The URL can be used to link to this page

Home My WebLink AboutCT 75-09B; Santa Fe Knolls; Soils Report; 1985-07-02EBERHART & STONE, INC. DAN R. EBERHART. CEG GEOTECHNICAL CONSULTANTS GERALG L. STONE. RCE 2211 E. WlNSTONROAD.SUlTEF.ANAHEIM.CA92606*(714)991-0163 5205AVENlDAENCINAS,SUlTEC.CPIRLSBAO,CA92W6.(619)438-9416 GEOTECHNICAL INVESTIGATION SANTA FE KNOLLS, C.T. 75-9 (6) CARLSBAD, CALIFORNIA W.O. 1343 July 2, 1985 Prepared For: The Anden Group 6544 Corte Montecito Carlsbad, California 92008 Anden w-0. 1343 TABLE OF CONTENTS TEXT REPORT ON INVESTIGATION Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1 Proposed Site Grading and Development . . . . . . . . . . . . . . . . . . . . . . Page 1 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2 Location Topography Vegetation Drainage Previous Land Use Previous Grading Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paae 3 Research Maooinq Subsurface Investigation and Sampling Geotechnical Enqineerinq Evaluation . . . . . . . . . . . . . . . . . . . . . . . . Page 3 Slope Stability Bearing Value Geology ,..............................,.................... Paqe 4 Setting Surficial Units Bedrock Units Geologic Structure Faulting Ground Water Landsliding Seismicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6 Ground Shaking Liquefaction Ground Rupture EBERHART 8 STONE, INC. Anden W.O. 1343 TABLE OF CONTENTS TEXT (cont'd.) OPINIONS AND RECOMMENDATIONS Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8 Slopes Faulting Landsliding Ground Water Seismicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paqe 9 Ground Rupture Ground Shaking Liquefaction Seismic Design Geotechnical Parameters for Gradinq . . . . . . . . . . . . . . . . . . . . . . . . Page 9 Shrinkaqe, Bulkinq and Subsidence Excavation Characteristics Canyon Subdrains Transition Lots Blanket Fill Rock Area Overcut Settlement Slopes Stabilization Fill Slooes Stabilization Fill Backdrains Grading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12 Observation and Testinq Clearing Selective Grading Overexcavation Subdrain Placement Fill Placement Oversized Rock Placement Conventional Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 13 Bearinq Value Exoansive Soil Guidelines, Foundations Adjacent a Top-of-Slooe Post-Tensioned Structural Slabs . . . . . . . ..*.................. Page 14 Sumna~y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 EBERHART 0 STONE, INC. Anden TABLE OF CONTENTS W.O. 1343 APPENDIX References ................................................ A-l Description of Laboratory Tests ........................... A-2 Location Map .............................................. Plate 1 Seismicity Maos ........................................... Plates 2a thru 2c Seismic Parameters ........................................ Table I Summary of Laboratory Test Data ........................... Table II Guidelines for Residential Foundations Based on Soil Expansion ........................................ Table III Unified Soil Classification ............................... Plate A Boring Logs ............................................... Plates A-l thru A-14 Standard Soecifications for Gradinq Projects .............. Pages 1 thru 6 Gradinq Details ........................................... Plates GO-1 thru GO-5 Geologic Maps (pocket enclosures) ......................... Plates 3a thru 3d Geologic Cross-Sections (pocket enclosure) ................ Fla%e 4 EBERHART 8 STONE, INC. Anden -I- W.O. I343 REPORT ON INVESTIGATION PURPOSE AND SCOPE Presented herein is a report on this firm's Geotechnical Investigation for Santa Fe Knolls, C.T. 75-9 (91, Carlsbad, California. The puroose of this investigation was to determine the nature of the earth materials underlying the site in consideration of the proposed qrading and resi- dential development. The scope of this investigation included the followinq: * Review of the oublished and unpublished geotechnical and seismic data within and near the site. ' Review of the previous geotechnical reoorts within and near the site. a Review of aerial photographs. ' Review of the grading plans. ' General site reconnaissance and qeolooic msppinq. ' Exploratory drillinq. ' Selective samplinq. ' Laboratory testina. 0 Geotechnical evaluation of orooosed qradina. 0 Discussion of site seismicity. ' Preparation of this report; PROPOSED SITE GRADING AND DEVELOPMENT The tentative map indicates that the site will be developed for the construction of 211 single-family residential structures, open space, and interior streets. Grading plans for 138 (Lots 1-43 and 45-1391 of the 211 lots have been prepared and are the base map for this investigation. Cut-and-fill grading is proposed to create level building pads for the proposed structures. Cut and fill slopes are proposed at a slope ratio of 2:l (horizontal to vertical) or flatter. The maximum heights of cut and fill slopes are 25 feet and 60 feet, respectively. The proposed structures are anticipated to be slab-on-grade, wood-framed, one- and two- story residential dwellings, yielding light sructural loading. EBERHART P STONE, INC. Anden -2- SITE DESCRIPTION Location The subject site is an irregular-shaped parcel of W.O. 1343 land consisting of about 70 acres of undeveloped land in the city of Carlsbad, California. The site is bounded on the west by Mision Estancia, by an existing residential development on the south, and by undeveloped land on the northern and eastern sides of the site. The site in relation to the surrounding area is shown on the accompanying Location Map, Plate 1. Topoqraphy Topograohy at the site consists of northeast-southwest trendinq rollino hills with interveninq tributary side canyons. The oroject site ascends qently to the northeast along the ridqeline, then steepens near the northeastern prooerty boundary. Maximum topoqraphic relief over the site is approximately 155 feet. Natural slopes vary to a maximum slope ratio of about 2:l. Veqetation The site is blanketed with a liaht to moderate growth of natural qrasses and weeds. Heavy brush and scattered large trees occup;~ the larger side canyon swales. Drainaqe Onsite drainage is directed to the north and south into the major canyons offsite. Previous Land Use Much of the site has farming. No manmade Previous Grading been utilized in the past for cattle grazing and dry structures were observed. Portions of the subject site have been partially graded along the Mision Estancia road alignment. This grading was performed by others for the major water line construction. EEERHART 8 STONE,INC. Anden -3- INVESTIGATION W.O. 1343 Research A review of the published and unpublished geologic and seismic data within and near the site, and a review of previous Geotechnical Reports, was accomplished. This included a study of aerial stereo photograohs from 1953, 1964, and 1973 for the site and surrounding areas. Geologic data from these sources were trans- ferred to the 50-scale grading plans and were subsequently field checked. Mapping Surface and subsurface qeoloaic mapping was accomplished utilizing the 50-scale grading plans to plot geologic units, structure, and subsurface exploration. This was accomplished by several of this firm's project oeoloqists durinq the period of October and November 1984. These data have been plotted on the enclosed Geologic Maps. Subsurface Investiqation and Samolinq Subsurface exoloration, during this firm's investigation, consisted of exca- vating 9 bucket-auger borings, 10 feet to 50 feet deep. Bucket-auaer borings were logged by one of this firm's project oeologists and the Principal Enqineerlng Geo!oqist during October 1984. Visual and tactile identifications were made of the materials encountered, and their descriptions are presented on the boring logs. Bulk and relatively undisturbed samales were obtained at selected depths for laboratory testing. GEOTECHNICAL ENGINEERING EVALUATION Slope Stability Evaluation of the gross stability of fill slopes, cut slopes, and buttressed slopes under static and pseudo-static conditions was oerformed. Calculations were made with the aid of a micro-computer and a program develooed by Douqlas E. Moran, Inc., utilizinq the simplified wedqe method of analysis as described hy Duncan and Buchignani (19751. Values for shear strenoth and unit weight were utilized from laboratory test results. For pseudo-static evaluations, a hori- zontal factor of 0.15 was utilized. A oseudo-static evaluatinn was not oer- formed when evaluating stability of slopes where the failure surface was less than 12", in accordance with the standards estahlished by Los Anqeles and Orange Counties. Surficial fill slope stability was evaluated in accordance with methods established by the Orange County Slope Stability Committee. ERERHART 8 STONE, INC. Anden -4- W.O. 1343 Bearing Value Calculations for recommended bearing values for the oroposed structures were performed in accordance with the Terzaghi equations. GEOLOGY Setting The site is located on gently rollinq hills along the western flank of the Peninsular Ranqe Province. Bedrock underlying the site consists of sandstone and claystone of the Eocene Delmar Formation and metavolcanic rocks of the Jurassic Santiaqo Peak Volcanics. Residual soil and colluvium mantle the bedrock. Surficial Units Surficial units on and immediately adjacent the site consist of artificial fill (Qaf and Qafu), residual soil (no map symbol), and colluvium (Qcol). The loca- tions and extent of these units are indicated on the geologic map. A brief description of each of these units follows. Artificial Fill (Qaf): Artificial fill is oresent along Mision Estancia and extends onto the tract. This material was placed under the observation and testing of Southern California Soil and Testing, Inc. It consists of a mixture of silt, sand, and clay derived from the adjacent bedrock. Fill was reoortedly placed on firm soil and colluvium and was not placed on bedrock. Artificial Fill (Qafu): Non-structural artificial fill was olaced on the tract ad,jacent Mision Estancia. No testino of these materials was net-formed by Southern California Soil and Testina, Inc. Residual Soil (no map Symbol): Residual soil, up to three feet thick, mantles most of the bedrock on the site. Residual soil is locallv absent in the steeoer slonino areas of the Delmar Formation and many areas of the Santiaqo Peak Volcanics. It consists of brown silty sand to silty clay, which is dry to moist, loose to stiff, desiccated, and locally porous. Colluvium (Qcol): Thick accumulations of colluvium blanket the side-slopes and areas within the bottoms of drainaqe swales. Colluvium consists of brown to gray-brown silty clay, whi,ch is dry to moist, soft to firm, locally desiccated, and low in density. EBERHART 8 STONE, INC. -5- W.O. 1343 Bedrock Units Bedrock units underlying the site consist of marine sediments of the Eocene Delmar Formation unconformably overlying the metavolcanic rocks of the Jurassic Santiago Peak Volcanics. The distribution and extent nf these units are indi- cated on the geoloqic map. A brief description of each of these units follows. Delmar Formation, Sandstone (Tdmss): Rocks of the sandstone unit consist predo- minantly of sandstone with occasional thin seams of cla,y and siltstone interlayers and interlenses. Sandstone varies in color from gray to brown, is typically very fine to fine prained, internally massive to poorly bedded, well consolidated and locally lightly cemented. Occasional concretionary beds 1 foot to 2 feet thick are also present within this unit. This unit conformably overlies the claystone unit. Delmar Formation, Claystone (Tdmcl): Rocks of the claystone unit consist of claystone and clayey siltstone with occasional interlayers and interlenses of sandstone. They conformably underlie the sandstone unit and unconformably overlie the Santiago Peak Volcanics. Claystone varies from brown to green to gray to blue-gray in color. Bedding is typically poorly developed and discon- tinuous. In general, the upper ten feet of this unit is highly weathered and fractured and, consequently, has low strength parameters. These weak materials are the result of creep, shallow surficial slumoing, and wettinq and drying cycles. Below a depth of about ten feet, rocks are well consolidated and lightly cemented. Santiaoo Peak Volcanics (Jmv): Rocks of the Santiaqn Peak Volcanics are of basaltic and andesitic comoosition. They are typically dark qray, fine grained to micro-crystalline and very dense. The upoer portions of the volcanics are weathered to various depths and partially altered to clay. Below the weathered zone, very dense volcanic rock is oresent. Geoloaic Structure -- -__ Subsequent to their deposition over the Santiago Peak Volcanics, the sediments of the Delmar Formation have undergone only minor uplift and folding. Beddina planes are ooorly develoned to massive. Where beddino was observed, dios of 5' to 15" were measured, striking in all directions. These variable beddinq attitudes represent typically undulatory, cross-bedded, and discontinuous planar features. Geologic structure within the volcanics is typically absent; however, moderate fracturing and high-angle joint patterns are common. EBERHART 8 STONE, INC. Anden -6- W.O. 1343 Faulting Geologic literature and field exploration do not indicate the oresence of hiqh- anqle normal or reverse faulting on or immediately adjacent the subject site. Some evidence of beddino alane faulting was observed. Ground Water Minor water seepage was present within Borings B-l, B-2, and B-5 within the claystone unit of the Delmar Formation. Natural springs and water seepage were observed adjacent the Delmar Formation/Santiago Peak Volcanics contact in the northern portion of the subject tract. Landsliding No major deep-seated landslides were observed during this firm's field explora- tion. However, several shallow surficial failures were mapped in the vicinity of Lots 3-7 and 30. These rotational failures apoear to involve residual soil and highly weathered bedrock. SEISMICITY Ground Shakinq The Southern California area is seismically active. Because of the ornximitv of the site to several nearby active and ootentially active faults, moderate around shaking could occur at the site as a result of an earthquake on any one of them. The fault zone capable of oroducina the stronoest shakino at the site is the Rose Canyon. The site in relation tn the active and potentiallv actitle faults in the reoion, as well as eoicenters of orevious earthquakes, is oresented on Plates 2b and 2c, respectively. Ground resoonse during a seismic event may be estimated for a oarticular site on the basis of previous ground motion studies, data from previous earthquakes, activity of the faults influencing the site, and current state-of-the-art understanding of seismic forces. Seismic parameters for active ano potentially active faults within a loo-km radius of the site are oresented in Table I. ERERHART 8 STONE, INC. -7- W.O. 1343 Anden The orobability of any site in California exoeriencinq seismic accelerations of varying levels during a loo-year oeriod has been computed by Housner as follows: Acceleration (%Q) % Probability (100 yrs) 15:o El 20.0 25.0 30.0 35.0 99 98 a7 63 37 19 a.7 Liquefaction Since the factors generally considered to contribute to liquefaction are not present at the site, the potential for liquefaction is considered nil. Ground Rupture Since no active faults lie within or adjacent the site, ground ruoture at the site due to fault disnlacement is not anticipated. EBERHART 8 STONE,INC. Anden -2% W.O. 1343 OPINIONS AND RECOMMENDATIONS Recommendations in this report are opinions based upon this firm's exoloration, testing, and professional judgment. Opinions and recommendations are applicable to the proposed development of the site under the purview of this reoort, and should be incorporated into project design and construction practice. Based on this investigation, the site may be developed for future residential use, as indicated on the tentative map and grading plans, provided that the recommendations and specifications presented herein are incorporated into design and construction practice. Grading should be conducted in accordance with local codes, this firm's standard gradinq specifications, and the recommendations within this report. GEOLOGY Slopes No cut slopes with adversely oriented planar features are anticipated that would _ require buttressinq. Some cut slooes with locally adversely oriented planar features, hiahly frac- tured rock, residual soil or colluvium, are anticioated and igill require replacement with stabilization fills. Fatiltinq I____ Geoloqic hazards due to active faulting are not present at the subject site!. Landsliding No deep-seated landslides were encountered on or adjacent the subject tract. Ground Water Adverse effects on the proposed development as a result of ground water are not anticipated. Subdrains are recommended below all proposed canyon fill areas and within slope stabilizations. EBERHART 8 STONE, INC. Anden -9- W.O. 1343 SEISMICITY Ground Rupture Ground ruoture due to fault displacement is not anticipated. Ground Shaking Moderate ground shaking could occur at the site as a result of an earthquake. Liquefaction In consideration of proposed grading, material types, current ground water con- ditions, and anticipated ground shaking, the possibility of liquefaction is con- sidered remote. Seismic Desiprl The oroposed structures and foundations should be designed to resist seismic forces in accordance with the criteria contained in the 1985 Uniform Building Code for seismic zone 4. GEOTECHNICAL PARAXT'RS FOR SR?DI?IG - -----__ Shrinkaae, Bulkinp and Subsidence Based on the results of laboratory testinq and evaluation of the WmW?d aradina, the 3veraae shrinkaae and bulkina factors for each material tyne are estimated as follow: Material Tvog Artificial Fill (Qaf) Artificial Fill (Qafu) Residual Soil Colluvium (Qcol) Sandstone (Tdmss) Claystone (Tdmcll Volcanics (Jmv) Shrinkaqe -~ Bulkinq --~ -- -- 15% -- 15% -- 10% -- -- 5% -- 5% -- 5% Since compressible alluvial deoosits are to be overexcavated from areas to receive significant amounts of fill, subsidence is anticioated to be neqliqible. EBERHART 8 STONE. INC. Anden -lO- W.O. 1343 Excavation Characteristics The following excavation characteristics of the various material types at the site have been developed based on exploratory borings, mapping, previous geotechnical investigations, and experience with these materials. Some blasting is anticipated within the Santiago Pea~k Volcanics below a deoth of 5 feet. Material Type Easy* Ripping Moderatelv?* Difficult Rippinq Difficult** Oversized Ripping Materials Artificial fill (Qaf) X -- -- -- Artificial fill (Qafu) X -- -- -- Residual Soil X -- -- -- Colluvium (Qcol) Sandstone (Tdmss) Claystone (Tdmcl) X -- -- -- X X X X X X -- -- Volcanics (Jmv) X x x X *D-9 with double riooers **D-9 with sinale riooer Sa'.urated materials will likely be encountered in swales and areas of overex- cavation overlyinq the volcanics. The depth and location of seepage or qround water are indicated on the geoloqic map and borinq logs. Canyon Subdrains A subdrain system will be required beneath the proposed fills in canyon areas. Tentative locations are indicated on the enclosed Geologic Map. Details for canyon subdrains are presented on Plate GD-1. Transition Lots The proposed mass grading will create transitions of cut-to-fill within pad areas. For this condition, the transition should be eliminated by overex- cavation of about 3 feet of the cut portion of the pad and replacement as a compacted fill blanket, as indicated on Plate GD-5. This is accomplished to orovide uniform bearing conditions for foundations. EBERHART B STONE,INC. Anden -11- W.O. 1343 Blanket Fill To reduce the potential for water infiltration and miqration from pads above stabilization fills, a blanket fill will be required. These pads should be overexcavated about three feet and replaced with a blanket of compacted fill. Rock Area Overcut To provide for ease of pipe trench and footing excavations, street and nad areas exposinq volcanic rock (Jmv) should be overcut. Pad areas should be overcut 3 feet below oroposed grade and street areas should be overcut to the depth of the deepest prooosed pipeline. Materials excavated from these areas should be placed in the deeper fill areas. Materials from the sandstone unit (Tdmss) should be utilized for compacted fill in overcut areas. Settlement Compressible artificial fill, colluvium, an d residual soil are recommended to be overexcavated. Therefore, settlement beneath prooosed fill is not anticipated. Settlement of the proposed compacted fill is anticipated to occur during construction. Slopes Cut and fill slopes should be constructed at a ratio of 2:l (horizontal to ver- tical) or flatter. The proposed favorably oriented cut and fill slopes r,f up to about 25 feet and 60 feet, respectively, are considered grossl,y and su~'icial1.y stable. All cut slopes will be reviewed by the enoineering geoloqist t!urinq grading to verify the anticipated conditions. Fill slopes should be keyed into firm materials. Details for fill kevs are ore- sented on Plate GD-4. Stabilization Fill Slopes The following oroposed cut slopes 'are anticioated to exnose locall,y adverselv oriented planar features, highly fractured rock, or surficial soils, and will, therefore, require replacement with stabilization fills. Their locations and key dimensions are indicated on the Geologic Map. Details for stabilization fills are presented on Plate GD-3. Back-cuts for stabilization fills should be no steeper than 2:l. Flatter back-cuts may be necessary for temporary stability during construction. Key Key Reference Location Width Depth Section Rear of Lots l-5 15' 3’ A-A' South of Calle Acervo 15’ 3’ A-A' Rear of Lots 7-8 20’ 3’ -- EBERHART 8 STONE. INC. Anden -12- W.O. 1343 Stabilization Fill Backdrains A backdrain system will be required for each stabilization fill constructed. Details for backdrains are presented on Plate GO-2. GRADING Observation and Testinq Prior to the start of gradinq, a meeting should be held at the site with the developer, grading contractor, civil enqineer, and qeotechnical consultant to discuss the work schedule and qeotechnical asoects of the grading. Gradinq, includinq clearing, overexcavation, and fill placement, shall be accomplished under the full-time observation and testing of the geotechnical consultant. Clearinq Vegetation, trash, and other deleterious materials should be removed within areas to be graded and wasted from the site. Selective Grading In order to minimize expansive soil and rock at pad and street grades, selective grading is recommended. Subsequent to overexcavation and subdrain placement, the following order of excavation and fill placement is recommended. 0 excavate rock and rock area overcut from volcanics (Jmv) and place in deep fill areas. 0 excavate claystone (Tdmcll and olace in deep fill areas. 0 excavate sandstone (Tdmssl and place in shallow fili areas, rock over- cut areas, and upper three feet of buildinq pads and roadways. Overexcavation . The surficial units, consisting of artificial fill, residual soil, colluvium, slumps, and the upper portions of weathered bedrock, are considered unsuitable in their present state for support of the oroposed fill and/or structures. Therefore, overexcavation of these materials to firm underlyinq bedrock will be required prior to fill placement. The location, extent and estimated depth of overexcavation of these materials are indicated on the Geologic Map. Actual depth and extent of overexcavation will be determined by the goetechnical con- sultant during grading. Overexcavated soil, free of veqetation or other dele- terious materials, may be reused as compacted fill. Prior to fill placement, overexcavated areas should be scarified to a depth of six inches, moisture-conditioned to near optimum, and compacted to 90% or more of the laboratory maximum density. EBERHART 8 STONE, INC. Anden -13- W.O. 1343 Subdrain Placement Subsequent to overexcavation, the canyon subdrain systems should be constructed. Tentative locations are indicated on the Geologic Map. Details for canyon subdrains are presented on Plate GO-l. The final locations of the subdrain systems will be determined by the geotechnical consultant during grading. Fill Placement Subsequent to overexcavation and subdrain construction, fill placement may proceed. Fill should be placed in loose lifts restricted to about six inches in thickness. Each lift should be moisture-conditioned as needed to obtain near- optimum conditions, then compacted to 90% or more of the 1aborator.y maximum den- sity. Each lift should be treated in a like manner until the desired rough grades are achieved. Oversized Rock Placement Oversized rock, greater than 12 inches, ma.v be qenerated during qradina from excavations within the sandstone (Tdmss) and volcanic (Jmv) units. Oversized rocks greater than 12 inches, but less than 3 feet, may be olaced in the deeper fill areas in accordance with Plate 60-6. Rocks larqer than 3 feet should be reduced in size or removed from the site. CONVENTIONAL FOUNDATIONS The followino preliminary recommendations have been develooed for one- and/or two-story residential structures. Wood-framed, slab-on-grade construction yielding light structural loading is anticipated. These recommendations are for planninq and estimating purposes onl:v and are subject to revision based on as- graded conditions. Based on the proposed gradinq and anticipated light structural loading, post- construction settlement should be within generally accepted tolerable limits. Foundations for an individual structure should be embedded within the same bearing material, such as entirely within bedrock or entirely within compacted fill. Based on soluble sulfate content of the onsite materials, Type II or Type V cement should be utilized in concrete for foundations. EBERHART B STONE, INC. Anden -14- W.O. 1343 Bearing Value For preliminary design purposes, an allowable bearing value of 2000 pounds per square foot, based on an embedment of 12 inches into compacted fill or bedrock, may be used for continuous footings or square pad foundations. This value is for dead load plus live load conditions and may be increased by one-third in consideration of wind or seismic loadings of short duration. In designing to resist horizontal soil loadinqs, a lateral bearinq resistance of 200 pounds per square foot, per foot of embedment, and a friction factor of 0.3 may be utilized for foundations embedded in compacted fill or bedrock. Expansive Soil Guidelines The potential expansion of the onsite~soil tyoes ranqes from Low to Very Hiqh. General guidelines for residential foundations based on soil expansion are ore- sented in Table III. Upon completion of rough oad grades, a lot-by-lot eva- luation of foundation bearing materials will be made, at which time specific recommendations for construction will be oresented. Foundations Adjacent a Too-of-Slope The bottom outer edge of foundations adjacent a top-of-slope should be set back from the slope surface a horizontal distance of one-half the slope height under consideration. The horizontal distance should not be less than five Feet and may be limited to ten feet. POST-TEN_SIONEO STRUCTURAL SLABS - As' an alternative to conventional concrete foundations, post-tensioned structural slab systems may be utilized. Post-tensioned structural slab foundation systems should be designed by a struc- tural engineer to resist expansive soil and orovide relatively uniform bearinq over the slab area. Allowable bearing should be limited to a value of about 1000 pounds per square foot. A cut-off footing should be provided along the perimeter of post-tensioned slabs, with an embedment of about 12 inches below lowest adjacent grade. Though presaturation of slab subgrade is not a requirement, optimum moisture conditions should be maintained or reestablished just prior to the placement of slab concrete. A visqueen-type moisture barrier should be olaced at grade below concrete slabs and be overlain by one inch of protective sand cover. This moisture barrier should be heavily overlapped or sealed at splices. EBERHART B STONE, INC. Anden -15- W.O. 1343 SUMMARY The ooinions and recommendations presented in this reoort are based upon site conditions as the.y existed at the time of this firm's investiqations, and further assume that exploratory borinqs are representative of subsurface con- ditions throughout the site. Although not anticipated, materials adjacent and/or beneath those observed may have different characteristics. This firm's opinions and recommendations are further based upon laboratory testinq, experience with similar projects, and professional judqment, No warranty is expressed nor implied. This report is subject to review by the controlling governmental body. Respectfully submitted, Robert J. Fulton Project Geologist Dan R. Eberhart President CEG 965 and RJF:DRE:GCS:mab (5) d@-@f Gerald L. Stone Vice President ?CE 32233 EBERHART 8 STONE, INC. Anden EBERHART L STONE, INC. W.O. 1343 APPENDIX Anden A-l REFERENCES W.O. 1343 Publications Greensfelder, R.W., 1974, Maximum Credible Rock Accelerations from Earthquakes in California, C.D.M.G., MS-23. Hayes, Walter, W., 1980, Procedures for Estimating Earthquake Ground Motions, U.S.G.S., Professional Paper 1114. Housner, G.W., 1970, Strong Ground Motion, Earthquake Engineering, edited by R.W. Wiegel. Hutton, L. Katherine, Allen, Clarence R. and others, Southern California Array for Research on Local Earthquakes and Teleseims (SCARLET), Preliminary Epicenters for 1975 through 1984, CalTech - U.S.G.S. Jennings, Charles W., 1975, Fault Mao of California, C.D.M.G., Map No. 1. Kennedy, M.P. et al., 198C, Recency and character of faultino Offshore MetroDOlitan San Dieqo, California, C.D.M.G., MS-40,31,42. Moran, D.E., Slosson, J.E., Stone, R.O., Yelverton, C.A., 1973 Geology Seismicity and Environmental Imoact, A.E.G., Special Publication. Moyle, W.R. Jr., 1974, Geohydroloqic Map of Southern California, U.S.G.S., Water Resources Investigations 48-73 ooen file. Ploesel, M.R., and Slosson, J.E., 1974, Repeatable High Ground Accelerations from Earthquakes, California Geology. Real, C.R., Toppozada, T.R., and Parke, D.L., 1978, Earthquake Epicenter Map of California, C.D.M.G., MS-39. Rogers, T.H., 1965, Geologic Map of California, Santa Ana Sheet, C.D.M.G. Schnabel, P.B. and Seed, H.B., 1973, Accelerations in Rock for Earthquakes in Western United States, S.S.A., Vol. 63, No. 2. Seed, H.B., Idriss, I.M. and Kiefer, F.W., 1968, Characteristics of Rock Motions During Earthquakes, E.E.R.C., 68-5. Previous Reports Preliminary Soils Investigation, La Costa far south, easterly area, Ranch0 La Costa, Carlsbad, California, by Benton Engineering, Inc., dated February 28, 1975 (75-I-2OBC). EBERHART 8 STONE, INC. Anden W.O. 1343 A-l (cont'd) Supplemental Soils Investigation, La Costa far south, easterly area, Ranch0 La Costa, Carlsbad, California, by Benton Engineering, Inc., dated November 11, 1975 (75-lo-9BC). Review of Tentative Map, CT 75-9, Santa Fe Knolls, Ranch0 La Costa, California, by Benton Engineering, Inc., dated April 20, 1976 (75-lo-9BC). Supplemental Soils Investigation, two areas adjacent to Santa Fe Knolls, Ranch0 La Costa, Carlsbad, California, by Benton Engineerinq, Inc., dated July 7, I976 (75-l-2OBC1. Review of offsite improvement plans, CT 75-9, Santa Fe Knolls, Carlsbad, California, by Benton Engineering, Inc., dated January 17, 1977 (76-3-18F ). ia, by Earthwork quantity estimates, Santa Fe Knolls, Unit 1, Carlsbad, Californ Benton Engineering, Inc., dated March 21, 1979 (79-2-8F). Preliminary Geotechnical Investigation, southeast area water line, Ranch0 Santa Fe Road and Mision Estancia, Carlsbad, California, by Southern California Soil and Testing, Inc., dated February 14; 1984 (25028, No. 1). Buttress Recommendations, southeast area water line oro~ject, Mision Estancia, Carlsbad, California, by Southern California Soil and Testinq, Inc., dated March 1, 1984 (25028, No. 2). Report of field observation and relative compaction tests, orooosed southeast area !#ater line, Ranch0 Santa Fe Road and La Costa Avenue, Carlsbad, California, by Southern California Soil and Testinq, Inc., dated May 18, 1984 (25026, No. 4). AERIAL PHOTOS Agency USDA 4-11-53 AXN-8M 16,17,18 USDA 4-09-64 AXN-4DD 5,6,7,8 USDA 4-09-64 AXN-4DD 80,81,82 San Diego County 10-31-73 73/20 21,22 Date Fliqht No. Photo No. EBERHART 8 STONE. INC. Anden W.O. 1343 A-2 DESCRIPTION OF LABORATORY TESTS Classification Field classifications were verified in the laboratory by visual and tactile identification. Soils have been classified in accordance with the Unified Soil Classification System. Moisture-Density Moisture-density determinations were conducted on relatively undisturbed samples. The results are presented on the boring logs. Maximum dry density and optimum moisture were determined in accordance with ASTM D1557-70 and are oresented in Table II. Potential Expansion Determinations of ootential soil expansion were made on representative samples in accol,dance with ASCE Exnansion Index Test (IJBC Standard 29-2). The results are oresen%ed in Table II. Sulfate Content Determinations of soluble sulfate content were made on reoresentative samples, by Soil and Plant Laboratorv, Inc., in accordance with California Method of Test No; 417A. The results are presented in Table II. Direct Shear Direct shear tests were conducted on remolded samples. The samples were tested in brass rings with 2.5-inch inside diameters. The rate of strain used was 0.05 in./min. The specimens were inundated for approximately 24 hours under normal loads and during shearing. The results are presented in Table II. EBERHART B STONE, INC. LOCATION MAP - ____ -_- ---_-- scale From: Ranch0 Santa Fe, Ca. 7.5’ Quadrangle, USGS Anden - Santa Fe Knolls I EBERNART 8 STONE INC. GEOTECHNICAi CONSULTANTS ?,,I FM, WNSTON RoAO,S”ITt F.ANA”EIM, CAILIFORNI/\92eca W.O. 5343 1 DATE: 7-2-85 SITE LOCATION 1 PLATE: I EXPLANATION OF SYMBOLS FOR SEISMICITY MAPS FAULT MAP, PLATE: 2-b ACTIVE AND POTENTIALLY ACTIVE FAULTS . . . . . . /I” TOTAL LENQTH OF FAULT ZONE THAT BREAKS QUATERNARY DEPOSITS OR THAT HAS HAD SEISMIC ACTIVITY FAULT SEQMENT WITH SURFACE RUPTURE DURING A HISTORIC EARTHQUAKE, OR WITH ASEISMIC FAULT CREEP. (From A.E.G. Recently Active Faults in So. Callf. Region Ma l’ 1973 a C.O.M.G. Fault-Rupture Hazard Zones in Calif. htop, IS 0) 1 EPICENTER MAP, PLATE:2-c APPROXIMATE EPICENTER LOCATl9NS IN THE SOUTHERN CALIFORNIA REGION WITH : A&.IGNEO MAGNITUDES GREATER THAN 5.0 A 7.0 - 7.9 0 El.0 or Greater (From U.S.G.S. Earthquake Eplcantar Map of Calltarnlo,l978 B CalTech-U.S.G.S. Prsllmlna~ry Epicenters for l-75 thrU 5-84) ppROXIMATE SITE LOCATION / &l_F -_-A--- --- -GC; A- 100 KILOME TE S I D Y “.\.. ,- b Y-y------’ Sea ‘**-. ,z...’ g%$$ 4+*+ f rJ /.---4*A / i’ OF CALIF: -0 9 0 -n 0 R I A I. a w I +- Cl 100 km radius \ cl ;i 00 q 0 N q i i \ i c .--, T ;J’ be-) ---7 i L ,I-, “J?lZ ON I SO&id &A q Cl o- -&- \ b I n Bh The Anden Croup POTENTIAL C&“S*TI”E FAULT San Jacinto 46NE Newport/ lnglewood \1~L:*.:~“, . . . . ..-. , Elsinore Agua Blancai Coronado Bar Rose Canyon IISTANCE ‘+m SlTl ‘0 F*“LT kn,,.*l 28NiV 23NE ENOTH OF ‘A”LT “0,. I, 30-24; 35-17c SO-85 RICHTER MAONIT” OF HlSTORlCAL iARTHWAI(E 3r*.,w than 5 6.20 (19543 6.40 (1958) 6.50 (1968) 5.50 (1980) 6.10 (1980) 6.30 (1922) 5.40 (1941) 6.00 (1910) 5.00 (1920) 5.10 (19401 6.30 (1954) 5.20 (1967) Uo known xistorical earthquake! PPPROXlMATE AGE OF OST RECEN, SURFACE SPLACEHENT -ound failure rt no definitf wwn rupturt axene 1,,000 yr.5 raternary 2 million yrs mternary 2 million yrs TABLE 1 SEISMIC PARAMETERS HAXlY”M CREDlELE EARTHOUAKE 7.50 .I1 7.00 .06 7.60. .15 .23 .23 W.O. 1343 6.30 6.35 6.40 CH PEAK .08 31 1EPEnJABLE . .08 .I3 .12 .18 .28 16 .28 17 .28 17 .25 12 M I S..d. km** end Kll,,r.. ,969 e, NW Hownr,1070,a Bolt OS,,> 'REDOMININT D”RP.TION PLRlOD )F STRON(I AT SITE HM,NO A tS.esnd*l ITE ts.cm** (NC.,. 5) (NO,. 6) .32 24 Anden W.O. 1343 i BORING DEPTH NUMBER (ft.) uses B-l s-10 SM B-l 17-22 CL B-l 25-34 CL B-l 34-43 CL B-4 2-10 ML TABLE II SUMMARY OF LABORATORY TEST DATA ANGLE OF MAX.DRY OPTIMUM INTERNAL SOL. DENSITY MOISTURE COHESION FRICTION EXPANSION SULF. (PCf) (%) c (psf) # (degr) INDEX (%) 116 13 280 2? 3e .!vn *J 111 17 340 21 96 .120 117 14 300 20 a7 .024 115 15 280 21 68 .053 116 14 300 24 105 .725 I , / \ , / Anden TABLE III W.O. 1343 Clllnrl ,.,e.z mn m,,*lnlTlnrlT mAPcr. n., cnm, C”r3ILIClnLr c I i;“I”CLII~C3 r”R r”~~~?uI-.I ,“,.J.DA3C” y!. J&#,L LArN*a,“,-, _- ~, POTENTIAL FOOTINGS . . SLABS fXPANSlON (UBC 29-21 EMBEDMENT REINFORCEMENT THICK. REINFORCEMENT PRESAT. BASE 1 STORY 2 STORY 3 STORY COURSE Very Low Very Low 12” perimeter 18” perimeter 24” perimeter 12” perimeter 18” perimeter 24” perimeter (O-20) (O-20) 12” interior 12” interior 18” interior 18” interior 24” interior 24” interior i / \ / \/ Low 12” perimeter 18” per/meter 24” perimeter 2 No. 4 bars: 4” nom. 6”xti”. #lOx#lO (21-50) 12” interior 18” interior 24” interior 1 top, 1 bottom W.W.F. moisture Medium (51-90) 18” perimeter 18” perimeter 24” perimeter 2 No. 4 bars: 4” net 6”x6”, #6x#6 120% of 4” 12” interior 18” interior 24” interior 1 top, 1 bottom W.W.F. optimum 0; moisture - No. 3 bars @ 24” O.C. each way High 24” perimeter 24” perimeter 24” perimeter 4 No. 4 bars: 4” net 6”X6”, #6x#6 120% of ,,, (91-130) 12” interior 18” interior 24” interior 2 top, 2 bottom W.W.F. optimum or or moisture - 2 No. 6 bars: No. 3 bars @ 18” 1 top, 1 bottom O.C. each way Very High 24” perimeter 24” perimeter 24” perimeter 4 No. 5 bars: 6” net No. 4 bars I? 18” 120% of 6” (7 138) 12” interior 18” interior 24” interior 2 top, 2 bottom O.C. each way optimum or or moisture - - 2 No. 8 bars: No. 3 bars 4 12” 1 top, 1 bottom O.C. each way Notes on the following page are considered part of this table. Anden / t NOTES TO TABLE III W.O. 1343 11 These guidelines are based on site soil expansion and should not preclude more restrictive structural or agency requirements. As an alternative to conventionally reinforced concrete foundations, post- tensioned structural slab systems, designed by a structural engineer, may be utilized. 21 Footing embedments should be measured below lowest adjacent grade. At the time of concrete placement, footing excavations should be moist and free of desiccation cracks. 3) A reinforced concrete grade beam should be constructed across garage entrances, with similar depth and reinforcement as adjacent perimeter footings. 4) For soil with a potential expansion greater than “Low”, interior isolated spread footings and/or partial length footings are not recommended. i 51 Where presaturation is recommended beneath interior slabs, the recommended moisture should penetrate to the depth of the perimeter footings. The moisture content should be tested by the geotechnical consultant 24 hours prior to the placement of concrete. Though presaturation of slab subgrade is not a requirement for Very Low and Low expansion potentials, optimum moisture conditions should be maintained or reestablished just prior to the placement of slab concrete. 6) Below proposed slabs-on-grade in areas to be tiled or carpeted, a visqueen-type moisture barrier should be placed at grade and be overlain by one inch of protective sand cover. This moisture barrier should be heavily overlapped or sealed at splices. 7) Where a base course is recommended beneath interior slabs, it should consist of pea gravel, clean sand, or other granular material acceptable to the geotechnical consultant. The above moisture barrier/sand cover requirement may be included as part of the recommended base course thickness. 8) Slab reinforcement should be supported at mid-slab height. 9) Garage slabs should be placed separate from footings. Garage slab reinforcement may be omitted if slab cracking can be tolerated, provided that the slabs are saw cut or jointed for crack control. 101 For soil with a potential expansion greater than “Low”, slabs should be free-floated or structurally tied to perimeter footings. Structural ties could be provided by the placement of No. 3 bars @ 24” O.C., bent from’perimeter footings about three feet into the slab. Unified Soil Classification (Including Identification and Description) . = 51 E .g ! z i 7 .I I ii ,I: 8 n ; .- ? ‘i r .f w i 5 : C : I 0” Or+r da,. ,I mrdiun lo bllb PIas. .v4i- ~ bilb r44; la “11, Sli.hl to ~CiW, o~.:inic ,ill. medium For .ilnlpl. cw.cc. w.llvrdrd Ir~..l..and mixtar. rdl da, Ibindrr. ,a All me”* ,i*a on Ibi. cllan an “. 5. sundad. CONSISTENCY CLASSIFICATION Co$e~ive Bedrock Moisture Condition SP - %+d,a;d Penetration R - Relatively Undisturbed sample B - ~Bulk Sample J-- Stabillred Groundwater p- Groundwater Seepage d (I - Blow count for 6” 7 intervals 12 - Blow count for 12” interval Loose Soft Soft Medium Dense Firm Moderately Hat-c Dense Stiff ‘Hard Hard Very Hard Dry Damp Moist Very Moist Wet EBERHART 8 STONE INC. GEOTECHNICAL CONSULTANTS 2711 EAST WNSTON ROAD. SUITE f .ANAWEIH. CALIFDRNU 92808 1.0. 1343 1 DATE: 7-2-85 1 PLATE A BORING LOS No. I Aok ,/kg,,fu I-G/ W.Q. 1343 ulentnt/ Project: J%J/, Date: I0 ,/2 y/p4 Locatlon: La, /J- 6 Qd Sheet:/ot 2 Est. Surface Elev: 2 f 0 2 Total Depth: 46-j Rig Type: 2 Y*flu,k, f A*,er 96: IV jl6) (3) 4r II /07 r Tdw --- /06 Zl pr> Q7) /If- /L FIELD DESCRIPTION E .y m .’ ,,, Surface Cond~tlons: J,3hl y ,,*,-:~ By: Notre: PVii/8~0 b&;qb f ’ ‘id,, !-earn , 4ed4F,./i, ,:/jfjr O- z~- ‘; 2,500 * \ 73 JLe e:cf ZIrn-4 i- *: /:Iga e t; LA* CL<‘/Jd.‘, /I’; &eJd*, 5-c ieav J EBERHART & STONE, INC. ’ PlateA-/ BORING LOG No./ w.0. /3Y3 Client/ Project: /&A / rqa fq Fe /v&/lr Date: /o/z p/ f Y Locatlan: CA ,!r 62 _ Sheet:zof 2 Eet. Surface Elev: 2 go+ Total Depth: 46’ Rig Type: 254" fiurhf/4rQer f17)( 17 It3 17 t /.5-f 20 Jdj c $0 126 gy-pz&“e: F’ELD DESCR’PTloN BY: fl JF i/ ~~ EBERHART & STONE, INC. Cm/ ProJect: Location: Est. Surface Elev: BORING LOS No. 2 e h /I/r mu Sheet/of 2 Rig Type:, 2 ‘/ ~? / ’ 1, Total Depth: LICh Y??<V - - J- ‘6 - Is $5 is ;{ - - - oi 26 - - %i e% 1 .ij z= az $0 - - - 16 13 - - 3i -I $ $ - - Yh - FIELD DESCRIPTION BY: flJF 1 Notes: ~;IJ;~ q Weiyb t O%idof;*a Jf~,ti~.~‘* 5: rhe-,fl J a -2s- ‘: ” Zs-dO* e/4; r: mol,r6eB I; fr;hJLIJ. 2 r-30’ : /I-o0 Jt fi : be&y hd t Con tf.k-7 u0w.1 drOtiud help, - EBERHART & STONE, INC. Plate-A BORING LOG No. 2 /&LA% /.J4* 7% w.0. /? 4-s CAent / ProJect: f% [fww/h- Date: /a/Z s/ru Locatlon: 6fv.r a lbd z Sheetzzof Est. Surface Elev: 217t Total Depth: .3 ! ’ Rig Typo: 2 9 ” flw c bt? r A 4 9 + - 8, u ;i - #2.! = FIELD DESCRIPTION By: AJF iurface Cond’titms: iubsurface Cx?dltlons: Classlflcation, color, moisture tightness; etc. I-- Remarks Notes: - EBERHART & STONE, INC. Plate& Est. Surface Elev: _ BORING LOG No. 3 $ g f!j 0 -- QiJ ‘0 - iJ -- Ir- !O- -g ‘r- f 3 3 i T- 1 - , - ‘W = - - z !; ;i , ‘5 i= !g ig - !r - L? - 16 = - - > c G - - z = - E n n g L - .L 7 - W.O. /3Y3 Date: /O./z 9/1$ Y _ Sheet:Lof / Total Depth: Rig Type:A’f” d*c kc f /Awqer 23 ’ v FIELD DESCRIPTION BY: /f JF -- EBERHART & STONE, INC. No CaVib33 Plate /4-S BORING LOG No.2 Est. Surface Elev: I- - 8s 2.5 ce si - - b I/L - ‘i L e; 1 .a z= “2 E 0 - - $ 18 - Y G f L-z- -3 - - 7 in4 Surface Conditlhns: /,3 k fyvq2,3 Subsurface CGdltlons: Classlficatlon, color. molsture 118 - 4 - - W.O. 1343 Date: / o/J O/BY FIELD DESCRIPTION BY: h'.JF I Notes: o)yYViv,c. Iy/e;~+/fr D -z?' : ZSOO~ c 20’. /2" fh,LLq J-a,JJtiiae. x I'lJlflf -- 4O"/FdO~ I,?4 CyeAu- ii tiaflre c~v-~,M(~/ 8:"hedJ3 Ora "cge,, hoi, 7. Qrcdafiple / IAQ.~.X- c oyI ta, eshavti tawv ce&t- EBERHART -5 STONE, INC. " BORING LOG No..dE- Client / Project: ALZ Locatlon: Cc7Y /c A,,, 30 b R 1 4 jr- Yo -R Yf- ‘zi 17 = '0 ‘0 = -4 = -I- , c. I 4 I ‘a, d -e -~ She&-&of t Total Depth: Rlg Type:, 2v If 8~ c kr f RYGV .+- q/ ’ / - ‘{ :I, ,” ) ,, (j -4 ^.^. = FIELD DESCRIPTION BY: A7 ?-/= I surface Conditlans: subsurface Condltlons: Classlflcatlon. colar. moisture tlghtness, etc. Remarks fiehfcr b; c.3 b 3cw rdf f -: c I.+ It dAyIci __ /l/a a 6 rluT>wajeTe 7i I- / ,J?%Y w f f- Notes: - EBERHART & STONE, INC. - PlateA- BORING LOG No. J- Went / Project: Ati Jew /IQyI -rl, F& //fvlo //, Locatlon: La/ h 6064 iYZ* ShfM~ / of 1 Est. Surface Elev: _ - - P-s “$ 1 ~ i 6: : - - - )Y - IIY - - . - - ‘i; $2 !a: 2 r$ % 0 - - - I2 - w - - 2 - - \ 4 6 2 - - ii - - Total Depth: Rig Type: 5-O ’ Notes: 4ro4-- fee@. da*.4 ii hoi/f; 1: jO/Mf d- ZZ’: J zrcro~ 1 v I 3 r Lto,J h vevtf LINU/, hfclqr s7 Fhkedfl 2J”S-o’ :/J-40* \ 0 rrJPtf*Y I r-f 4l’nr’na,13,iC‘lr.%ur A: heo/Ji / c :corrtac7 - EBERHART & STONE, INC. P1ate.Jf-S BORING LOG No. J-- - ; e! ; /7 za “2 2s - IY - ‘J - - Cilmt / Project: Locatlon: Est. Surface Elev: Notes \ C L/o.c-‘. 2”-3” t4vr.ck Clrn~ Jeuw. \ I I , k qi, t. 5-D 79 C‘J- f/@ur*$ Ved, .75?5a &An J-0 fecf f 39 feef EBERHART & STONE, INC. Plate,- CnsJlt / Pro)ect: Location: Est. Surface Elw: BORING LOG No. b & KID /lr She&/of / Total Depth: Rig Type-2 v “8~ /?C f Rci ~FY 2 i ’ I y* 6” 20 l2Z - -ii F% 1z z= EC s 0 - - - 9 7~ = - 5 2 e- 8 5 - - - &v = - I FIELD DESCRIPTION By: JF* 4” Surface Condltlons: t--- l I 1 . -: mw C 2 3 '.-veti\, k CI~ ri /I c f e31.j e-4 / ? ? Stpfifld 'd,,-/I;, 4 , ve fuSa/ Nofer: Yifivlq &iQI?I % fG / 8&h ti fee t J a-2J': z&3* iv0 trynuHJw-tet-. l?: 6edJy %:J~,nfe Jirfqtbed /VO Lavifi 4 EBERHART & STONE, INC. PW*A-lO BORING LOG No. 7 Ada4 / alent / Prolect: s*Jta Fe kflo//r Locatlon: &?1,/J-Lac w.0. 1393 Date: /D/?/ /ff79 Est. Surface Elev: _ L - 2 !: 2 #Z i= ;i [; e ; ’ , 1 i ! - 4 , L / Sheet:- of 2 -t Total Depth: Rig Type:2 Y ” & 3 / ’ uckef Av qer FIELD DESCRIPTION BY: /p + - ‘tlm: ;;Th;-. Jay jig hted CO~MYOL) I ‘05 ‘01 - foe ‘// ‘Y ‘A- ‘5 ‘Y - Classlflcation, color. moisture tightness; etc. Remarks I - IE eveeh. h~i.flY F;VM ec ’ %fv’ Notes: vi ViUrCj wQ;o/ (-J -“zr’ : ‘/&-cy* - : edd. ‘7 U-30 ; /J--00* - EBERHART & STONE, INC. - Plate A-N BORING LOG No.-iifw 5 s i F a ii 2s -g 5”a - x- w- w so- ulent / ProJWt: ,oPnf 4 F .- kvlo W.O. /3y3 e h!s Date: / 0 /Ii /gLt Locatlon: Sheet-&of z Est. Surface Elev: - f: Total Depth: 31 ’ Rig Type: 2y”Euckef Awe J I FIELD DESCRIPTION By: AJf ] ‘i; !?i ;i , s ix ;L: [g iurfaca Conditions: iubsurface CondItiona: Classiflcatlon, color. moisture tightness; etc. 0 2s’. -&‘” tL-,ic h L/@,, /aver Remarks $WZWOJ_ 7 - Ez - = ‘ , Notes: EBERHART & STONE. INC. PlateJILL BORING LOG No. 8 AMdew //a,~% Fe W.O. 134 3 Ulm / Proiect: IfI- 0 //J- Date: /Q/J/h Locatlon: fav/s-6ad I ~ Sheet: / of / 72 Total Depth: 2 r) ” /o ’ Rlg Type: FIELD DESCRIPTION BY: oP,TS I - R. Surf0 s” Surface Condbi~)ns: ; , 8 I 1 r i !I:; 3 . Subsurface C,ndltlons: Closslflcatlon. color. moisture tightness, etc. Remorks - = IO', wror'.,?, FiY& I = I= - Notes: - - .~_ EBERHART & STONE, INC. BORING LOS No. 7 Client / ProJect: Ac7h /.Gnj/ Fe- fbo/~ Location: Lwl~&d Sheet: / of / 3Oki Total &pth:yRipTypa: Bgckcf- /!uzer Est. Surface Elev: _ I FIELD DESCRIPTION By: - - - - rl Surface Conditlqms: ii 0” L ,% Subsurface Conditions: Closslficotlon. color. moisture tightness, etc. Remarks nnro;/ L /!4 (‘,. /ty C/d “, rb$o y fi,i :v,,:';;;,xa k=d " i ..’ . Eli_ . t-t------- I I II------ l I E - - Notes: ViVifiy We;qM 1 J 4 - 0 - zr’ : zj-go* - - EBERHART & STONE, INC. Plate.&&? . . I- STANDARD GRADINJ SPECIFICATIONS 1.0 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 The specifications contained herein and the standard details attached hereto represent minimum requirements for grading operations on construction projects. Variance from these specifications will not be permitted unless specifically approved by the soil engineer. These reconendations should not be considered to preclude more restrictive requirements of the regulating agencies. DEFINITION OF TERMS BEDROCK - a relatively solid undisturbed or in-place rock existing at either the ground surface or beneath surficial deposits of soil. Bedrock will be identified in the field by the project engineering geologist. ENGINEERED FILL - a fill of which the soil engineer or his represen- tative during grading has made sufficient observations and taken suf- ficient tests to enable him to conclude that the fill has been placed in substantial compliance with the governing specifications. ENGINEERING GEOLOGIST - a geologist holding a valid certificate of registration i.p the specialty of engineering geology. FILL - any deposits of soil, rock, soil-rock blends ,or other similar materials placed by man. GOETECHNICAL CONSULTANT - the soil engineering and engineering geology consulting firm(s) retained to provide technical services for the pro- ject. For the purpose of these specifications. observations by the soil engineer and engineering geologist include those performed by persons employed by and responsible to the geotechnical consultant. GRADING - any operation consisting of excavation, filling or combinations thereof. IMPORTED OR BORROW MATERIAL - any fill material hauled to the project site from off-site areas. RELATIVE COMPACTION - the degree of compaction (expressed as a percen- tage) of dry density of a material as compared to the maximum dry den- sity of the material. Unless otherwise specified, the maximum dry density shall be determined in accordance with ASTM method of test 01557-70. SOIL ENGINEER - a licensed civil engineer experienced in soil mechanics. 3.0 3.1 3.2 3.3 3.4 4.0 4.la 4.lb 4.2a 4.2b 4.3a SITE PREPARATION Clearing and grubbing shall consist of the removing of all vegetation such as brush, grass, woods, stumps, trees, roots of trees and all otherwise deleterious natural materials from the areas to be graded. Clearing and grubbing shall extend to the outside of all proposed excavation and fill areas. Demolition shall include removal of all buildings, structures, utilities and all other manmade surface and subsurface improvements from the areas to be graded. Trees, plants or manmade improvements not planned to be removed or demo- lished shall be protected by the contractor from damage or injury. All deleterious material generated during clearing, grubbing and demoli- tion operations shall be wasted from areas to be graded. All clearing, grubbing and demolition operations shall be performed under the observation opthe soil engineer. EXCAVATIONS Unsuitable Materials: Material which is unsuitable shall be excavated as directed by the soil engineer. Unsuitable materials include, but may not be limited to dry, loose, soft, wet, compressible and non-engineered or otherwise non-approved fill materials. Material identified by the soil engineer as unsatisfactory due to its moisture conditions shall be overexcavated, watered or dried as needed and thoroughly blended to a uniform near-optimum moisture condition prior to placement as compacted fill. Site Protection: The contractor shall be responsible for the stability of all temporary excavations. Recommendations by the soil engineer shall not be considered to preclude those requirements of the regulating agencies. Precautions shall be taken during the performance of all site clearing earthwork, 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 ade- quately direct surface drainage from all sources away from and off the work site. Slopes: Unless otherwise reconnnended by the geotechnical consultant and approved by the regulating agencies, permanent cut slopes shall not be steeper than 2:l (horizontal to vertical). -3- 4.3b If excavations for cut slopes ExJose loose, significantly fractured or otherwise unsuitable material, o,erexcavation and replacement of the unsuitable materials with a compacted stabilization fill will be required as directed,by the soil engineer or engineering geologist. Unless otherwise specified by the soil engineer, stabilization fill construction shall conform to the requirements of Grading Detail GO-3: 4.3c All lot pad areas, including side-yard terraces, above stabilization fills or buttresses shall be overexcavated to provide for a minimum of three feet of compacted fill over the entire pad area. Pad areas with both fill and cut materials exposed and pad areas containing both very shallow (less than three feet) and deeper fill shall be overexcavated to provide for a uniform compacted fill blanket a minimum of three feet in thickness. Cut areas exposing significantly varying material types shall also be overexcavated to provide for a minimum three-foot thick compacted fill-blanket. 4.3d For cut slopes made in the direction of the prevailing drainage above the cut, a diversion swale (brow ditch) should be provided at the top of cut. The diversion swale configuration should conform to the applicable code requirements and should be ,-eviewed by the soil engineer prior to installation. 4.3e For pad areas created above cut l)r natural slopes, positive drainage shall be established away from the top of slope. This may be accomplished utilizing a berm and/or an appropriate pad gradient. 5.0 COMPACTED FILL 5.1 Compaction: All fill materials shall be compacted as specified below or by other 'methods specifically approved by the soil engineer. Unless otherwise specified, the minimum degree of compaction (relative compac- tion) shall be 90% of the laboratory maximum density. 5.2a Placement: Prior to placement of compacted fill, the ground surface approved by the soil engineer shall be scarified, watered or dried as needed, thoroughly blended to achieve near-optimum moisture conditions, then thoroughly compacted to a minimum of 90% of the laboratory maximum dry density. 5.2b Compacted fill shall be placed in thin horizontal lifts not exceeding eight inches in thickness prior to compaction. Each lift shall be watered or dried as needed, thoroughly blended to achieve near-optimum moisture conditions, then thoroughly compacted by mechanical methods tc a minimum of 90% of the laboratory maximum dry density. Each lift shal be treated in a like manner until the desired finished grades are achieved. -4- 5.2~ When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:l (horizontal to vertical), horizontal keys and vertical benches shall be excavated into the adjacent slope area. Keying and benching shall be sufficient to provide a minimum of three feet of vertical bench height within firm natural ground or approved compacted fill. All keys and benches shall be approved by the soil engineer or engineering geolo- gist at the time of grading. No compacted fill shall be placed in an area subsequent to keying and benching until the area has been approved by the soil engineer or engineering geologist. Typical keying and benching details have been included on the accompanying Grading Details- GO-3, GO-4, and GO-5. 5.2d Within a single fill area where grading procedures dictate two or more separate fills, temporary slopes (false slopes) will be created. When placing fill adjacent to a false slope, benching shall be conducted in the same manner as the above described. A minimum three-foot vertical bench shall be established within the adjacent approved compacted fill (i.e., the material underlying the surface loose material) prior to placement of additional fill. Benching shall proceed in approximately three-foot increments until the desired finished grades are achieved. 5.3a For field control purposes, "near-optimum" moisture shall be considered to mean optimum plus-or-minus two percent unless otherwise approved by the soil engineer at the time of grading. 5.3b Prior to placement of additional compacted fill following an overnight or other grading delay, the exposed surface of previously compacted fill shall be processed by scarification, watered or dried as needed, thoroughly blended to near-optimum moisture conditions, then recompacted to a minimum of 90% of the laboratory maximum dry density. 5.3c Following a period of flooding, rainfall or overwatering by other means, no additional fill shall be placed until the existing ground surface is thoroughly scarified, aerated, overexcavated if directed by the soil engineer, blended to achieve near-optimum moisture conditions, then thoroughly compacted to a minimum of 90% of the laboratory maximum dry density. 5.4a Fill Material: Excavated onsite materials which are approved by the soil engineer may be utilized as compacted fill provided all trash, vegetation and other deleterious materials are removed prior to placement. 5.4b Where import materials are required for use onsite, the soil engineer shall be notified at least 72 hours in advance of importing in order to sample, test and approve or disapprove materials from proposed borrow sites. No import materials shall be delivered for use onsite without prior approval of the soil engineer. 5.4c Rocks 12 inches in maximum dimension and smaller may be utilized within the compacted fill, provided they are placed in such a manner that nesting of the rock is avoided. Fill shall be placed and thoroughly compacted to the minimum requirement over and around all rock. 5.4d Rocks greater than 12 inches, but less than 3 feet, maximum Dimensions (oversized rock) require special placement procedures if they are to be utilized within compacted fills. 5.4e Rocks greater-than 3 feet should be broken down or disposed of offsite. Oversized rock should not be placed within the upper 10 feet of any fill and no closer than 15 feet to any slope face. Where practical, over- sized material should not be placed below areas where structures or deep utilities are proposed. Oversized material should be placed in windrows on a clean, overexcavated or unyielding compacted fill or firm natural ground surface. Select native or imported granular soil (S.E.=30 or better) should be placed and/or thoroughly flooded over and around all windrowed rock, such that no voids remain. Windrows of oversized material should be staggered so that successive strata of oversized material are not in the same vertical plane. Details for oversized rock placement are presented on Grading Detail GO-6. 5.5a Slopes: Unless otherwise recoInmended by the soil engineer and approved by the regulating agency, compacted fill slopes shall be limited to a slope ratio of no steeper than 2:l (horizontal to vertical). 5.5b All compacted fill slopes shall be overbuilt and cut back to grade exposing the firm compacted fill innercore. Th,e actual amount of over- building may vary as field conditions dictate. If the desired results are not achieved, the existing slopes should be overexcavated and reconstructed. The degree of overbuilding shall be increased until the desired compacted slope surface condition is achieved. Care should be taken by the contractor to provide thorough mechanical compaction to the outer edge of the overbuilt slope surface. As fill slope construction proceeds, the slope surface shall be thoroughly backrolled with a sheepsfoot roller at vertical height intervals not exceeding four feet. 5.5c Following the attainment of the desired slope height, the outer surface of overbuilt slopes should be cut back to a desired finished surface contour. Care should be taken by the contractor not to excavate beyond the desired finished slope surface. 5.5d In lieu of overbuilding and cutting back, alternative construction pro- cedures may be attempted where specifically approved by the soil engineer prior to grading. Prior to such approval, the contractor shall submit to the soil engineer a detailed written descriptionof the proce- dure he proposes to utilize. Within such a description, the followihg guidelines may be included: Unless slopes are overfilled and cut back to grade, the outer faces of all fill slopes shall be backrolled uti- lizing a sheepsfoot roller at intervals not exceeding four feet of ver- tical slope height. Vibratory methods may be required. -6- During construction of the fill slopes, care should be taken to maintain near-optimum moisture conditiors over the entire slope height. Following achievement of the desired slope height, the entire slope face should be thoroughly compacted utilizing a vibratory sheepsfoot roller. Upon completion of the above procedures, the faces of all fill slopes should be grid-rolled"over the entire slope height with standard grid-rolling type of equipment. Prior to grid-rolling, care should be taken to main- tain near-optimum moisture conditions. 5.5e Following slope construction in the manner described above, if the required uniformly compacted fill slope condition is not achieved, over- filling and cutting back should be adopted. Completed slopes not approved by the soil engineer should be overexcavated a minimum of 12 feet (horizontal) and replaced by the overfilling and cutting back pro- ' cedure described above. 5.5f Where placement of fill above a natural slope or above a cut slope is proposed, the fill slope configuration should conform to the applicable requirements as indicated on Grading Detail GD-4. 5.59 For pad areas above fill slopes, positive drainage shall be established away from the top of slope. This may be accomplished ntilizing a berm and/or an appropriate pad gradient. TYPICAL CAN’YON SUBDRAIN, CANYON PROFILE -- C-v/u ANO :,~~ ALLuLWAL RS+~OVAL. ALTERNATIVE A- PREFERRED ALTERNATIVE C BACKHOE TRENCH DOZER V TRENCH M,“S C”&c .-UT DC .-/LTaR .y”?xAAu Al* - OR P,PE WLL ma R4uR~O~ 2. .4*sam.*mNs .s*d”LD ‘3s rzao-wau w ,NLy Jmr. ALTERNATIVE B -. nhycrm Mm ry/M 4r a Y.vlEMcILY arreip ~rurritrnuu pu -7-,.4 LOLVZR -la.v oc nrr. JN WY c&a c4c*r* OF pII.=oANrh7N z5Awul.D Be c o&z m .=/L7U .?9AILuIL. BACKHOE TRENCH 3. gPy..&y&,unrLLs 0zxwIyNd .4rpADbED. s.uwLD AN0 scL7IoNb c*.4wmzr~D W/N COLL4rCI. mm SMYLD dd OF -. *+ywJ “Km,nc”Tm rv S.z~~DuIC $N*L,L BAT .y.pr BY TRAZT C”cA.hurR d*JcD ox AlpF QSAW OFF.. 4 fiI7R .*,wxR/*‘ S*ouLD CONMZ OFST.Tx oc cIuJ-mw4 - . CLASS il PKR.wwdLC FIL7zi+ ,y,~,~&umANS s.e?-,od “-,.*a \ j: ,& AL~R.“A~,“b d v4’ - ,&A F/L,-U FAMK@-OS m-/m) S”O/JL~ as YSLB.. P FAaee 6 ,‘,‘,liL ox P-,LrAx .=AaRh SMALL aa? APPROezD bY -74 -& 70 -m4 “GWC e GRADING DETAIL / b p . 6 /NC” LUA..,~XR .-an#vaNrLn P#a- EBERHART BI STONE INC. GEOTECHNICAL CONSULTANTS 111, EAST WMTON ROAO. SUITE F . ANI”EIY. CALIFORNIA emu STANDARD GRADING SPECIFICATIONS TYPICAL SUBDRAIN FOR BUTTRESS, STABILIZATION OR SIDEHILL FILL MASSES @iv/,u, I- /NC”- o/&y.s~m?, PVC OR A55 S&/40 PUIT/c bvn-H 7hw/#y”.y OF B ““mm~LY sP4csn $ztY O,Ah,STCR PW.=O~AT,O~ 47 /SO ANdLC PIP FOOT OF P/J=z ,,+3TALLSD W/7-” pbAFoAATk%+3 w So?707 OF P/AI. PROV/~~ CAP A7 UP-1.y .cAID OF P/.-S. SLOPS *?- 2% 7-v OUZLLT P,PS. N ODES : 1. F/LTLR rl/TSR,AL SA.W”LD S# STATS OF CA Y FOR,WA CLASS 2 PrRiysAd~S .=,LT-, C.4‘~#Z/INS J~T~o.+.’ SE-/.osrJ. 2. 7ArNCU FOR ourUT P/pLS 7-o ss -F/U~O ,@‘/rh’ CO+-ACrrO WM. SO/L. 3. For, 7ZRRAc.cB OLo- sJAWDRI/W~ AND Lw7LsTJ -Lo .¶a PUAINSD 70 OUTLaT ASOV‘C T”.Z TLRRICL. 4. Trr lv.zur*/TY qr sudDm/N AT- “/AiL OF dAWcu?- A”0 coR.4ssAo”n/Ns o.vTLsT SHauLD as DcTsu~/NvLD ,N 7x1; NLLO .sY ~~TPCYNKIAL -SYITANI: GRADING DETAIL EBERHART & STONE INC. GEOTECHNYAL CONSULTANTS 111, E*SI WINSTOW RclAO.S”IT~ F .ANA”EIY.CALlFORNIA 91808 STANDARD GRADING SPECIFICATIONS IPlATE GO-2 TYPICAL STABILIZATION FILL FIG. I 1111 EAST WINsrON ROAO.S”ITE F .~NIHelH,C~LIFORNILI9~ 06 STANDARD GRADING SPECIFICATIONS L TYPICAL BUTTRESS FILL FIG 2 \I I t a= ALPORT d-*: ?kAT/.z& dflL6f.d “cuua~r~ sfc..yw AfL: GRADING DETAIL EBERHART 8 STONE INC. -- GEOTECHNICAL CONSUlTANTS TYPICAL FILL WER NATURAL SLOPE H Cculuti”~ rlND ~,rul+*Hls wsuc-“au 4?47xR/IY *aMe* : ~/xawnI. s.lc.*/M t!wnuL aAt. ,./a+! TYPICAL FILL OVER CUT SLOPE WD OM “NW- .+TLANY ~R,O,N*L ‘¶LAIcY: “cu,Jzo,vmL S~,L.*rn. vkw7LALd,L.,y&! CUT SLOPS hv aso- dOTW OF Xaw”T DOUJ.. SLOPE SIC.&. 0.9 ry*?xm4L .I-- ?a oaozacr/Nlc*L =cw‘YLT*m GRADING DETAIL EBERHART & STONE INC. GEOTE~HNICAL CONSULTANTS 2211 LAST WlNSTcJN mm SUITE F . INIWEIM. CALIFORNI.4 92806 STANDARD GRADING SPECIFICATIONS IPLATE CD-U TYPICAL REMOVAL OF TRANSITION LOTS ‘0 / #~ ./ ,@D@~ / - ,‘-A , “+3--l ////////A ~3YU (’ Tfll/j,, _~._,_. --f 4”‘Le~lcl”AR AND m-P..?- 70 P4qjSCT STA.wcyI*~S 7 RW OR wwr0rIIm.L 6-m.csl A?.w sumw, “CCaP7AaLs 7n NWm.3 .Gw PLAU czoIz~Y”/c4& coA%uLr&vr GRADING DETAIL EBERHART 8 STONE INC. GEOTECHNICAL CONSULTANTS 211 I EAST WINSTON ROAD: SUITE F ANAHLIU. CAIJFORIIIA wR?i STANDARD GRADING SPECIFICATIONS PLATE CD-5 TYPICAL ROCK WINDROW PROPDIID .=m@a”aD 04.PI TYPICAL WINDROW DETAIL (ledge view) oy.sRsmaD yrra.?ML Ge”Y”LIA ay”Ts.u*L *a -,$.a a? amP?-u -La aa -I .=LooDLo 70 NLL &e,.sn &VP lcoyN0 - PROFILE VIEW rr- SCOVLD a.e NOTES: PLICLO WD ?a a%.+0 NV7 “IdllD EBERHART @. ENE ING.- I.. ~QLLoH/.v0 7. coAfa.+zr*w OF Iya l acxk naQm?zAls.e5, au7 AIrnR GEOTECHNICAL CONSULTANTS -m - l&r.. *eamuML nu.aor b&Aawlv -as 7?awouS”LY co,yprc%sD Fxu,y rryp =.,m*--= 2111 ~AsTwINsTor4 RoA0,su,TE F.~NIW~I*.ULIIOR*IIs~ P. TAU Co.vm.cmR SylLL Paac+za s , ~-KJrc@=.+-LOC*7/.%/a~ ZJ D/--L /N CR#.sT R q M 6.xaMz/a - DRPrn OE YT,UT . -,.--. IuF..~cfs.-/T= MA /rUm.:YI-I.. . ,c dvRIp0 Llocx. I :2-a dc -- H/,~~-- STANDARD GRADING SPECIFICATIONS IPLATE CO-6