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HomeMy WebLinkAboutCT 81-18; G.R. CAPITAL N/S UNICORNIO DR.; SOIL INVESTIGATION; 1981-11-06r ..... .. . ., REPORT OF SOil INVESTIGATICN La Costa Condominiums Lots 515, 516, 517, Map 7076, La Costa M~adows, Unit #3 La Costa area, Carlsbad, California JOB NO. 81-1968 06 November 1981 prepared for 1'.\.4 ..... ,~, '.- • ,-----------------------, .. __ ._-------------------------'-G & R CAPITOl. CORPORAT,a-{ p prepared by GEOTECI*4ICAL EXPlORATlaf, INC. 8145 Ronson Road, Suite H San Diego, CA 92111 • ';.. .. '~;.'" •• ,. . . GEOTECHNICAL EXPLORATION, INC. SOIL &: FOUNDATION ENGINEERING GROUNDWATER • GEOPHYSICS • ENGINEERING GEOLOGY -06 November 1981 G & R CAPITOL CORPORATION 359 San Miguel, Suite 102 Newport Beach, CA 92660 Subject: REPORT OF SOil INVmlCATl<JIf La Costa Condominiums Lots 515, 516, 517, Map 7076 JOB NO. 81-1968- ,---La-Co.sta-Meadows,-Unit.,jf3.;)..-------------__ La Costa area, Carlsbad, California Gentlemen: In accordance with your request, Geotechnical 'Exploration, fnc. hereby submits the -. following report summarizing, OUT work and test results, as well as our conclusions and recommendations concerning t~ subject project. It is our understanding the existing fill soils located on the subject site were placed under the supervision-and testing of , -Benton Engineering, Inc., during a previous grading operation. Our firm placed random test pits in the existing fill S9ils, after the grading operation was completed, in order to verify that the soil conditions were not modified after the controlled grading _. -. operation' was completed and to determine the depth to and con'ditlon of the underrying natural ground soils. Our field work was performed on October 29,.1981. SCO~ ()F WORK It is our understanding that the s'ite is beinlJ developed to receive a 28-unit condominium complex. The p~oposed structures are to be a maximum of tWQ stories in height and. will be-constructed of standard-type building materials, utilizing conventional, continuous foundations or spread footings. A Plot Pian, illustrating the approximate location of all fill materials and cut and fill slopes, is enclosed as Figure No. I. With the above in mind, the Scope of Work is briefly outlined as follows:.. . 1. Identify and classify the surface and subsurface soils to depths, in conformance .with the Unified Soil Classification System (refer to Appendix A). • La Costa Condominiums (X) November 1981 •• ,". ., ... .:..., .... - Job No. 81-1968 Page 2 2. Determine the allowable bearing pressures for the natural ground and the soils to. be used 'in compacted fill, based on their shear-strength characteristics and our experience with the soils. 3. Recommend treatment for any expansive soils that could cause detrimental damages to the proposed structures. 4. Determine the extent, d~pth and condition of existing fill soils on the site. 5. Predict the settlement of the natural-ground. soils, as well as existing compacted fill soils under the proposed structural, loads. SITE The. site,. consisting of approximately one acre, is located approximately 150 feet east of Cacatua S~reet, on the north side of Unicornio Street in the La Costa area of the' City of ·Carlsbad. The property is bo rae red' ort the west and north bY. residential· properties and on the east by a graded, vacant lot. ---.~----., _. --~ - At the time of our inspection',' a previous grading operation on the site generated a relatively level building pad with drainage to the south. The site; prior to grading, appears to have consisted of moderately to steeply sloping hillside (sloping to the north) terrain. Prior to grading, on'""site vegetation appears to have consisted of a moderate growth of grasses and weeds. A combination tut-and-fill slope, a maxi~um of 60 fe~t in height, has been placed at the 'north end of the subject property. This slope possesses a slope ratio of 1.5 horizontal to 1.0 vertical (as' referenced by an undated Site Plan by HenrY Warley Associates and identified as their Job No. 81-59) and dips to the north-nortnwest. Surficial slipp~ge and erosional rills were obserV~d on the· face of the slope (this p'roblem is specifically addressed in Reconwnendation ,15h .e. [a Costa Condominiums 06 November 1981 FIELD , Job No. 81-1968 Page 3 Six test trenches well! placed on the site to determine the overall depths and the' extent Of the existing fill soils, and the condition of the bearing soils. The / excavations were located in the field by referring to a. Site Plan, prepared by Henry Worley Associates~ undated. The excav~tions were visually inspected by our Field Engineer, and samples were taken of the. predominant soils throughout the field operation. Test' tre"-~h logs. have been prepared on the basis of our inspection and the results have been summarized on Figure No. II. The predominant soils have been --------'-€las5ified-i~€onfoFmafl€e_with_th~ Unified-SOiI-Clas-sUi«::ation-Sy.stem-{refer-tO-Appendix--------~-.. - • A). SOILS The fill soils encountered primarily ranged from less than 1.0 feet in thickness at the south end of the site to 5.0 feet in thickness at the north end. The fill soils consist primarily of greenish-gray, sandy, silty clays and clayey, silty sands. The uppermost 0.5 feet of fill is relatively loose., However, fiel.d dens{ty tests taken of fill 'soils beneath this uppermost layer indicate they are moderately to well compacted.. The filt soits possess highly to critically expansive characteristics as' tneasliredby the County of San DiegoTest for Expansive Soils. The fill soils well! found to be under'hlin with, formational materials consisting of medium dense to dense, brown~ non-'expansive, fine . ' to medium sands with-a heavy day binder and gray-green, fractured claystones. The claystones were tested and found to be highly to critically expansive. All natural ground topsoils appear to have been removed from the site ~uring the previ<?us grading oper.ation. GROLNOWATERj Nogrot,lndwater problems were encountered during the course of our field investi-, . gation and we do not expect significant problems to develop in the future--if the property is developed as presently designed. It. should be kept in mind, however, that CIJly required grading operations may change surface drainage patterns and/or reduce . I • La Costa Condominiums ~ November 1981 Job No. 81.,.1968 Page 4 permeabilities due to the densifjcation of-compacted soils. Such changes of surface and subsurface hydrologic conditions, plus irrigation of 'landscaping or significant increases in rainfall, may result in the appearance of minor amol,lnts of surface or near-surface water at locations where nOl)e existed previously. The damage f.rom such water is expected to.be minor and cosmetic in nature, if good positive drainage is im- plemented at the completion of construction. Corrective action should be taken on a site-specific basis if, and when, it becomes necessary. lABORATORY TESTS -------._----.-_. L~boratory tests were performed on the disturbed and undisturbed soLI samples in order to determine their physical and mechanical properties and their ability to sup- port the proposed structures. The following tests were conducted on the sampled soils: 1. Moisture Content 2. Density Determinations 3. Mechanical Analysis 4. Expansion Tests 5. Oirect Shear Tests 6. Consolidation Tests The moisture and. density_ determination relationship on undisturbed soil samples gives qualitative information regarding the soil strength characteristics and soil conditions to be anticipated .during the future grading operation. The mechanical analysis was performed on selected soils according' to A.S. T .M~ 422-52T. The mechanical analysis was used to aid in the classification of die soils according to the Unified Soil Classification System • Expansion-tests were determined from the County of San Diego -Test Method for Expansive Soils. Expansive soils are classified as follows: • La. Costa Condominiums (» NO\'ember 1981 o to 3 percent 3 to 6 percent 6 to 12 percent Above 12 percent Job No. 81-1968 Page 5 low or Considered "Nqnexpansive". Medium High Very High According to the County of San Diego Test for Expansive Soils, swells of less than 3 percent are classified as nonexpansive soils. Direct shear tests. were performed upon undisturbed-:-and remoldedbuik s~mples in order to determine the soil stren.gth and supporting capacity for the natural-ground soils and these same soils to be used in the. compacted fill. The shear. tests were made with a constant strain direct shear machine. Specimens to be tested were saturated and then sheared under various normal loads without appreciable drainag~ of the samples • . Consolidation Tests were performed on lmdisturbed natural-ground soils and' remolded soils expected to be used in the compacted fills. The soils are containect: in 1-inch high brass rings and loaded into a consolidometer.. The specimens are subjected to increased loads and the resulting consolidations noted. The consolidation tests aid in determining anticipated settlements of the natura' ground under the proposed building loads. Field density tests were performed in accordance with A.S. T .M. 0-1556. Maximum density determinations were performed in accordance. with A.S.T.M. 1>-1557. The relative .~ompaction results, as summarized on Figure No. II; are the ratios of the field densities to the laboratory Maximum Dry DenSities, expressed as percentages. CO«:lUSla-IS AND RECOMM~o"'tl~S The following conclusions and recommendations are based upon too" practical field. investigations conducted by our firm, and resulting laboratory tests, in conjunction with our knowledge and experience with the soils occuring on the subject site. .; r-~------------~----------------------------------~~------~~~~~~-----~ . ~~-=--... -.-.:....:..~.'":.. . • ,La Costa, Condominiums 06 November 1981 Job No. 81-1968 Page 6 1. The site was found to be overlain with 0.5 to 5.0 feet of compacted fill soils. T~e filts co!"sist of green-gr~y, silty, sandY clays. The clays were tested and found to possess up to 12.0 percent swell, as ~asured by the County of San Diego Test for Expansive Soils. The fill,s are underlain by good bearing, formational materials consi'sting of bedded, 'gray-green claystones and brown, 'non-expansive, fine to medium sands. ""(he formational claystones also possess up to 12.0 p~rcent swell as measured by the County of San Diego Test for Expansive Soils. - lesU-oJtne:--lrFpJace-fillsolts-yietc:tecr fiel<:.r--densitles-of-Slpercenr--anq89, percent of Maximum Dry Density. Although fill soils must, in general, be compacted to 90 percent of Ma}(imum Dry Density to be considered as accept- able, we feel that the filt soils tested are in a sliitabre condition-due to their criti~ally expansive nature. This density condition can actually prove to, be beneficial in regard to minimization of potential distress and cosmetic damage resulting from expansion of the clayey SoUSa Be assured that the in-place density of the fill soils was taken into account by this firm jn recommending design bearing capacities and predicti'ng future settlement of the proposed structures. 2. Unless properly dealt with, the highly to critically expansive ,characteristics of' the on-site ,soils described previously' can cause significant damage to the structures an4 associated improvementS' (such as those planned for the subject property). ,In ~rder to reduce significantly the potential for such damage, on~ of the recommendations herein must be followed: -. 2.1, If the planned, structures and improvements are to be constructed using, standard, nonexpansive-soils, design. criteriiil, ,the site shall be prepared as follows: 2.1.1 The highly to critically expansive soils s,hall be rerooved from aU structl,lral areas to a minimum distance of five feet outside perimeter footings. The clay soils shall be rerooved to a minimum depth of 3 feet , , , below the proposed, rough, finish-grade elevation~. • e " La Costa Condominiums 06 November 1981- Job No: 81-1968 Page 7 2.2 1.1.2 Excavated areas shall be backfilled with nonexpansive soils (such as on-site, brown, fine to medium sands or soils obtained from an approved off-site borrow pit). The nonexpansive select materials must be placed and compacted to at least 90 percent of Maximum Dry Density; in accordance with the requirements of the City of Carlsbad Grading Ordinance. Upon sati~factory completion of the backfilling operation, continuous ,and spread footings, may be designed, in accordance with the soil-bearing value assigned to the compa~ted nonexpansiw fill materials. The continuous and spread footings shall have a minimum width of 12 inches and extend, a minimum depth of 12 inches into the compacted fill soiJs-Ht-is-re£ommended-two~story-struetures-be-,founded-;-on-18-inehf---,----- deep footings). 2.1'.3' Areas receiving-improvements, such' as patios; sidewalks, A.C. pavement (parking areas), et cetera,shall be underlain by at least six inches of non-expansive fill materials, and be reinforced with 6 x 6 - 10/10' steel wire me'sh. If it is intended to construct the proposed structures and improvements on the expansive clay soils without preparation of the site (as ,described in' Recommendatfon No. ,~.1)~ the-following' recommendations . become' applicable: 2.2.1 The continuous foundations and spread footings s'hall ", extend a minimum depth of 2,4 inches into fhe firm natural, ground or compacted fill. The continuous foundations shaU, be reinforced with four No. 4 steel bars (or ~uivalent); two bars shall be located near the top of the foundations and two bars near the bottom~ Continuous foundations must be carried across garage entranc~s. 2.2.2 Concrete floor slabs, if used, shaft be founded on at ,least six (6) inches of sand or decomposed granite, overlying visqu,een. The slabs shaH be reinforced with No.3 steel bars placed on 24-.inch centers (both ways). It is suggested suspended wooden ,floors be utilized where possible. • La Costa Condominiums ~ November 1981 -e Job No. 81:'1968, Page 8' 2.2.3 Prior to pouring footings and foundation$, and prior to placement of .floor slab base sections, the clayey soils shall be thoroughly watered such that tht."Y possess a moisture content of 2 percent above . optimum moisture content (or more) at a depth of 1-2 inches &elow the . footing grade. 2.i.4 It is recommended that all noristrlictural concrete slabs (such as patios, driveways, sidewalks, et cetera),and all parking areas, be founded on at least six inches of nonexpansive soils and be reinforced ._---_. with 6 x 6 -10/10 steel wire mesh. 2.2.5 The use of isolated interior piers should be avoided. 2.2.6 Garage slabs should be deSigned as free-floating, to allow independent movement of the slabs and perimeter footings. 2~2.7 Provide positive drainage aWay from all peri~ter footings with (}-vertical fall of at least six .inches· in horizontal distanCe of s,ix: feet outside house walls... 3. Utilizing an Angle of Internal Friction of at least 21 degrees, and a cohesion of 4CX). pounds per square foot (with the appropriate Terzaghi Equation), the maximl,.lm safe soil-bearing value (at a depth of 12 inches into' the n~tural materials or compacted fill soils on this site) is at least 2,000 pounds per square foot.. This SOil-bearing value may be utilized in the design of continuous foundations and spread footings when founded a minimum of 12 inches into the firm natural ground OF compacted fill. It 'is recortnnended' that two-story structures, be founded on 18-inch reep footings. Foundations embedded in the highly expansive soils must be 24 inches deep. Thiss,!if-bearing value may ,be increas~d one':'third for design loads that include wind or seismic analysis. If imported soils are required, the il11port soils shall be non-expansiVe and' shall be obtained from an approved borrow area. La Costa C0!1d0n:tiniums • ~ November 1981 Job No. 81 :-"1968 Page 9 A soil-bearing value for imported soils, should they be utilized on the site, can'" not be given until the materials source is known. It is anticipated, however, that a valu~ of at least 2,{XX) pounds per square foot will be obtained for footing depths of 12 inches. 4. Based on our lahoratory test results and our experience with the soil types on the subject site, the soils will experience settlement in the magnitude of less than 0.5 inches under a structural load of2,{XX) pounds per square foot. 5; The acti¥!! earth pressure when 'retaining the green-gray clayey soils (to be utilized in the design of walls, et cetera), shall be based on an Equivalent Fluid Pressure of 70 pounds per sqlJare foot. 6 • The ac:tiw earth pressure to be utilized when retaining the brown, fine to medium sands shall be based on an Equivalent Fluid Pressure .of 35 pounds per cubic· foot. The passive' earth pressure of the green-gray; dayey . soils (to be used for design . _ _ ___ of buUdi,ng foundations and footings to. resist the lateraL forces) shall be based, on an Equivalent Fluid Pressure of 2O(J pounds ,per cubic' foot (at any depth). An Equivalent Fluid Pressure of 300 pounds per cubic foot may be utilized when . founded in the brown; fine to medi!Jm sands. 7., A Coefficient of Friction of 0.3 times the dead load may be used between the bearing soils and, concrete wall foundations or structure foundations and. floor slabs when founded on the· green'-gray, claystones and fills. A Coefficient ·of Friction of 0.4 may be utilized when founded on the brown, fine to medium sands. 8. The compacted fill soils that occur withIn 5 feet 'of the 'face of the fill slopes will possess poor lateral . stability, even though they have been compacted. Proposed structures and other improvements (such as walls, fences, patios, side- .. r-----------------------------------------------~~--------------~--~~ ~ • La Costa Condominiums 06 November 1981 ' Job No~ 81-1968 Page 10 walks, swimming pools, driveways, asphalt paving, et ce~era), that' are located within .5 feet cif the face of compacted fill slopes, could suffer differential movement as a result of the poor lateral stabilitY of these soils. Foundations and footings of proposed structures" walls, et cetera, when found- ed 5 feet and further away from the top of compacted fill slopes, may be of staridar~ design in conformance with the, recommended· soil-bearing value. If the proposed foundations and footings are located closer than 5 feet Insi'de the, top of compacted fill slopes, they shall be deepened to 1 foot below a lin~ beginning-ar-a-p~int-5-feer horirontalty-inside-the-fitrsloper Cfrtd-projecte<t;-----·-----,- outward and downward, parallel to the face of the fill slope (see Figure No. V). 9'. It 15 recommended existing compacted fill slopes and natural cut slopes' be planted with an erosion-resistant plant suitable to soils prone to shrinkage cracking, in conformance with the requirements of the County of San Diego. 10. Planter areas and planter boxes shall be sloped to drain away from the founda- tions, 'footings and floor slabs. Planter boxes shall be constructed with a s,ub-.. surface drain, installed in gravel, with the direction of, subsurface and surface 'flow away from' the foundations, footings and floor slabs, to an adequate drain-' age facility. 11. T~e existi'ng debris and vegetation observed on the site must be removed prior to the preparation of building pads and/or areas to receive structural improve- ments. 12. Any backfill ;oils placed in util.ity trenches, .or behind retair:ting walls, which support structures and other improvements (such as patios, sidewalks, drive- ways,' pavements, et cetera), other than. landscaping; shall be compacted to at ,teast 90 percent of Maximum Dry Density • 13.'. It is our opinion that natural-ground cut slopes of maximum inclinations of 1.5 horizontal to 1.0 vertical shall be stable and free from deep-s7ated failures. for ,~ slopes not exceeding 60 feet in height. c, , 1 e La Costa Condominiums (X) November 1981 '" • L_ _ ,.. Job No. 81-1968 Page 11 14. It is our opinion that compacted fill soils of maximum .inclinations of 1.5 horizontal to 1.0 vertical shall be stable and free from deep-seated failures fOf slopes not exceeding 10 feet in height. 15. Adequate measures shall be taken to properly finish-grade the site after the structures and other improvements are in. place. prainage waters from this site and adjacent properti~s are to be directed away from tops of slopes, founda- tions,floor slabs and footings, onto the natural drainage direction for this area or into properly designed and approved drainage facilities. Proper sub$urface and s'urface drainage will ensure that no waters will seek the level of the bearing ---'-----501 trurnter th'e' fOlffntati'Onr, f(5ot'lngr~m<t fto~)r-s labs-;;-Failure"" to-observe-thl5---' ---- recommendation could result in uplift or undermining and differential settlement • of the structures or other improvements on the site. The observed surficial slippage and erosional rills on the face of the existing cut-and-fill slope indicate that surface waters have, in the past, been al,lowed to E;xit the site over the slope face~ Particular care should be taken to direct . future· drainage waters away from the slope, in order to minimize the potential of future failures. Geotechnical Exploration, Inc. will assume no liability for damage' to structures w~ich is attributable to poor drainage. 16. ' No swimming pools· or 'subsurface. struct,ures shall be placed in the: highly expansive soils' without being properly designed by a structural engineer arid/or sojfs engineer. GRADING NOtEs Any additional' required grading operations shall be perfor~ iilaccordan<;e with the general requirements of the City of Carlsbad Grading Ordinance, under the supervision of a qualified soils engineer or supervised field' soils technician. It is the responsibility of the Owner and/or Developer to ensure that' the recommenda- ttons summarized in this report are carried out in the field operations. La Costa Condominiums ~ Novemb.er 1981 l.lMITATIa..S Job No. 81-1968 Page 12 Our conclusions and recommenda~ions have been based on all available data obtained from our field investigation and laboratory analysis, as well as our experience with the soils and formational materials located in this portion of the La Costa area. Of necessity,' we must assume a certain degree of continuity between exploratory excavations and/or natural exposures. It is, therefore, necessary that all observations, -~----GonGlusion-s-and-reGommendatiens-be-verified-at-th~ ~ime-additional-grading... operations----- begin, or when· footing excavations are placed. In the event discrepancies are noted, '. we should be notified immediately so that an inspection can be made and. additional recommendations issued;. if required •. Compaction tests were taken in randomly placed trenches and indicate the existing soils were property pr~pared and compacted. However, our firm cannot assume liability for' the integrity ~f the entire fill pad since our firm was not. present during the actual·grad.ing operation. The fiJI soils on the subject site . were previously tested (during the grading. operation) by Benton Engineering, Inc. The test results are .' . summarizecF irftheir report-entitled ·Final' Report of Compaction Filled GrolJOO ~nd Classification of Soil Condtions·, lots 413 to 584, inclusive, and certain street areas, La Costa Meadows Unit No.3, and dated October 19, 1972. This report should be co~sidered valid for a period of three (3) years, and is subject to review by our firm following that time. If significant modifications are made to the building and/or grading plans, esp,ecially with respect to the height and location of cut' and fill slopes and the height and location of proposed structures, this report must be. presented to US for immediate review and possible revision. The firm of GeotechniCal Exploration, Inc. shall not be held responsible for changes to the physical condition of the prop~rty, such as addition' of fill solis or changing drainage patterns, which occur subsequent to issuance of this report. -'-. • La Costa Condominiums ~ November 1981 Job No. 81-1%8 Page 13 Once again, should any questions arise concerning this report, please do not hesitate to contact us. Reference to our Job No. 81-1968 will expedite response to your inquiries. Respectfully submitted, GEOTECI-fIIICAL EXPlORATIO'of, INC. JBR/CWl/pj Enclosures· ". • REFERENCE: This Plot Plan was prepared from an undated Site Plan by Henry Warley Associates, identlfied as their jo~INo. 81-59. LEG END ) o ---------~ ,11:'# I TI "'-,... -- 'II Property Line Pr9posed Structures Existing Brow Ditches Test Trench Locations Existing Cut Slope .D~iY 1 i ght Li ne Existing fill . slope , c ,... ... ~~ ___ ........... _ ...... ~ ,-_~--.....-.. ,-". .--~ ..... TEi Thia Plot "-' .. nat 10 be ~ lot Ieg8I ~ ~ MCldImtnIIionI"'IIP9WII~. !Nto AduII6 p(Op«'ty ......... and'locMiona . I ~ lNIY'be ob&airwci !roM. the ~. yiIdIng ~,~ ~ .~8uiIr GradinfJ·P\MS.., ._ .... _ ..... _ .. _~_r ___ ~.---._ ... __ .. _ ..... .... ...... .... .... PLOT ------- 1.5: I PLAN -...... --~ -....-----~ ---'.-~-- / 'X T-2 I T-6 rhO .~. .1 i 'PMK\N~' T..,l ...... '--- .-, -----, ----. "- -..:~;;::::=::..:-~=:;::-.. ;..:-.:::::;;:.::'=-.:::::; =-':.==::~-:;::::-.= -.'.:':'.::.::~.-:-+--.-... _----., (J"l r rrYf""')1\I'O . I \, I ( • \ )'-\ • 'v i / SCALE; 1-11 := 40 1 1.5: , ,. -- '------~ -~--- 1f 1T-3 PARKINq !T-5 !T-4 ~~.:::-.=:~u~.:;.,_;.; _._ I~h 1Jf'\ A 1 -lqf,R , Log of Test Trenches -.~ CI ~ 0 , II. ..I . C u 5611 Description -:E .&: (Unified Soli Classification) -Q. Q. ftI IJ .. 0 " Trench No. 1 ---~~--~ i' ,,'. Loose to medTUiTl.;aen-se-, 5 ffglit ry a'amp, green, gray :'.. " ,-', and brown si ltv' sandy clay (SC-CH) FILL I~ 'I ,I:-l 2-',1 ~l',', Medium-dense? slightly da~p, greenish-gray, ~ighly­tl'Ci" ,fractured, clayey $andy SIltstone , ~. (SM-ML) 4 1:(1'1:1 FORMAT ION, 118.7 11.0 +1.0 Trenclr No. 2--O~M~{~~~~tr-------------~,·------------~,~-----------'----~--~~~~~ !\ ' ,-: , Loose to med i urn-dense, slight ly damp, green, gray and ",", ~ brown, silty sandy clay 0-"'~ 10: \' " 2<~Q),: "" "i\ '.! >-",. ~ (SC-CH) FILL ~" .. " ~ ~1(Qi: Medium-dense, damp~ green-gr(tH silty sandy claystone 4 "<::.{ .,) . FORMATION ~!5~ Dense, mottled tan, green, gray and brown, fine-to ~:':,}.:\I~edium-grained sandstone with abundant mai-inefossils ::;'.: ~::. 6-:?@::: Medi,um-dense to dense, damp, light-brown, fi'rie 'tq ::,\:/:~;: medium sand with a, few marirTstfssils FORMATION o Bag Sample o Undisturbed. Sampla *In-Place Density "In-Place Moisture· 26.0 8.4 , . ., .1. I Job No. 81-1968 . figure No.-~ I a- +11.2 l .. c -.c Q. GI :0 Trench No_. ~ Log of Test Trenches _ Soli Des,erlptlon (Unified Soli Clalilfleallon) ----~·I·o-,,"y ------_.. -_.. --_._ ... -------------- ~-":--~f\ Loose, dry, gray to green-brown, silty sandy - .j" , \ clay (SC-CH) 2 ~"G):. \.. ---becomes med i um-. r:-.~': . dense, FILL ....... '. -Medium-dense to dense, damp, mottled brown and gray-brown fine to medium sand with heavy clay bi.nder, and containing o~caS'ioral marine-fossi.1s (Sp-SC) FORMATION Trench No. 4 o ... ; i:" '::>' ,', Loose to medium-dense-, sl ightly damp, green, gray E(~~ and brown s i 1 tv sandv c lav (SC-CH)F I LL 2'-r,91-f Medium-dense, dry. gray siltstone; highly fractured T Ifill and laminated (MH) 1 I d L-----------------,!!e.~!.1les less fq~lc~t~u..!..re~d!:!-._!...:FO~R.!!.M.!!'A!;!T..!I:.:::O.!.!N~ 4-~ :~'8 1(\ t,; 6 ~<.-'~: Dense, slightly damp, green-gray silty sandy , .~ ~ claystone (CL-CH} , :-..... ,. o 8.g S.m,pla o Undllturbed Sample ·In-Place Denllty ··In-Plaee Moisturec FORMATION ~_ p",.. J. • :J! o - 1.20.0 10.1 -+5.0 +9.2 _ J I Jo~ No. 81-1968 Flgqre No. . I I b • .. ~ (--._- .- i u.. c -.r: -Q. " o Log of Test Trenches 5011 Description , (Unified Soli Clllllflcitlon) 0.-Trench No.5 ,:.7~::.~·.~ Loose'to'mecff um:'de~s-e ,"s 1 ight 1 y' damp;' green', "g'ray' ' "' . ''' .. ' and brown 5 i 1 ty sandy clay (SC-CH) FILL . , 2 ~~'~'~~--~~~~--~'~--~--------~~'~----------~--~ ::~'cB:~: . .,: .. "" 4 -~.: :::":: : " "" ,.'. .", ,; ~ 6 -. ':.: ' ," '/ ,'. . .. , Medium-dense to den~e, damp, light-brown medium sand with slight clay binder (Sp-SC) fine 1;0 FORMATI,ON Medium-dense, dry to damp, slightly f~actured green-gray silty sandy clqyston~ . tCL-CH) FORMAT I ON Trench No. 6 c " 0 :. .-.---,u .;[ a:: E o (J .. -01 --+, c: -0 c: .2 -3 .. ,.-c-tt O 0.111 )(c ",,0 (J O'~~~----------~--------~--------------------------~----~--~--~--~ ' .. " ::.::: Loose to medium-dense, s light I y damp, green, gray (Q).' and brS/wn si lty sandy clay (SC-CH) FILL ... :. " " 2~:~,.-.~~;.~.~--------------~--·-----------------~-----------4 :. ' .. ,:" :.: ~.~. .~"~.~' 4 .::,;\)./ Medium-dense to dense, damp, golden brown, fine to medium sand with occasion~l marine fossil layers (SP) FORMATION --... -.. --.-.--~.-,----.--.........,.---~-----------_4 Very dense. mottled tan,green, gray and brown, fine- to medium-grained sandstqne)containing abundant marine fossi Is ~SP , FORMATlO~: , Medium-de'nse to dense, d~mp, gray-green fine to 'med i urn sand wi th heavy clay binder· (SC-CH) FORMATION o Bag Simple *In-Place Density uln-Place Moisture o Undisturbed Simple ·..Lt Job No. 81-1968 F!gure No. I Ie 140 130 120 Ho- 100 !O \ ~ . '\ ~ \ , 1 \ " " \ ~. 1\\ \ \ \ \ \ \ ~ V ~ I !J -'ti ~ '(j I-:x:: (!) W' ~ !: -z .::J )0-cr a . , MAXIMUM DRY DENSI TV (pet) FILL SUITABILITY TESTS \ \ ,~ ~--3 k"~ ~\···"1 ~ ~\ \ \~\ \ '\ \ " , .\ \ \ 1\' \ and 2 DIRECT St£AR· TEST DATA I 2 APPARENT COHE SION fplf) APPAR£.NT FRier ION ANGLE 100 80 60 MECHANICAL ANALYSIS .3 714 4 10 40 200 ---------~--------,-- ~, \ 40 1\ i\ ~.~ 1\.' 20 \\ \ 0 410 28 \ \ \ 1000 100 10 1.0 0,1 0.01 0.001 \ G \. ~OB \ \ \. !'\ r\\. RAIN SIZE IN MILLIt-1ETEAS . . I .2 '3 ~r"2.70 . 118.7 118.5 120.0 SPECIFIC GRAVity OPTIMUM MOISTURE , 11.0 11 .-4 , 10.1 . ~R~·60 ~~C2.50 'CONTENT (%r'-. , .~ ZERO AIR VOIDS CURVES M·OISTURE CON·TENT % &1 eo 0 _ 10 . 20 30 40 LABORATORY COMPACTI.ON TEST SOIL TYPE SOIL CLASSIFICATION I Gray-green, clayey sandy silt 2 ~ray-green, silty sandy clay 3 Brown, clayey flne to medium sand SWELL TEST DATA . I 2 INITIAL DRY DEN SIT Y (pc f) 104.5 106 INITIAL WAT ER CONt EN T (%). 10.5 10.0 LOAO (~..! f) 144 144 PERCENT SWELL 1.0 11.2 B~ING, TRENCH· DEPTH NO. NO. 3 108 9.4 144 5.0 3.0' 3' 2.0' .3 6.0' JOB NO.: 8.1-1968 '. FIGURE NO: HI . r :> u L.I..I ex: :::I Vl V"I L.I..I ex: a.. Z 0 - I- ~ 0 .- ...J 0 Vl Z. 0 U • • -------~---~----------.~-----~--o . OOO'OL~~--~~--~~~~4--4--1 ~~~~~~~--+--+--+-~--~~~~~ ~ u.. 0" V"I ...... I/) ..0 ....J QJ S- :::S'. Ill, I/) QJ S- '0.. ,... to E S- O Z -= 1=-.. _ ~.I---- OOOE I +---~--.~--v----~-- 0002 I I V .. J' -------------.... ---' 000 L -----'" -r/~ ----/-f-- - -f-" . " - -.... ---.. - ----- I I --:....-11-1--~-.;...I--:-~--I-----~-~----- 005 J OOV~+-~~~Ul~~~~-+~--~+-~-+~~+-~~~----~+-~~ OOE I'l~~~~~-+~~~--r-~~~~~--~-+--~~--~~'. o N :t: OOZ~~~J~~~~~~~~~~~~~~~~~~~ I -----~---------~-~---~~-------- Job No.81·-1968 .F1gu.re .No. IV Propoeed Structure , Concrete Floor Slab 5' 011 • ........ Top of Compacted Fi 11 Slopp. /' Compqcted. Fill Slope (MaximUm Inc linaticn 1. 5 : 1.0)· -' h!inf~r::enta--nod~F-loo:'r~ _ : I ; Foundations Slabs fo llowi'ng the Rp.c-" -.- Footing 0"!'11P. nda t;tofrg;-'crf-the Ar~hite-ct;"-- or Structuralqinecr. ---=~-------~ --:--------ConcretE! Foundation -"';;'-'-~ . . -: ---'-~~ ...,... - . ' --:----. .:.=- . --~. --- . __ .. _----_. - Compacted F'i: n ~ ---'5' 0"---'- .:--'-- T Y PIC A L SSCTIQN . (Showing Proposed Foundation Located Within Five Feet of Top of Compactt:d 'Fill Slq;e) PISTANC ~ FRO~ • TOP (W SLOPF.: 0 I 1 I 2 I J 1.' 1.5 . 1.0 . 5211 44" 36/1 28" 20" TOT AJ. DEPTH OF FOOTING Fill Slc;>pe 2.0 : 1.0 42" 36 11 30" 24" -18" Fill Slope Job No. 81-1968- Figure No.·V • • =< APPENDIX A UNIFI'ED SOIL CLASS'IFICATION CHART, SOIL DESCRIPTION COARSE-GRAINED More than half of material I. larger than a No. 200 sieve' GRAVELS, CLEAN GRAVELS More than half of coarse fraction is larger than GW Well-graded gravels,gravel and s~nd mix- NO.4 sieve size, but smaller ,than 3" tures, little or no' fines. GP Poorly graded gravels, gravel and sahd mix- tures, little or no fi,nes. GM Silty gravels, poorly grad~d gravel"sand-silt GRAVELS WITH FINES ,,-----(appreeiable-ameunt)--,----mixtures.---- SANDS, CLEAN SANDS More than half of coarse fraction is smaller than a NO.4 sieve. SANDS WI1:H FINES (appreciable amount) FINE·GRAINED 'GC Clay gravels, poorly graded gravel-s~nd-silt mixtures. SW Well-graded sand, gravelly sands, little orno no fines. SP Poorly graded sands, gravelly sands, littie or no fines. SM Silty sands, poorly graded'sand and silty mixtures: SC Clayey sands, poorly gra,ded sane! and clay mixtures. More than half of material I. smaller than a No. 200 sieve SILTS AND CLAYS Liquid Limit Less Than 50 • Liquid Limit Greater Than ,50 HIGHLY ORGANIC SOILS '. ML Inorganic silts and very fine sands, rock flour, sandy silt and clayey-silt sand mixtures with a slight plastiCity. CL InorganiC ,clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, clean clays. OL OrganiC silts and organiC silty cfays of low plasticity. ' MH InorganiC Silts, micaceous or diatomaceous fine'sandy or silty soils. elastic silts. CH Inorganic clays of high plasticity. fat clays, , ' OH OrganiC clays of medium to"high plasticity. PT Peat and other hiQhly organic soils.