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HomeMy WebLinkAboutTract Map 3883 Lot 229 Rough Grading , . . I~ .l__HJE. Soils Co. E-mail: thesoilsco@aol.com \,Q,. ~ \..c)T 2211 ! May 25, 2001 ! \'vIr. Bernie Schumacher . 41760 Bargil Court Temecula, California 92591 I SUHJECT: REPORT OF ROUGH GRADING Proposed Single-Family Residence SWC of Via Norte and A venida Centario Temecula, Riverside County, California Work Order No. 248101.22 I REFERENCE: T.H.E. Soils Company, dated February 9, 2001, "Limited Geotechnical Investigation, Proposed Single-Family Residence, SW Comer of Via Norte and Avenida Centario, Temecula, Riverside County, California", Work Order No. 248101.22; I Dear Mr. Schumacher: INTRODUCTION ! In accordance with your request, we have prepared this Report of Rough Grading presenting the : results of our observation and testing during rough grading at the subject site. All compaction test 'results are included in this report in Appendix B, Table I. The subject site (SWC of Via Norte and 'Avenida Centario) was graded in accordance with the requirements of the City of Temecula and the ! 1997 Uniform Building Code (UBe). The 40-scale "As-Built" (provided by you) was utilized during grading and to locate our field density tests and ,was utilized as a base map for our test locations presented as Plate 1. !ACCOMPANYING MAPS AND APPENDICES Location Map - Figure I (2,000-scale) Density Test Location Map - Plate I (30-scale) 'Appendix A - Laboratory Test Results 'AppendixB - Results of Compaction Tests IT.H.E. Soils Co. W.O. 248101.22 \ . . Mr. Bernie Schumacher May 25, 2001 Page 2 . Proposed Development The proposed development calls for the construction of a wood-framed, stucco exterior, single- . family residence with attached garage. The subject structure will be founded entirely in fill. : Site Description The subject site is located in a large parcel residential development (Meadow View area) in the city I ofTemecula in southwest Riverside County, California The site is bordered on the north, east, and , west by existing large parcel residential lots and on the south by a vacant undeveloped lot proposed I for large parcel single-family residential development. The geographical relationships of the site i and surrounding area are shown on our Site Location Map, Figure 1. I Prior to grading, the subject site was a vacant undeveloped parcel located on the north side of a I large hill, which. sloped to the north toward Via Norte. Natural gradients on the pre-existing slope . varied from approximately 17% on the south side to less than 33% on the north side of the lot. . Vegetation on site, prior to grading, consisted predominately of a low dense growth of annual weeds . and grasses. OVEREXCAVATION & RECOMPACTION OHSERVATIONS & TESTING I Prior to grading, the site was cleared of vegetation, which was removed from the subject site. Rough : grading operations consisted of the excavation of a keyway along the toe of the proposed fill slope. The keyway was founded approximately 4 to 5-ft below the existing ground surface and a minimum of I-ft into dense sedimentary bedrock materials of the Pauba Formation. The keyway was tilted at . a minimum inclination of 2% into the existing hillside. The exposed earth materials within the I keyway were scarified a minimum of 12-inches below the exposed surface, moisture conditioned to ! near optimum moisture and recompacted to 90% of the dry density as determined by ASTM 1557. ! Benching was maintained into medium dense to dense sedimentary bedrock materials during , grading operations. All topsoil/colluvial soils were removed during benching operations and were . utilized as fill materials. I Rough grading operations included the overexcavation of the cut portion of the building pad a minimum of 5-ft beyond the building footprint and a minimum of 3-ft below the original ground . surface or a minimum of 2-ft below the bottom of the footing. The grading contractor staked the building footprint prior to overexcavation. Medium dense to dense sedimentary bedrock was ! exposed throughout the entire overexcavation. The exposed bedrock materials exposed within the removals were scarified a minimum of 12-inches below the exposed surface, moisture conditioned . to near optimum moisture and recompacted to 90% of the dry density, as determined by ASTM .1557. TH.E. Soils Co. w.o. 248101.22 v T .H.E. Soils Co. Phillie: l\}lI91 6iS-9669 FAX: (909) 67S-9769 11 'll.i CelllfJI Street, Suite A. \\'ildulI\Jf, C\. 92.i9.i . . :;.L.-/' J~~<(?"'-':' ; ~ li~' ~ - . RO.AO , -';'::;' ,,-_.~ -~fW /'^ C~. ~ "- ~ I-~ . ~ , ,j,: '-. "_.. ~: ~ '. ~ o . 1000 2CXlO SCAl.E: FT. 3000 '000 SITE LOCATION MAP w.o. # 248101.22 Dale: MAY 2001 Figure: 1 :3> '. . Mr. Bernie Schumacher May 25, 2001 Page 3 On-site fill materials generally consisted of on-site silty sands (Unified Soil Classification -SM) derived from the on-site sedimentary bedrock and topsoil/colluvial materials, Fill placement and compaction was achieved utilizing a Caterpillar 0-8 dozer. Moisture conditioning was accomplished utilizing a water truck. The fill was placed in 4 to 6-inch thick lifts and moisture conditioned, as needed, to bring the material to near optimum moisture content, and was then properly compacted. A minimum degree of compaction of 90% was required, as determined by ASTM 1557. TESTING PROCEDURES Field Density Testing Field density testing was performed in accordance with ASTM Test Method D2922 (nuclear gauge). Areas failing to meet the minimum compaction requirements were reworked and retested until the specified degree of compaction was achieved. The elevations and the results of the field density tests are presented in Appendix B, Results of Compaction Tests, Table I. The approximate locations of the tests are shown on the Density Test Location Map, Plate 1. Maximum Density Determinations Maximum Density/Optimum Moisture determinations were performed in the laboratory on representative samples of on-site soils used in the fill operations. The tests were perfurmed in accordance with ASTM 01557, Test Method A The test results, which were utilized in determining the degree of compaction achieved during fill placement, are presented in Appendix A, Table L Expansion Index Testing Expansion index testing was performed on a representative sample of the upper I-ft of the earth materials during the prelimil1llry report. The results yielded an expansion index of 0, which indicated that on-site soils exhibit very low expansion potential. Soluble Sulfate Content Based on our previous soluble sulfate testing performed on a representative sample of the on-site earth materials anticipated to be exposed on the pad surface, from a corrosivity standpoint, Type II 'Portland Cement can be used for construction. A representative sample of the on-site earth material exposed in the upper I-ft of the pad surfuce was obtained for testing. Due to the time constraints of this report, the results were not available at the completion of this report and will be added as an addendum once received. Babcock & Sons, Laboratory of Riverside, California performed the laboratory analysis, which is included in Appendix A. T.H.E. Soils Co. W.O, 248101.22 ~ , , I ! . ,b N 13 .~I.8C~ \ \. \ \ /' , , -.-,...... l'1 I 0 \ m -+-- z -, (j) \ - '" ~ ~ , -< I '-~, ~ I m (j) ~ i r ! 0 () )> ~ - 0 Z s: )> ""U / -.--'-___n - -!I~~-t ----. --.-.-- --~--_. ----1 -,-- .::.~:=~.~. : _ l:rto ""'--I 0....... ---- , -- --.-~ ~ ===- -'- W.O. NO. 248101.22 PLATE 1 '. . l'vIr. Bernie Schumacher May 25, 2001 Page 4 Cut-to-FiU Transition The proposed building pad was overexcavated a minimum of2-ft below the bottom of the proposed footing elevation, eliminating the transition. The exposed bottom of the overexcavation was scarified a minimum of 12-inches below the exposed surfuce, moisture conditioned to near optimum moisture and recompacted to 90% of the dry density, as determined by ASTM 1557. Total and differential settlements, under static loads of footings supported on compacted fill materials and sized for the allowable bearing pressures, are not expected to exceed about o/.-inch for a span of 40~ft. These settlements are expected to occur primarily during construction, RECOMMENDATIONS . Foundation System Design The foundation elements should be founded entirely in compacted fill materials. T.H.E. Soils Company should perform a footing inspection, prior to placement of reinforcement to insure the proposed footing excavations are in conformance with the job specifications. The footings and slab should be designed in accordance with the recommendations presented in the above referenced limited geotechnical soils report (T,H.E. Soils Company, 2001) presented as follows: Where the site is prepared as recommended, the proposed structures may bear on continuous and isolated footings. For one-story houses the footings should have a minimum width of 12-inches, and be placed at least 12-inches below the lowest final adjacent grade. For two- story houses the footings should have a minimum width of 12-inches and placed at least 18- inches below the lowest final adjacent grade. As a minimum, all footings should have one No.4 reinforcing bar placed at the top and bottom of the footing. The following parameters should be considered for lateral loads against permanent structures founded on fill materials compacted to 90 percent of the maximum dry density. Soil engineering parameters for imported soil may vary. Equivalent Fluid Pressure for Level Backfill Active: 35 pcf Passive: 462 pcf Coefficient of friction (concrete on soil): 0.35 T.H.E. Soils Co. W.O. 248101.22 Cp . . Mr. Bernie Schumacher May 25, 2001 Page 5 If passive earth pressure and friction are combined to provide required resistance to lateral forces, the value of the :passive pressure should be reduced to two thirds of the above recommendations. These values may be increased by one third when considering short-tenn loads such as wind or seismic forces. An allowable safe bearing capacity of 2,200 pounds per square foot (pst) may be used for design of continuous footings that maintain a minimum width of 12-inches and a minimum depth of at least 12-inches below the lowest adjacent grade and founded a minimum of 12-inches into compacted fill materials. The bearing value may be increased by 10% for each additional foot of depth and/or width to a maximum of 3,400 pst: The bearing value may be increased by one-third for seismic or other temporary loads. The house slab should be underlain by a moisture/vapor barrier consisting of a 6-rnil plastic membrane covered with 2-inches of "clean" sand. 'The structural engineer should design footings in accordance with the anticipated loads, the soil . parameters given, and the existing soil conditions, . Surface Drainage Surface drainage should be directed away from foundations of buildings or appurtenant structures. All drainage should be directed toward streets or approved permanent drainage devices. Where landscaping and planters are proposed adjacent to foundations, subsurface drains should be . provided to prevent ponding or saturation offoundations by landscape water. Construction Monitoring Observation and testing, by T.H,E. Soils Company is essential to verify compliance with recommendations and to confirm that the geotechnical conditions encountered are consistent with the recommendations of this report. T.H.E. Soils Company should conduct construction monitoring, at the following stages of construction: . Following excavation of footings for foundations . During fill placement . During utility trench backfill operations LIMITATIONS This report is issued with the understanding that it is the responsibility of the owner, or his representative, to ensure that the information and recommendations contained herein are brought to the attention of the project architect and engineer, The project architect or engineer should T.H.E. Soils Co. W.O. 248101.22 '\ . . Mr. Bernie Schumacher May 25, 2001 Page 6 incorporate such information and recommendations into the plans, and take the necessary steps to see that the contractor and subcontractors carry out such recommendations in the field, This firm does not practice or consult in the field of safety engineering, We do not direct the contractor's operations, and we cannot be responsible for other than our own personnel on the site. Therefore, the safety of others is the responsibility of the contractor. The contractor should notifY the owner ifhe considers any of the recommended actions presented herein to be unsafe. The findings of this report are valid as of the report date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties, In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and revision as changed conditions are identified. SUMMARY Our description of rough grading operations, as well as observations and testing services, are limited to those grading operations performed between May 5, 2001 to May 10, 2001. The conclusions and recommendations contained herein have been based upon our observation and testing, as noted. It is our opinion the work performed in the areas denoted has been accomplished in accordance with the job specifications and the requirements of the regulating agencies. No conclnsions or warranties are made for the areas not tested or observed. This report is based on information obtained during rough grading. No warranty as to the current conditions can be made. This report should be considered subject to review by the controlling authorities, T.H.E. Soils Co. W.O. 248101.22 co '. . 'l'vIr. Bernie Schumacher May 25,2001 Page 7 IThis opportunity to be of service is sincerely appreciated, If you have any questions, please call. .y ery truly yours, T.R.E. Soils Company ~,) IJo P. Frey Pr . ect Geologist ~!1iJC11d L; ~ J~ es R. H';;ris:~Vo/~~'''P\-W roject Manager I JPF IITR/JRH:jek T.H.E. Soils Co. W.O. 248101.22 '\ '. T.H. E. Soils Co. APPENDIX A Laboratory Test Results . W.O. 248101.22 \0 :. . TABLE I Maximum Density/Optimum Moisture 0/0 Description LbstW Moisture I Dark Brown Silty Sand 128.0 8,6 TAHLE II EXPANSION INDEX TEST LOCATION EXPANSION INDEX EXPANSION POTENTIAL Pad Surface 0 to I-it 0 Very Low !T,H,E. Soils Co, W.O. 248101.22 \\ '. T.H.E. Soils Co. APPENDIX B Results of Compaction Tests . W.O. 248101.22 \1/ .. . TAlJLEI RESULTS OF COMPACTION TESTS Date: May 2001 Job No.: 248101.22 Name: Schumacher Test Test Elevation Moisture Unit Dry Relative Soil Test Location No. Date Depth Content Density Compaction Type (Feet) (%) (pCF) (%) 1 05/07/01 1185 15.4 115.0 90N 1 See Plate 1 2 " 1187 10.3 115.8 91N 1 " 3 " 1189 13.1 115.0 90N 1 " 4 " 1190 10.9 116.0 91N 1 " 5 05/08/01 1192 9.9 121.2 95N 1 " 6 " 1194 8.2 118.5 93N 1 " 7 05/10/01 1196 8.7 118.6 93N 1 " 8 " 1198 8.9 118.5 98N 1 " 9 " 1200 12.9 115.1 90N 1 " 10 " FG 10.2 115.4 90N 1 " 11 " FG 10.0 116.3 91N 1 Slope Test SEEIPLAN FOR TEST LOCATIONS SC -,Sand Cone ASTM Dl556; DC-Drive Cylinder ASTM D2937; N-Nuclear ASTM 3017; NG-Natural Ground + 85% = Passing Test **TEST FAILED, SEE RETEST T.H.E. Soils Co. W.O. 248101.22 \"? '