DETAIL STANDARD SPECIFICATIONS FOR GRADING Page 23 of 23 RECEiVED JUL 20 2001 ENGINEERING DEPARTMENT