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1991-2610 G/PE Street Address 1;1~5 I 311 (,1 Category Serial # ~~fO 8I Name I Description Year Plan ck. # recdescv , , i I I I I ~ I I ... I I I I . .. . '-"... ....--.. -_.._.- _...... .._--_.. ....------......--..---.----- --.........--. --.-. " . '~:'~~<'; ;\/~~'~~~> ~~r;¡:~~? GeQSoil,,'~*r'1 ne~ '.~.;.;;:.."" \:'. ,;,~/ "-"'-4,I;,w/.'...,"'" ~ Geotechnical Engineering. Engineering Geology 5751 PalrnerWay, Suite D . Carlsbad, California 92008 . (619)438-3155 . FAX (619) 931-0915 September 30, 1988 W.O. 717.2-S0 SHEA HOMES 10721 Treena Street, Suite 200 San Diego, California 92131-1039 Attention: Wes Popplewell Subject: Final Soils and Geologic Report, Tract 4574, Phase II, Lots 1-5, 14-15, 21, 25-26 and 28-71 City of Encini~as, San Diego County \ Gentlemen: This report presents a summary of the engineering testing services and geologic observation provided by GeoSoils, during the earthwork phase of the subject development. Inc. The grading began on May 16, 1988 and ended on September 30, 1988. The purpose of the grading was to construct level buildipg pads ! and access roadways for proposed single family residential structures. Earthwork recommendations based were on the referenced reports and on evaluation our of conditions encountered during grading. fõ)Œ Œ Œ ~ W Œ[ID Uü JUL 2 2 1991 CITY OF ENCINITAS . DEPT. OF PUBLIC WORKS ENGINEERING DEPT. Los Angeles Co. (818) 785-2158 . Orange Co. (714) 647-0277 . Riverside Co. (714) 677-9651 t ~: .'-J l ~J l ~- J~ ,. ,. I. I I r I ..------------..------....----- . ., SHEA HOMES W.O. 717.2-SD SEPl'EMBER 30, :1988 . PAGE 2 . "". . ENGINEERING GEOLOGX General Geologic conditions exposed during the process of grading were frequently observed by our staff geologist. Fill keys, removals, cut slopes, and general grading procedures were included in these observations. Geoloqic Units \ Topsoil/Colluvium: Topsoil/colluvial soils on site consist of generally dark brown to dark reddish brown sandy clays with common rock fragments. These materials are porous and considered unsuitable. for structural support. These soils were removed and recompacted within pad and driveway areas to a minimum of 90 percent relative compaction. Alluvium: Alluvial deposits were present in canyon bottoms. These deposits consist of sandy and gravelly clays and clay. This material was removed, moisture conditioned and recompacted as fill within driveways and building areas. Bedrock: Sedimentary rocks, mapped as the Lusardi Formation, were found to underlie Lots 2, 36-39, 63, 67, and 68. These sediments are GeoSofls, Inc. SHEA HOMES W.O. 717.2-SD SEPTEMBER 30,1988 PAGE 3 mainly weathered clayey sandstones and sandy claystones with fairly abundant volcanic rock fragments and boul~ers. thls unit varies significantly due to weathering. Density of Partial removal and recompaction of this material in structural areas was performed prior to fill placement. Metavolcanic and andesitic rocks of the Santiago Peak Volcanics underlie Lots 1-5, 14-15, 21, 25-26, 28-36, and 40-71, These rocks are typically gray with rust colored staining near the surface, becoming less stained with depth. Density typically increases with depth. Hardness and rippability are related both to the density and degrees of fracturing. A zone of randomly intruded dense and blocky volcanic rocks and friable, slightly dense to medium dense granitic rocks was excavated on Lots 44, 45 and 53 (see Geotechnical Maps, Plates lc and Ie). This is thought to represent one of the feeder vents . i t associated with the Jurassic Age Santiago Peak Volcanics and is not a part of the younger Cretaceous Age granitic rocks located to the east (Reference 1). SOILS ENGINEERING Preparation of Existing Ground 1. Deleterious material such as concentrated organic matter and miscellaneous debris was disposed of offsite prior to GeoSofls, Inc. þ ¡\ . i ;;: ,', SEPTEMBER 30, 1988 PAGE 4 SHEA HOMES. W.O. 717.2-SD 2. " ¡ :i ,.! placing fill. Minor dry grasses were thinly spread into the fill so as not to create any concentrations. All loose and compressible soil was removed to bedrock or existing competent fill in driveway and pad areas to receive fill. The existing fill was placed under the supervision of GeoSoils, during construction the roads. Inc. the of Removals were made as outlined in our referenced. report or as field conditions warranted. \ 3. A keyway at least 12 feet wide, 2 feet deep into competent bedrock, and tipped into the slope was excavated at the toe of all fill slopes. 4. Benching was performed as nee~ed into competent bedrock as fill proceeded. 5. A cut-fill transition was exposed at pad grade across Lots 4-5, 14, 21, 28, 30-35, 38-39, 41, 44-45, 49-52, 54-66 ¡and 69-71. The cut portion building envelope and of the (includes five foot beyond the building footprint), was overexcavated to a depth of 36 inches and brought back to grade with compacted fill to provide more uniform foundation support conditions. 6. cut pads, that exposed dense volcanic were over rock excavated to a depth of three feet within the building GeoSofls, Inc. þ SHEA HOMES W.O. 717.2-SD SEPTEMBER 30,1988 PAGE 5 7. envelope, (includes five foot outside the building pad) and replaced trenching. with materials facilitate fill to compacted The remaining portions of the graded area were over shot three feet to also facilitate trenching. When overexcavations, were removals, keys benches or complete, the exposed surface was scarified to a minimum depth of 6 inches, brought to at least optimum moisture content, and compacted. , Fill Placement 1.' Fill consisted of onsite materials which were placed in thin lifts, approximately six to eight inches in thickness, brought to at least optimum moisture content and compacted using scrapers and 834 rubber tire dozers, "Terex" D-8 2. compactor. Rock fills, located on Lots 25. 26, 35. 37, 39.& 44, 4r, 47, and 53 consisted of occasional boulders and rock 48, fragments placed in 1 i fts one to two (:t) foot thick and generously watered. Each lift was compacted by a D-8 or D-9 dozer. Rock fills within pad areas were capped with soil fill materials approximately 3(:t) feet in thickness. A 12(z) feet thick soil cap was built between the face of slo~e and rock fill. Subdrains were installed to drain rock fills. GeoSoils, Inc. . . "':'.;;ii}"~:t.if':\>~ .. :.:; :..' '. '. .. .¡- ,,':. ; .:} SHEA HOMES w.o. 717.2-SD SEPTEMBER 30, 1988 PAGE 6 ,! .,: ., <I ~; proj ect surveyors (Hunsaker and Associates) were asked to ;' 1:. located all subdrains. Homeowners and landscapers should be aware of these drains and should not cover or clog the outlets. Due to the rocky nature of the fill materials generated, placement of +ill was observed by excavating pits within the rock fills by a representative of this office to check that sufficient effort was used to compact the fill and to fill , 1, \ any voids. This included monitoring lift size, moisture conditioning. Efforts were made to remove cobbles larger ~ " than eight. inches in one dimension within the upper three (:tJ feet of the' building envelope fir}~. Where possible, , density tests were taken to check compaction. 3. Rocks greater than four feet in one dimension were broken to smaller sizes or removed' from the fill. Rocks up to fo,ur ! feet in one dimension placed within windrows or isolated j. f; r I ¡- t. " , H: . ì Ii: .. \; within the soil fill are typically located approximately five feet or more below pad grade. :1, F , I ! 4. The approximate maximum depth of fill is 30I feet on Lot 53. ,. I' 5. Fill placed on surfaces having a slope gradient steeper than 5: 1 were keyed and benched into bedrock or compacted fill " .r. '" previously tested by this office (i.e. roadways slopes). ,Ii 01 ; .! GeoSofls, 'nc. þ I ......----------- _.! 9. 10. ...----------- . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30,1988 PAGE 7 . 6. Lots 29, 36, 37, 46, and 47 are fill lots. 7. Pad areas exposing a cut-fill transition were overexcavated and capped with 36-inch fill a blanket, in proposed structural areas as located by the project surveyors, to provide more uniform foundation support conditions. This was performed on Lots 4-5, 14, 21, 28, 30-35, 38-39, 41, 44- 45, 49-52, 54-66 and 69-71. 8. On Lot 33 a large hard rock outcrop was left in place, outside the limits of the ~roposed structure. It was located by the project surveyors, being as approximately eight inches below finish grade. The approximate location is indicated on the enclosed map (see Plate 19). ' Lots 1, 2 and 3 are cut lots exposing hard volcanic rock. The proposed building foot prints, located as by the surveyors, were- overexcavated approximabÙy three (.:t), feet i and replaced with compacted fill materials. As only the proposed building envelopes were overexcavated on transition and cut lots, relocation of buildings would create differing cut/fill foundation conditions (i.e. , transitions, shallow rock, etc.). We suggest that this- office be notified prior to any relocation of any building, for special foundation recommendations or additional grading should be considered. GeoSoils, Inc. ,== - . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 8 Field Testing 1. Field density tests were performed using either the sand cone method (ASTM D-1556-82) or the nuclear method (ASTM D- 2922-18). Test results are enclosed as Table I at the end of this report. Estimated locations of the field density tests are shown on the Compaction Test Location Map, Plates 1a through 1j which utilizes the 1"=40' grading plans prepared by Hunsaker and Associates as a base map. 2. Field density tests were taken at periodic intervals and random locations to check the compaction effort by the contractor. Due to the granular nature of the fills observation pits were excavated in some areas to see that voids were filled and sufficient moisture was present. Where test results indicated less than 90 percent relative compaction, the contractor was notified and the area was reworked until retesting indicated a minimum relative compaction of 90 percent. Based on the grading operàtions observed, test results herein are considered representative of the compacted fill. 3. Visual classification of the soils in the field was the basis for determining which maximum density value to use for a given density test. GeoSoils, Inc. f SHEA HOMES W.O. 717. 2,-SD SEPTEMBER 30, 1988 PAGE 9 Slo\?es 1. Cut slopes exposing weathered volcanic and sedimentary rocks are considered to be subject to minor to moderate erosion. Planting should reduce the maintenance r~quired for those slopes. A paved brown ditch, along the top of all cut slopes, should be considered to control erosion. 2. Compactiqn on the face of all fill slopes was achieved by building to grade and track walking with a D8, D9 or D6 dozer. \ 3. All slopes are considered grossly stable and should remain so under normal rainfall conditions if an adequate program of landscape maintenance is provided. Localized surficial erosion and raveling should be anticipated due to the rocky nature of the slopes. The cut slope Lots 1 and 2 are considered subject to raveling as portions of the slope are over steepened. 4. Slopes should be planted with deep rooting, drought resistant vegetation as soon as possible after construction to aid erosion control and surficial stability. Irrigation for planted areas on and above slopes should be minimized to just support the vegetation and avoid developing artificial groundwater accumulations. GeoSoils, Inc. SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 10 LABORATORY TESTING Compaction Tests To determine compaction character of the site soils, compaction tests were performed in accordance with ASTM test 0-1557-78 on representative soil samples from the site. The maximum density and optimum moisture were determined and are summarized as below: Soil Type A-Reddish brown, gravelly clayey SAND .B-Medium to dark red brown, silty SAND C-Brownish orange, clayey SAND D-Mottled greenish, CLAY E-Sandy CLAY F-Brown'CLAY G-Orange brown, gravelly silty SAND H-Medium olive brown, sandy CLAY Maximum Dry Densi tv (pet) optimum Moisture Content' 124.0 12.0 123.0 13.0 116.0 109.0 111. 0 116.0 122.0 112.0 17.5 21.0 16.5 17.5 14.5 18.5 Expansive Soils Expansive soil conditions have been evaluated for each lot. Representative samples of the soils near pad grade were recovered for classification and expansion testing. Based on laboratory test results, soils on site varied from moderate to critically expansive. 1. Swell tests shall be performed on remolded samples compacted to 90 percent maximum density at 80 percent of optimum moisture in a brass ring having an inside diameter of 2.365 inches and a height of 1.0 inches. Surcharge loads are to þ GeoSofls, Inc. , ,i: ! .' SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 11 :r :1 ,;. be applied and each sample will be Submerged in water for 24 " !! iÌ hours. The vertical swell is recorded as a percentage of the original sample height. 2. Expansion Index tests were performed for typical soil types. Testing was in accordance with standard 29-2 of the Uniform Building Code.. ,j , ~! 3. \ Results of the swell and expansion index tests are presented in Table II. i '! , ! a minimum width of 12 inches and a minimum depth 'in it ! ¡ :¡ , t: , ¡I I IiI . J. :1 ; ¡ : :1 : :1 'J I~ FOUNDATION RECOMMENDATIONS Design 1. An allowable bearing value of 1,500 pounds per square foot may be used for design of continuous footings which maintain accordance with recommendations for construction, presented below, but should not be less than the minimum " I, 1\ i,1 ; ~ :f :ï í'l ' , d , , ¡ J !'¡ I, , I ! j recommendations of the Uniform Building Code and the City of Encinitas. 2. A friction coefficient for concrete on natural or compacted soil of 0.4 and a lateral passive pressure value of 250 pounds per sqúare foot per foot of depth to a maximum value GeoSofls, Inc. þ SHEA HOMES w.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 12 , , of 1,500 pounds per square foot may be employed to determine resistance to lateral loads. 3. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one third. For design of isolated poles, the allowable passive earth pressure may be increased by one hundred percent. 4. The base of all footings should be at least 7 feet from the face of any descending slope. \ Construction Initial laboratory test data indicates that the surface soils on this site are moderately to critically expansive in nature. The. following recommendations take into consideration the expansion potential of the underlying earth materials and the presence of rock fills., Due to the presence of extremely hard rock on cut lots or rock fills existing approximately 3 feet below grade on fill lots, special construction methods will be required. It should also be noted that special construction methods will be necessary for any structures not shown on the enclosed Geotechnical Maps. Due to the large spans between walls for some of the proposed one story structures we recommend that the project structural engineer evaluate carefully the loading conditions. The following construction procedures are recommended: GeoSoils, Inc. þ , ..' -'-'",.- "'-'.""'-'----.-.'--'-- '-"'."..'--..-...-..-.......--.... . . .... ....-----.---..---...- . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988. PAGE 13 Foundations - All Lots Excavations below approximately 3 feet will be extremely difficult due to the presence of either hard rock or rock fills. 1. Exterior footings should be founded at a minimum depth of 24 inches below the lowest adjacent ground surface. Interior footings may have a minimum embedment of 18 inches below the top of the lowest adjacent concrete slab surface. However, a minimum penetration of 12 inches into the soil is required. Interior isolated piers are not recommended. All footings should be reinforced with a minimum of four No. 4 reinforcing bars, two near the top and two near the bottom. Isolated exterior post supports should be founded at a depth of 30 inches below adj acent grade and tied to the main foundation. 2. A grade beam, reinforced as above and a minimum 12 inches in width, should be utilized across garage entrances. The base of this grade beam should be at the same elevation as the"';- bottom of the adjoining footings. 3. Concrete slabs should be underlain with a minimum of four inches of washed sand or crushed rock. In addition, where moisture condensation is undesirable, a vapor barrier GeoSoils, Inc. .- --- ,..,."""",c.-- . -,"-._--=-"""-,-=~,,,==----- ~' ~::: . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 14 consisting of a minimum of' six mil polyvinyl chloride or equivalent membrane with all laps sealed should be provided. At least one inch of moist sand should be placed over the membrane to aid in uniform curing of the concrete. Consideration should be given to placement of expansion joints within Plan I slabs. 4. six inch by six inch, No.6 by No.6 welded wire mesh or its Concrete slabs, including garages, should be reinforced with ~ . equivalent. All slab reinforcement should be supported to t ensure placement near the vèrtical midpoint of the concrete. 5. Garage slabs should be poured separately from the residence footings and be quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained d ¡ , with expansion joint material to permit relative movement. 6. presaturation is recommended for ;these soil conditiòns. ¡ The moisture condition of each slab area should be equal to or ;.., greater than 120 percent of optimum for highly expansive soils to a depth of 24 inches below slab grade and verified . ¡ by this office within 48 hours of pouring slabs and prior to placing visqueen or reinforcement. 7. Alternatively, post tensioned foundations and slab systems , . , may be used. 120 percent of optimum moisture at 18 inches below slab If these are used, presaturation to at least, GeoSolls, Inc. , ¡ . ¡ , j . ; . , i ' I I I I I I I I _h_... _. ...- -- -----------_n___.__-- . SHEA HOMES W.O. 717.2-SD -..- --_0_.. SEPTEMBER 30,1988 J>AGE 15 ' grade is recommended and perimeter cut off walls at least 18 inches deep should be constructed. Post Tensioning As an alternative to any of the above designs, a post tensioned foundation system may be utilized. If used, we recommend that' perimeter cut-off walls consistent with the above footing depths, be provided and presaturation to the above recommended moisture contents be obtained. Retaining Walls Retaining walls may be designed for an equivalent fluid pressure backdrain or weepholes Covered with a minimum of 12 inches of as shown on the following table. Surface Slope of Retained Material Horizontal to Vertica¡ Level 5 to 1 4 to 1 3 to 1 2 to 1 Retaining walls should be provided gravel, a compacted fill blanket at the surface, and proper surface drainage devices. Equivalent Fluid Weight Lb./3 30 32 35 38 43 with pipe a and gravel" section of this report. Footings may be designed as per the "Foundation Recommendations" GeoSoils, Inc. -'- . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30,1988 PAGE 16 If the passive earth pressure is added to the friction, then the passive pressure should be reduced by one third. Additional active pressure should be added for a surcharge condition. UTILITY TRENCH BACKFILL Utility trench backfill should be placed and compacted to the following standards: ~ I , 1. Ninety percent of the laboratory standard, if native material is used as backfill. 2. As an alterative, for the interior of the slab, clean sand (SE>30) may be utilized and jetted in place. Ninety percent relative compaction is recommended regardless of the , I, placement technique. Observation, probing and testing to I, ... verify adequate results is recommended. , I 3. Exterior trenches paralleling a footing and extending below a 1: 1 plane projected from the outside bottom edge of the footing should be compacted to 90 percent of the laboratory standard. Sand backfill should not be allowed in these , . ! trench backfill areas. Density testing along with probing should be accomplished to verify the desired results. GeoSoils, Inc. . ¡ I ! f i ' , , SHEA HOMES W.O. 717.2-SD SEPTEMBER 30,1988 PAGE 17 j : 4. . All trench excavations should conform to CAL-OSHA and local safety codes. Foundation Observation 1. All footing excavations should be observed by a representative of this office prior to placement of steel. 2. Soil generated from footing excavations to be used onsite i perimeters, or in parking or landscaped areas. This 1 I ¡ should be compacted to at least a relative compaction of 90 percent, whether it i~ to be placed inside the foundation, the structural area and towards the street. , ~ \ ~ . J tl 1 ~ material must not alter positive drainage patterns away from Drainaqe positive site drainage should be maintained at all times. Water should directed away from the foundation and descending slopes. Water should not allowed to pond and seep into the ground. Pad drainage should be directed towards the street or other approved areas. At the time of this report, drainage from the tomato farm above Lots 55 through 59, appears to be creating surficial seepage in the natural swales above Lots 57 and 58. We recommend placement of a gravel cut-off drain behind the cut slopes on Lots 57 and 58 to hinder migration of seepage into the cut slope. We suggest the depth(s) of the drain(s) to correspond to the thickness of GeoSoils, Inc. þ , .. ...-.--- --.. '---.---------- . SHEA HOMES W.o. 717.2-SD SEPTEMBER 30, 1988 PAGE 18 surficial soil plus one foot and the Upper porous zones of the weathered bedrock. (:t) feet deep. We anticipate this to be no more than six lowest point of the gravel drain, daylighting into the paved v- ditch constructed along the top of the trench should be capped A solid 4-inch pvc pipe should extend from the with native soils to hinder surficial downward migration of surficial water. Construction of the gravel drains should be observed by a representative of this office. '" Considering the nature of the bedrock and presence of rock fills ~ local seepage might occur on th'e lots. Subdrains have been constructed to accommodate water where it is anticipated. rainfall. However, ,other zones could develop due to heavy irrigation or If observed this office, should be consulted. . , Additional Grading Difficult excavating within the tract should be anticipated three I I , : feet (i:) below finish grade due to soil caps, hard rock cut '" areas, and shallow rock fills. Difficul t excavation should be anticipated within driveway areas on Lots 1, 2, 3, 4, 5, 15, 28, 31, 33, 35, 51, 52, 56, 57, 58, and 59 due to either shallow rock I \ fill or cut portions not overexcavated. The west facing fill slope off the driveway for Lot 32, and the cut slope for Lot 49 have been locally constructed steeper than i j i ì i I I : i . I ,j ¡ GeoSoils, Inc. i I \ . SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 19 the recommended 2:1 gradient. This should be corrected prior to fine grading or paving of the driveway. A one to three (:1:) foot high vertical slope has been created along the southern edge of Rim Rock Circle from Station 9+00 to Buman Road. Unsuitable, surficial materials have been exposed which should be trimmed back or removed. A portion of the cut slope in the cul-de-sac on Rim Rock Circle below Lot 71 has been over-excavated creating loose rock and 'Clebris. 'We recommend removal of the loose material and trimming back the unstable surficial soils. We anticipate a large amount of sheet flow runoff to occur down the driveway for Lots 64 and 65. The design engineer should review this for installation area of additional erosion protection. This may include asphalt berms across the entrance to Lot 64 and the bottom of the entrance to Lot 65. All rocks which have the potential to roll down slopes to adjacent properties should be stabilized. This office should be notified in advance of any additional fill placement, regrading of the site, or trench backfilling after This includes enlarging pad rough grading has been completed. areas, extending slopes, realignment of driveways, utility trench and retaining wall backfills. GeoSoils, Inc. ~ ¡ I ì; , , ¡ , ~ I ~. ,J . ! . . , ¡ :. ! . , , i ¡ , I l i i . i I i i I '--'---.'---.. f SHEA HOMES W.O. 717.2-SD SEPTEMBER 30, 1988 PAGE 20 REGULATORY COMPLIANCß cuts, fills and processing of original ground under the purview of this report have been completed under the periodic observation of and with selective testing by GeoSoils, Inc., and are found to be compliance with the grading còde of the City of Encinitas, California and the County of San Diego. Our findings were made and the recommendations prepared in conformance with generally accepted professional engineering practices and no further warranty is implied nor made*. !his report is subject to review by the controlling authorities for this project. *Refer to: California Business and Professions Code, Sec. 3. Section 6735.5 and Sec. 21. Section 8770.6. GeoSoils, Inc. ~ ..J I I : I ,. , 1 . '.--. ----. . . ~ , SHEA HOMES W.O. 717.2-5D -..-.. ---..----...- SEPTEMBER 30, 1988 PAGÉ 21 If be of further service, please do not hesitate to ~is ~ortunity to be of service is sincerely appreciated, you should have any questions Very truly yours, GeoSoils, Inc. EPL/CEL/TEM/mlc Ch is E. Lillback, incipal Engineer Enclosures: Plates la through lj - Co~action Test wcation Maps Table I - Field Density Test Results cc: (6) Addressee GeoSoils, Inc. ~ . I I : i ..-? , .. , ! . i I ¡ . I ! - : ¡ I INVESTIGATE 'w RfPORT SAN CARLOS ENGINEERING CONSULTING ENGINEERS 7655 M ELOTTE ST. SAN DIEGO, CA 92119 (619) 697-1967 SOIL CiVIL STRUCTURAL BUILDING DESIGN HOUSING INSPECTION REGISTERED PROFESSIONAL ENGINEER 17109 Mr. Bill Folsom Folsom Tennis Enterprises 5803 Mission Gorge Road San Diego, California 92120 Subject: Report of site preparation, grading and compaction of fills. Tennis Court 3402 Bumann Road Enci nitas, California Dear Mr. Folsom: Pursuant to your request, the undersigned civil engineer has completed tests, inspections and surveillance required to for site preparation, grading and compaction of fills on the subject project. All trash and debris have been removed from the areas to be graded and the site prepared and graded in accordance with my recommendations. Keys were properly cut and topsoils recompacted under my surveillance. A tennis court pad was developed on the property. The grading consisted of excavating, mixing and recompacting rocky materials previously deposited on the site and minor cuts and fills. Laboratory tests performed in accordance with ASTM test method 0-1557 indicate a maximum dry density ot 116.0 pct and optimum moisture of 17.5 % for the representative soils compacted on the site. Bearing soils on the site consist of stony clays with an Expansion Index of 102 @ 144.7 psf. The Unified Classification is (CL)/(ML). As the grading progressed, compaction procedures were observed and tests were made in accordance with ASTM test method 0-1556. Results of these tests are presented on Page "A" and their approximate locations are shown on Figure No.1. Mon, Dec 23, 1991 -2000 C- 1 Bumann Road Tennis Court Compactionllnspection Repo rt Co ntinued: Based on the results of tests and observations, ! hereby certify that all fills placed on the property have been compacted to within 90 percent of maximum dry density. The site has been properly prepared and graded in accordance with my recommendations. The site is suitable for its intended use. RECOMMENDA TIONS The expansive nature of the surface soils should be carefully considered in the design, construction and maintenance of a tennis court facility on the site. If you should have any questions after reviewing this report, please do not hesitate to call. We appreciate this opportunity to provide our professional services. Sincerely SAN ARLOS ENGIN EERING Attachments Mon, Dec 23, 1991 -2000 C- 2 Bumann Road Tennis Court Compaction/Inspection Report Continued: [pj.\@rÆ ~j.\~ TABLE OF FIELD DENSITY TEST RESULTS Test De pt h Field Field Laboratory Relative No ot Moisture Density Density Compaction Fill (& dry wt) (pet) (pet) (% Lab Den) ---- ----- -------- ------ --------- --------- 1. Key 16.9 105.6 116.0 91. 03 2. Key 16.8 104.9 116.0 90.43 3. 21 17.1 106.2 116.0 91.55 4. 31 17.1 106.6 116.0 91.90 5. 41 17.6 106.5 116.0 91.81 6. 41 17.7 107.2 116.0 92.41 7. 41 17.2 107.0 116.0 92.24 8. 21 17.5 104.8 116.0 90.34 9. 11 17.3 106.8 116.0 92.07 Mon, Dee 23, 1991 -2000 C- 3 ~ IlPPJ?ox /M87"E ¿O~;?'ÐN of F£J £7£,,</5/T y Tcsr...s Æ I \ 1 \ , \ l ) ¡ ~~ \ ~ ;i~' I en' '(, ,,(¡\ \ i I \ .1 ~;: I .., \ ~A \ , ~}.. ! v8 t6¿A po ,1 1(5 í& f-J t- í {L {,Ov -:r. ~ ~ ~ \:Q F/ 6 (./ ¡;? é ,A/¿;. 2: -