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Home My WebLink AboutCT 72-18; CT 72-18; Soils Report; 1972-07-31PRELIMINARY SOIL INVESTIGATION BDIVISION CARLSBAD TRACT 72-18 CARLSBAD, CALIFORNIA FOR J.W. KLUG DEVELOPMENT CO., INC. 4540 CAMPUS DRIVE NEUIPORT BEACH, CALIFORNIA 92660 31 JULY 1972 wm \ A "pI$ m@A SOIL AND MA’l-J.CRIAL ‘l-I.CYTING LABORATORY nC Ll”DIY rnl,UN #Mr SOIL AND MATERIALTESTING LABORATORY OF NORTH COUNTY. INC. ,- 31 July 1972 423 HALEAVE.- ESCONOIOO. CALIF. 92025 ESC0N0I00 -746-2333 3. W. Klug Development Co., Inc. 4540 Campus Drive Newport Beach, California 92660 Re: Job No. Proposed Carlsbad Carlsbad 72-74 Subdivision Tract 72-18 , California Gentlemen: Enclosed is our report of the preliminary soil investigation done in accordance with your instructions for the above refer- enced sits. The investigation consists of 13 test pits dug with a back- hoe to depths of 6 to 10 feet below the existing ground surface. The stratigraphic profile was verified by visual inspection of the ravines and numerous outcrops. Appropriate laboratory testing and engineering analyses were performed. The results of this investigation along with our recommen- dations are to be found in the accompanying report. We would welcome the opportunity to meet with you and the grading contractor before start of work to discuss the report and the grading operation. Respectfully submitted, SOIL AND MATERIAL TESTING LABORATORY OF NORTH COUNTY, INC. t Registered Civil Engineer #18,987 Registered Geologist #512 TABLE OF CONTENTS I. II. III. IV. V. VI. VII. VIII. General Information Purpose of Investigation Field Investigation A. Surface Conditions B. Test Pits C. Subsurface Conditions Tests and Results A. Grain Size Analyses B. Expansion Tests C. Density Tests D. Direct Shear Test Bearing Capacity Slope Stability Conclusions and Recommendations Reference Page 1 k APPENDIX Plate Plot Plan 1 Logs of Test Pits 2 to 14 Slops Stability 15 Specifications for Construction of Controlled Fills Unified Soil Classification Chart SOIL AND MATERIAL TESTING LABORATORY nr UrlDIY C”llUN 0-r PRELIMINARY SOIL INVESTIGATION PROPOSED SUBDIVISION CARLSBAD TRACT 72-18 CARLSBAD, CALIFORNIA I. GENERAL INFORMATION A preliminary soil investigation has been completed far the proposed subdivision of Carlsbad Tract 72-18 legally described as a Portion of Lot I, Rho Aqua Hedionda, City of Carlsbad, County of San Diego, State of California. It is understood the site is intended to be developed for one and two story wood frame residential structures. The foundations will consist of concrete floor slabs and continuous concrete wall footings. Based upon the map given us by Klema Engineers, Inc. dated 6/27/72 the maximum cuts and fills should be lees than 30 feet. The subdivision will be developed in three units for a total of 159 lots. II. PURPOSE OF INVESTIGATION The purpose of this investigation is to determine the following: 1 - the existing soil conditions, 2 - the presence and effect of any expansive soils or existing fill, 3 - the allowable soil bearing pressure, 4 - the presence of near surface bedrock, 5 - the stability of the proposed slopes, 6 - any obvious geologic hazards, 7 - any construction problems that can be anticipated, and to make appropriate foundation recommendations. -111. FIELD INVESTIG~ATION A. Surface conditions The shape and surface of the subject sits is irregular and can SOIL AND MATERIAL TESTING LABOKATOHY or hl0rn-r” CnUNN. 1N11. beet be described by Plate 1 (from the Tentative Map by Klema Engineers, Inc., Escondido dated 6/27/72). The approximate contours shows there is one main wash in the center which drains the area from the northeast to the southwest. The general relief can best be described as canyon-like topography urith several vertical banks indicating the general firmness of the strata. There are no buildings or other man-made structures on the property which oould hinder grading. B. Test Pits Thirteen exploratory test pits were dug with a backhoe on IS July 1972 to collect samples and confirm the stratigraphic profile seen on ravine banks and outcrops throughout the site. Disturbed and undisturbed samples of the soils excavated were obtained for laboratory analysis. The soils were visually classified by field identification procedure in accordance with the Unified Soil Classification. A simplified version of this classification is included at the end of this report. Continuous logs of the soils encountered during the investigation were recorded in the field. The logs of the test pits shown on Platss 2 to 14 are ba.sed on the field logs, on laboratory inspection of the samples, and on the soil test results. C. Subsurface Conditions The soils on the site to the depth of interest for this project consist of recent marine sediments ranging in texture from silty sands and weakly cemented sandstones to sandy clays and clayey sands. No durable bedrock that would require blasting was encountered. There was no soft compressible material revealed during the in- vestigation. The soils found during the investigation have been grouped SOIL AND MATERIAL ‘I’RSTING LABORATORY m.? .,-m-P” _m....- .-.e into seven soil types based on similar engineering properties as indicated below. The distribution and other pertinent details are elaborated on in the.logs, Plates 2 to 14. SOIL DESCRIPTIONS Soil Soil Descriptions Unified Soil Type Classification 1 Brown Silty Medium Sand - alluvial SM 2 Brown Clayey Sand - alluvial SC 3 Dark Gray Silty Sand - topsoil SM 4 Red Brown Silty Sand - weakly cemented SM 5 Light ,Green Clayey Sand SC 6 Light Green Siltstone ML 7 Dark Gray Sandy Clay CL Generally speaking, the granular sandy materials appear stable in their native condition and will make good fill material. The clayey soils will require special preparation as discussed under Section VII, "Conclusions and Recommendations". IV. TESTS AND RESULTS A. Grain Size Analyses Eight grain size analyses were performed on the soils encountered in general accordance with ASTM D422-63 for classification purposes and as a guide to the engineering properties. The results follow: GRAIN SIZE ANALYSES Location Soil Percent Passing U.S. Standard Sieve No. Unified Soil Type 4 10 40 100 200 Classification *TP 12 Q 2' 1 99.2 97.5 74.1 39.0 27.7 sm TP 2 Q 93' 2 100.0 99.3 67.6 44.8 40.3 SC TP 6 Q +' 3 100.0 99.8 72.3 31.3 24.2 SM -~ TP3Q2' ,4 100.0 99.9 78.5 21.4 13.4 SM TP B Q 4' 4 100.0 99.4 78.2 .51.2 42.2 s m TP 11 Q 4+' 5 100.0 99.6 69.3 25.4 12.7 SC TP 4 @ 2'- ; 100.0 99.4 79.2 46.5 28.5 mL TP 7 Q 3' 100.0 98.8 79.1 59.0 52.2 CL SOIL AND MATERIAL TESTING LABORATORY *TO _ T-c+ q i+ cl* N(IRTH COUNTY. INC. These tests indicate a uniformity in the granular soils. ,- B. Expansion Tests Three expansion tests were performed on the clayey soils found during the investigation, Soil Types 6 and 7, to determine if these materials would constitute a structural hazard to the buildings with respect to volumetric soil change. The test labeled "remolded" in the results below was performed on a sample remolded to 90% of the maximum dry density at optimum moisture content. The other tests were performed on "undisturbed" samples. In all cases the tests uere done on 23 inch diameter 1 inch high ring samples luhich were first air dried. The samples mere loaded with 1 psi, instrumented, air dried,and then submerged in distilled water until the expansion stopped. The percent of expansion was recorded as the ratio of the final change in height to the initial height. EXPANSION TESTS Location Soil Test Initial Air Dry Saturated Percent Type Type UI zf W d W ,Y Expansio *TP 4 Q 2' 6 R 11.5 112.2 3.5 112.8 17.4 115.8 3.2 TP 4 Q 4' 6 U 8.3 122.4 2.7 124.3 15.6 117.2 4.6 TP 7 Q 3' 7 U IO,. 3 113.3 6.9 114.1 25.6 97.5 16.2 *TP = Test Pit U = undisturbed sample R = remolded sample w = moisture content ($) x = dry density (pcf) These tests show Soil Type 6 is moderately expansive while Soil Type 7,which is found in a little swale near Test Pit 7, is highly expansive and special precautions as outlined in Section VII SOIL AND MATERIAL TESTING LABORATORY Dr NORTH CDUNTY. INC. should be followed when encountered during grading. D. Density Tests 'I - Laboratory Compaction Three laboratory compaction tests wers performed on proposed fill soils to determine the maximum dry density and optimum moisture content as specified by ASTM D1557-64T (method A). This test uses the minus #4 sieve soil in a 4 inch diameter 4 inch high cylinderical mold. The sample is formed with a 10 pound hammer falling 18 inches for 25 blows on each of 5 layers. LABORATORY COMPACTION Location Soil Type Max.Dry Optimum Density Moisture (pcf) Contents ($) Test Pit 3 Q 2’ 4 124.0 11.3 Test Pit 11 Q 4*' 5 120.7 11.8 Test Pit 4 Q 2' 6 125.6 11.2 2 - Field Density Tests Four field density taste lucre taken in various strata to determine the natural conditions of moisture and density. The tests were performed according to ASTM D1556-64, the sand cone method. Moisture contents and densities mere also determined by direct measurements from the undisturbed samples. The ratio of the field dry density to the laboratory maximum dry density is defined as the relative compaction. Thsse results are presented on the logs, Plates 2.to 14. E. Direct Shear Tests Direct shear tests were performed on representative samples of Soil Types 4 and 5, the lightest granular foundation material. Three SOIL AND MATERIAL TBSTING LABORATORY OF NORTH COUP4l-Y. INC. i specimens of each soil type were prepared by remolding the soils in 2$ inch diameter 1 inch high rings to 90% of the maximum dry density at 3% over optimum moisture content. These conditions a,pproximate the compacted fill. The specimens ulare loaded luith normal loads of . 5, 1.0, and 1.5 KSF respectively and sheared to failure in the undrained condition. The results follow. DIRECT SHEAR TEST Location Soil Dry Angle of Apparent Type Density Internal Cohesion pcf Friction (0) (psf) Test Pit 3 Q 2' 4 111.6 35 200 Test Pit 11 @ 43' 5 108.6 34 200 V. BEARING CAPACITY The values of internal friction and apparent cohesion derived from the direct shear tests were used in the Terzaghi Formula in accordance with the procedure outlined in Reference 1, page 170, to compute the allowable bearing capacity. Terzaghi Formula: Bearing Capacity = 2/3cNlc + dDfN1o + *#BN; Assumptions Depth of Footing, Df = 1.0' Width of Continuous Footing, B = 1.0' Nlc, N' q' N; = dimensionless parameters found from Fig. 75, Ref. 1. Factor of Safety = 3. ALLOUJABLE BEARING CAPACITY Soil Soil Description Bearing Type Capacity (psf) 5 Light Green Clayey Sand 1607 8011. AND MATlCltIA~L TKSTING ~Lil3OiL4TOI<Y OF NDRTM COUNTY. INC. VI. SLOPE STABILITY .- A slope stability analysis was made on an assumed 35 foot height of Soil Type 5 with strength parameters from the direct shear test. A slope ratio of I* (horizontal) to 1 (vertical) wae used. The analysis was done in general accordance with 'the slip circle method as described in Refaranca 1, Art. 31. An earthquake force of . 1 times the mass weight was used, how- ever, seepage forces wers not considered applicable. The Janbu chart method, Reference II, was used to locate the critical circle. The distances used in the computations wera scaled from the enclosed Ulorksheet. The calculations yield a factor of safety of 1.4 which is considered safe for cut slopes in the natural material. -T I. CONCLUSIONS AND RECOMMENDATIONS 1 - It is recommended that the preparation of the native soil and all grading be done in accordance with the enclosed "Specifications for Construction of Controlled Fills" except where superseded by the following recommendations. 2 - Loose surface soils in areas of shallow fill and orig- inal grade should be excavated and recompacted to at least 90% of the maximum dry density. The approximate depth of loose soil is in the order of one to two feet as shown on the logs. The exact depth of recompaction should be determined by a qualified soil engineer in the field during the initial pra- :paration. 3 - The expansive soils such as Soil Type 6, in the vicinity - of Test Pit 4, Soil Type 7 near Test Pit 7, and the stockpiled material in the southwest corner should be kept at least 24 feet from SOIL AND MATERIAL TESTING LABORATORY QF NORTH EOYNTY. INC. final grade. There should be ample nonexpansive granular material on site to cover the undercut clay lots. Conventional concrete footings may be used if all lots are covered with the nonexpansive soil. 4- As an alternative to covering the clay lots with nonex- pansive soil it is recommended that these areas be excavated to a depth of 23 feet below final grade and recompacted to 87% to 92% of the maximum dry density and at least 3% wet of optimum moisture content. The foundations should usa the following minimum design. a - Extend the footings 2 feat below the lowest adjacent ground level. b - Use two #5 reinforcing rods. Place one rod 4 inches from the top of the footing and the other 4 inches from the bottom. c - Use 6x6/10x10 wire mesh in a 4 inch (actual) thick slab. d - Use 5 inches of pea gravel, a plastic liner, and one inch of clean sand under the slab. If the pad has been allowed to dry after grading, it should be presaturated prior to casting the slab to attain the proper moisture content and limit expansion. To presaturate the pad, dig the footings slightly above the final depth, and cover the pad with the gravel. Soak the pad until the gravel is saturated and there are several inches of water in the trenches. Cover the gravel with the plastic liner, extend to the bottom of the trench, place the sand, and allow the pad to stand for several days. Ulhen the correct moisture condition has been attained, as determined by the soil engineer, the trenches should be mucked to firm material and the concrete poured SOIL AND MATERIAL TESTING LABORATORY OF NDRTH CDUNTY, INC. within two days. The operation should be supervised by a qualified soil engineer who may modify the above procedure depending upon field conditions. 5 - Slope ratios of 13 (horizontal) : 1 (vertical) and 2:l may be used for cut and fill slopes respectively. A constant check will be made by a qualified geologist during grading to inspect the cut slopes for thin clay seams or other adverse geologic conditions and to make appropriate corrective recommendations. 6 - If our recommendations are followed, a one foot deep, one foot wide, continuous concrete footing may be safely designed to sustain a uniform load of 1600 psf. Footings located closer than 5 feet from the top of the slope should be extended in depth until the bottom edge of the footing is 5 feet horizontally from the outside face of the slope. 7 - If soils are encountered during the grading other than those described in this report, or if imported fill is used, additional tests will be required to ascertain their engineering properties. B - It is recommended that a meeting between the owner, grader, and this laboratory be held prior to grading to discuss the report and the grading operation. VII. REFERENCE 1 - Terzaghi and Peck, Soil Mechanics in Enqineerinq Practice, John Wiley, N.Y., 1948. SOIL AND MATERIAL TRSTING LABORATORY OF NORTH COUNTY. INC. 2- Janbu, N., Journal of the Soil Mechanics and Foundation Division, A.S.C.E., Vol. 93, No. SM6, Nov. 1967. Respectfully submitted, SOIL AND MATERIAL TESTING LABORATORY OF NORTH COUNTY, INC. Claude B. Parker Registered Civil Engineer #IS,987 Registered Geologist #512 pe Distribution: 8 Addressee SOIL AND MATERIAL TICSTING LABORATORY DF NORTH COUNTY. INC. r on bottom of wash grades clean ---- bG OF BORING ..--__.- . ..-.. - alluvial - firm maintains vertical bank Field Density Test SOIL & MATERIAL TESTING-LADORATORY OF Nc.rtTH COUNTY INC. .- ,- 0 Cliff Exposure 0 to 3' Brown Silty Medium Sand : : : : : : : j : :j alluvial .:.:: l- ; SMlii maintains vertical bank ::,:: :j::: 2- : ':: .:::. .:::: : i I j ; i ; : : 3 .:::: on bottom of wash '. 4 grades clean ,% (. loose '. 5- ' '. , z 6- .'. 7- 5 .' ' 8 Soil Type 1 : '~ Brown Clayey Sand moist 9- : 0 moderately soft IO- 11 - 12 - 13 - grades sandy Soil Type 2 Bottom )a~: 18 July 1972 Klug - Carlsbad Tract 72-18 Job No. 72-74 iy: C. Parker Carlsbad, California Plote No. 3 SOIL & MAYECJIAL TESTING-LADGQATQQY 0, NORTH COUNTY INC. - LOG OF BORfNG - BORING NO. Tpst Pit. $5 ; u= z 2: 2; - 6 i;', > ,- 32 .a?” $2 ELEVATION SAMPLING 2 Li$ ;, g 2 2 z> $ $4 METHOD Backhoe ds 00 C- 2; CJd G9. k Q ".- 0s :!z A Dark Gray Silty Sand - topsoil : : : loose, dry : 'sm' ; 1~ Soil Type 3 i ;,:i Red Brown Silty Sand : : j : : : 2,a 0 : : : j weakly cemented : : : : t2.3 : : j 93.8 l75.6 3 4 i : : jii.. :I : : : ::::: :...: : : : j:,/: . : : I : .:;:: i : jii : ; 11 Soil Typ a 4 2;; Bottom )cJe: 18 July 1972 Klug - Carlsbad Tract 72-18 'ObNo. 72-74 Carlsbad, California Plate No. 4 SQIIL d;r MATEQIAL TES71NG-LADOQATODY OF *caRTI' E""?‘," '*<'. - ,- _.__-- ~-__~ LOG OF BORING BORING NO. TpSk pit #4 z c "'1 - ELEVATION $2 fs: %Z $2 mu SAMPLING Backhoe r; METHOD - 3ark Gray Silty Sand l- Light Green Clayey Sand weakly cemented Light Grean Siltstone - firm 11.6107.L-e5. 3- 4- A ML 5- 6- difficult digging Soil Type 6 Bottom 7- 8- 9- 'ate: 18 July 1972 Klug - Carlsbad Tract 72-18 'ObNo. 72-74 Y: C. Parker Carlsbad, California Plate No. 5 SOIL & MATERIAL TESTING-LADORATORY OF NORTH COUNTY INC. _~~_ - - ___.. _,--.. ---.- .._. ~.. -~.-~_. LOG OF BORING z "CL + 8: !Ge 22 $2 $2 ‘ou ;pEy$. Test p-y-y--J SAMPLING Backhoe I> i g METHOD 2 oo s $2 :;9 gz j 2 EI~OW~ Silty Medium Sand ::; ;I ::: :: : ii:: : : : l- ::. .:::: i sIyi; 2-a controlled fill : : : :j ::i:: 8.0 103.C : ; : : ;:I:: :. :: 3- : : : : : : :,: .: ::::: 4 Soil Type 1 ?{i Red Brown Silty Sand ::::: . ...! :: j: 5- 0 Native il. :I:;; firm :;.:: ;: { 6- ii,; j:. ,. :;:: ; . 7- weakly cemented ; SM': .,, : :'I :;:jj 8- I:!:: : ii. .: ::j ;: 9- ::. .: : : : j: ::: . . ::.:: ::: 1: IO Soil Type 4 Yj;: Bottom Sand formation continues at least 12' below top of ravine south 1 I hh: 18 July 1972 Klug - Carlsbad Tract 72-18 'ObNo' 72-74 3~: C. Parker Carlsbad, California Plate No. 6 SOIL t& MATERIAL TESTING-LABORATORY OF NORTH COUNT” INC. i d -__.~ ---- _~~_~._~_ LOG OF BORING cl I! 2- 3- 4- Dark Gray Silty Sand - topsoil loose, dry to 18" : SM : ,. .: : : : : :i i:: : : : : : Soil Type 3 ii iij Red Brown Silty Sand : : : : : j : : : : . . weakly cemented ;:: : . 5- cl 6 ;j I:: .: ;:: :: 1:: : : : : ,:: 7----l Tyne 4 I:.:: :;::I Bottom )ate: 18 July 1972 Klug - Carlsbad Tract 72-18 JobNo. 72-74 iy: C. Parker Carlsbad, California Plate No. 7 SQIL dir MATERIAL TESTING-LABORATORY or NORTH COUNTY INC. 1 lark Gray Sandy Clay y cil’: dry, brittle Soil Type 7 /,A _,,I - - 2 D .ight Green Clayey Sand weakly cemented 3 grades with light green coarse sand, weakly cemented 4 5 grades with streaks of yellou~ coarse sand 6 ,7 8 9 IO - 0 Soil Typ e ! Bottom - - )ak: 18 3uly 1972 Klug - Carlsbad Tract 72-18 'ObNo. 77-7Li 3y: C. Parker Carlsbad, California Plate No. 8 r c _____.- _..-~-.-_~ ~~__-.~..----.-. - .,._. -., .~~ .~. ~...~. LOG OF BORING - I BORING NO. Test Pit #7 e $2 ELEVATION -” SAMPLING METHOD Backhoe - SOIL & MATERIAL TESTING-LABORATORY OF NOllT” COUNTY INC. l- LOG OF BORING 1 2 3 4 5 6 7 8 9 IO - 0 cl - - c 23 zdg - BORING NO. Test Pit #8 ELEVATION --- SAMPLING METHOD -uchho 0 6 i lark Gray Silty Sand I. ST loose. dry Soil Type 3 !.I~. : : Red Brown Silty Sand : : : : ;.a: , weakly cemented : : : :::: 1: : : : j : :,;: ::.: : : ; ; : ! ; I . . i j j/i : . : ':I: : : : : . .:.. I j::: ::., : : 1 :,. ,I difficult digging Soil Type 4 Bottom Exposures on surrounding 10 to 15 vertical cliffs show brown sandy formation above 30% 18 July 1972 Klug - Carlsbad Tract 72-18 By: C. Parker Carlsbad, California 1; SM' - - ob No. 73-76 L z r, ,., I- ( ,I ‘;, ‘i 2: ‘3 lofe No. 9 SGIL & MATERIAL TESTING-LAUGRATGRY OF NORTH COUNTY INC. - - A 0 LOG OF BORING - - BORING NO. Test Pit #9 ELEVATION SAMPLING METHOD Backhoe Red Brown Silty Sand weakly cemented Dark Gray Silty Sand loose, dry q Soil Type 3 i. ., : : ,,- ::: ii:,, : ,;j:, : ::_., : ‘,, difficul t digging soj - - - ‘ate: 18 July 1972 Klug - Carlsbad Tract 72-18 ‘ObNo. 72-74 sy: C. Parker Carlsbad, California Plate No. IO SGIL iy MATeRlAL TtSTlNG-LADGRATGRY OF NORTH CDUNTI INC. LOG OF BORING On conspicuous white hill Test Pit #IQ Light Green Clayey Sand weakly cemented i 1 2 3 4 0 1 2 3 4 5 t 7 E s difficult digging Soil Type 5 j:;:::.::($? Bottom I , A - IO' away in surale : :I’ : ;I r--T ;, s rfl ’ A Dark Gray Silty Sand - topso Ii1 loose, dry Soil Ty 7 Brown Silty Medium Sand alluvial ppe 3 ,‘I.,.,., .1 :j::: - - :.... . :, ::.. ..,. .:::. _:: .:I .:: : :, ., : ::::. :: ,, : : :I:.. :/ : i ./: : I SM,:i : : : : : : ::::. :‘:” :,:: ::.:: . ’ : : : !I : ::,, : : 1::: : : : : : : : : : : : ,;;. <nil T e j.;.:,z! .dYLi Light Green Clayey Sand weakly cemented difficult digging - - Soi1 Type 5 - n 1 - - - July 1972 J Klug - Carlsbad Track 77-1~1 J&No. 77-74 ^ ., .---_ .- .- - ! by: C. Parker 1 LarlSDSd, Jalifornia Plotr No. ‘1 A - - hk: 18 ; SOIL & MATERIAL TESTING-LADGRAlRRY OF NORTH COUNTY INC. s- LOG OF BORING z_+- g; z - 1 2 3 4 5 - - - - 0 - - BORING NO. Test. Pit. #L-l.1 ELEVATION SAMPLING METHOD RnrkhnE difficult digg ing Snil Tvnn 5 ;;::,.,.. (. ,I ,.';",. Bottom Red Brown Sil,ty Sand y&m, Light Green Clayey Sand weakly cemented me: 18 July 1972 Klug - Carlsbad Tract 72-IE BY: C. Parker Carlsbad, California 6.4 9.7 ,2.6 - ob No. 72-74 late No. 12 SOIL di MATERIAL TESTING-LADORATQRY OF NORT” COUNTY INC. I-- / LOG OF BORING - lark Gray Silty Sand - loose,dry : plz- ;SM : : Irow Silty Medium Sand ::j: :::; : . . alluvial :::: :::: lj : : firm : : . : ;SM : : : : . ::jj : : : : : : ; i:j! i;:: . j : :::j " : Soil Type 1 ! :i; 6 - l- Bottom BORING NO. Test Pit #I 2 ELEVATION SAMPLING METHOD Backhoe - 4 5 E:lE I July 1972 'Klug - Carlsbad Tract 72-18 *y: C. Parker Carlsbad, California - - - - ob No. 72-74 I late No. 13 SQIL & MATItRlAL TESTING-LABORATC)RY 0, NORTH COUNTY INC. LOG OF BORING -I- / I L BORING NO. TPet Pit. #I7 ELEVATION SAMPLING METHOD Backhoe cc w- 2.2 $2 - - n )ark Grav Siltv Sand - loose, dry i’snlr I Soil Tboe !5 ._ ied Brown Silty Sand weakly cemented soil Type 4 1 .ight Green Clayey Sand - cobbles : weakly cemented E very difficult digging Soil Type 5 , n SM P ,: : ;. : : _' : ..' .:; _: fl : : : ,;. j i/:2 SC: @ ;:; :::,. :' : '_.,.',. g ::, ,:.:,: ;:. :.:: ,..',.",.. :,. A - - - - - Bottom white formation seen in exposure to south to extend at least 2 25 to elevation of level ground belo Klug - Carlsbad Tract 72-18 ob No. 72-7Q Carls~bad, California late No. 14 )Q'C 18 July 1972 'y; C. Parker SOIL & MATERIAL TESTING-LAGORATORY OF NORTH COUNTY INC. SCXLE d l HM. 0!5T. TO CEN-l-F?JID X . VEf2-X 015T. 10 CENlROlD h * HEIGKl- OF SLICE II~LENGTHcFARCH CC l ANGLE SLOPE STAB1LI-W ANALYSIS ASSUME CALCULGTE c$ = ANGLE OF INTERNPL FRICTIGN(“) W z WEIGHI-= bh8 & = UNIT CG-IESION (paf) C - COHESIQN = LP tl = UNIT WEIGKT MIL ( pcf) $J ’ HEIGHT OF WATER b . WIDTH OF SLICE R. RADIUS VW@ UNIT WEiGKT WA-I-ER(pcf) MOMENTS RESISTING = FFcrm OF sAFETY = MOMENTS DRIVING R&2) + R(b tm.0~ (hX+.!+) t0s.a d(bhW)+X(.ibhW) \ ~~~A~DMA~R~ALTESTI~GLAI~~RATOR~ oc NDF1T" DOUNN, INC. TANBU ANALYSIS: 4s 34. H=35’ c .2oopsf: SLOPE r&-r Y = 109 PCC. h,,=v a 12.4 xn -4’ Yo67’. ~ ‘SC&E , “:20 : ,, ~... .~~~- .~~._. . . ~.,~~ _, I Y _~ .^_ ._..... . . . --_ // ,/’ ’ .+ ,/ ’ i.l ,,I’ l ? 7 , .’ ,l’ f / I ,! L-. ,_ 1 t)OIL AND MATISRIAL TESTINO LABORATORY ^_ ..^m-” ^^..u- .I^ .T,,R A!.? 71.7 x . . z . . > % 3 :< i 7 :.: 5 ti 2 > ; ” T! ” .” .y z : -: < 2 -7 3 ., i :: 3 z i I u :: c: .!.ICE --..- 1 2 3 ~-_- 4 -~-- --. ) Sl OPE STAOII n-Y ANAl...~~~YS~~~ - _ __.^ -__. ~_____--.._--~_l.- I_., _.~I- c$= 340 x= 109 ,; :;, _ A-LWI,.~ I-'!!? !~2!d% !, ~~.-_'Jxiv.lcos-5 cj (bllS) + y (.I bhY) tan.4J = .675 &= x C== 200 b: 20 R= 76 14 26 22 13 --, _.-.- _.-__-_. Q(c.k> !I 2,8 0 --- 19520 -. $34401 i97,6Ol . 0 ~IY 0 0 0 03 _. ..-.. h 1/z= 5 _~~~- 13 _~-- 11 ---~ h/2: 4 IO FS -- 11 Y -~- 545 417 199 -~ 436 1, - 21~1 _-.~_ .-.- ‘S -._~ ~O,O -.~ - ~---. -.~ - ~---. __, -__ ---- __, -__ ---- -- -- 36 36 .809 1417 .809 1417 19 19 ,946 1199 ,946 1199 1134 1134 1,163,48L 1,163,48[ b=13 b=13 9 9 .988 436 .988 436 430 430 286,767 286,767 ___ ~__ -..--. ___ ~__ -..--. .__ ~~~ ._~._.._ ~__--._--~ .__ ~~~ ._~._.._ ~__--._--~ 2,985,14-i 2,985,14-i .~~_ _.^ - --. --- .~~_ _.^ - --. --- I + 2,985,147 .= I + 2,985,147 .= 4,'25,147 = 1.4 4,'25,147 = 1.4 '+- -~ '+- -~ go3 ) 038-.---3,r1-4l~L- __ go3 ) 038-.---3,r1-4l~L- __ .-..-- .-..-- (bhX) -. -.- 0,9oc ----. ,8,34C -___- 5,98C 5666 _ ..-. ~. _, ..-. 59 46 _-.-.. 26 12 2 i -- t’hx) d ~_--. - 43;101 .__. 3436s 23481 8,011 638,: ---- --- 44 5 ..- 6 7 5 ,~- _~.-..__~__i L,;s;(.V%;, , .7,96Ci! 53036 --~--. 69666 41376 -- i,O38 ~---. ~_ SOIL AND MATERIAL TESTING LABORATORY OF NORTH COUNTY. INC. 423 HALE AVE.-- EeCONo,oO. CALIF. 92015 EeCONo,DO - 746-2.333 SPECIFICATIONS FOR CONSTRUCTION OF CONTROLLED FILLS GENERAL DESCRIPTION: The construction of controlled fills shall consist of adequate preliminary soil inv'estigations, and clearing, removal of existing structures and foundations, preparation of land to be filled, excavation of earth and rock from cut area, compaction and control of the fill, and all other work necessary to complete the grading of the filled areas to conform with the lines, grades, and slopes as shown on the accepted plans. CLEARING AND PREPARATION OF AREAS TO BE FILLED: (a) All fill control projects shall have a preliminary soil investigation or a visual examination, depending upon the nature of the job, by a qual- ified soil engineer prior to grading. (b) All timber, trees, brush, vegetation, and other rubbish shall be rs- mowed, piled and burned, or otherwise disposed of to leave the prepared areas with a finished appearance free from unsightly debris. (c) Any soft, swampy or otherwise unsuitable areas, shall be corrected by drainage or removal of compressible material, or both, to the depths in- dicated on the plans or as directed by the soil engineer. (d) The natural ground which is determined to be satisfactory for the support of the filled ground shall then be plowed or scarified to a depth of at least six inches (6") or deeper as specified by the soil engineer, and until the surface is free from ruts, hummocks, or other uneven fea- tures which would tend to prevent uniform compaction by the equipment to be used. (e) No fill shall be placed until the prepared native ground has been approved by the soil engineer. (f) Ulhere fills are made on hillsides with slopes greater than 5 (hori- zontal) to 1 (vertical), horizontal benches shall be cut into firm un- disturbed natural ground to provide lateral and vertical stability. The initial bench at the toe of the fill shall be at least 10 feet in width on firm undisturbed natural ground at the elevation of the toe stake. The soil engineer shall determine the width and frequency of all suc- ceeding benches which will vary with the soil conditions and the steep- ness of slope. (g) After the natural ground has been prepared, it shall be brought to the proper moisture content and compacted to not less than 90% of max- -imum density, A.S.T.M. D1557-64T. - (h) Expansive soils may require special compaction specifications as directed in the preliminary soil investigation by the soil engineer. (i) The cut portions of building pads in which rock-like material exists may require excavation and recompaction for density compatibility with the fill as directed by the soil engineer. MATERIALS: The fill soils shall consist of select materials graded so that at least 40 percent of the material passes the No. 4 sieve. The material may be obtained from the excavation, a borrow pit, or by mixing soils from one or more sources. The material used shall be free from vegetable matter, and other deleterious substances, and shall not contain rocks or lumps greater than 6 inches in diameter. If excessive vegetation, rocks, or soils with unacceptable physical characteristics are encountered, these materials shall be disposed of in waste areas designated on the plans or as directed by the soil engineer. If soils are encountered during the grading operation which mere not reported in the preliminary soil invest- igation, further testing will be required to ascertain their engineering properties. Any special treatment recommended in the preliminary or sub- sequent soil reports not covered herein shall become an addendum to these specifications. No material of a perishable, spongy, or otherwise unstable nature shall be used in the fills. -PLACING, SPREADING AND COMPACTING FILL MATERIAL: (a) The selected fill material shall be placed in layers which shall not exceed six inches (6") when compacted; Each layer shall be spread evenly and shall be thoroughly blade-mixed during the spreading to insure uniformity of material and moisture in each layer. (b) UJhen the moisture content of the fill material is below that speci- fied by the soil engineer, water shall be added until the moisture con- tent is near optimum as determined by the soil engineer to assure thor- ough bonding during the compacting process. (c) Ulhen the moisture content of the fill material is above that speci- fied by the soil engineer, the fill material shall be aerated by blading and scarifying, or other satisfactory methods until the moisture content is near optimum as determined by the soils engineer. (d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than the specified maximum density in accordance with A.S.T.M. D'l557-64T. Compaction shall be by means of tamping or shespsfoot rollers, multiple-wheel pneumatic-tired rollers, or other types of rollers. Rollers shall be of such design that they will be able to compact the fill to the specified density. Rolling of each layer shall be continuous over its entire area and the roller shall make sufficient passes to obtain the desired density. The entire area to be filled shall be compacted to the specified density. SOILANDMATERIALTBSTINGLABORATORY OF NORTH COUNTY. INC. 9 -(s) Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting operations shall be continued until the slopes are stable but not too dense for planting and until there is no appreciable amount of loose soil on the slopes. Compacting of the slopes shall be accomplished by backrolling the slopes in increments of 3 to 5 feet in elevation gain or by other methods producing satisfactory results. (f) Field density tests shall be made by the soil engineer for approx- imately each foot in elevation gain after compaction, but not to exceed two feet in vertical height between tests. The location of the tests in plan shall be spaced to give the best possible coverage and shall be taken no farther than 100 feet apart. Tests shall be taken on corner and terrace lots for each two feet in elevation gain. The soil engineer may take additional tests as considered necessary to check on the uniform- ity of compaction. UJhere shespsfoot rollers are used, the tests shall be taken in the compacted material below the disturbed surface. No additional layers of fill shall be spread until the field density tests indicate that the specified density has been obtained. (g) The fill operation shall be continued in six inch (6") compacted layers, as specified above, until the fill has been brought to the fin- ished slopes and grades as sholun on the accepted plans. SUPERVISION: Supervision by the soil engineer shall be made during the -filling and compacting operations so that he can certify that the fill was made in accordance with accepted specifications. The specifications and soil testing of subgrade, subbase, and bass materials for roads, or other public property shall be done in accordance with specifications of the governing agency. SEASONAL LIMITS: No fill material shall be placed, spread, or rolled during unfaworable weather conditions. Ulhen the work is interrupted by heavy rain, grading shall not be resumed until field tests by the soil engineer indicate that the moisture content and density of the fill are as previously specified. In the event that, in the opinion of the engineer, soils unsatisfactory as foundation material are encountered, they shall not be incorporated in the grading and disposition will be made at the engineer’s discretion. .- SOIL AND MATERIAL TESTING LABORATORY OF NDRTH CDUNTY. INC. -3- UNIFIED SOIL CLASSIFICATION CHART GROUP SYMBOL SOIL DESCRIPTION ,.- I. COARSE GRAINED IMore than 50% #ZOO sieve) GRAVELS [Morehan 50% #4 sieve ‘but smaller than 3 inches) GUI GP Non Plastic GM GC SANDS (More than 50% smaller than #4 sieve) Non Plastic ..- II. FINE GRAINED -(More than 50% smaller than #200 sieve) Liquid Limit less than 50 SW SP SM SC ML CL GRAVEL, well graded gravel- sand mixture, little or no fines. GRAVEL, poorly graded grawal- sand mixture, little or no fines. GRAVEL, SILTY, poorly graded gravel-sand-silt mixtures, GRAVEL, CLAYEY, poorly graded gravel-sand-clay mixture. SAND, well graded, gravelly sands, little or no fines. SAND, poorly graded, gravelly sands, little or no fines. SAND, SILTY, poorly graded sand-silt mixtures. SAND, CLAYEY, poorly graded sand-clay mixtures. SILT, INORGANIC, silt and fine sand, sandy silt or clayey- silt-sand mixtures with slight plasticity. CLAY, INORGANIC, clays of low tc medium plasticity, gravelly clays, sandy clays, silty clays, lean clays. Liquid Limit greater than 50 OL MH CH SILT, ORGANIC, silts and or- ganic silt-clays of low plasticity. SILT, INORGANIC, silts micaceous or dictomaceous fine sandy or silty soils, elastic silts. CLAY, INORGANIC, clays of med- ium to high plasticity, fat clays. OH CLAY, ORGANIC, clays of medium .-- to high plasticity, III. HIGHLY ORGANIC SOILS PT PEAT, other highly organic swamp soils. SOIL AND MATERIAL TESTING LABORATORY OF NORTH COUNTY, INC.