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Home My WebLink AboutCT 76-12; Lake Calavera Hills; Soils Report; 1981-01-203467 Kurtz Street San Diego. Cal1fornia92110 714-224-2911 Telex 697-841 Woodwarcklyde Consultants January 20, 1981 Project No. 50216W-SI07 Pacific Scene, Inc. 3900 Harney Street San Diego, California 92110 Attention: Mr. Doug Nystrom UPDATE GEOTECHNICAL INVESTIGATION FOR THE PROPOSED LAKE CALAVERA HILLS TRACT 76-12 CARLSBAD, ~CALIFORNIA Gentlemen: We are pleased to provide the accompanying report, which presents the results of our updated geotechnical investi- gation for the subject project. The report presents our conclusions and recommendations pertaining to the project, as well as the results of our field explorations and labo- ratory tests. Our engineer and geologist assigned to this project are Messrs. Michael R. Rahilly and Robert J. Dowlen, respec- tively. If you have any questions, or if we can be of further service, please give us a call. Very truly yours, WOODWARD-CLYDE CONSULTANTS Richard P. While R.E. 21992 RPW/DS/MRR/RJD/rs Attachment (4) Pacific Scene, Inc. (2) Rick Engineering Company Consulting Engineers. Geologists and Environmental Scientists Daryl Streiff C.E.G. 1033 Project No. 50216W-SI07 . Woodward-Clyde Consultants TABLE OF CONTENTS PURPOSE OF INVESTIGATION BACKGROUND INFORMATION DESCRIPTION OF THE PROJECT FIELD AND LABORATORY INVESTIGATIONS SITE, SOIL, AND GEOLOGIC CONDITIONS Geologic Setting Topography and Surface Conditions Subsurface Conditions Fill Soils Topsoil and Cultivated Topsoil Alluvium Santiago Formation Santiago Peak Volcanics Structure and Faulting Ground Water DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS Potential Geologic Hazards Faulting and Ground Breakage Liquefaction Landslides Page 1 2 3 4 4 4 5 6 6 6 7 7 8 8 8 9 9 9 10 10 Project No. 50216W-SI07 TABLE OF CONTENTS (continued) Woodward-Clyde Consultants Ground Water General Soil and Rock Conditions Excavation Characteristics Slope Stability Grading Foundations RISK AND OTHER CONSIDERATIONS FIGURE 1 - SITE PLAN AND GEOLOGIC MAP Page 10 12 12 13 15 17 18 APPENDIX A - FIELD INVESTIGATION A-l FIGURE A-l - KEY TO LOGS FIGURES A-2 THROUGH A-6 - LOGS OF TEST BORINGS FIGURES A-7 THROUGH A-12 - LOTS OF TEST PITS APPENDIX B - LABORATORY TESTS B-l FIGURE B-l - GRAIN SIZE DISTRIBUTION CURVES FIGURE B-2 - FILL SUITABILITY TESTS APPENDIX C - SPECIFICATIONS FOR CONTROLLED FILL C-l APPENIDX D - GUIDE SPECIFICATIONS FOR SUBSURFACE DRAINS D-l APPENDIX E - OVERSIZE ROCK PLACEMENT AREAS E-l _ Project, No. 50216W-SI07 Woodward-Clyde Consultants UPDATE GEOTECHNICAL INVESTIGATION FOR THE PROPOSED LAKE CALAVERA HILLS TRACT 76-12 CARLSBAD, CALIFORNIA This report presents the results of our update geotechnical investigation at the site of the proposed Lake Calavera Hills Tract 76-12 residential subdivision. This report supercedes an earlier report by Soil, Geology, & Testing Consultants, Inc. (SGT), dated January 28, 1977. The site is approximately 2 miles southeast of the intersection of Route 78 Freeway and El Camjno Real, in the Calavera Hills area of Carlsbad, California. PURPOSE OF INVESTIGATION The purpose of our investigation was to assist Pacific Scene, Inc., and their consultants in evaluating the property and in project design. This report presents our conclusions and/or recommendations regarding: 0 Potential geologic hazards, 0 Excavation characteristics of subsurface materials, 0 Site grading (including preparation of probable areas to receive fill), Project No. 50216W-6107 Woodward-Clyde Consultants 0 Characteristics of probable fill materials, 0 Presence and effect of expansive soils, 0 Slopes, and 0 Foundations. BACKGROUND INFORMATION For our study, we have discussed the project with Mr. Doug Nystrom of Pacific Scene, Inc., and we have been provided with topographic maps prepared by Rick Engineering Company, including: 0 "Grading Plans For Calavera Hills, Carlsbad Tract 76-12" (scale 1" = 30'), dated October 30, 1977, 0 "Lake Calavera Hills Unit 1, Tentative Map and PUD Plan No. 4 of Carlsbad Tract No. 76-12" (scale 1" = 200'), latest revision dated December 14, 1976. In addition, we have reviewed applicable geologic and geotechnical data, including the following: 0 "Report of Rough Grading Operations, Waste Water Treatment Facility, Calavera Hills, Carlsbad, Cali- fornia," dated June 9, 1980, prepared by B.R.G. & Associates, Inc. 0 "Soil and Geologic Investigation, Lake Calavera Hills, Unit No. 1, Tamarack Avenue, Carlsbad, California," dated January 28, 1977 prepared by SGT. 0 "Faulting in the Oceanside, Carlsbad, and Vista Areas, Northern San Diego County, California," dated 1975 by Dennis Hannan, in Studies on the Geology of Camp Pendleton, and Western San Diego County, California, San Diego Association of Geologists. ,Project No. 50216W-SI07 Woodward-Clyde Consultants 0 "Geologic Map of a Portion of the San Luis Rey Quadrangle, San Diego County, California," dated 1972, by Kenneth L. Wilson, MS Thesis, University of California, Riverside. 0 "Faults and Special Studies Zones - Quad 7, Ocean- side," dated March 3, 1976, by Mapping Section, San Diego County Department of Transportation. 0 Stereographic aerial photographs, AXN 4DD - 197, 198, Index Sheet No. 2, flown by Cartwright Aerial Surveys 1964 for USDA. DESCRIPTION OF THE PROJECT We understand that the proposed project will subdivide approximately 53 acres into 138 single-family residential lots. Ten additional acres on the site have been reserved for open space areas and a proposed school site, No specific investigations for these areas were made. We understand that the proposed construction will be limited to one- and/or two-story, wood-frame and stucco residential structures, supported on continuous footings and having slab-on-grade floors. The available grading plans indicate cut and fill slopes will have maximum heights of 30 feet and 60 feet, and maximum slopes inclinations of 2 to 1 (horizontal to vertical). The project also includes improving Tamarack Avenue from El Camino Real to the subdivision, a distance of approxi- mately one mile. Project No. 502L6W-SI07 Woodward-Clyde Consultants . FIELD AND LABORATORY INVESTIGATIONS Our field investigation, conducted between Novem- ber 18 and 26, 1980, included making a visual geologic reconnaissance of the existing surface conditions, making two bucket auger borings and 16 backhoe test pits, and obtaining representative soil samples. The borings were advanced to depths of 32 feet and 80 feet, and the backhoe pits were advanced to depths ranging from 3 feet to 12 feet. The locations of the test explorations are shown on Fig. 1. A Key to Logs is presented in Appendix A as Fig. A-l. Simplified logs of the borings and test pits are presented in Appendix A as Figs. A-2 through A-12. The descriptions on the logs are based on field logs, sample inspection, and laboratory test results. Results of labo- ratory tests are shown at the corresponding sample locations on the logs and in Appendix B. The field investigation and laboratory testing programs are discussed in Appendixes A and B. SITE, SOIL, AND GEOLOGIC CONDITIONS Geologic Setting The site lies within a boundary zone between the Tertiary and Quaternary age sediments of the coastal foot- hills, and the Jurassic and Cretaceous age igneous and metamorphic rocks that form the highlands to the east. 4 Project No. 50216W-SI07 Woodward-Clyde Consultants Topography and Surface Conditions The site is on a south-trending series of ridges that have moderate to steeply sloping flanks. The site is bounded on the east and west by major south-draining canyons; two additional drainage ravines are present in the southern portion of the site (Fig. 1). Elevations across the site range from approximately 135 feet near the southeastern boundary, to approximately 308 feet (MSL Datum) at the northern boundary. Elevations for the proposed Tamarack Avenue range from approximately 60 feet near the terminus of Tamarack Avenue, to approximately 190 feet where the roadway enters the subdivision. Man-made features on the site include numerous unimproved roads and scattered piles of agricultural debris, such as plastic sheeting, stakes, and organic matter. We understand that crops, such as tomatoes, were once raised on the site. The vegetation on the ridge tops consists of a heavy growth of native weeds and grasses; the hillsides support a dense growth of chaparral. Vegetation along the Tamarack Avenue alignment consists primarily of tomato fields in the canyon bottoms, and heavy chaparral on the hillsides. A water line for the Costa Real Municipal Water District is present within the proposed Glasgow Drive ease- ment, and a northwesterly-trending, 150-foot wide SDG&E easement is present near the existing Tamarack Avenue (Fig. 1). 5 Project No. 50216W-SI07 Woodward-Clyde Consultants Offsite improvements that will be affected by the proposed extension of Tamarack Avenue consist of two canyon fills constructed as part of the Calavera Hills Waste Water Treatment Plant, which is presently under construction at the northwestern corner of the site. Subsurface Conditions The site, which includes Tamarack Avenue improve- ments, is underlain by fill soils, cultivated topsoils, Quaternary age alluvium, the Eocene age Santiago Formation, and the Jurassic age Santiago Peak Volcanics. These units are described below; their approximate area1 extents, with the exception of the residual soils, are shown on Fig. 1. The geologic map symbol for each unit is given after the formal name for the unit, except for the topsoil. Fill Soils (Qf) - Fill soils are present within the Tamarack Avenue easement adjacent to the waste water treat- ment plant. The B.R.G. & Associates, Inc., report dated June 9, 1980 indicates that the natural ground was prepared and fill was compacted to at least 90 percent relative com- paction. The report also indicates that portions of the Tamarack Avenue fill slope within the plant area have already been constructed. Topsoil and Cultivated Topsoil (unmapped) - A loose and porous soil mantle, consisting of either natural sandy 6 Project No. 50216WSIO7 WoodwardXlyde Consultants clays and/or cultivated silty sands and sandy clays, was found to range from approximately 1 to 2-l/2 feet in thick- ness across the site. Alluvium (Qal), Alluvial deposits consisting of porous and compressible silty to clayey sands are present in the drainage bottoms. As indicated in Test Pits 12 and 16, these soils appear to be less than 5 feet thick. In the Tamarack Avenue easement, alluvial soils consisting of loose to medium dense sandy clays and clayey sands, such as those found in Test Pit 18, are present to depths in excess of the 10-l/2 feet excavated. Similarly, a review of Trenches 9 and 10 of the SGT report indicates alluvial depths in excess of 7 and 10 feet, respectively. Santiago Formation (Ts) - This unit is moderately well indurated, dense, gray to greenish-gray, very fine to coarse silty to clayey sand. Interbeds and clasts of sandy to silty clay are present within the sand. Generally, the sands are well sorted; definite layering by grain size and clay content is often exhibited through a vertical section. Lateral variations and gradations are also common, however, and most of the beds appear to be lenticular across the site. Cemented zones are known to be present in this unit; zones up to 2 feet in maximum thickness have been observed in other areas. Project No. 50216W-SI07 Woodwarddytje Consultants Santiago Peak Volcanics (Jsp) - Highly fractured, irregularily weathered metavalcanic rock of the Santiago Peak Volcanics is present in the vicinity of Lots 1 through 4 and 140. Structure and Faulting Our field investigation indicates that the Eocene age sediments on the property generally dip on the order of 20 to 150 (average 9' ), primarily toward the northwest. There are, however, numerous local undulations in bedding, particularly near the contact with the adjacent hardrock unit. Noticeable fractures and minor discontinuous faults were encountered in several of the test pits, trending north-northeast through much of the site. These faults, which are common to the Carlsbad area, were not observed to offset surface soils, and are considered inactive. Similar fault traces were reported in the SGT report. Joint and fracture patterns are noticeable in the hardrock areas on and near the site. These features trend between north-northeast and north-northwest, and exhibit relatively steep dips. Ground Water A permanent ground water table was not reached in any of our test borings. However, minor "perched" water 8 Project No. 50216W~SIO7 WoodwardXlyde ConsUltants seepage and "wet" zones were found at various levels in the borings. Generally the water was seeping from coarse sand layers that overlie sands containing a large amount of finer grained materials. The source of this water is un- known, but may, in part, be associated with agricultural irrigation and increased infiltration of rainwater during the last three wet winter seasons. DISCUSSIONS, CONCLUSIONS, AND RECOMMENDATIONS The discussions, conclusions, and recommendations presented in this report are based on the results of our field and laboratory studies, analyses, and professional judgment. Potential Geologic Hazards Faulting and Ground Breakage - Our reconnaissance, literature review, and field explorations did not reveal the presence of any significant faulting on the site. Based on our test pits, it appears that the previously-mentioned fault traces are not confined to a particular "zone," but rather appear to be present randomly throughout the site. In our opinion, these faults can be considered inactive and should not pose a significant geologic hazard to site development. The geologic literature we reviewed indicates that the nearest known active fault zone along which seismic 9 Project No. 50216W-SI07 Woodward.Clyde Consultants events of magnitude 4 or greater have occurred is the Elsinore Fault zone, mapped some 21 miles northeast of the site. The closest significant faulting is the northern extension of the Rose Canyon Fault zone, which is mapped approximately 10 miles southwest of the site. No magnitude 4 or larger earthquakes have been recorded on the Rose Canyon Fault zone. Liquefaction - The formational sediments on the site are very dense. These sediments contain thin perched water seepages at various levels; however, there is no apparent permanent ground water table within probable grad- ing depths. Due to the dense nature of the soils and the general absence of a permanent, shallow ground water table, in our opinion, these soils are not susceptible to liquef- action. Landslides - Our review and field investigations did not reveal the presence of any landslides on the site. Likewise, no remolded clay seams or near-horizontal bedding plane faults, were encountered in the test borings or pits. Ground Water Based on our experience, we believe that a seasonal, shallow perched ground water table may be present in the alluvial 10 Project No. 50216W-SIO7 . Woodward-Clyde Consultants soils, as well as in near-surface fractures in the metavolcanic rocks in the general site area. In our opinion, the conditions within the proposed development area indicate a low to moderate probability for ground water seepage problems developing in the future. In our opinion, these conditions and resulting problems can be reduced by installing subsurface drains. Recommendations for the need, extent, and locations of such drains are best made in the field during grading. General guidelines for subsurface drains in canyons and draws are presented under "Grading." We recommend that positive measures be taken to properly finish grade each lot after the residential struc- tures and other improvements are in place, so that drainage waters from the lots and adjacent properties are directed off the lots and away from house foundations, floor slabs, and slopes. Even with these provisions, experience has shown that a shallow ground water or surface water condition can and may develop in areas where no such water condition existed prior to site development; this is particularly true in years of heavy rainfall and in residential subdivisions where a substantial increase in surface water infiltration results from landscape irrigation. 11 Project.No. 50216W-SI07 Woodward-Clyde Consultants General Soil a'nd Rock Conditions The surficial soil and geologic units on the site are grouped into three classes: soils that are moderately to highly expansive (~topsoils, the clayey materials of the Santiago Formation, and the weathered clayey upper zone of the Santiago Peak Volcanics) compressible soils (topsoils and alluvium in the drainage areas), and soils suitable for use at finish grade (sandy materials of the Santiago Forma- tion). These latter materials may be slightly to moderately expansive, but have been used at finish grade in other areas. Nominal reinforcement of foundations and slabs-on-grade is typically used with these soils. Based on preliminary earth package studies, in our opinion, sufficient quantities of finish grade soils will be generated during the proposed grading to provide each pad with at least a 2-foot cover. Excavation Characteristics In our opinion, the topsoil, residual soil, and formational sediments can be excavated with light to mod- erate effort by heavy-duty grading equipment. It should be noted that well cemented layers could be encountered during grading. Excavation of these and similar materials may require heavy ripping, and may result in oversized rock (larger than 24 inches). 12 .Project No. 50216W-SI07 Woodward-Clyde Consultants Excavation of the Santiago Peak Volcanics hard- rock unit generally depends on the type of material, the degree of weathering and decomposition, and the spacing and orientation of the fractures. Due to the limited presence of these materials on site and the fact that proposed cuts are less than 5 feet in depth, we expect that design grades can be achieved with heavy ripping. Excavation for utility trenches in these materials may require pre-blasting. Slope Stability Our selection of soil parameters for analysis of the slopes is based on the results of laboratory tests performed on selected samples and on our experience with the Santiago Formation in the Carlsbad area. We have performed stability analyses for the proposed slopes by the Janbu method using the following parameters, which we consider conservative: 8 = 330, C' = 500 psf and y = 125 pcf, for undisturbed materials; and @ = 25', C' = 400 psf and y = 125 pcf, for compacted soils. The results of those analyses indicate that the proposed 2 to 1 inclined slopes have calculated factors of safety against deep-seated slope failure in excess of 1.5 for static condi- tions. Stability analyses require using parameters selected from a range of possible values. There is a finite possibility 13 Project No. 50216W-SI07 Woodward.Clyde Consultants that slopes having calculated factors of safety, as indi- cated, could become unstable. In our opinion, the proba- bility of slopes becoming unstable is low, and it is our professional judgment that the slopes can be constructed. We recommend that the outer zone of fill slopes, a horizontal distance equal to the height of the slope, be composed of properly compacted, granular soil. We recommend that the face of each fill slope be compacted at maximum 4-foot intervals during construction and trackwalked upon completion. All slopes should be properly drained and maintained to help control erosion. We recommend that an engineering geologist from our firm inspect all cut slopes during grading to verify actual geologic conditions and to provide design modifications, if needed. If adverse conditions are encountered during inspec- tion, slope buttressing may be required. Buttress recommenda- tions will be given during grading, if necessary. The fill soils within the zone of influence of the Tamarack Avenue extension in the waste water treatment plant are reported to be compacted to at least 90 percent relative com- paction. Based upon our analysis, the lots within the subject site will be supported on a prism of fill which does not bear on the existing waste water treatment plant fill. 14 Project No, 50216W-SI07 Woodward-Clyde Consultants Grading We recommend that all earthwork be done in accor- dance with the attached Specifications for Controlled Fill (Appendix C). Woodward-Clyde Consultants should observe the grading and test compacted fills. We recommend that a pre-construction conference be held at the site with the developer, civil engineer, con- tractor, and geotechnical engineer in attendance. Special soil handling or the grading plans can be discussed at that time. We recommend that all loose, porous topsoils, alluvium, and other loose soils not removed by planned grading be excavated or scarified as required, watered, and then recompacted prior to placing any additional fill. We recommend that the soil engineer evaluate the actual depth and extent of excavation in the field at the time of grading. We recommend installing subsurface drains beneath the fills placed in the major subdrainages on the site in accordance with the attached Guide Specifications for Sub- surface Drains (Appendix D). We recommend that each sub- surface drain be extended "upstream" in the drainage to the point where it is covered by a minimum of 10 feet of fill. We recommend that oversize rock fragments, that is fragments between 2 and 4 feet in maximum dimension, be 15 Project No. 50216W-SI07 placed in accordance with the attached Oversize Rock Place- ment Areas (~Appendix E). We recommend that rock fragments larger than 4 feet in size not be used in fills. Highly expansive clayey soils may be encountered at grade in areas of shallow cuts and fills Cdaylight areas), or where claystone is encountered in deeper cuts. We recommend that these clayey soils be excavated, where encoun- tered over the entire level lot areas to a minimum of 2 feet below finish grade, and then be replaced with properly compacted, nonexpansive soils or slightly to moderately expansive soils available on the site. The more clayey soils can be placed and properly compacted in the deeper fill areas. We recommend that the upper 2 feet of materials in the fill areas be composed of finish grade, granular soils. Finish grade soils are defined as granular soils that have a potential swell of less than 6 percent when recompacted to 90 percent of maximum laboratory density at optimum moisture content, placed under an axial load of 160 psf, and soaked in water. We recommend that soils swelling between 3 and 6 percent be compacted at moisture contents of 3 to 5 percent over optimum water content when they are used within 2 feet of finish grade. 16 Project No, 50216W-SI07 Woodward-Clyde Consultants We recommend that an engineering geologist inspect all cut banks and slopes during grading to evaluate possible seepage and geologic problems. Final recommendations for controlling seepage problems can be presented at that time. The attached Guide Specifications for Subsurface Drains (Appendix D) shows several recommended methods for col- lecting cut slope seepage. Foundations We recommend that foundations for structures founded in natural or properly compacted, nonexpansive soil be designed for an allowable soil bearing pressure of 2,000 psf (dead plus live load). In our opinion, this bearing pressure can be increased by up to one-third for transient loads caused by wind or seismic forces. For these bearing pressures, we recommend that all footings be founded a minimum of 12 inches below compacted fill or undisturbed cut lot grade, be a minimum of 12 inches wide, and be founded a minimum horizontal distance of 8 feet from slope faces. We recommend that foundations founded in slightly to moderately expansive material be reinforced top and bottom with at least one No.4 steel bar, and that the con- crete slabs-on-grade be a minimum 4 inches thick and be 17 Project No. 50216W-SI07 Woodward-Clyde Consultants undeslain by 4 inches of coarse, clean sand and reinforced by 6x6, lO/lO welded wire mesh. A plastic membrane should also be provided under slabs. RISK AND OTHER CONSIDERATIONS We have observed only a small portion of the pertinent soil, rock, and ground water conditions. The recommendations made herein are based on the assumption that rock and soil conditions do not deviate appreciably from those found during our field investigation. If the plans for site development are changed, or if variations or undesirable qeotechnical conditions are encountered during construction, the geotechnical consultant should be con- sulted for further recommendations. We recommend that the geotechnical consultant '~-, / review all final foundation and grading plans to verify tha c. the intent of the recommendations presented herein has been ! properly interpreted and incorporated into the contract J documents. We further recommend that the geotechnical consultant observe the site grading, subgrade preparation under concrete slabs and paved areas, and foundation excava- tions. It should also be understood that California is an area of high seismic risk. It is generally considered 18 Project No. 50216W-SI07 Woodward4Zlyde Consultants economically unfeasible to build totally earthquake- resistant structures: therefore, it is possible that a large or nearby earthquake could cause damage at the site. Professsional judgments presented herein are based partly on our evaluations of the technical information gathered, partly on our understanding of the proposed con- struction, and partly on our general experience in the geotechnical field. Our engineering work and judgments rendered meet current professional standards. We do not guarantee the performance of the project in any respect. This firm does not practice or consult in the field of safety engineering. We do not direct the con- tractor's operations, and we cannot be responsible for the safety of other than our own personnel on the site; there- fore, the safety of others is the responsibility of the contractor. The contractor should notify the owner if he considers any of the recommended actions presented herein to be unsafe. 19 Project No. 50216W-SI07 APPENDIX A FIELD INVESTIGATION Woodward-Clyde Consuyants Two exploratory test borings and 16 test pits were made at the approximate.locations shown on Fig. 1. Our field work was performed from November 20 to 26, 1980. The test borings were made with a truck-mounted 30-inch diameter bucket auger. The test pits were excavated by a John Deere Model 310-A backhoe. Representative samples of the subsurface materials were obtained from the test explorations and returned to our laboratory for testing. The locations of the test excavations and the elevation of the ground surface at each location were estimated from the plan prepared by Rick Engineering Company. A-l - Location I ‘SC - 65 Boring Number Elevation I iAMPLE IUMBER SOIL DESCRIPTION r Very dense, damp, brown silty sand (34) $ -I 5 WATER LEVEL A, time Of drilling or as indicated. SOIL CLASSIFICATION ---I soil Clarrificationr ate based on the ““ifkd sot, Clarrlflcatlon svrtem and inchde cob‘. n!oi*l”re and conli$lency. Field dercriollonr Ilaw been modified fO rettect reT”lt6 0‘ laboratory answer where app,0p,,ate. - DISTURBED SAMPLE LOCATION Obtained b” collecting the auger C”ltingl in a plaltlc or Cloth bag. - DRIVE SAMPLE LOCATION MODIFIED CALIFORNIA SAMPLER sample with recorded tdowr per ‘0.x *as obtained with B Modi‘led California drive rampIer 12” inside diameter. 2.5- O”tllde dlsmeteri lined With sample tuber. The *mp,er war driven I”,0 the sot, at the bottom Of the hole with a 140 pound hammer falling 30 mcher. INDICATESSAMPLE TESTED FOR OTHER PROPERTIES GS- Grain si*e Dirtributlon c-r - Conrolldallon Tcr, LC - Laborator” Compactlo” ucs - ““confined cnm~rerrlon Ter, Test PI - Atterberg l.,mitr Test lx- Direct Shear Tes, ST - Loaded Swell Test TX- Triaxial cmwrerr,on Tert cc - Confined Comprerrion Test NOTE: I” this COl”nl” rtle result. Of there tests ma” be recorded where applicable. BLOW COUNT Number of blows needed to advance sampler 0°C loot or 81 I”dcafed. DRY DENSITY Pounds per Cubic Fcmf MOISTURE CONTENT Percent Of Dry Weight NOTESON FIELD INVESTIGATION 1. REFVSAL indiuter ,tl* inability 10 exrend .Icd”lli.“. PracticalI”. with equipmnt being “ted in the invartigatian. KEY TO LOGS TRACT 76-12 ORAWNW: ch MECKED BY: ;:‘:j PROJECT NO: 50216W-SI07 DATE: I-5-81 FICVRE NO: A-l WOOOWARO-CLYOE CONSULTANTS 20- 25- Boring 1 Approximate El, 232' iAMPLE WMBER SOIL DESCRIPTION 1 Hard, dry to damp, dark brown, sandy clay (CL) CULTIVATED TOPSOIL Dense, damp to moist, pale brown, silty sand (SM) SANTIAGC FORMATION Irregular contact attitude N32'E 6'N Becomes pale olive, very fine sand with olive sandy clay seams Very dense, moist, very pale brown, silty sand (SM) with scattered coarse sands SANTIAGO FORMATION Normal fault from 12'-20'-up to 'a" qouqe zone; Attitude N9'E 70'N at 11%' Attitude N14'E 80'N at 19%' Coarse sand l- Coarse sand Dense moist, liqht qray, fine sand (SM) SANTIAGO FORMATION Medium sand layer *PO, description of rymtm~r. ree ~igure A-1 Continued on next page LOG OF TEST BORING 1 TRACT 76-12 DRAWN BY: ch CHECKED w: 1.:3 PROJECTNO: lI,W-SI07 DATE: l-5-81 PlOURE Not A-2 WOOOWARO-CLYDE CONSULTANTS Boring 1 (Cont'd) DEPT c: 2, 45 50 55 60 65 70 75 80 - 1 - ‘MC - - - T 01 - ‘DO - - 6 - ‘BC - - -f- */ R s h 1 1 I iAMPLE IUMBER SOIL DESCRIPTION :$a.:.>Tq Z~E. (Continued) dense, moist, light gray, , -6 fine sand (34) SANTIAGO FORMATION t Cemented zones Cemented zones Becomes dark gray i-v.- Cemented zones Cemented zones Dense, moist, light gjray, medium sand (SP) SANTIAGO FORMATION Minor water seeps at 71' ?$< Dense, moist, light gray, silty very fine sand (SM) SANTIAGO FORMATION *For description Of rymbolr. see Figure A-1 Bottom of Hole LOG OF TEST BORING 1 (CONT'D) TRACT 76-12 DRAWN By: ch CHECKED BY: LJC PROJECT NO: 5"216W-ST"7 D*TE:1-5-81- FIGURE wo: p.- 3 WOOOWARO-CLYDE CONSULTANTS IN - 5- 10 - 15- 7 YiG - ‘DO - - , GF - - - DTHE rEsrS - SOIL DESCRIPTION 1 Loose, dry, brown, clayey sand to silty sand (SC-SM) TOPSOIL Medium dense, damp, reddish-brown, silty sand (SM) CULTIVATED TOPSOIL Dense, moist, light gray, silty sand (SM) SANTIAGO FORMATION Boring 2 Approximate El. 221' - Estimated bedding attitude N14OE 9'N at 8' t- Wet sand - Bedding attitude N51°W 9's at 24$' ::-9:::. " Bottom of Hole A-l 'Far description Of rymbolr, see Figure LOG OF TEST BORING 2 TRACT 76-12 DRAWN BY: ch CHECKEDBY:~~~ PROJECTNO:50216W-ST07 DATEl-5-81 FlO"RENO: A-4 WOOOWARO-CLYDE CONSULTANTS ;S 3-2 [ Test Pit 3 Approximate El. 273' SOIL DESCRIPTION Loose, dry, dark qray-brown, silty sand (SW TOPSOIL Medium dense, dry to damp, dark gray-brown to light red, silty sand (SM) RESIDUAL SOIL Dense, damp to moist, light yellow-brown, silty sand (SM) SANTIAGOFORMATION Occasional $" thick clay interbeds from 11-5' Bedding attitude N13OE 9ON at 5' Bedding attitude N2'E 15'N at 7' 4 fractures-attitude N22'W 85'S at 8' Bottom of Hole Test Pit 4 Approximate El. 262' DEPTH TEST DATA PPA *OTHER SAMPLE *MC ‘LID WC TESTS NVMBER SOIL DESCRIPTION I / 1 t:c:::<*::a LOOSt?, dry, gray-brown, silty sand (SM) TOPSOIL Medium dense, damp, dark Tray-brown, clayey sand (SC) RESIDUAL SOIL Dense, moist, light gray, silty fine to medium sand (SM) SANTIAGO FORMATION Wet sand Bedding attitude N54OE 4ON at 8% Becomes darker gray and finer qrained Bottom of Hole ‘For ck%cription Of rymbolr. see Figure A-l LOG OF TEST BORINGS 3 AND 4 TRACT 76-12 DRAWN BY: ch C”ECKED BY: $22 PRO,ECT NO: 50216W-SIOI DATE: l-1-81 PlOURE no: A-i WOOOWARO-CLYDE CONSULTANTS Test Pit 5 Avxoximate El. 256' SOIL DESCRIPTION Stiff, damp, olive-brown, sandy clay (CL) \ \ CULTIVATED TOPSOIL Stiff, damp to moist, dark olive, sandy clay to silty clay (CL-CHl;(occasional clay parting surfaces) SANTIAGO FORMATION 5 10 15 Contact attitude N30'E 5’N at 8' Very dense, moist, liqht gray, silty sand \ (91) SANTIAGO FORMATION - - - Hard, damp, dark olive, silty clay (CH) (many clay parting surfaces) SANTIAGO FORMATION Bottom of Hole Test Pit 6 Approximate El. 222' 1 - T OP - ‘DO - - - L ‘BC - - SOIL DESCRIPTION Medium dense, dry, gray-brown, silty sand (SM) TOPSOIL Medium dense, damp, dark brown, clayey sand (SC) RESIDUAL SOIL -2 C Very dense, damp, pale brown, silty sand (SM); (poor bedding) SANTIAGO FORMATION Bottom of iiole LOG OF TEST BORINGS 5 AND 6 TRACT 76-12 DRAWNBY: ch CHEC~EOBY:j~h~ PRO,ECTNO:5021hW-SI07 DATE: I-5-81 FIOURE wo: A-6 WOODWARD-CLYDE CONSULTANTS Test Pit 7 Approximate El. 215' SOIL DESCRIPTION Loose, dry, brown, silty sand (SM) \ TOPSOIL L Medium dense, damp, gray-brown, clayey \ sand (SC) RESIDUAL SOIL \ L - - - - - _ _ Grading to - - _ - - - - - \ Dense, damp, light olive to grav, silty sand (SM) SANTIAGO FORMATION Dense, moist, olive-gray, thinly bedded, fine to medium sand (SM) SANTIAGO FORMATION Bedding attitude N18OE 12'N at 8' Bottom of Hole i I i i i i Test Pit 8 Approximate El. 207' SOIL DESCRIPTION DEPTH 1 LIE IN FEET *MC 5 I 3 ! I I ,THEC ‘ESTS SAMPLE UMBER 3-1 [ 3-2 [ 3-3 I: Dry to damp, brown, clayey sand FILL Medium dense, damp, brown, clayey sand (SC) RESIDUAL SOIL S Dense, damp, dark olive-gray, silty fine sand (SM): thinly bedded SANTIAGO FORMATION Dense, damp, light gray, silty sand (SM) SANTIAGO FORMATION Reverse fault, 10" displacement, shear zone hairline to 5" thick at 4?I' Bottom of Hole LOG OF TCST PITS 7 AND 8 TRACT 76-12 DRAWN BY: ch CWXKEO Elv:1^3!, PROJECT ~0: 50216W-S107 1 DATE: 1-5-81 F,G”RE wo: A-7 WOODWARD-CLYDE CONSULTANTS OEPT c IN FEE 5 10 - i G- - - El - 00 - 5 10 15 - - BC - - - 4 - VC - - - ,THEI ‘EFJS - :S OWEF TESTS I I SAMPLE #UMBER 3-l [ SAMPLE ‘UMBER LO-1 [ LO-1 [ Test Pit 9 Arxxoximate El. 212' SOIL DESCRIPTION I Loose, dry, brown, silty to clayey sand (SM-SC) CULTIVATED TOPSOIL Dense, damp, light gray, silty sand (SM) SANTIAGO FORMATION At 4'-fracture zone (%" wide)-unable to determine any offset Attitude N15'E 78OS Bedding attitude N82'E 5ON at 4'3" Refusal on cemented sand Test Pit 10 Approximate El. 223' SOIL DESCRIPTION 1 Loose, dry, brown, silty sand (SM) TOPSOIL Medium dense, moist, dark brown, clayey sand to sandy clay (SC-CL) CULTIVATED TOPSOIL Dense, moist, light qray, silty sand (SM) SANTIAGO FORMATION Bottom of Hole A-l 'For description 0‘ r"mboll, see FilJ"c? I 1 LOG OF TEST PITS 9 AND 10 LOG OF TEST PITS 9 AND 10 TRACT 76-12 TRACT 76-12 DRAWNBY: ch DRAWNBY: ch C"ECKE0 BY: Dr C"ECKE0 BY: Dr PROJECTNO: 50216W-ST07 PROJECTNO: 50216W-ST07 DATE l-5-81 DATE l-5-81 FIGURE NO: A-8 FIGURE NO: A-8 WOODWARD-CLYOE CONSULTANTS I OEPTW OEPTW TEST DATA TEST DATA IN IN FEET G-r *MC * ‘00 T ‘BC 5 5 i 10 15 i 0EP-f L IN FEE, 5 10 15 Test Pit 11 Approximate El, 145' WMPLE IUMBER I SOIL DESCRIPTION Ll-l[ Ll-2[ Ll-3 C .l-4[ AMPLE IUMBER .2-11 .2-3[ ‘For dercriptian Of rymbalr. see Figure A-l Hard, dry to damp, olive-brown, sandy clay (CL) RESIDUAL SOIL \ Dense, damp to moist, gray, silty sand (SM) SANTIAGO FORMATION Hard, moist, dark gray, silty clay (CH) SANTIAGC FORMATION Contact attitude N65OE 3ON at 9' Hard, moist, dusky red, silty clay (CL-CH) SANTIAGO FORMATION Becomes gray-brown Bottom of Hole Test Pit 12 Approximate El. 136' SOIL DESCRIPTION Loose, damp, pale brown, silty sand (SM) ALLUVIUM Stiff, moist, olive-brown, silty clay (CH) SANTIAGO FORMATION 1 Becomes very stiff and olive-gray Bottom of Hole LOG OF TEST PITS 11 AND 12 TRACT 76-12 DRAWN BY: ch CHECKEDBY: l?Jp PROJECT NO: 50216W-SI07 D*TE:l-5-81 F,O"RE NO: A-9 WOOOWARD-CLYDE CONSULTANTS OEPT c IN FEE, 5 ‘BC 9 i. DTHEl rEsTS R I I k 1 1 i 1 L3-2 Test Pit 13 Approximate El. 261' .4-l C ~4-2 C .4-3 [ SOIL DESCRIPTION Loose, dry to damp, brown, silty sand (SM) CULTIVATED TOPSOIL Dense, moist, pale brown, silty sand (SM) SANTIAGO FORMATION Bedding attitude N56'E 1l'N at 6' Bottom of Hole Test Pit 14 Approximate El. 247' SOIL DESCRIPTION Loose, dry to damp, brown, silty sand (SM) CULTIVATED TOPSOIL Medium dense, damp to moist, dark brown, clayey sand (SC) RESIDUAL SOIL ------ Grading to - - - - -- Dense, damp, liqht olive-qray, silty sand (SW SANTIAGO FORMATION 2 sub parallel fractures at 7' Attitude N22'W 89ON Beddinq attitude N30'W 12ON at 8' Bottom of Hole LOG OF TEST PITS 13 AND 14 TRACT 76-12 DRAWNBY: ch CHECKED BY: c\i- PROJECT NO:50216W-ST07 DATE: I-5-81 FlOURE No: A-]” WOODWARD-CLYOE CONSULTANTS Test Pit 15 DTHER TESTS l- Approximate El. 254' SAMPLE l”MBER SOIL DESCRIPTION 1 Loose, dry, brown, silty sand (SM) CULTIVATED TOPSOIL Medium dense, moist, dark qray-brown, clayey sand (SC) RESIDUAL SOIL Dense, moist, light gray-brown, silty sand (SW SANTIAGO FORMATION Fault trace, undetermined displacement at 3'-attitude Nl'W 72OS Bedding attitude N87OW 5'N at 4%' Bottom of Hole Test Pit 16 Approximate El. 154' WLE NVUER SOIL DESCRIPTION I Loose, moist, light brown to brown, mixed silty to clayey sand and sandy clay (SM-SC-CL) ALLUVIUM I Hard, moist, liqht olive, silty clay and rock fragments (CII-GC) SANTIAGO PEAK VOLCANICS Dominant fracture attitude approximately N53OE 81°S Bottom of Hole LOG OF TEST PITS 15 AND 16 TRACT 76-12 DRAWN BY: ch 1 c”ECKED BY: %’ ’ 1 l’, PR~JECTNO:~O~~~W-S~C~ DATE: I-5-81 FGURE NO: il-1~ 1 WOOOWARO-CLYDE CONSULTANTS Test Pit 17 Amxoximate El. 290' SOIL DESCRIPTION Loose, dry, brown, silty sand (SM) RESIDUAL SOIL I Very dense, damp, brown, fractured metavolcanic rock SANTIAGO PEAK VOLCANICS Dominant fracture attitudes: N43OW 77OS, N47OE 76'S Bottom of Hole (Refusal) Test Pit 18 Annm~imat~ Pl 1 AA’ . ._= - -. . -...- - - I ^ . _ - - DEPTH TEST DATA IN *OTHER WLE TEtTE NUMBER SOIL DESCRIPTION FEET l = l DD WC ~~-~. I I I;#/,~ Loose to medium dense, moist, dark gray- brown, clayey sand to sandy clay (SC-CL) ALLUVIUM ‘For deYripti0” 0‘ l”nlboll, see Figure A-l LOG OF TEST PITS 17 AND 18 TRACT 76-12 DRAWN BY: ch 1 CHECKED BY: KY: 1 PROJECTNO:50216W-S107 DATE: 1-5-81 FIGURE wo: A-12 WOOOWARO-CLYDE CONSULTANTS Project No. 50216W-SI07 APPENDIX B LABORATORY TESTS Woodward&lyde Consultants The materials observed in our test explorations were visually classified and evaluated with respect to strength, swelling, and compressibility characteristics. The classifications were substantiated by performing grain size analyses on representative samples of the soils. A laboratory compaction test was performed on a sample of probable fill soil. The grain size distribution curves are shown on Fig. B-l. The results of the compaction test are reported on Fig. B-2. B-l GRAVEL COBBLES I SAND SILT and CLAY Coarse Fine Coarse Hed i urn Fine 1 Mesh Opening - Ins Sieve Sizes Hydrometer Analysis I I I I 76 32 lOOI, , Ii? 4 tlr IO 16rn3030 6080 IWml !I ! I! I , 0 90 IO 80 m 70 30 60 WE f “= 50 “g E 40 60: 30 70 m 80 IO 90 I III III I I I -t YIOO IM) VI IO,0 5.0 I,0 0. I 0.05 0.01 0.005 0.001 GRAIN SIZE IN MILLIMETERS 1 SAMPLE 1 CLASSIFICATION AND SYMBOL 1~~ ~; LL I *PI ~1 *LL - Liquid Limit *PI - Plasticity Index I GRAIN SIZE DISTRIBUTION CURVES I TWCT 76-12 DRAWN BY: i CHECKED BY: ;:;,p PROJECT NO: 502 16cJ-SIO7 DATE: l-5-*0 FIGURE NO: p,- , WOOOWARO-CLYDE CONSULTANTS -t ’ -&y-j S,LT b CLAY t I iooo ~100 10 1.0 0.1 0.01 0.001 GRAIN SIZE, mm MECHANICAL ANALYSIS I PLASTICITY CHARACTERISTICS Liquid Limit, % Plasticity Index, % Classification by Unified Soil ZERO AIR VOIDSCURVES Dry Density, pcf initial Water Content, % Final Water Content, % Apparent Cohesion, psf Apparent Friction Angle, degrees I SWELL TEST DATA Initial Dry Density. pcf Initial Water Content. % Final Dry Density, pcf Final Water Content, % Load, psf Swell, percent I I I I Optimum Moisture MOISTURE CONTENT, 96 LABORATORY COMPACTION LABORATORY COMPACTION TEST TEST METHOD: J%Z,?-O 1557-70 A I FILL SUITABILITY TESTS TRACT 76-12 DRAWN BY: sh CHECKEOLtY:j”” PRo,ECT~o:50316W-SI07 -4 OATS: l-5-80 F,O”RE NO: B-2 W”““WlD” ,.I “nc *n”C,*. %...,I” Project No. 50216W-SI07 APPENDIX C SPECIFICATIONS FOR CONTROLLED FILL I. GENEPAL These specifications cover preparation of existing surfaces to receive fills, the type of soil suitable for use in fills, the control of compaction, and the methods of testing compac- ted fills. It shall be the contractor's responsibility to place, spread, water! and compact the fill in strict accord- ance with these specifications. A soil engineer shall be the owner's representative to inspect the construction of fills. Excavation and the placing of fill shall be under the direct inspection of the soil engineer, and he shall give written notice of conformance with the specifications upon completion of grading. Deviations from these specifications will be permitted only upon written authorization from the soil engineer. A soil investigation has been made for this pro- ject; any recommendations made in the report of the soil investigation or subsequent reports shall become an addendum to these specifications. II. SCOPE The placement of controlled fill by the contractor shall include all clearing and grubbing, removal of existing unsat- isfactory material, preparation of the areas to be filled, spreading and compaction of fill in the areas to be filled, and all other work necessary to complete the grading of the filled areas. III. MATERIALS 1. Materials for compacted fill shall consist of any mater- ial imported or excavated from the cut areas that, in the opinion of the soil engineer, is suitable for use in con- structing fills. The material shall contain no rocks or hard lumps greater than 24 inches in size and shall contain at least 40% of material smaller than l/4 inch in size. (Mater- ials greater than 6 inches in size shall be placed by the contractor so that they are surrounded by compacted fines; no nesting of rocks shall be permitted.) No material of a perishable, spongy, or otherwise improper nature shall be used in filling. 2. Material placed within 24 inches of rough grade shall be select material that contains no rocks or hard lumps greater than 6 inches in size and that swells less than 6% when compacted as hereinafter specified for compacted fill and soaked under an axial pressure of 160 psf. C-l ‘\ / Project No. 50216W-SI07 3. Representative samples of material to be used for fill shall be tested in the laboratory by the soil engineer in order to determine the maximum density, optimum moisture content, and classification of the soil. In addition, the soil engineer shall determine the approximate bearing value of a recompacted, saturated sample by direct shear tests or other tests applicable to the particular soil. _ 4. During grading operations, soil types other than those analysed in the report of the soil investigation may be encountered by the contractor. The soil engineer shall be consulted to determine the suitability of these soils. IV. 1. (a) (b) 2. (a) (b) Cc) COMPACTED FILLS General Unless otherwise specified, fill material shall be compacted by the contractor while at a moisture content near the optimum moisture content and to a density that is not less than 90% of the maximum dry density deter- mined in accordance with ASTM Test No. D1557-70, or other density test methods that will obtain equivalent results. Potentially expansive soils may be used in fills below a depth of 24 inches and shall be compacted at a moisture content greater than the optimum moisture content for the material. Clearing and Preparing Areas to be Filled All trees, brush, grass, and other objectionable mater- ial shall be collected, piled, and burned or otherwise disposed of by the con.tractor so as to leave the areas that have been cleared with a neat and finished appear- ance free from unsightly debris. All vegetable matter and objectionable material shall be removed by the contractor from the surface upon which the fill is to be placed, and any loose or porous soils shall be removed or compacted to the depth shown on the plans. The surface shall then be plowed or scarified to a minimum depth of 6 inches until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used. Where fills are constructed on hillsides or slopes, the slope of the original ground on which the fill is to be placed shall be stepped or keyed by the contractor as shown on the figure on Page 4 of these specifications. The steps shall extend completely through the soil mantle and into the underlying formational materials. c-2 I~, , Project No. 50216N-S107 Cd) 3. (a) lb) (cl (d) (e) V. 1. _ After the foundation for the fill has been cleared, plowed, or scarified, it shall be disced or bladed by the contractor until it is uniform and free from large clods, brought to the proper moisture content, and compacted as specified for fill. Placing, Spreading, and Compaction of Fill Material The fill material shall be placed by the contractor in layers that, when compacted, shall not exceed 6 inches. Each layer shall be spread evenly and shall be thorough- ly mixed during the spreading to obtain uniformity of material in each layer. When the moisture content of the fill material is below that specified by the soil engineer, water shall be added by the contractor until the moisture content is as specified. When the moisture content of the fill material is above that specified by the soil engineer, the fill material shall be aerated by the contractor by blading, mixing, or other satisfactory methods until the moisture content is as specified. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the contrac- tor to the specified density. Compaction shall be accomplished by sheepsfoot rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compacting equipment. Equipment shall be of such design that it will be able to compact the fill to the specified density. Compaction shall be continu- ous over the entire area, and the equipment shall make sufficient trips to insure that the desired density has been obtained throughout the entire fill. The surface of fill slopes shall be compacted and there shall be no excess loose soil on the slopes. INSPECTION Observation and compaction tests shall be made by the . sol1 engineer dursng the frilling and compacting operations so that he can state his opinion that .the fill was constructed in accordance with the specifications. 2. The soil engineer shall make field density tests in accordance width ASTM Test No. D1556-64. Density tes.ts shall be made in the compacted materials below the surface where the surface is disturbed. When these tests indicate that the density of any layer of fill or portion thereof is below the specified density, the particular layer or portion shall be reworked until the specified density has been obtained. c-3 ?I, & Project No. 50216W-SIO7 VI. PROTECTION OF WORK 1. During construction the contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water. He shall control surface water to avoid damage to adjoining properties or to finished work on the site. The contractor shall take remedial measures to prevent erosion of freshly graded areas and until such time as permanent drainage and erosion control features have been installed. 2. After completion of grading and when the soil engineer has finished his observation of the work, no further excava- tion or filling shall be done except under the observation of the soil engineer. a/-- Strip as specified Original ground ;, ,,.. ‘,‘L ,‘, :.~/ ~<?~.. ,., ,, sl.i.di.ng does not occw I?cmx7c a11 topsoil NOTES : The minimum width of "B" key shall be 2 feet wider than the compaction equipme&, and not less than 10 fee.t. The outside edge of bo.ttom key shall be below topsoil or loose surface material. Keys are required where the natural slope is steeper than 61 horizontal to 1 vertical, or where specified by the soil engineer. c-4 Project No. 50216W-SI07 APPENDIX D GUIDE SPECIFICATIONS FOR SUBSURFACE DRAINS I. DESCRIPTION Subsurface drains consisting of filter gravel or clean gravel enclosed in filter fabric with perforated pipe shall be installed as shown on the plans in accordance with these specifications, unless otherwise specified by the engineer. II. MANUFACTURE Subsurface drain pipe shall be manufactured in accordance with the following requirements. Perforated corrugated ADS pipe shall conform to ASTM Designa- tion F405. Transite underdrain pipe shall conform to ASTM Designation C-508 (Type II). Perforated ABS and PVC pipe shall conform to ASTM Desginations 2751 and 3033, respective- lYt for SDR35; and to ASTM Designations 2661 and 1785, re- spectively, for SDR21. The type pipe shall conform to the following table. Pipe Material Maximum Height of Fill (feet) ADS 8 (Corrugated Polyethylene) Transite "underdrain" PVC or ABS: SDR35 SDR21 III. FILTER MATERIAL 20 35 100 Filter material for use in backfilling trenches around and over drains shall consist of clean, coarse sand and gravel or crushed stone conforming to the following grading require- ments. Sieve Size Percenta e Passin g Sieve 1" 100 3/4" 90 - 100 3/U" 40 - 100 4 25 - 40 8 18 - 33 30 5- 15 50 o- 7 200 o- 3 D-l Project No. 50216W-SI07 This material generally conforms with Class II permeable material in accordance with Section 68-1.025 of the Standard Specifications of the State of California, Department of Transportation. IV. FILTER FABRIC AND AGGREGATE Filter fabric for use in drains shall consist of Mirafi 1405 (Celanese), Typar (DuPont), or equivalent. The aggregate shall be 3/4-inch minimum to 1-l/2-inch maximum size, free draining aggregate. Filter fabric shall completely surround the aggregate. V. LAYING Trenches for drains shall be excavated to a minimum width of 2 feet and to a depth shown on the plans, or as directed by the engineer. The bottom of the trench shall then be covered full width by 4 inches of filter material or with filter fabric and 4 inches of aggregate, and the drain pipe shall be laid with the perforations at the bottom and sections shall be joined with couplers. The pipe shall be laid on a minimum slope of 0.2 percent and drained to curb outlet or storm drain. After the pipe has been placed, the trench shall be back- filled with filter material, or 3/4-inch minimum to 1-1/2- inch maximum size free-draining aggregate if filter fabric is used, to the elevation shown on the plans, or as directed by the engineer. D-2 Project No. 50216W-SI07 TYPICAL SUBSURFACE DRAINS FOR LOCAL SEEPAGE Compacted FTypical Seepage Line V lter Material or Filter Fabric 6" Perforated Pipe Drain to Curb Outlet or Storm Drain ,-Compacted Native Soil c’;t”/J ‘or seepage 6" ?erforated Pipe Drain to Curb Outlet or Storm Drain cut Slope --A,/ CGlllp;:Ct~d Seepage Line Ilativc Soil -1: Fil t(?r I;l;ltcrial or Fil tcr Fabric -..,-- 6" I'(!t.:nr<l l.~d I'i ,I? Drain lo Curb Out:1 it or !;lo~~x Ilrxir~ D-3 Line Project No. 50216X-SIO7 TYPiCr L SI:CTION , SUBSURFACE DRAINS IN DMWS / ORIGIIIAL GROUND FILTER FABRIC ALL AROUiJD -, DJtAIN PIPE: 6 IllCH DIAMCTER D-4 Project No. 50216WSIO7 TYPICAL SECTION SURSURFACC DRnINS IN DRAWS / ORIGINAL GROUND \ $, 71 # “-\ CC:IPACTZD FILL EXCAVATION \ / \ z& &+ \ t $5 \ \-- 7ILTCR MATERIAL: 7 cf/ft OF LENGTH, i.1 I N . 'I , 1 Cl’ :,liil ,‘I aimIN PIPE: DIXETER Mi\X'IXlN Il\~:IGilT OF FILL Af,OV,: ii')',",'Oil $!y AI,I.I~IVT,',T, CI.I:A::nLl'l (I-T. ) ii :!(i 3 ‘5 I Oil 6 1:X,, D-5 Project No. 50216W-SI07 APPENDIX E I. .- varl*! 1s:: ..$I” --- &&y , I frcm -f- to ~;/ 1 >+._,.,.--:.. Fill plxcd in aCCO:dlncn wit!3 spec :i.sic?.tion* For Cor.trolled Fill / fl” Lorisi OVERSIZE ROCK PLACEMENT AREAS (No Scale) LEGEND 0 Place no oversize rocks in this area. m Oversize rock can be placed in this area. NOTES (1) Oversize rocks are those rock fragments between 2 feet and 4 feet in maximum dimension. (2) Rocks between 2 feet and 4 feet in size should be pro- perly isolated and completely surrounded by properly compacted soil. (3) No rocks greater than 4 feet in maximum dimension can be used in fills. (4) The oversize rock should be surrounded by sufficient fines to obtain proper compaction. (5) No oversize rock can be placed within 4 feet of finish lot grade or within expected depth of utilities, which- ever is deeper. E-l