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Home My WebLink AboutCT 72-28; Skyline Road & Park Drive; Soils Report; 1981-11-13- - - - - - I - L - - - - .* . . i I . _ 0. KG KENNETH G. OSBORNE 6: ASSOCIATES EWNEERING DEPT. MBRARY cltyotcarhbad 2075 Las Patma Drlva CMWA CA 92009.4859 - 0” KG KENXETH G. OSBCVWE & .C&OCIATES - - CEOTECHNICAL IWESTIGATION ,- - - Tract No. 72-28 West of Skyline Road and North of Park Drive Carlsbad, California - Client: Pacesetter Homes, Inc. 4540 Campus Drive Newport Beach, California 92660 Attention: Mr. Art McCatil . - L - - . : Job No. 3380-l November 13, 1981 - I - -----. ..- .~ -. .-- .-- -... ^ .-,. . . .I ,dDY” d”ELl, IC _ eIn.IC ,.A, hMkl,d 09-J.A _ ,?.A\ crnc.nn, e - - - - r - - - - - m -~ L - - - - - TABLE OF COXTENTS INTHODUCT]ON-------------------------------~------- 1 SIJBSURFACE INVESTIGATION--------------------------- 1 OTHER INVESTIGATIONS------------------------------- 2 LABORATOR)’ TESTING--------------------------------- ~2 S:TE DESCRIPTIONS---------------------------------- 2 VICINITY CRAP-------------------------------------- pIan GEOLOGY Geologic Setting------------------------------ Se~ismicity------------------------------------ STRL’CTUR.41 FEATURES Bedding---------------------------------~----- Faults---------------------------;-------------- Ground Water---------------------------------- Formations Colluvium-------------------------------- Santiago Formation----------------------- SOIL ENGIFEEKING----------------------------------- co~c~~~sIo~~---------------------------------------- Geolcgic-------------------------------------- Soi1 Engineeyinfi------------------------------ RECOMMENbATIOSS Soi1 Bearing---------------------------------- Settlement------------------------------------ Lateral Soi1 Pressure------------------------- Retaining Wa,ll Design------------------------- Expansive Soils------------------------------- Concrete Slab Cmstructicm-------------------- 3 3 4 I!& 4 7 8 8 8 9 10 - n KG tJ:sStIIti c;. Iwkwsti & :\sslY:\l~t+ , - , - I I- - L - - - Shrinkage and Subsidence---------------------- Soluble Sulfates------------------------------ Stability of Excavations---------------------- Subdrains and Seepage Control----------------- Special Grading Specifications---------------- General--------------------------------------- REFERENCES APPENDIX Laboratory Testing Procedures----------------- Grading Specifications-General Prcvisions----- Boring Logs----------------------------------- Direct Shear Summary-------------------------- Typical Slope Repair for Seepage-------------- Bcying Locations------------------------------ 10 -j’ . . 11 ,_ ; 11 .. 11 12 13 A-B C-D E-H I-J K map - - .Iob No. 3380-l - Page 1 IYTRODUCTION -i. . . This report presenis the results of a Geotechni ca). Investigation performed cn the property located along the ‘. westerly side of Skyline Road and north of Park Drive in the City of Carlsbad, California. This property, .which covers an Grea of approximately 59 acres, has been designated as Tract 72-28. Planned for constructicn are wood-frame multi-family dwellings to be founded on 160 graded lots. It is expected that the structures will be constructed on boi:h continuous and pad footings with slab-on-grade cor.crete floors. The exact structural loads for the buildings are unknot-n at this time. However, for the purpose of analysis? it has been assumed that continuous footings will carry 1200 pounds per lineal foot of which 90 percent is dead load and that pad footings will carry 15 kips each of which 50 percent is dead load. If it is found that the acrual loads are substantially different from those assumed. this office should be notified for reevaluation. - - - .- r - . - - SLBSLRFACE IFVESTIGATION The field investigrtion consisted of excatrating four explosatcry borings to depths ranging from 7 to 2C feet. The borings were drilled using a 16 inch bucket auger drilling rig. Selected specimens of the in situ soils tiere obtained by using a 1.4 inch I.D. drive tube sampler equipped with brass liner rings. In addition to these relatively undisturbed specimens, bulk samples of the soils were obtained for additicnal laboratory analysis. These scil samples served as the basis for the laboratory testing and the engineering conclusions ccntained in this report. ThC logs of the bcrings and a plot plan shcwing approximate boring loca tions are included with this report. - m Kt:SStil.H C;. ~~9WKSti .$i ,As~~Xw‘I.Al-t:\ - Job No. 3360-l Page 2 - - .- - - - - . - . - - The elevations shown on the boring logs were deter->. mined by measuring from topographic features shown on the ’ ’ topographic map cf the prvperty as prepared by Rick . . Engineering Co. of Carlsbad, California. OTHER INVESTIGATIONS In addition to the subsurface investigation described, a cursory examination of significant geologic features and exposures was made on the site and adjacent properties as well as a re\Tiew of pertinent published and unpublished geotechnical and geolcgic reports. LP.53R.4TCRY TESTING The laboratory testing consisted of performing classi- fication, strength, settlement, soluble sulfate, and expmsj on tests, determining in situ dry .density and moisture content, and determining the moisture-density relationship of major scils. Descriptions of test standards used in this investiga- tion, in addition to other tests not used in this investiga- tion, are included in the Appendix of this report. SITE DESCRIPTiOK The ar*a of investigation is b,ccnded on the north and northwest by existing residences. The south end is about 50 feet north of Far-k Drive and 1000 feet north of Agua Hedionds Lagoon. Topographically, it is an irregular spur, or ridge, trending more or less north-south and descending southward toward the lagoon. Surface drainage is along several small valleys and gullies descending from the main ridge to the east, south. and west. The ground slopes at a very lcw gradient for most of the proposed development) except along the southeast, south, and southwest margins, where slopes steepen to a ratio of approximately 2:1, and locally as steep as 1:l. m . I I . . I,I u c. #\~R<WVL A, A .,,, < ,\, ,~I I SF: ti.J C.S., -AIe+s @FV Qu#O. SITE LOCATION .- - I - - i- i - r - I - I- ,.. i - I - . - - - - Job No. 3380-l Page 3 The site is vacant except for native shrubs an#, grasses which cover most of the area, and these have apparently grown since cessetion of previous agriculturay activities. Several unimproved dirt roads also traverse the property. A preliminary grading plan by Rick Engineering, dated 12 May 1981 (at a scale of one inch equals 100 feet), indicates that 160 residential lots are to be constructed by cutting and filling operations, both with 2:l slope ratios. The maximum proposed vertical height of finished slopes will vary from 40 to 50 feet. GEOLOGY Geologic Setting The subject area is a typical portion of western San Diego county. Bedrock is a series of flat lying sedimen- cary rocks. These are locally overlain by some marine terrace deposits and residual soil. Although crystalline metemorphic and granitic rocks are present beneath the sediments, their ~depth is too great to be of importance in this project. Seismic;ty There are no known active faults in or near the subject area. The nearest known active fault,’ the Elsinore Fault, lies approximately 30 miles to the east. It is believed to be capable ;of an M72 earthquake which would not seriously affect the Carlsbad area. A fault which may connect the Newport-Inglewood Zone with the Rose Canyon Fault lies off-shore about 10 miles. The activity of this fault is controversial but its distance and uncertainty rule it out as a major threat to the proposed development. The San Miguel Fault in Baja, . . . . m ‘.:. b.l~XSI:l-H G. ~XHORSI: e. \S~~~-l;\l~l:~ .- - - - - - - - Job No. 3380-l Page 4 California, is likewise of minor concern. Although it i-s’- known to be active, it is too distant to adversely affect . . .r the Carlsbad area. The probability of earth shaking, ground rupture, liquefaction, and seismic sea waves (Tsunami) is extremely remote. STRUCTL'RAL FEATURES Bedding Strdtification, which is a poorly developed, sub- pl andr structure, is generally present in the Santiago Formation. Except in very silty, clayey zones such as shale, it does not form planes of geologic weakness or fissility. Owing to indistinct bedding planes, cross- bedding and poor exposures, the precise attitude of bedding cannot be measured. On the basis cf scant data and regional conditions, it is concluded that bedding ranges from essentially flat to 5 or 10 degrees southward. Faults There are few faults in this region and none were seen within, or near, the tract. Just beyond the extreme south- west corner cf the prcprrty, there is an exposure of fractured sandstone which resembles a fault but no offset of bedding is apparent and it is unlikely that the zone trends into the subject area. ., i Grour.d Gater None of the borings, (maximum depth 20 feet), encountered the water table. There are no springs, seeps or excessively moist areas on or near the tract. Therefore, it is concluded that the existing, natural ground water conditions will not present problems during grading or to the completed project. . . . m .:~..:~ . ,;, .- : LI XSl.1 H (I. 0>RcM\l. d. ;\%LX I.\1 1.5 Job No. 3380-I Page 5 - r - i :~ - - - Formations i * . . Colluvium , I ,A few' feet of residual soil, derived from .. weathering of the sandstone, blankets the area except where eroded in gullies along the margins of the tract. This material is predominantly sandy although it is clayey or silty in a few small areas. Such material is moderately expansive. Santiago Formation, Map Symbol Ts This formation, which is equivalent to the De1 Mar Formation, is mainly a sandstone although interbeds of siltstone and shale are common. The sandstone varies from firm to coarse grained and is moderately well cemented. In some places, it is very uell cemented and could not be penetrated in drilling beyond the upper weathered zone. Individual strata are 1 to 3 feet thick and show considerable lateral variation in grain size, cross bedding and channelling. SOIL EXGINEERIRG Development of the tract will consist of constructing a series of graded terraces for streets and houses which will involve excavating the sandstone and siltstone bedrock and placing these earth materials as compacted fill. The earthvork construction, as proposed, is expected to result in slopes which will be fill over cut and building sites with both cut and fill. In addition, major fill slopes will be required as planned in the eroded canyons at the tract boundary. The slopes for the project are planned at ratios of 2 horizontal to 1 vertical, as previously mentioned in the Site Description portion of this report. m KISSI:TH G. ‘.-NKWSI1 d. ..\+;1’(‘]..W1~ - Job No. 3380-l - CONCLUSIONS Page 6 * . - - - r - i - f . I - - In our opinion, the site is suitable for development . . as proposed provided the recommendations contained in this report are included in the project design, specifications, and construction. Geologic 1. South facing cut slopes may’ expose unsupported south-dipping strata. The dip angle is low, the rocks are not well bedded, and the cuts are not high. However, the possibility of slope instability exists and all cuts should be inspected early in grading so that modifications or stabilization can be made if necessary. 2. Although ground water presents no problems under existing conditions, the increase of water accompanying development could create potential seepage problems. In-situ sandy strata are permeable whereas the clayey and silty interbedded layers are tight and impermeable. Ground water can move down through sandy layers and be forced to mobe laterally by the clay layers to surface at the face of cut slopes, or be impounded behind compacted fills. In either case, the resulting pore pressure could cause slope instability. Cut slopes should be inspected for potential seepage conditions and if determined to be unsuitable, slopes should be stabilired and subdrains installed. 3. Seismic hazards existing at this site are very low. No faults are present on the site and all known active faults are far distant enough as to have little effect on the site. The probability of ground rupture, earth shaking, liquefaction, Tsunamis, and other seismic hazards are absent or minimal. 4. Some of the clay-rich strata in the bedrock are expansive and soils which are clayey ,are also modera.tely~ to highly expansive. n KG h;l~ssi:7H G ~-sR~~llSi[i h .455~~‘)(:l:\l~l~~ - Job No. 3380-l Page 7 .- - - . .- .- - .- 5. Slopes cut in sandy portions of bedrock and/or... soil possessing little cohesion are easily eroded. Proper . . drainage and planting will be necessary to control runoff: . _ on slopes on this project. 6. Strongly cemented sandstone is exposed in this vicinity and it is possible that grading may encounter such rock which will be difficult to rip and which may generate oversize material. Soil Engineering 1. Subject to inspection by the engineering geologist, cut slopes made at 2:l slcpe ratios are stable. 2. Properly compacted fill slopes placed at a 2:l slope ratio are stable. 3. The heavily eroded areas at the tract boundary may present problems with establishing fills. 4. Considerable excavation will be required in the eroded canyons at the tract boundary. Consideration should be given to filling the eroded canyons. 5. Soils derived fron. excavations range frcm non- expansive to moderately expansive. 6. Soils on this project possess favorable strength characteristics. 7. A subdrain system may be required within the eroded canyons at the tract boundaries. 8. Overexcavation of the cut portion of the cut-fill lots will be required tosprovide uniform foundation bearing. 9. There are no landslides on or near the tract. RECOMMENDATIONS Soil Bearing The site is considered suitable for construction of the proposed facilities using both continuous and pad footings for support providing the recommendations presented herein are followed. m ‘. ‘~ (~ ‘. : ,‘I ...‘< -:~.:, LF\\;I 1 Ii 6 0~l30R\I ci 4\\\‘K I \I I4 - - - - - .- - - - - - - - - - Job No. 3380-l Page 8 Footings may be designed for an allowable bearing.,' value of 2200 pounds per square foot for footings placed to ' ' a minimum width of 12 inches and a minimum depth of 12' . . inches below the 1oi;est adjacent finished grade. This value may be increased to 2600 pounds per square foot for footings placed to a depth of 18 inches. An increase of l/3 of the above bearing value is permissible for short dura- tion loading. The above bearing values have been based on footings placed into approved natural ground or tested compacted fill. Settlement Settlement of fills and structures sill be negligible provided loose surfaces soils and fills are properly compacted. Lateral Soil Pressure For purposes of designing the structures for lateral forces, an allowable lateral soil pressure of 345 pounds w square foot per foot may be used for the building design. A coefficient of friction of 0.4 'may be used for concrete placed directly on the natural soils. Retaining G?all Design Retaining walls may be designed using the following parameters: Bearing - 2200 psi Active earth pressure, level backfill - 35 psf/ft Sliding coefficient - 0.4 Passive earth pressure - 345 psf/ft The nonexpansive natural soils are considered adequate for backfill of retaining walls. Retaining walls should be provided with adequate drain- age to prevent hydrostatic pressul-es. n K-f-i tXSSlTH (i. cNkXW\;li & .At;~~X~LW1~ - - - - - - - I- - I - 1- 1- - I - m - - - - Job No. 3380-l Page 9 Expansive Soils The results of tests indicate that the soils existing * ' on the site vary from nonexpansive to moderately expansive; . . Soils derived from the upper areas of the project were found to possess very low expansion potential. However, the existing fill in the lower area was found to be moderately expansive. The test results are as follows: Sample Maximum Optimum Location Densitv Moisture B-l, O'-1' 123.0 10.2 B-i, 3'-4' 118.7 11.6 B-i, 5,'-6' 131.0 9.7 B-4, 3'-4' 130.1 9.4 lower fill, offsite 126.5 10.6 lower fill, offsite 126.5 11.3 Expansion Index 0 0 1 0 40 45 Tentative recommendations for minimizing the effects of expansive soil are as follows. A final determination will be made at the completion of grading. Subgrade Treatment 1. Just prior to placing concrete floor slabs, the moisture of the soil should be at least 3 percent above optimum. This moisture content should extend to a depth of 12 inches. Subgrade not meeting this requirement should be flooded. The flooding should be done after the footings are placed. ., : 2. The subgrade for garage floor slabs should conform to the above requirement. Footing Treatment 1. Exterior footings should be constructed to a minimum depth of 12 inches. The exterior footings should be reinforced with one No. 4 bar placed in the top of the footing and one No. 4 bar placed in the bottom. n KG ~li.~Xlil’l-l li ~wkYc~I: a :\2s‘x:I:i1 IiS - .-. - - - -. .- - - - - - ,~ Job No. 3380-l Page 10 2. Interior footings should be constructed to ,a, minimum depth of 12 inches. The interior footings should be reinforced with the same reinforcing as exterior footings.> * 3. Footings should be carried across garage door openings as a grade beam. These should be reinforced as for exterior footings. Fl~oor Slabs 1. Concrete floor slabs should be at least 4 inches thick nominal. 2. The floor slabs should be reinforced with 6x6-10/10 xelded uire mesh or equivalent bar reinforcing. 3. Garage floqr slabs should be free floating and cast independent of footing stems. A positive separation should be provided between footing stems and concrete floor slab. Garage floor slabs should be reinforced with 6x6-10/10 welded wire mesh. In lieu of reinforcing, the garage slabs may be saw cut into quarters. Concrete Siab Construction It is recommended that concrete floor slabs in areas to be covered with moisture sensitive coverings be con- structed over a 6 mil plastic membrane. The plastic membrane should be properly lapped, sealed, and protected with sand. It is taut ioned that concrete slabs in areas to receive ceramic tile or other crack sensitive floor i i coverings must be designed and constructed to minimize hairline cracking. Shrinkage and Subsidence .Based on the in situ densities of the natural soil and assuming an average fill density of 92 percent relative compaction, calculations indicate that shrinkage will range . . . I - n KG ~l:ssnti 1;. ~-w~wSI! J. .~2s.1~‘1~\1’1:~ - I - -~ - I, - r - i i .- I- i- I .- - - - - Job No. 3380-l Page 11 from zero to 5 percent between the cut and fill operations. _.._ __ .~.~...~..~~ ,..... .,__..-- -1. -,.-- ,----,, c i In addition, it is estimated that there will be auof a . . foot of subsidence due to reworking the surfacg-~soils.:. These values are estimates .only and should be verified . . .~ ._.~. _ ,_ .,.. ., during the grading if earthwork quantities are critical. .~ Soluble Sulfates An investigation of the on-site soils was performed in order to determine the concentration of soluble sulfates. A representative sample was tested and the results are as follows: Sample % Soluble Locat ion Sulfates B-4, 3’-4’ 0.015 A soluble sulfate content less than 0.20 percent is not con- sidered detrimental to standard concrete mixes. As a re- sult, no special type concrete or construction is con- sidered necessary for soluble sulfates for this project. Stability of Excavations Even though no caving was experienced during the sub- surface exploration, it can be expected that instability of utility trenches will be experienced and, as a consequence, shoring or sloping excavations will be required to protect workers. The contractor should refer to the State of California, Division of Industrial Safety for minimum safety.standards. ., : Subdrains and Seepage Control It is expected that subdrains may be required within the canyon fill area and possibly for stabilizing cut slopes which are determined to be unstable because of seepage potent ial. The need for either drain will be.deter- mined at the time of construction. n KG~ c;I:ssI:l-li c;. irSlk7KSE d .\~~~x:)(:I.\I’I;~ - - - - - r - -. - .- L - I - I - - - - -- Job No. 3380-l For tentative design meters may be assumed. Drain pipe - 4" and 6" Page 12 purposes, the following para- L L ' . . schedule 40 PVC perforated pipe;' ._ are approved equal. Filter material - Class II permeable material as per Caltrans Standard Specs., 1978. Quantity cf filter material - 9 cubic feet per foot for main subdrain - 4 cubic feet per foot for minor lines A typical slope repair fcr seepage is shovn in the Appendix of this report. Special Grading Specifications The following special grading specifications are recommended for grading of this project in addition to the general grading specifications shown in the Appendix of this report: 1. In fill areas, all residual soils shall be removed to bedrock or approved soils. 2. In areas of shallow cut, all exposed residual soils shall be removed to bedrock or approved soil. 3. Keyways shall be cut at the toe of a11 fill slupes. The keyway shall extend through all residual SCilS into bedrock or approved soil. The depth of keyways shall be determined at the time of grading. 4. All loose soil in the eroded canyons shall be removed and recompactedi' 5. As fills are placed in areas flatter than 5:1, level benches shall be excavated into bedrock or approved soil. 6. Removal of alluviai soil from gulley bottoms shall be to sl-1ch a depth adequate to remove loose or dry soil. It is estimated that this removal will average 3 feet but extend up to depths of 8 feet in places. n KG USSlil~H C;. OSHOIISI: & .A~SLX:I.W~\ - Job No. 3380-l Page 13 ,- ,- - - - - - 7. The cut port icns of cut-f ill lots shall be .*. excavated to a depth adecjuate to provide a minimum cf 36 . * inches of fiil on the lot. r ‘I 8. All fill shall be compacted to a minimum of 90 - . percent cf maximum density., 9. Slopes shall be compacted to the slope surface. 10. All fill St&all be compacted to a minimum of 2 percent or more above optimum. 11. All keywdys, benches, and cut slopes shall be subject to inspection by the engineering geologist and/or the scil engineer. General It has been assumed, and it is expected, that the soil conditicns between the borings are similar to that encountered in the borir.gs. Hzvever, no warranty of such is implied in this report. ?.he recommendations contained in this report are based on the result5 of field investigation and labcratory testing and represent our best engineering judgment. If soil conditions encountered during the grading, or at any other time, differ substantially from those described in this rezcrt z this office should be notified immediately so that appropriate recoamendaticns can be made. This report is issued with the understanding that it is the respcnsibility of the caner or his representative to insure that the information and recommendations contained herein are called to the attention of the Project Architect - m Kl:SS1,1H c;. irSlkWSII A ,As~Lx:l.~l~lis .- - - - r - Y - RHY:dhd - . L- - - - - Job No. 3360-l Page 14 and Engineer and are inccrporated into the plans and speciY,. fications and that necessary steps are taken to see that * ' interested persuns have this information and that the Co% . . tractors and Subcontrtictors carry out such recommendations. Respectfully submitted, KENNETH G. OSBORKE & ASSOCIATES KCO:dhd Kenneth G. Osborne R .C.E. 14340 CEH : dhd Richard H. Merriami C.E.G. 650 szz-44.~ a+- Viki G. McFadden Staff Geolcgist - * :. . . . . > - . - i - REFEREKCES 1. Jones, B.F., 1954, Geology of the San Luis Rey Quadrangle, unpublished master thesis, Unversity of Southern California. 2. Kennedy, Michael P. and Peterson, Gary AL., 1975, Geology of the San Diego Metropolitan Area, California, California Division of Mines and Geology, Bull. 200. 3. Phillips, Irvin, 1939, Geology of the Oceanside Quadrangle, unpublished masters thesis, University of California, Berkeley. 4. Weber, F.H., Jr., 1963, Geology and Mineral Resources of San Diego County, California, California Division of Mines and Geology County, Report 3, 309 p. - 5. Preliminary Soil and Geology Investigation for the proposed Laguna Riviera - 29 acres, Carlsbad, California. Project No. 51101W-SJOl: - - - r - - - - - - a ‘- . . ,. j . . APPEKDIX LRBORATORY TESTING PROCEDURES - - - - f . - - - . 2 ’ SHEAR STRENGTH c 'r The shear strength of the soil is determined by per- . forming direct shear tests and unconfined compression tests. The direct shear tests are performed on both undisturbed specimens and on samples remolded to various densities which reflect anticipated conditions. The samples are either tested at in situ moisture or are saturated to simulate the worst field condition and sheared at a constant rate of 0.1 inch per minute. The relationship between normal stress and shear stress is shown on the attached Direct Shear Summary. The unconfined shear strength of selected undisturbed specimens is determined in accordance with A.S.T.M. Test Method D-2166. The results of these tests are shown on the Boring Logs. EXPANSION Tests for volume change with moisture are performed on compacted soil in accordance with Uniform Building Code Test Method 29-2. SETTLE‘MENT The settlement characteristics of the in situ soil are determined by performing standard consolidation tests on undisturbed or remolded specimens. The samples are tested in the original sample liner ring and the increment loads for consolidation are applied for periods of 24 hours by means of a single counterbalanced lever system. The pressure settle- ment curves are shown on the attached plates. MOISTURE DENSITY The moisture-density relationship of the major soil is determined in accordance with A.S.T.M. Test Method D-1557. This test may be modified to use three layers in lieu of five. The test results are shown on the Boring bogs. ,7‘/7a Page A - -. - - CLASSIFICATION * '- . . The following test methods are used to aid in the r ',I classification of soils in accordance with the Unified Soil . . Classification system: 1. A.S.T.M. Test Method D-422 :: A.S.T.M. Test Method D-423 A.S.T.M. Test Method D-424 The results of grain size tests are shown on the Grading Analysis sheets. The results of consistency tests are shown on the Boring Logs. - RESISTANCE "R" VALUE The resistance "R" Value of soils to support pavement - is determined by means of California Test Mehbd No: 301-G. SAND EQUIVALENT The sand equivalent of granular soils and fine aggregates is determined in accordance with A.S.T.M. Test Method D-2419. SOLIXLE SULFATE CONTENT The concentration of soluble sulfates in the soils is determined by A.S.T.M. Test Method D-516, Method A: - Page B GRADING SPECIFICATIONS GENERAL PROVISIONS .- - r - - m - I - RESPONSIBILITY . . .- r 1. The Soil Engineer and Engineering Geologist are the. . Owner's or Builder's representative on the project. For the purpose of these specifications, observation and inspection by the Soil Engineer includes the inspection performed by any person or persons employed by, and responsible to, the licensed Civil Engineer signing the soil report. 2. All clearing, site preparation, or earthwork per- formed on this project shall be conducted by the Contractor under the observation of a qualified Soil Engineer. 3. It is the Contractor's responsibility to conform to the Grading Specifications and the applicable grading ordinances. CLEARING 1. The site shall be cleared of all vegetable growth including but not limited to trees, stumps, logs, trash, heavy weed growth, and organic deposits. 2. All houses, barns, or other buildings shall be re- moved from the site. 3. Unless otherwise approved, the foundation and slabs left from the demolition of structures shall be removed from, the site. Included with the removal of foundations and slabs shall be the removal of basements, cellars, cisterns. septic tanks, paving, curbs, pipes or other deleterious materials. No cavity left from demolition shall be backfilled unless inspected by the Soil Engineer. 4. Unless otherwise specified, all cleared materials shall be removed from'the site. SITE PREPARATION 1. Loose soils within areas of fill shall be processed by either excavating and stockpiling the loose soil or by scarifying, adjusting the soil moisture content to the specified amount, and compacting to the recommended relative compaction. 7/7a Page C - 1 r - 1 I- - B - - 2. The soils within areas of fill shall be processed to a depth adequate to insure the removal of major tree roots and pipe lines and the compaction of cavities left from tr'ee . . removal. c :* 3. Excavations for the removal of subsurface structures-. shall be cleared of loose soil and filled with compacted soil. The backfill of such excavations shall be compacted to the recommended relative compaction. 4. Cesspools shall be pumped out and backfilled with clean sand or pea gravel. The sand backfill which shall be approved prior to use, and may be flooded and jetted for ob- taining compaction. Any unsuitable backfill of cesspools shall be removed. The preparation of cesspools shall be observed by the Soil Engineer. 5. Abandonment of oil wells shall be in accordance with California State Law. The backfill of cavities resulting from the abandonment of oil wells shall be compacted in thin lifts under continuous inspection of the Soil Engineer. 6. Unless otherwise specified, the tops of any abandoned subsurface structure shall be removed to a depth of 5 feet below the finished grade in building areas and to a depth of 10 feet below finished grade in all other areas. FILL PLACE!!NT 1. Unless otherwise approved, no cobbles over 12 inches in diameter shall be accepted in any fill. 2. All on-site and imported soils to be used for an engineered fill shall be subject to the approval of the Soil Engineer. 3. The placement of fill shall conform to the Special Grading Provisions. ., : - - Page D -. r - -. I- L- - r - I - - I I- I - i- I I i I SURFACE ELEVATIOh' 236 --- 1 ,. SAND, fine, silty, dry, 107 123 a7 1.7 2-1 ;I) rusty brown * *_ . . .._ .04 119 88 2.4 . 4-5:: r 'I slightly moist . . .: . .: 121 131 92 8.9 . 6- _'. moist, mottled with pay, .: . . dense, trace of clay very hard, dark rusty brown ittle clay, moist, light tan, slightly micaceous usty streaks Bottom of Boring No Ground Water TEST HOLE HO. B-l Paee E - - - _. i - r - i - I I - I .- I - - - - .- -~ SIJFU'ACE ELEVATION 183 103 i: . 2,” c . ;‘z \ . . 5 p” 24 - ;.: - - i-1 - i--i -2 - 5.: - - 1.: - - c ti s k ; ~ d 2 4 6 8 10 12 14 16 18 20 22 / : / i SP - SC - SM SW - SC - SM - SAND, fine, little silt, dry, ruity brown _ moist, fine to coarse ;a'nd** - with small clay lensesl,. . _ SAND, very clayey, fine/medium, moist rusty brown with blat) streafis, trace of roots SAND, fine to medium, silty, trace of clay, moist, dark brown, slightly micaceous fine sand, no clay fine/medium sand, hard fine/coarse, little clay SAND: clayey, rusty brown, moist, fine/coarse A ~~,:i~~rmif$~~bu~oist, whitt Bottom of Boring No Ground Water No Caving KE3SEl-H G. OSBOhSE h ASSOCI.4TES BORING LOG TEST HOLE NO’. B-2 :3880N"*~$:~81] SHEET 1 OF 1 Paoe F .- - - SURFACE ELEVATION - 116 - 136 118 - - . . .&J 4u : * I8 I\ Id? ic - I . :t 5 . J >u \ . . :Wi I2 - :e ;;: -v i2 I.5 V - SC SI SAND, clayey, f’ . brown, Lne/medium,d race of gravels an 54, salts slightly moist L ‘* . . SAND, silty, very f inc.;.-moist, light yellow tan with black - and brown clay streaks dense Bottom of Boring No Ground Water No Caving 1:ENXEl-H C. OSBORSE & ASSOCL4l-ES BORING LOG TEST UOLE NO. B-3 81 SHEET 1 OF 1 Page G - - r I .- 1 - r - I - I_ (i: - I t- - li r- - - - I - I - I I SURFACE ELEVATION G- 26 13 - - - . ;,' g; it ;z :- - - 124 130 97 2.: - L - 5- - L - - - - - - 6 8 CL CLAY, sandy, moist, r&.fy-. brown, dense, fine/medium- SM SAND, fine/coarse, silty,light brown and black clay str&E: yellowish tan, moist Bottom of Boring Refusal - too hard No Ground Water No Caving 1 . . f$ USSETH G. OSBORSE & ASSOCI.4TES ?$ :tl BORING LOG ci T&ST HOLE NO. B-4 : 53"OE NO. v 3380 b7??78ll SHEET 1 OF 1 P.oa I4 - DIRECT SRBAR SUMMARY - - i - - 1600 i . n k . 9 1200 s P E 6 ifI 800 vO 400 800 1200 1600 2000 NORMAL LOAD, P.S.P. JOB NmER mftt&o-/ ii BORING NUMBER / DEPTH 3’ MOISTURE u rr -4 UNDISTUP.BED -•- REH~LDED --Q- @ 906 MAXIMUM DENSFTY - - - ,~ -. - .- - i- t .~ - - - I - - - 3200 bI ui k . 2 2400 s E PC 2 ICOO to DIRBCT SBSAR SOWWARY JI III I I I I I III I I 11 l I] ICOO 2400 9200 4000 NOW! LOAD, P.S.F. JOB NUUBER 33.9 o- ..i t' BORING NUKBER / EEPTH -&Ccl- UWISTKXGED -*- REMOLDED - -Q- @ 9~OC PlAXIKUK DENSITY Page J -w- I -1 I 1 I IL-~ I -1 --I ~--- 7 i -1 ~1 “I I - I c I \ i . , 1 , * . ; : i : c cur *4occ CQMMCIrCb mu - OVIAP/AL AAlO arc&M ra/.w ld 6a4ac: uffb?? -- I rYP/CA L SL OPC UCPAIR F-ou SCCFACC ’ i i . , * : I