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HomeMy WebLinkAboutTract Map 21760 GeotechReportPreciseGrading(Mar.2,1994)-A -k Z-11400 7994 a Geotechnical Report of Precise Grading 58, 59, and 82 through 85 _%�M 0, Temecula Riverside County, California for Terra Nova Construction Company P.O. Box 612 Corona del Mar, California 92625 March 2, 1994 W. O. 589 -B -RC GeoSoils, Inc. • Geotechnical • Geologic • Environmental 24890 Jefferson Avenue • Murrieta, California 92564 • (909) 677-9651 • FAX(909)677-9301 Mailing Address: P.O. BOX 490 • Murrieta, California 92564 March 2, 1994 W.O. 589 -B -RC Terra Nova Construction Company P.O. Box 612 Corona del Mar, California 92625 Attention: Mr. Jim Rossman Subject: Geotechnical Report of Precise Grading, Lots 58, 59, and 82 through 85, Tract 21760, Temecula, Riverside County, California 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 provided for Lots 58, 59, and 82 through 85, Tract 21760, 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 on February 16, 1994, and was completed on February 24, 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 Unless superseded by recommendations presented herein, the recommendations contained in ' our previous referenced reports (GeoSoils, Inc., 1993) remain pertinent and applicable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 appropriately implemented. ' PREPARATION OF EXISTING GROUND 1. Major vegetation was stripped and cleared from the entire site prior to grading. ' 2. On lots 58, 82, 83, 84, and 85: 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 obtain a minimum relative compaction of 90 percent of the laboratory standard ASTM D ' 1557. V Terra Nova Construction Company Tract 21760, Temecula Lots 58, 59, and 82-85 W.O. 589 -B -RC March 2, 1994 Page 2 3. On lot 59: The pad area and at least 5 feet beyond in each direction was 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. 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, Plate 1. 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: 3 GeoSoils, Inc. Terra Nova Construction Company Tract 21760, Temecula Lots 58, 59, and 82-85 Soil Tvpe A - Silty Sand, Dark Brown F - Sandy Silt, Olive Brown Expansion Index Maximum Dry Density pcf 128.0 121.5 W.O. 589 -13 -RC March 2, 1994 Page 3 Optimum Moisture Content. % 9.5 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 58, 59 21 Low 82-85 27 Low CONCLUSIONS AND RECOMMENDATIONS 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. 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. 0 GeoSoils, Inc. i Terra Nova Construction Company Tract 21760, Temecula Lots 58, 59, and 82-85 W.O. 589 -13 -RC March 2, 1994 Page 4 We appreciate this opportunity to be of service. If you have any questions, please call us at (909) 677-9651. pFESS/ Respectfully submitted Ohq� GeoSoils, Inc. No. GE 211 Geotechnical gEn�gii-n�ee %!yl ' ==�� Sa�� � of CAUF�� Sherry LjEaton Project Manager Enclosures: Table I - Field Density Test Summary Plate 1 - Field Density Test Location Map Distribution: (6) Addressee GeoSoils, Inc. WORK ORDER: 589 -B --RC TABLE I Terra Nova FIELD DENSITY TEST SUIRIARY ' TEST DATE LOCATION ELEV MOIST DRY TEST SOIL NO OR CONT DEN REL HETH TYPE ' DEPTH % PCF COMP 159 2-16-94 Lot 85 1065.5 14.7 109.9 90.5 N F 160 2-16-94 Lot 84 1067.5 14.4 109.4 90.0 N F 161 * 2-16-94 Lot 83 1070.0 16.8 99.6 82.0 N F 161 A 2-24-94 Lot 83 1070.0 14.3 111.5 91.8 N H 162 2-16-94 Lot 58 1068.6 12.3 111.4 91.7 N F ' 163 164 2-23-94 2-23-94 Lot 84 FG Lot 83 FG 1069.5 1072.0 10.3 119.0 93.0 N A 12.4 117.8 92.0 N A 165 2-23-94 Lot 85 FG 1067.5 11.0 112.9 92.9 N F 166 2-23-94 Lot 82 1073.0 12.8 110.0 90.5 N F ' 167 2-23-94 Lot 82 FG 1075.0 9.7 118.0 92.2 N A 168 2-23-94 Lot 58 FG 1070.6 9.5 115.7 90.4 N A 169 2-23-94 Lot 59 FG 1074.2 9.6 117.3 91.6 N A ' Legend: - Failing Test A - Retest ' FG - N - Finish Grade Nuclear Densometer