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Home My WebLink About; Lake Calavera Hills; Soils Report; 1977-01-28--; - - - - - - - SOIL AND GEOLOGIC INVESTIGATION LAKE CALAVERA HILLS, UNIT NO, 1 TAMARACK AVENUE CARLSBAD, CALIFORNIA PREPARED FOR: Mr. Roy Ward 4321 Birch Street Newport Beach, California 92660 - - PREPARED BY: - Soil, Geology & Testing Consultarlts, Inc. 6280 Riverdale Street San Diego, California 92120 - TABLE OF Project Description and Scope. - Findings . . . . . . . . . . Site and Soil Conditions. Site Geology. . . . . . . - Faulting. . . . . . . . . Other Geologic Hazards. . - Recommendations. . . . . . . Site Preparation. . . . . - Earthwork. . . . . . . Transition Lots. . . . Alluvium . . . . . . . Foundations . . . . . . . . . . . . l . . . . . . . . . . . . . . . . . Expansive Characteristics. Bearing Capacity . . . . Settlement . . . . . . . - Slope Stability . . . . . . Earth Retaining Structures. - Field Explorations . Laboratory Testing . -_ - Plot Plan. . . - Trench Logs. . Boring Logs. . . . . . . . . . . . . . . . . . C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . . . . . . . . . . . . . . . . . . . NTE NTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ATTACHMENTS . . . . . . -Grain Size Analysis & Atterburg Limits . . . . . . . . . . . . Direct Shear Test Results, Maximum Density & - Optimum Moisture Content. . . . . . . . . . Expansion Test Results . . . . . . . . . . . PAGE NO. - Slope Design, Recommended Grading Specificaton, Special Provisions, Unified Soil Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chart , . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 3 3 3 3 3 4 4 4 4 5 5 5 6 PLATE NO. . . l&2 . . 3 11 - - . . 12 13 . .14 & 15 . . 16 . . 17 . .Appendices - REPORT OF SOIL AND GEOLOGIC INVESTIGATION PROPOSED LAKE CALAJJERA HILLS UNIT NO. 1 - CARLSBAD, CALIFORNIA - PROJECT DESCRIPTION AND SCOPE This report presents the results of our soil and geologic investigation Yor Lake Calavera Hills Unit No. 1. The site, consisting of approxi- lately 63 acres, is located roughly 4,000 feet east of El Camino Real aiong the proposed extension of Tamarack Avenue in the City of Carlsbad. "pproximately 10 acres of the site has tentatively been reserved for a uture school and was not included in the scope of this report. The remaining 53+ acres are planned for 138 single family residential lots and open space. It is anticipated that the residential structures will onsist of one or two story woodframe buildings with slab on grade con- ,truction. It is further understood that FHA and/or VA financing is being contemplated and, therefore, the findings and.recommendations .-hich follow have been presented with that in mind. Grauing for the project will generally consist of cuts and fills of less 'nan 20 feet, as indicated on the Tentative Map and PUD Plan No. 4, arlsbau Tract No. 76-12, by Rick Engineering, revised October 22, 1976. An exception to this will occur along the south side of Tamarack Avenue lanere a 2:l fill slope having a maximum height of 60 feet is planned. ,he aforementioned Tentative Map was used as an aid to our studies and analysis. The site configuration and exploration locations are shown -n Plate No. 1 of this report. This investigation was undertaken to: - a> Determine the physical properties of the prevailing soils including their supporting capacities and settlement characteristics. - b) Provide design information regarding foundations, slope stability and site grading as well as grading for the improvement of Tamarack Avenue. - cl Determine potential construction difficulties and provide recom- mendations concerning these difficulties. FINDINGS rite and Soil Conditions lopographically, the site is characterized by rounded hills and ridges borceriny on numerous randomly oriented drainage courses. On-site levations vary from a low of 160 feet along the southerly margins to ~. high of 300 feet in the northern extremes. Natural drainage is pri- marily to the south and west. NO man-made structures or significant past -rading was observed. The site is presently being used for agricultural urposes. - ; -T 710002 January 28, 1977 Page Two :- general, the soil conditions were found to consist of dense to r ry dense siltstones and sandstones ultimately underlain by weaker iudstones. These materials tend to be interfingered and somewhat ensitic and therefore, preclude accurate mapping. The siltstones 1 ri muustones are highly expansive while the sandstones are pre- l-miriantly nonexpansive. This-*condi-t-ion~~~~~~~~ecti~ ;r;a~~n~tck-zf;r;ec_l;ud~~~~~tu~a~~d~g.~u eAa-eaiaagndcsx~ansiw s-i-l*. With the exception of the fault zone area, it can be said : at, in general, theu~i~:Lt-stones-r~onc~t~~ed~a~ve-26~~ee~, _he,sanastones~between-~levationzZ-20-f~~~~~~-f~~~and.~he-m~~- ;Lone~elo-~-eZeva~i~n-22~~~~t. 'ne prevailing soils will be rippable with normal earth moving equip- ient, however, some hardrock may be encountered in the construction of > t No. 1 (opposite Trench No. 1) where a metavolcanic rock outcrop !,.croaches on roughly a third of the lot. -0se alluvial soils (on-site), are limited to the narrow ravine bottoms ; ri probably ao not exceed five feet in thickness. The proposed align- lent of Tamarack Avenue will cross a significant alluvial deposit at .Is western end in the vicinity of Trench No. 9. No free water was en- : untered, however, it should be anticipated that the upper three to iour feet of existing soils are soft and wet and will require removal ind recompaction to provide a stable subgrade. !-th the exception of Boring Nos. 6 and 7, groundwater or seepage was lot encountered in the test explorations. Boring Nos. 6 and 7 encountered i--small amount of seepage at a depth of 21 feet. The source of the seep- I e is not known but may be the result of tomato field irrigation. Close -nspection curing grading will be necessary to insure that if a seepage :-ndition is present, appropriate remedial measures can be readily in- . rporated. / -LTE GEOLOGY :-is area is underlain by fine sandstones and siltstones of the Santiago Yorikiation. In the Oceanside, Carlsbad area this Formation can be divided --to three separate members, known as Member A, Member B and Member -I * +mber A is generally characterized by green mudstones interbedded r' th greenish-gray sandstones. Member B usually consists of very fine :o medium grained, moderately well indurated sandstones. Member C generally is a coarse grained sandstone. At the project site Member i ana Member ti are apparently interfingered, with Nember B predominating. ~-low approximately elevation 200 mudstones of Member A are dominant. Yhe Santiago Formation is deposited upon metavolcanic rocks known as z-e Santiago Peak MetavolcanicsW These rocks surface in the extreme 1 rthern tip of this project and consist of highly fractured gray, larci metavolcanic rocks. f - ZT 710002 January 28, 1977 Page Three - AULTING Tnis site is cut by numerous north-northeasterly trending faults. -hese faults are apparently minor features and do not offset topsoil aterials within this project. Such faults are common in the Carlsbad- Oceanside area and are considered inactive. The majority of the faults -t this site appear to be concentrated in the areas of Trench NO. 11 nd Boring No. 6. A trench profile showing the faults encountered in Trench No. 11 is presented on Plate No. 8. It has been our experience in nearby areas that these faults are discontinuous enechelon features .nd cannot be traced for any significant distance. It is our opinion &hat these faults do not present a seismic hazard to the proposed develop- ment, however, if a structure is located across a fault which has juxta- -Jose& materials of considerably different shrink/swell characteristics, :hen foundation problems could result. Therefore, we recommend that our engineering geologist be present at the time of grading to inspect ".ot pads for this occurrence. We recommend that such pads be treated is patis which are underlain by expansive materials as recommended here- Inafter. -)ThEH GEOLOGIC HAZARDS No other geologic hazards, such as, landsliding, high groundwater, ->r potentially liquifiable soils were noted within the boundaries of the area investigated. Loose, wet, sandy material was encountered near the west end of the major drainage, just to the west of this project, -dnere the extension of Tama;ack Avenue is-proposed- If is constructed according to the recommendations within no significant geotechnical problems are anticipated. - RECOMMENDATIONS -Site Preparation Earthwork: All earthwork and grading contemplated for site preparation should be accomplished in accordance with the attached Recommended Grading -Specifications and Special Provisions. Utility trench backfill within five feet of the proposed structure and beneath asphalt pavement should be compacted to a minimum of 90 percent. The maximum dry density of each -soil type should be determined in accordance with A.S.T.M. Test Method 1557-70T, Method A or C. Tamarack Avenue this report, -Transition Lots: Foundations bearing partially on cut and partially on compacted fill are not recommended. The tendency of cut and fill soils to compress differently may result in unequal structural support and subsequent cracking of the foundation/slab system. Therefore, where this -condition occurs it is recommended that either 1) the footings be deepened such that all portions of the footing system bear on firm natural ground or that 2) the cut portion of the building pad be undercut at least one -foot below the base of proposed footings and replaced with properly com- pacted nonexpansive soil. ._ Alluvium: As indicated previously, it is anticipated that only minor amounts of alluvium will be encountered within the subdivision, and these -- -GT 710002 January 28, 1977 Page Four -ill generally be confined to the bottoms of.the two major drainage tri- ,utaries. Where existant, the alluvial soils shall be removed to firm natural ground and properly recompacted as structural fill prior to the olacement of additional fill and/or structural loads. ,'or the construction of Tamarack Avenue the alluvium should be removed and recompacted for a depth sufficient to provide a firm subgrade upon -1hich additional fill and/or pavement may be placed. We estimate that tiepth in the order of four feet over a length of 200 feet to 300 feet would be necessary. - 'oundations Expansive Characteristics: The expansive characteristics of the clayey ;oils tiescribed previously (siltstones and mudstones) will require special consideration and/or design so that structural damage is not likely to occur. - :t is recommended that wherever expansive soil is used in fill, it be plac,ed a minimum of 2.5 feet below finish grade and wherever it --ccurs within 2.5 feet of finished cut grade, it be removed and be .eplaced with nonexpansive soils. The lateral extent of this recom- menciation shall apply to the entire level building pad area. Con- Yentional footings designed as recommended hereinafter may then be lseu for the proposed structure.. It is our opinion that there is a sufficient quantity of nonexpansive -;oil to properly cap the proposed building pads provided that selective grading techniques are incorporated. If it is not economically feasible to cap all of the pads it will be necessary to use specially designed Sootings and on grade slabs to reduce the potential for structural dis- ress. Such recommendations would be included in the final compaction report after completion of grading. - searing Capacity: Conventional spread footings having a minimum depth and width of 12 inches and founded in either nonexpansive compacted fill or nonexpansive firm natural ground are recommended for the support of - -he proposed structures. Such footings may be designed for an allowable soil bearing pressure of 1,800 psf.for full live plus dead loads. This bearing pressure may be increased by one-third for wind and/or seismic -loading and should be decreased by one-fourth for dead load only. Aajacent footings founded at different bearing levels should be so located Lhat the slope bearing level to bearing level is flatter than one horizontal ;o one vertical. Where a footing will be located near the top of a slope the footing should be deepened such that the outside edge of the footing is at least five feet horizontally from the face of the slope. jettlement: The anticipated total and/or differential settlement for foundations designed as recommended in this report should be less than --three-fourths of-an inch. A majority of this settlement should occur luring construction. -. - j;GT 710002 January 28, 1977 Page Five -Slope Stability The proposed 2:l cut and/or fill slopes, will be stable with respect t0 -deep seated failure if limited to a maximum height of 70 feet. This allowable height was determined by using a factor of safety of 1.5 and a horizontal seismic force of O.lg (see attached "Slope Design" chart). -Slopes steeper than 2:l may also be safely constructed, however, the permissible height will be reduced substantially. If steeper slopes are anticipated, we should be advised so that additional analysis may be performed. - To reduce the potential for surface sloughing, all slopes should be planted with erosion resisting plants and surface drainage should be -uirected away from the top of all slopes. Earth Retaining Structures - Active and passive soil pressures for the design of earth retaining structures will be dependent upon the particular soil condition being considered. Should this information be necessary for design purposes, -please provide this office with the location and type of wall proposed. FIELD EXPLORATIONS - Twenty-one subsurface explorations were made at the locations indicated on the attached Plate No. 1 on May 10, 1973 and January 5 and 12, 1977. --These explorations consisted of two borings drilled by means of a rotary bucket type drill rig and nineteen trenches dug by means of a backhoe. The explorations were conducted under the observation of our engineering -geology personnel. The explorations were carefully logged when made. These logs are pre- sented on the following Plate Nos. 2 through 13. The soils are described -in accordance with the Unified Soils Classification System as illustrated on the attached simplified chart. In addition, a verbal textural descrip- tion, the wet color, the apparent moisture, and the density or consistency --are given on the logs. Soil densities for granular soils are given as either very loose, loose, medium dense, dense, or very dense. The consistency of silts or clays are given as either very soft, soft, -meaium stiff, stiff, very stiff, or hard. Representative core samples were obtained by means of a split tube sampler driven into the soil by means of the "kelly bar" of the drill rig. The energy required to drive the split tube sampler is indicated on the boring logs as the "penetration resistance". The core samples were carefully removed, sealed, and returned to the laboratory for --testing. Disturbed samples of typical and representative soils were also obtained -anu returned to the laboratory for testing. .' -- -GT 710002 January 28, 1977 Page Six - LABORATORY TESTING Laboratory tests were performed in accordance with generally accepted -nerican Society for Testing and Materials (A.S.T.M.) test methods lr suggested procedures. Representative samples were tested for their dry density and moisture content.' The results of these tests are present- -4a on the trench and boring logs. .l'he expansive potential of clayey soils was determined in accordance _with the following test procedure and the results of these tests appear )n Plate No. 17. Allow the trimmed, sample to air dry to a constant moisture content, - at a temperature of 100' F. Place the dried sample in the consolido- meter and allow to compress under a load of 150 or 645 psf. Allow moisture to contact the sample and measure its expansion from an - air dried to saturated condition. in addition, the gradation, maximum density and the angle of internal friction and cohesion was determined for typical and representative samples. The results of the tests are presented on Plate Nos. 14 through 16 of this report. - - - - - - .- - - /. r/’ I \ : \ r5a i I30 /’ sA TEST 7PeNcu LCGA-iV0f-d - &Q/&G 7-iESP LccLI7~0~5 i : I I I ZQ, / / / / ,’ I 0 / fl<dLd-’ /‘&se’ SOIL, GEOLOOY 6 TE=TlNQ CONSULTANTS, INC. Lake CalaJeras Hills Unit IJo. 1, Tamarack Avenue Carlsbad, California PLOT PLAN BY JC DATE l/25/77 - - . _- - 4 TECST 7223JC.4 LOC,A-T/W CJZ-AL4 : /,” JO0 - - I Lake Glaveras Hills SOIL, QEOLOGY 6. TESTING Unit No. 1, Tamarack Avenue CONSULTANTS, INC. Carlsbad, California BY DATE JC l/25/77 Inn NA - TRENCH NUMBER 1 -. Existing Elevation 290h DESCRIPTION - n, Wet, Loose, CLAYEY'SILTY Gray, Wet, Medium, CLAY Gray to Yellow-Brown, Moist, Dense, Highly FRACTURED METAVOLCANIC ROCK L - c 4 - 6 Bottom TRENCH NUMBER 2 Existing Elevation 271+ CLASS - DESCRIPTION Brown, Loose to Medium Dense, SILTY SAND Green-Gray, Mottled Yellow-Brown, Wet Medium to Stiff, SANDY CLAY Light Green-Gray, Moist, Dense, FINE SANDSTONE Blue-Gray, Moist, Very Stiff, SILTSONE Bottom (difficult digging) TRENCH NUMBER 3 Existing Elevation 264 f 0 CLASS DESCRIPTION - 4 Mottled Yellow-Brown, -- 6 E - Bottom (difficult digging) - FOR LEGEND SEE PLA: SOlL,GEOLOGY6TESTlNO CONSULTANTS, INC. - TRENCH LOGS Y - M - 118.3 10.2 3 NO. 11 Lake Calaveras Hills Unit ~\ro. 1, .Tamarack Avenue Carlsbad, California BY 1 DATE I - KLS l/5/77 JOB NO. - -. TRENCH NUMBER 4 Existing Elevation 257* - 0 y-f: . . . 2 1;:: III . . . . . . . -5 4 Ill . . _ . . . . ‘11 . . . . . . . . III . ,. . . . . . I 1 . - . . . . 8 Y SM/ SP DESCRIPTION Brown, Wet, Loose, SILTY,SAND Gray-Brown, Wet, Moist, CLAYEY SAND - .TRENCH NUMBER 5 Existing Elevation 250* CLASS DESCRIPTI.ON - Brown, Wet, Loose, SILTY SAND .Buff, Wet, Loose, CLAYEY SAND , Buff to Gray, Streaked Orange-Brown, Dense to Very Dense, Fine SANDSTONE - Y - M - Buff to Gray, Moist, Dense to very Dense, Fine SANDSTONE 117.3 10.7 Bottom TRENCH NUMBER 6 Existing Elevation 245f cL?ss DESCRIPTION Brown, Wet, Loose, SILTY SAND CL/ Light Brown, Wet, Medium, CLAY - ., 4- ;. :I *: : GSM Buff, Moist to Wet, Dense, Very Fine SANDSTONE . . ..:. Very Dense to Hard, Bottom (difficult digging) FOR LEGEND SEE PLATE NO.11 Lake Calaveras Ifills SOIL, OEOLOOY & TESTINQ Unit a?o. 1, Tamarack Avenue CONSULTANTS, INC. Carlsbad, California - BY TRENCH LOGS KLS DATE l/5/77 JOB NO. - TRENCH NUMBER 7 Existing Elevation 2?3f TRENCH NUMBER 8 - - - 0 CLAS 2 4 6 CH ML \ SM/ SP ML DESCRIPTION Green-Brown, Wet, Soft,'CLAY Y - M Green-Yellow-Brown, Wet, Soft to Medium, 'SANDY SILT Green-Gray to Orange-Brown, Moist, Dense, Fine SA-NE Blue-Gray, Moist, Very Stiff, SILTSTONE Bottom (slow digging) _ CLASS DESCRIPTLON CL Gray-Brown, Xet, Medium, CLAY / SC/ Tan to Brown, Moist, Medium, 2&y /CL SANDY CLAY I - / &H 1 Brown, Wet, Stiff, CLAY 4-K /I / Buft to Brown, Moist, Dense, CLAYEY TO CLEAN SAND /SC/ / ACH Brown, Moist, Dense to Stiff, CLAYEY SAND TO SANDY CLAY Bottom FOR LEGEND SEE PLATE NO. 11 SOIL, QEOLOGY 6 TESTIN(3 CONSULTANTS, INC. ~~ TRENCH LOGS 111.2 19.0 113.6 11.5 Lake Calaveras IIills Unit No. 1, Tamarack AVcIlue Carlsbad, California BY KTS DATE l/5/77 IAl ..n i I I i j i i t F I ij t !/ i t I -. - TRENCH NUMBER 9 A CLASS. DESCRIPTION SM Brown, Wet, Very Loose, SILTY SAND < SAND Dark Gray-Brown, Wet, Loose, CLAYEY 6 Gray-Brown, Taoist, Loose, SILTY CLAYEY SAND Dark Brown, Wet, Stiff, SANDY CLAY Bottom SM SM/ Brown, Wet, Loose, SILTY CLAYEY SC SAND SM TRENCH NUMBER 10 DESCRIPTION SIZTY SAND Li ht Tan-Brown, Wet, Very Loose, Gray-Brown, Wet, Loose, FAIRLY CLEAN SAND Bottom FOR LEGEND SEE PLATE NO.11 SOIL, DEOLOOY G TESTINO CONSULTANTS, INC. - TRENCH LOGS I Y M - 101.9 13.2 102.6 10.0 Lake Calaveras Hills Unlit No. 1; Tamarack Avenue Carlsbad, California BY DATE KLS l/12/77 i - TRENCH NUMBER 11 - - - - FOR LEGEND SEE PLATE NO.11 d . . . . . . . 8 :::: . I -2-i 0 c”s . : 2.*.$:( . . . . I II . . . /$:I:,: ,: :I$ 6-1 :I:) ; _. . I II . . . . . . . Sill I IO : 1: ,:l] SW SW SM 3P SM sM/ SP SW SP DESCRIPTION Brown, Wet, Loose to Medium, SILTY C!T.AYEY S ANlT Buff to Gray, Wet, Dense to Very Dense, Fine SILTY SAND TO MEDIUM CLEAN SANDSTONE Bottom Note: This trench was extended for 160' to the west. See attached Trench Profile, Plate No. 8 TRENCH NUMBER 12 DESCRIPTION Brown, Wet, Loose, SILTY SAND Gray-Tan, Wet, Dense, SUGARY SANDSTONE Gray r Wet, Dense, Very Fine SANDSTONE Bottom Y M - 111.1 10.1 10.3 112.3 11.1 Lake Calaveras Hills SOIL, GEOLOGY 6 TESTING Unit No. 1, Tamarack Avenue CONSULTANTS, INC. Carlsbad, California - TRENCH LOGS BY KLS DATE , l/12/77 JoB No* -I,nfincl mr \.%.- ..- ^ - - CLASS 0 * . :.* . . : . 2- f :* : : .- : . 4-. . . . . . . _ II’ : : :I: I 1 6Q: $1: .I _. . . . . II 8-j:,:,: . SM sM/ SP TRENCH NUMBER 13 DESCRIPTION Brown, Wet, Loose, SILTY SWD Gray , Wet, Dense, Very Fine SANDSTONE Bottom - TRENCH NUrYiBER 14 DESCRIPTION Brown, Wet, Loose, SILTY SAND Pink and Green, Wet, Soft to Stiff, CLAY Green-Gray, Moist, Stiff, SILTSTONE Gray , Moist, Very Dense, SILTY SANDSTONE Green-Gray, Moist, Verv Stiff, SILTSTONE- a Bottom FOR LEGEND SEE PLATE NO. 11 BOIL, GEOLOGY 6 TESTING CONGULTANTS, INC. Y M - 14.2 Lake Calaveras Hills L'nit No. l,,' Tamarack Avenue Carlsbad, California s .-- - - TRENCH NUMBER 15 - - - - DESCRIPTION Brown, Wet, Loose, SILTY SAND Green-Gray and Orange, Wet, CLAY Blue-Gray, Wet, Medium to Stiff CLAY Blue-Green, Moist, Very Stiff MUDSTONE Bottom TRENCH NUMBER 16 . -- _- - - .- DESCRIPTION Brown, Wet, Loose, CLAYEY SAND Green-Gray to Purple, Moist, Stiff to Very Stiff, SANDY CLAYEY SILTSTONE WITH THIN LENSES OF CLAY Buff to Orange, Moist, Dense SANDSTONE Gray-Green, Moist, Stiff, SILTSTONE Bottom FOR LEGEND SEE PLATE NO.11 I SOlL,GEOLOGY 6TESTING CONSULTANTS, INC. Lake Calaveras Hills Unit No. 1; Tamarack Avenue Carlsbad, California BY DATE TRENCH LOGS KLS l/12/77 JOB NO. -- --__ .-- - ^ TRENCH NUMBER 17 * CLASS DESCRIPTION Brown, Wet, Loose, SANDY CLAY Blue-Green, Wet, Medium to Stiff CLAYEY SILTSTONE Blue-Green, Moist, Very Stiff, CLAYEY SILTSTONE Bottom TRENCH NUMBER 18 DESCRIPTION - VI. . . SM . . . . Brown, Wet, Loose, SILTY SAND . . . / . 'I'I.SM/ Buff to Green-Gray, Wet to Moist, - 2- 9.1:‘: SP Medium to Dense, SANDSTONE . . Bottom - TRENCH NUMBER 19 - - EY J33;n, Wet, Loose, CLAYEY SILTY SW SP DESCRIPTION Buff to Green-Gray, Moist to Wet, Dense SANDSTONE I Bottom 1; Sample Location - Y: Natural Dry Density (pcf) M: Natural Moisture Content (% of Y) 1 5OlL, QEOLOGY S TESTING Lake Calaveras Hills Unit No. l-, Tamarack Avenue CONSULTANTS, INC. Carlsbad, California - BY DATE TRENCH LOGS JOB NO. em---- 0 7; J --- i -- BORING NUMBER 6 SS DESCRIPTION E Y M SM Light Brown, Dry, Loose/SILTY SAND SM Light Gray/Pale Yellow, Humid to Moist, Dense, SILTY SAND 29 119.9 9.8 ;I \- , . I i ’ ~ t -. SW !4L Fault Movement Zone, Interbedded, Moist, Dense, SILTY SANDS AND SANDY SILTS (Fault NlS-25W70SW) SM White-Tan, Moist, Dense, SILTY SAND Pink-Olive, Moist, Stiff, SANDY 40 110.9 18.0 SM -- ii SILT and Orange-Brown, Moist, Dense SILTY SAND (Horizontally Bedded) -------- Olive Slight Seepage Pink-Tan, Moist, Hard, SILT + SM Olive-Gray, Moist, Very Dense, SILTY SAND 52 123.6 10;s 30 99.5 21.3 YL Olive-Gray, Moist, Humid, CLAYEY VERY SANDY SILT FOR LEGEND SEE PLATE NO. 11 SOCJTHERN CALIFORNIA JESTING LABORATORY, INC. Lakes Calaveras Hills 8280 RtVERDALE STREET Unit No. 1, Tamzrack Avenue SAN DIEGO, CALIFORNIA 92120 Carlsbad, California I - BORING LOG BY CHC DATE 5/10/73 I 308 No. 71 nnn3 PLATE NO. ,? . --_c__ P -- -- 0 5 3 BORING NWBER 7 . - - - - - 1 1 I I I I I I I I I I I I I I I L I 7 I I I I I I I I I I I I . CL SM ML SM SM DESCRIPTION Brown, Moist, Soft, SANDY - CLAY Light Green, Humid, Dense.to Very Dense, SILTY SAND (Cm Ff) Light Green, Humid, Hard, Very SANDY SILT and Dense, VERY SILTY SAND Light Orange-Brown, Humid, Very Dense, VERY SILTY SAND (Slight Seepage at 21 Feet) FOR LEGEND SEE PLATE NO. 11 9 43 116.0 14.0 Y M 52 118.2 13.5 48 113.6 7.5 48 - SOUTHERN CALIFORNIA TESTING LABORATORY, INC. 0.280 RIVERDALE STREET SAN DIEQO, CALIFORNIA 02tl0 Lake Calaveras Hills Unit No. 1, Tamarack Avenue Carlsbad,' California - BORING LOG BY CHC DATE s/10/73 JO0 NO. 71 nnn7 PLATE NO. 17 GRAIN SIZE ANALYSIS AND ATTERBURG LIMITS k Tll T13 SAMPLE @ 6' @ 6' @ f&t’ B6 @ 17' -7 A.. 1 1 1 1- !z 0 w 1 3 iz 5 z 1 c Iis 1 g d s 1 (3 1 1 I - s #4 100 100 ch #8 5 99 100 93 >. #I6 93 100 99 100 84 #30 63 100 99 97 99 79 *j5' , , 30 , 87 , 85 , 93 , 94 , 73 1 #'O" 1 15 1 25 I-- ; - I 32 I 84 I 75 1 52 $200 10 11 19 65 I 53 32 & .05 mm 5 47 40 24 - 5 .005mm is 17 13 10 : ,001 mm I 8 I 6 I 5 LIQUID LIMIT PLASTIC LIMIT PLASTICITY INDEX -I UNIFIED CLASSIFICATION SM/SW 'Sp/SM SM ML ML4 SM SOIL, GEOLOGY 6 TESTING CONSULTANTS, INC. TABLE OF TEST RESULTS I BY KLS I DATE l/24/77 I GRAIN SIZE ANALYSIS AND ATTERBURG LIMITS r SAMPLE 6" , I L I 4" 3" 2" 1%” #4 #8 #16. 100 , 100 Inn #30 99 98 97 $50 96 94 84 #loo 81 80 72 $200 51 43 45 I I c LIQUID LlMlT - PLASTIC LIMIT . PLASTICITY INDEX - I UNIFIED - CLASSIFICATION ML SM SM , - SOlL,GEOLOGY&TESTING CONSULTANTS, INC. . ..-. ..-. ..-- TABLE OF TEST RESULTS BY KLS DATE l/24/77 i--ECT SHEAR TEST RESULTS AMPLE L I @9’ i@17' i. @31' 7@2.5-3' 7 @6' - ; @22-23' - DESCRlPTlON ANGLE OF INTERNAL FRICTION ( ‘: Remolded @ 90% 35 Undisturbed 43 Undisturbed I 3s Remolded @90% Undisturbed 'Remolded @ Natural 4XIMUM DENSITY & OPTIMUM MOISTURE CONTENT - : T.M.: 1557-70 METHOD: A COHESION INTERCEPT Ipsf) 275 250 I -SAMPLE MAXIMUM OPTIMUM DESCRIPTION DENSITY MOISTURE (pcf 1 CONT. (%I u. @9-10' Fine Sand. ,_ _ I 121.9 11.2 f @0.5' Brown, Sandy Clay 115.9 13.7 @2.5-3.5 Light Green, Silty Sand 111.9 16.0 SOIL, GEOLOGY 6 TESTING CONSULTANTS, INC. Lake Calaveras Hills Unit No. l', Tamarack Avenue Carlsbad, California BY KLS DATE l/24/77 JOB NO. -t~rr...... -1 iAMPLE I T7 @5' I T17 @2' I B6 @6' - I I I 1 I DITION i-IAL M.C.(V.) Undist.-AD Undist.-AD '3ndi&t.-AD .4.9 2.3 1.7 I ITIAL DENSITY(PCF)j 111. 2 ‘1 99.1 I 111.6 -AL Mt.(%) I 28~6 1 7.2 O_RMA L SU?Ess(PSF) 150 150 150 PAN SION (*le) 20.3 16.2 I 0.6 aAMPLE - : NDITION &TIAL M.C .+/. ) 1.. rlAL DENSITYt PCF) .-4A L M .C. t.1.) KRMAC ST FESS wsl3 : ;PANSION (V.1 B7 @O-1.5' I B7 @6' I B7 @22-23' I 1 Remolded 1 I @90% -AD Un'dist . -AD 1 Undist.-AD' 3.5 4.2 4.5 105.6 117.3 114.6 I 1 25.6 15.9 16.2 150 ! 645 1 645 13.2 I 3.1 I 4.7 Undist.-AD 3.9 116.7 21.5 150 11.6 t . Undist.-AD 7.5 99.5 31.1 150 10.8 - iAMPLE -3NDITION INITIAL M.Cs(*/.) -_ - 4ITIAL DENSITY(PcF) .‘=lNAL M.C. (.I.) NORMAL STRESS (PSF) -XPANSlON to/.) @o)L.Qo~?V 6 TESTINO CONSULTANTS, INC. 1 Lake Calaveras Hills Unit No. 1, Tamarack Avenue Carlsbad, .California BY KLS DATE l/24/77 CI .-- ,- . ,.. Stat~siticd~iandlylSis ok 2 3~ 'tr=a*'dircies reG:als 'that use'br k~ factor of safety of 1.89' f and Taylor's charts is not significantly different from the use of a factor of safety of 1.5 and a seismic load of O.lG .The chart below,is based on factors of safety of 1.5 and 1.89 and Taylor's chart. Enter the chart from the bottom left I with the given slope ratio. GO up to the appropriate"gl"curve S!;peHe+ght $with Seismic. (dashed for seismic) proceed ,P$ 8: right to the"c"curve. Read Slope Ratio .b' Slopeheight without Seismic ’ 8s r.4 5.2470 - . APPENDIX A, PAGE l JOB NO. 710002 DATE 1/28/77 - RECOMMENDED GRADING SPECIFICATIONS GENERAL PROVISIONS - GENERAL INTENT The intent of these specifications is to establish procedures for clearing, compacting natural ground, preparing areas to be filled, and placing and compacting fill soil to the lines and grades shown on the accepted plans. The recommendations contained in the pre- liminary soil investigation report and/or the attached Special Pro- visions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. INSPECTION AND TESTING .- A qualified soil engineer shall be employed to inspect and test the earthwork in accordance with these specifications. It will be ne- - cessary that the soil engineer or his representative provide ade- quate inspection so that he may certify that the work was or was not accomplished as specified. It shall be the responsibility of _- the contractor to assist the soil engineer and to keep him appraised ' of work schedules, changes and new information and data so that he may make these certifications. - If, in the opinion of the soil engineer, substandard conditions are encountered {such as questionable soil, poor moisture content, in- adequate compaction, adverse weather, etc.), he will be empowered - to either stop construction until the conditions are remedied or corrected or recommend rejection of the work. - Soil tests used to determine the degree of compaction will be per- formed in accordance with the following American Society for Test- ing and Materials test methods: -. Maximum Density & Optimum Moisture Content: A.S.T.M. D-1557-70 Density of Soil In-Place: A.S.T.M. D-1556-64 -PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris shall be removed, piled and burned - or otherwise disposed of., After clearing, the natural ground shall be scarified to a depth of six inches, brought to the proper mois- ture content, compacted and tested for the minimum density specified - APPENDIX A, PAGE 2 JOB NO. 710002 DATE l/28/77 - in the Special Provisions or the recommendations contained in the preliminary soil investigation report. - When the slope of the natural ground receiving fill exceeds 20 per- cent (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. tent soil condition. Benches shall be cut to a firm compe- The lower bench shall be at least ten feet wide and all other benches at least six feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified hereinbefore for compacted natural ground. Ground slopes flatter than 20 percent shall be benched when considered necessary by the soil engineer. - FILL MATERIAL Materials placed in the fill shall be approved by the soil engineer - and shall be free of vegetable matter and other deleterious sub- stances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks, - expansive and/or detrimental soils are covered in the Special Pro- visions. Expansive soilsl soils of poor gradation or strength characteristics may be thoroughly mixed with other soils to provide _ satisfactory fill material, but only with the explicit consent of the soil engineer. . i PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed six inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to a minimum specified density with adequately sized equip- ment, either specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary soil investigation report. Field tests and inspections to check the degree of compaction of the - fill will be taken by the soil engineer or his representative. The location and frequency of the tests shall be at the soil engineer's discretion. In general, the density tests will be made at an inter- - val not exceeding two feet in vertical rise and/or 500 cubic yards of embankment. SEASON LIMITS .- Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling.operations shall - i APPENDIX A, PAGE 3 JOB NO. 710002 DATE l/28/77 not be resumed until the proper moisture content and density of the fill has been achieved. Damage resulting from weather shall be re- paired before acceptance of work. UNFORESEEN CONDITIONS In the event that conditions are encountered during the site pre- paration and construction that were not encountered during the preliminary soil investigation, Soil, Geology & Testing Consultants, Inc. assumes no responsibility for conditions encountered which dif- fer from those conditions found and described in the preliminary soil investigation report. -- - .- - /) ;I jj II i! I .-