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Home My WebLink AboutTract Map 21760 GeotechReportPreciseGrading(Feb.8,1994)11 z •V- i di FE p 16 ^^` Geotechnical Report of Precise Grading 10 through 16 and 24 through 32 Tract 21760, Temecula Riverside County, California for Terra Nova Construction Company P.O. Box 612 Corona del Mar, California 92625 February 8, 1994 W. O. 589 -B -RC GeoSoils, Inc. I 1 1 Geotechnical • Geologic • Environmental 1 24890 Jefferson Avenue • Murrieta, California 92564 • (909) 677-9651 • FAX(909)677-9301 Mailing Address: P.O. BOX 490 • Murrieta, California 92564 1 February 11, 1994 W.O. 589 -B -RC Terra Nova Construction Company 1 P.O. Box 612 Corona del Mar, California 92625 1 Attention: Mr. Jim Rossman Subject: Geotechnical Report of Precise Grading, Lots 10 through 16 and 24 ' through 32, Tract 21760, Temecula, Riverside County, California 1 References: 1) "Geotechnical Evaluation of Hydroconsolidation and Settlement Potential, Tract 21760, Temecula, County of Riverside, California," W.O. 589 -A -RC, by GeoSoils, Inc., dated June 7, 1993. ' 2) "Summary of Existing Graded Lots Potentially Requiring Remedial Earthwork, Tract 21760, Temecula, County of Riverside, California," W.O. ' 589 -A -RC, by GeoSoils, Inc., dated March 5, 1993. In accordance with your request, this final geotechnical report of precise grading is 1 provided for Lots 10 through 16 and 24 through 32 in Temecula, Riverside County. The site was previously graded under the observation and testing services of Soil Tech, Inc. (1990). Precise grading within the subject project, under purview of this report, began 1 on January 21, 1994, and was completed on February 3, 1994. Unless superseded by recommendations presented herein, the recommendations contained in our previous referenced reports (GeoSoils, Inc., 1993) remain pertinent and applicable and should be 1 appropriately implemented. PREPARATION OF EXISTING GROUND 1 1. Major vegetation was stripped and cleared from the entire site prior to grading. 1 2. On lots 15, 24, 25, 26, 27, and 28: The pad areas and at least 5 feet beyond in each direction were overexcavated 36 inches and the bottom was then scarified 12 inches, brought to at least optimum moisture content, then compacted to 1 obtain a minimum relative compaction of 90 percent of the laboratory standard ASTM D 1557. 1 1 GeoSoils, Inc. U Terra Nova Construction Company Tract 21760, Temecula Lots 10-16 and 24-32 W.O. 589 -B -RC February 8, 1994 Page 2 3. On lots 10, 11, 12, 13, 14, 16, 30, 31, and 32: The exposed subsoils were scarified to a depth of about 12 inches, brought to at least optimum moisture content, then compacted to a minimum relative compaction of 90 percent of the laboratory standard. Fill Placement Fills consisted of native onsite materials that were placed in thin 6- to 8 -inch lifts, brought to at least optimum moisture content, then compacted to obtain a minimum relative compaction of 90 percent of the laboratory standard. Field Testing 1. Field density tests were performed using nuclear densometer-methods ASTM D 2922-90 and D 3017-81 and sand -cone method D 1556-90. The test results are presented in the enclosed Table I. The estimated locations of the field density tests are shown on the enclosed Field Density Test Location Map, Plates 1 through 3. 2. Field density tests were taken at periodic intervals and random locations to check the compactive effort provided by the contractor. Based upon the grading operations observed, the test results presented herein are considered representative of the compacted fill. ' 3. Visual classification of the soils in the field was the basis for determining which maximum dry density value to use for a given density test. ' 4. Compaction tests have been numbered in a continuous sequence for the tract. Only tests taken on the subject lots are presented herein on Table I. LABORATORY TESTING ' Maximum Density Testing The laboratory maximum dry density and optimum moisture content for the major soil types within this construction phase were determined in general accordance with ASTM test method D 1557-91. The following table presents the results: IP GeoSoils, Inc. LI 'J E 1 Terra Nova Construction Company Tract 21760, Temecula Lots 10-16 and 24-32 Soil Type E - Sandy Silt, Brownish Yellow F - Sandy Silt, Olive Brown Expansion Index Maximum Dry Density pcf 119.5 121.5 W.O. 589 -B -RC February 11, 1994 Page 3 Optimum Moisture Content, % 14.5 12.0 Expansive soil conditions have been evaluated for each lot. Representative samples of the soils near pad grade were recovered for expansion index testing. Expansion Index tests were performed for the typical foundation soil types exposed at pad grade in general accordance with UBC Standard #29-2 as outlined in Section 2904(b) of the Uniform Building Code. These test results are shown below: Lots Expansion Index UBC Classification 10-12 34 Low 13-16 21 Low 24-32 71 Medium CONCLUSIONS AND RECOMMENDATIONS Our previous report, dated March 5, 1993, recommended that lots 12 through 15 be overexcavated 36 inches in order to mitigate for a potential cut/fill transition line. During grading under purview of this report, these lots were processed 12 inches. Excavations for footings should be observed by a representative of our firm. If a cut/fill transition line is observed, recommendations for mitigation will be presented at that time. Recommendations for foundation design parameters, foundation construction, and utility trench backfill were presented in our referenced report, dated June 7, 1993. All findings, conclusions, and recommendations remain pertinent and applicable except as superseded herein. REGULATORY COMPLIANCE Processing of original/existing ground and placement of compacted fills under the purview of this report have been completed using the observation and selective testing services provided by representatives of GeoSoils, Inc. Earthwork was performed in general compliance with the Grading Code of the City of Temecula, California. GeoSoils, Inc. 0 ' Terra Nova Construction Company W.O. 589-13-13C Tract 21760, Temecula February 11, 1994 ' Lots 10-16 and 24-32 Page 4 Our findings were made in conformance with generally accepted professional engineering practices, and no further warranty is implied or made. GeoSoils, Inc. assumes no responsibility or liability for work, testing, or recommendations performed or provided by others. This report is subject to review by the controlling authorities for ' this project. We appreciate this opportunity to be of service. If you have any questions, please call ' us at (909) 677-9651. Respectfully submitted, ' GeoSoils, Inc. _ 4ROfESSIO* ' "En William a No. GE 217 z rr Geotec, E �R73-�L��Ar Sherry L. Eaton Of CA0� ' Project Manager Enclosures: Table I - Field Density Test Summary ' Plates 1 through 3 - Field Density Test Location Map Distribution: (6) Addressee F 11 F J ' GeoSoils, Inc. WORK ORDER: 589 -B -RC TABLE I Terra Nova Construction FIELD DENSITY TEST SUMMARY TEST NO DATE LOCATION ELEV MOIST DRY TEST SOIL OR CONT DEN REL METH TYPE LOT DEPTH PCF COMP 137 138 * 1-24-94 1-24-94 28 1096.5 14.6 107.7 90.1 N E 138 A 1-24-94 27 27 1098.0 15.8 101.2 84.7 N E 139 1-24-94 26 1098.0 14.5 107.8 90.2 N E 140 1-26-94 15 1100.0 14.5 109.5 91.6 N E 141 1-26-94 15 1102.6 14.5 112.1 92.3 SC F 142 2-02-94 25 1104.6 13.1 111.6 91.9 N F 143 2-02-94 26 1103.0 13.4 109.6 90.2 N F 144 2-02-94 27 1102.6 12.9 109.5 90.1 N F 145 2-02-94 28 1100.9 13.1 109.4 90.0 N F 146 2-02-94 29 1099.1 12.0 109.7 90.3 SC F 147 2-02-94 1097.6 13.0 115.0 94.7 N F 148 2-02-94 30 31 1096.2 12.9 110.3 90.8 N F 149 2-02-94 32 1094.2 13.0 110.4 90.9 N F 150 2-02-94 10 1093.1 13.0 109.8 90.4 N F 151 2-02-94 11 1094.1 12.9 109.7 90.3 SC F 152 2-02-94 12 1096.2 12.0 110.4 90.9 N F 153 2-02-94 13 1099.0 12.0 109.8 90.4 N F 154 2-02-94 14 1101.0 12.2 109.7 90.3 N F 155 2-02-94 24 1102.0 13.6 111.6 91.9 N F 156 2-03-94 25 1104.0 13.3 111.3 91.6 SC F 157 2-03-94 1104.4 12.1 110.1 90.6 N F 158 2-03-94 24 16 1106.2 12.9 111.0 91.4 N F 1106.7 12.7 109.4 90.0 N F LEGEND: * - Failing Test A - Retest N - Nuclear Densometer SC - Sand Cone _ �,. f .� �,�,�,,,�....�, r-�w^.'�^ ...'`•'"..rte �r�'r rt�,n�r+.-•r.,.+.., �...:.�-.�,..,: � r �w •1 .. �yv.� � ��v.,. 41 • �„ •,r.. v+�" �„�,�,;K..�+•'Y"r'"y""• 4s'w.. - ' � � , . �,?'mrei•:r «. y ° ° J. •,qy„ . 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