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Home My WebLink About; Shell Oil, ECR & Marron Rd; Soils Reports; 1969-06-19El Carnino Heal and Marron Road Northeast Corner of Carlsbad, California SHELL OIL COMPANY San Diego, California P. 0. BOX 20158 BY LISA ENTERPRTSES, INC. GEO-EXETA LABORATORIES 1786 West Lincoln Avenue Anaheim, California 92801 Suite "E" 776-5900 June 19, 1969 .Job Number F-423-69 Page 1 ot 9 !IO e~idence was found to indicate the existence of any previous structures. ?ill was encountered at depths ranging from two and one-half (2s) feet to three and one-half (33) feet. Graund water was ,~r~,:ount'~re:d at a depth of sixteen (16) feet. I~:xplor-ation Thr. subsurface was explored by drilling three (3) six (6) inch diamntrr borings to depths of fifteen (15) to twenty (20) feet below the existing ground surface. The borings were placed in rjtratpgic Locations where the major buildings are to be construct~d, in a manner to determine the overall subsurface conditions. Locations of the borings are shown on the attached Plot Plan, Plate "A". All of the borings were logged by our field engineer and both undisturbed and dir;turbed samples of the soils encountered were obtainpd €or laboratory testing and inspection. Logs of the Page 2 of 9 GSO-EXETP LAB1 IRATORIES LISA BNTERPRI5ES, INC. ,rOB NUMBER F-423-69 Exphratjon (Cont'd) borings are shown on Plates "B" through "D". The soils are c1a::::iiied in accordance with the Unified Soil Classification .>yst-rn: described on an attached Plate. Also attached is a l'latn showing the type of sampler used in obtaining undisturbed samples. ,. Lnbnratory Testing The tield moisture content and dry densities of the soils encountered were determined by performing tests on the undisturbed samples. Thc results of these tests are shown on the Logs of iiorings, Piates 'ID" through "1)". Density and field moisture infi)rn!atior is useful as indicators of the nature and quality of thr material. ilirect shear tests were performed on selected, undisturbed samples of the soi?~s in order to determine the strengths and supporting capacities of the soils. The method of performing these tests is to extrude the sample into the test apparatus, to zpply the riormal load, and to then allow sufficient time to elapsc to dissipate any excess hydrostatic pressure. The sample i.7 then subjected to a strain-controlled single plane shear trct.. The method of applying the normal and shearing load is such as to allow the sample to change in volume without producing an associated change in the normal stress. The shearing stress Page 3 of 9 LISA ENTERPRISES, INC GEO-J?XETA LABORATORIES JOB NUMBER F-423-69 !.abL:rstory ?‘e:;ting (Cont fd) is mr;.asured at d constant rate of strain of approximately 0.01 inches per minute. .‘~:r.l,.cted samples of soil were tested at confining pressures similar trt those of the materials in situ. Additional :;pc’ci.mens fram the same samples were also tested at increased normal pressures in order to determine the increase in shear strengths associated with increased intergranular pressure. The test results are plotted graphically on Plate “E”. The resulting values are as follows: Sa i I. Type Clayey sand .‘;andy clay Angle of Internal Friction (Degrees) 36 20 (p.s.f.) Cohesion 50 650 Values Used: @ = 36O, C = 50 pounds per square foot Consolidation tests were performed on saturated specimens of the typical foundation soils. Consolidometers are designed to receive the undisturbed soil samples and brass rings in the ficld condition. Porous stones placed at the top and bottom of each specimen permit free flow of water into or from the specimen during the test. L,abor.?tr,ry Testing (Cont'd) .,ucce:ssiiv- l:~ad incrpmcnts were applied to the top of the SF>C?C~T:P~ and progrcssivn and final settlements under sach increment werr' recorded to an accuracy of 0.0001 inch. The final settlements so obtained are plotted to determine curves shown on Plates "G" and "HI'. .- An expar~sion test was conducted on a representative sample of clay soils encountered at depths of two and one-half (2;) to three and one-half (33) feet below the existing ground surface. The method of performing tho test is to confine an air dried sample laterally, subject it to a surcharge of 60 pounds per square foot, saturate the sample and allow it to expand for a minimum of twenty-four (24) hours. The test results are as follows: So i I Type Sandy clay Expansion ($) 8.0 Classification Expansive Page 5 of 9 C011<.1usi~?ns and Rt~a~rnm~ndatir~ns !::>il Conditior~ Mdtr.rial un:Ir-rlying the site consists of a two and one-half (2.:) t? tt1rf.e and cne-half (3;) foot overburden of clayey !:and which is a natural fill excepting a small portion near thc center of the sitr, which is man-made. Underlying the .-:and is i:n approximately nine (9) foot stratum of organic wncly clay underldin by an approximately three (3) foot :stratum (of inorganic sandy clay underlain by a deposit of zarlriy clay to the depth of exploration. I!F’p,.r sandy soils are porous and dry. The organic clay is rrmderat6?ly ~xpansiv~. The sandy clays and clayey sands at 1owr.r dcpths (below twelve (12) feet) are moderately firm. i.’r’~!c. prvund watf?r rxists at an approximate depth of sixteen (16) feet. i)i.::ign It is recommended that continuous footings be usrd to support thr propo.5e.d building. A safe bearing value of 2,000 pounds per square foot may be used for design of the footings provided the recomrnendati\>ns listed under the heading “Grading” are f~oll.owed. Footings should be a minimum of twelve (12) inches wide, emb~dded twelvr (12) inches below the lowest adjacent Page 6 of 9 I'jcesign (Corlt 'd) grade and reinforced by a minimum of two number four (14) rcinf:,rcing bars, one placed near the top and one near the bottom. l~'lot~r slabs should be reinforced by a minimum of 6" x htP, #lo x fl7@ welded wire mesh. I.atnra1 loads will he resisted by the friction between floor slabs and subgrade and by the passive resistance of the soil against footings. A coefficient of friction of 0.4 may be used b'xtween slabs and subgrade. The passive resistance of the sdl may be taken to be equal to the pressure developed by a fluid with a density of 700 pounds per cubic foot. Active lateral soil pressure may be taken to be equal to the pressure developed by a fluid with a density of 49 pounds per cubic foot. Grading Prior to general grading operations, the construction areas shduld he stripped of all vegetation and other deleterious material. It is recommended there be two (2) feet of compacted soil under footings and one (1) foot under the building slab. Compacted depth under footings should extend ior a distance of five (5) feet on each side of the footing. Page 7 of 9 GEV-EXETA I,AI1ORATC'~RII.'S LISA ENTEl?PRISES, INC . JOB NUMBER F-423-69 !:radjng (Cdnt'd) .!?xcavati.,ns of six (6) inches under the slabs and two and :,n;-half (2)) feet along footing lines will be necessary. ,. ,civatinn - bottoms should then be scarified to depths of sjx (6) to eight (8) inches, watered or dried to near optimum moisture content and recompacted to a minimum of SO$ of- the maximum dry density obtainable by A.S.T.M. Penignation 1) 1557-66T Method of Compaction, modified to three (3) layers. F'ill and backfill should be placed in a maximum of six (6) inch loose layers and compacted to at least 90% of the above specifii.d standard at near optimum moisture content. Subgrade in paved areas should be scarified to depths of right (8) to ten (10) inches and recompacted to at least 90$ compaction at near optimum moisture content. Additional fill should be similarly compacted to 90% compaction. Clay excavated for fuel tank placement may not be used as fill material on the site. (All import soils should be grariular and non-expansive. Flexible paving should have a minimum section of three (3) inches of AC over four (4) inches of Aase Rock compacted to a minimum of 95% compaction. 1 Page A of 9 Grading (Cont Id) /;I1 grading operations should be performed under the supervisj.:~n of a qualified soils engineer. The rrcornmendations contained in this report are based on the results of specific field and laboratory investigations as noted. If conditions are encountered during construction that appear to be contrary to the findings of this report, this office should be notified so that proper modifications may be made. A J /. & .,< ,” - ~ “ Hv: I)avo Andcrson. Staff Engineer .- Reviewed by: D. E. Goss, P.E., C-12037 Respectfully submitted by: r'r I I Plate "A" J , '1 I CL Tan fin- sandy clay Medium moist, medium firm. Light gray clayey sand. Very Ground water. Uepth of undisturbed sample Depth of bag sample 6 . 9 7.5 722.0 96.2 Vertical Scale: 1" = 3.0' Man made fill. OH Black fine to course sandy clay. Medium moist, medium firm. 13.2 16.6 112.7 108.0 CL Fine sandy clay. Medium moist. medium firm. Depth of undisturbed sample Vertic~l Scale: 1" = 3.0' Plate "C" GI.:O-i*:XETA LABOiblTOHTES LISA ?;NTERPRTCES, INC. JOB mrMnm F-423-69 l3OIlING THREE Dry Density Cl~assification Moisture (p.c.f.1 SC Tan clayey fine to medium 1.5 99.9 sand. Pry, firm. Wind or alluvial fill. OH Fine to course sandy clay. Medium moist. medium firm. CL Fine sandy clay. Medium moist. medium firm. Depth of undisturbed sample Vertical Scale: 1” = 7.0’ + DIRECT SHEAR TEST i -i P late "E" BORING TWO AT FIVE FEET CONSOLIDATION TEST DATA 0 Y LOAD, KIF'; c 9 9 w PER SQUARE WT I30RING TJIREE AT ONE FOOT CONSOLIDATION TEST DATA + I Y ? 9 ? ? 0 c N .r LOAD, IC1 ? PER SQUARE FOOT 501L CLA 5 5lFlCATI OU CHART