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Home My WebLink AboutTract Map 3552 Lot 29 Compaction Results Rough Grading .. . L~7'~~;2..&Z w. C. HOBBS, CONSULTING ENGINEER 30833 LILAC CIRCLE MURRIETA, CALIFORNIA 92563 (909) 696.7059 1'R3~z.. LoT' Z'\ Project No: 04063-2 Date: March 14, 2005 I Mr. Morry Leon ; 29887 Via Puesta Del Sol ITemecula, California 92561 : Subject: Report of Compaction Test Results, Rough Grading for Residence, Lot 29 of Tract 3552, Palma Drive, City of Temecula, County of Riverside, California ; References: Preliminary Soil Engineering Evaluation, Lot 29 of Tract 3552, Las Palmas Drive, City of Temecula, Riverside County, California dated Nov. 29, 2004, and prepared by W. C. Hobbs, Consulting Engineer : Dear Mr. Leon, : Contained herein are the results of compaction testing and obseNations made during rough grade 'operations for the house pad and driveway area at the subject site. The location of the tests are :plotted on a portion of the original grading plan attached at the back of this report. The results of ,laboratory and field density testing are contained in the attached Appendix A. lit should be noted that obseNation and testing for the pad and drive areas was performed on a :periodic basis, and portions of the information relative to procedures used was provided by the ;grading contractor and by direct obseNation. This obseNation,and testing was performed in accordance with generally accepted engineering practices. The conclusions and recommendations contained in this report were based on the data :available and the interpretation of such data as dictated by our experience and background. Hence, :our conclusions and recommendations are professional opinions; therefore, no other warranty is :offered or implied. 'Accompanying Illustrations and Appendices Test Location Map, Plate 1 'Appendix A, Summary of Field Density and Laboratory Test Results ~ . . I Mr. Leon, Lot 29, Tract 3552, Palma Drive I Project No: 04063-2 Page: 2 Summary of Earthwork I General ! Site grading was conducted during the month of March, 2005, by PDQ Heavy Equipment and : Grading of T emecula, Califomia I Rough Grading I Areas to receive fill or to be processed were first stripped of vegetation that was disposed of properly : on the site or otherwise removed from the site. The ground to receive fill was scarified to a depth of , 12 inches, broughtto near optimum moisture content and compacted to the minimum requirements , prior to the placement offill. All areas offill placement were prepared properly and are suitable. The . building pad to 5 feet from the edge was processed a minimum of 12 inches below proposed final : grades, moisture conditioned to near optimum moisture content and compacted. Supplementally, :the entire pad and building area was over excavated such that a fill layer a minimum of 3 feet in ,thickness exists on the entire pad building area. : Fill was processed and or placed in 12-inch loose lifts, brought to a uniform near optimum moisture :content and compacted to a minimum of 90 percent relative compaction. This is relative to the 'maximum dry density as determined in accordance with ASTM test designation D 1557-78. : Grading was accomplished with the use of a D-4 size Dozer, Scraper and Motor Grader. Water was 'added when necessary with the use of a fire hose drawing from a meter. Compaction was achieved :by repeated passes of the heavy equipment over each lift of fill. Iln'the rear yard area, a keyway was excavated a minimum of 2 feet into competent earth materials. :As the fill progressed up the slope, loose surface materials from previous fills were benched and :deleterious materials such as weeds and roots were removed from the soil that was later utilized for :compacted fill. CONCLUSIONS AND RECOMMENDATIONS :CONCLUSIONS (1 ) Test results indicate that fill placed as a result of this grading, to the horizontal and vertical limits as indicated, has been compacted to at least 90 percent relative compaction. A total of 8 tests were conducted and the results are tabulated at the back of this report. The approximate locations of the field density tests are indicated on the Test Location Plan, Plate 1. (2) Fill Materials consisted of onsite slightly silty sands and sand. w. C. HOBBS, CONSULTING ENGINEER 2... ~ ~ . . I Mr. Leon, Lot 29,'Tract 3552, Palma Drive I Project No: 04063-2 Page: 3 : (3) Based on obseNation and classification, the soils on the pad area appear to have an expansion ; potential of low to very low. : (4) Groundwater was not encountered in any of the excavations during rough grading operations. I RECOMMENDATIONS The recommendations contained herein are contingent upon W. C. Hobbs being retained to provide ,the following seNices in order to confirm design assumptions and review the field conditions of any : excavations. iBearing Value and Footing Geometry :A safe allowable bearing value for foundations embedded into native bedrock materials or properly :compacted fill is 1500 psf. This value may be increased at the rate of 1 00 psf per foot of depth and 1100 psf per foot of width over the minimums, but should not exceed 1800 psf. Continuous footings 'should have a minimum width of 12 inches and depth of 12 inches and conform to the minimum :criteria of the UBC for single and or multistory construction for low expansive soils. The use of !isolated column footings is not discouraged, however, where utilized, should have a minimum !embedment of 12 inches below lowest soil grade. The minimum distance of the bottom of footings 'on the outside edge and the native slope face is 8 feet. iSettlement 'The bearing value recommended above reflects a total settlement of 0.5" and a differential :settlement of 0.5". Most ofthis settlement is expected to occur during construction. :Concrete Slabs 'All concrete slabs on grade should be 4 inches thick. They should be underlain by 2 inches of sand or gravel. Areas that are to be carpeted or tiled, or where the intrusion of moisture is objectionable, should be underlain by 6 mil visqueen properly protected from puncture with an additional 1 inch of :sand over it. This arrangement of materials would result in a profile downward of concrete, 1 inch of sand, 6 mil visqueen, 2 inches of sand and subgrade soil. Contractors should be advise that when pouring during hot or windy weather conditions, they should provide large slabs with sufficiently deep weakened plane .joints to inhibit the development of irregular or unsightly cracks. Also, 4 inch thick slabs should be jointed in panels not exceeding 12 feet in both directions. :Concrete Concrete on this job may consist ofT ype II portland cement. Type V cement will NOT be required. W. C. HOBBS, CONSULTING ENGINEER .3 \ . . IMr. Leon, Lot 29,Tract 3552, Palma Drive : Project No: 04063-2 Page: 4 1 Recommendations, continued I Reinforcement : Continuous footings should be reinforced with a minimum of one number 4 steel bar placed at the Itop and one at the bottom. Slabs should be reinforced with a minimum of number 3 steel bars : placed at the center of thickness at 18-inch centers both ways or welded wire fabric equivalent to '10xlO 10/10 may be used. It is understood that the sectional values for the two schedules are : different, and is of no design concem. The steel bars have been proven to have a better : performance history and selection is up to the builder. Additional requirements may be imposed by Ithe structural engineering design. I Retaining Walls ; Retaining walls should be designed to resist the active pressures summarized in the following table. 'The active pressure is normally calculated from the lowermost portion of the footing to the highest : ground surface atthe back of the wall. The active pressures indicated in the table are equivalentfluid ,densities. Walls that are not free to rotate or that are braced at the top should use active pressures : that are 50% greater than those indicated in the table. RETAINING WALL DESIGN PRESSURES Slope'of adiacent Qround Active Pressure Passive Pressure 2:1 30 pcf 42 pcf 300 pcf 200 pcf LEVEL 'These pressures are for retaining walls backfilled with noncohesive, granular materials and provided ,with drainage devices such as weep holes or subdrains to prevent the build-up of hydrostatic : pressures beyond the design values. It is imperative that all retaining wall backfills be compacted to : a'minimum of 90 percent relative compaction in order to achieve their design strength. Failure to : provide proper drainage and minimum compaction may result in pressures against the wall that will : exceed the design values indicated above. Surface waters should be directed away from retaining ,wall backfill areas so as not to intrude into the backfill materials. W. C. HOBBS, CONSULTING ENGINEER ~ . . IMr. Leon, Lot 29,Tract 3552, Palma Drive : Project No: 04063-2 Page: 5 I Recommendations, continued I Lateral Loads 'The bearing value of the soil may be increased by one third for short duration loading (wind, ! seismic). Lateral loads may be resisted by passive forces developed along the sides of concrete I footings or by friction along the bottom of concrete footings. The value of the passive resistance for I level ground may be computed using an equivalent fluid density of 300 pcffor level ground. The total I force should not, exceed 3000 pst. A coefficient of friction of .40 may be used for the horizontal ! sbiVconcrete interface for resistance of lateral forces. If friction and passive forces are combined, I then the passive values should be reduced by one third. I Fine Grading I Fine grading of areas outside of the residence should be accomplished such that positive drainage I exists away from all footings. Run-off should be conducted off the property in a non erosive manner I toward approved drainage devices at the street or the rear of the property per approved plans. I Construction litis advisable to have the foundation excavations obseNed by a soil engineer prior the placement I of construction materials in them as consequential changes and differences may exist throughout I the fill and natural soils on the site. , The ground left at the surface has very high erosion potential. It is strongly recommended that I erosion control measures be placed as soon as practical to minimize damage. , The opportunity to be of seNice is appreciated. Should questions or comments arise pertaining to I this document, please contact the undersigned, in writing, for clarification. I Respectfully Submitted, I W. C. HOBBS, CONSUL TI Addressee (4) Appendix A, Plate 1 W. C. HOBBS, CONSULTING ENGINEER S' . . APPENDIX A SUMMARY OF LABORATORY TEST RESULTS CUNe Letter Soil Description Maximum Densitv pcf A Silty, SAND fn to med. Tan Grey to Srown(SM) 126.9 Maximum density and optimum moisture determined in accordance with test method ASTM D 1557-78. Optimum Moisture % 10.4 W. C. HOBBS, CONSULTING ENGINEER " : . . Appendix A Summary of Field Density Tests Project No: 04063-2 Report Date: March 15, 2005 Project for Mr. Morry Leon Test # Date Location Elevation Curve Max. (pct) M.C.% Dens. (pct) Compo % Remarks 1 ,Mar-05 PAD AREA 1052 A 126.9 10.8 114.8 90 FILL 2 ,Mar-05 PAD AREA 1054 A 126.9 11.9 115.5 91 FILL 3 ,Mar-05 PAD AREA 1056 A 126.9 10.9 117.4 93 FILL 4 ,Mar-05 PAD AREA 1058 A 126.9 11.3 116.3 92 FILL 5 ,Mar-05 PAD AREA 1060 A 126.9 12.4 116.9 92 FILL 6 ' Mar-05 PAD AREA 1062 A 126.9 11.7 118.1 93 FILL 7 ,Mar-05 PAD AREA 1060 A 126.9 12.6 115.7 91 FILL 8 ,Mar-05 PAD AREA 1062 A 126.9 11.2 114.5 90 FILL Field Density Tests were conducted in accordance with ASTM D 2937 fp Denotes finished pas test. 1 ~ ~ \ .....j::(/)~ Q::lfi:5~o ~.....Q..;t:Q..<u. IZ o;c!o ~>-o 12 <:I: <::lv.d:::(I)-t ...... l-(f,Io:<u.~f35: !g~ Z>-OluOn.Zfij 1ft:.. ~~,,;C:OLlJ~~1- .....- t-""!i:o.........-< .(/)o a:~o:z:C:O:t~:i !~~ ~a:o<c::> w o::e; WClX>=<t!:l~~ '0. Clo!:::~Qa:i;!!iim il:!:l~ ~~:t<~.....~u.. i;;;!~ U::?fi3!!iLfg::e~ I!DO:: 0:0:>00:0<.., ~~ ca:<g:::lOllJt'? ~.. om <:: ..~. . <;; '" ",0 -", ......, "'~ , '" ' OJ:: M 1-(1) ~ ~5 Lf~ ",0 ~~ ;~ ~"' ::io. 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