Loading...
HomeMy WebLinkAboutTract Map 9833-1 Lot 26 Compaction Test Rough Grading :./ , . . w. C. HOBBS, CONSULTING ENGINEER 30833 LILAC CIRCLE MURRIETA, CALIFORNIA 92563 (909) 696-7059 Project No: 06001-5 Date: July 12, 2006 , Mr. and Mrs. Householder : 33269 Elizabeth Road I Temecula, California 92592-4388 : Subject: Report of Compaction Test Results, Rough Grading Proposed Residence, Lot 26 of Tractil338 '!,.. ~)). , 31685 Pio Pico Road, City of Temecula Riverside County, Calif., APN 959-020-026 : Dear Mr. and Mrs. Householder, : Contained herein are the results of compaction testing and observations 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 ;Iaboratory and field density testing are contained in the attached Appendix A. 'It should be noted that observation 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 observation. This observation 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 ~pendix A, Summary of Field Density and Laboratory Test Results IN3ltW:lVd30 S>ll:IOM emsnd 'iln:J3V'J3LJO HI:J 900l l. 1 lnr \ ~ , . . !Scott Householder, Lot 26 of Tract 9338-1, 31685 Pio Pico, Temecula : Project No: 06001-5 Page: 2 Summary of Earthwork : General :Site grading was conducted during the month of July, 2006, by Gene Burchett Grading of 'Temecula, Califomia. : Rough Grading Weas to receive fill orto 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, brought to near optimum moisture content and compacted to the minimum requirements ,prior to the placement of fill. All areas of fill placement were prepared properly and are suitable for 'fill. Particles larger than 12" were removed and not placed in any fills. Fills place on the site were : placed at a lift thickness of less than 12 inches. Fill is located primarily on the south side of the pad. IThe resulting building area remains entirely in cut, however, the entire building area and 5 feet beyond has been over excavated and recompacted to provide a more uniform character of the . bearing soils. HI was 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. The entire building :area is in cut soils. : Grading was accomplished with the use of a D-6 size Dozer. Water was added when necessary 'withthe use rainbirds and a firehose drawing from a metered hydrant. Compaction was achieved : by repeated passes of the heavy equipment over each lift of fill. :At the toe of slope, a keyway was excavated a minimum of 2 feet into competent earth materials. :As the fill progressed up the slope, loose surface materials 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 7 tests were :conducted and the results are tabulated at the back of this report. The approximate locations of the ifield density tests are indicated on the Test Location Plan, Plate 1. To the best of my knowledge, the ;grading within the area of responsibilities is in accordance with applicable provisions of the C.B.C. (2) Fill Materials consisted of onsite silty sands. W. C. HOBBS, CONSULTING ENGINEER z.. . . iScott Householder, Lot 26 of Tract 9338-1,31685 Pio Pico, Temecula Page: 3 'Project No: 06001-5 : (3) Based on observation and classification, the matrix soils on the pad area appear to have an 'expansion potential of 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 services in order to confirm design assumptions and review the field conditions of any : excavations. I Bearing Value and Footing Geometry ,Asafe allowable bearing value for foundations embedded into native ground or properly compacted I fill is 1500 psf. This value may be increased at the rate of 100 psf per foot of depth and 100 psf per I foot of width over the minimums, but should not exceed 2000 psf. Continuous footings should have : a minimum width of 12 inches and a minimum depth of 18 inches and conform to the minimum : criteria of the UBC for single and or multistory construction for moderately expansive soils. The use : of isolated column footings is not discouraged, however, where utilized, should have a minimum I embedment of 12 inches below lowest soil grade. The minimum distance of the bottom of footings : on the outside edge and any slope face is 8 feet. : Settlement 'The bearing value recommended above reflects a total settlement of 0.5" and a differential : settlement of 0.5" over a horizontal distance of 20 feet. Most of this settlement is expected to occur I during construction and as the loads are being applied. I 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, I should be underlain by 6 mil visqueen properly protected from puncture with an additional 1 inch of I sand over it. This arrangement of materials would result in a profile downward of concrete, 1 inch I 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. ,A1so,4 inch thick slabs should be jointed in panels not exceed in!] 12 feet in both directions to : augment proper crack direction and development. W. C. HOBBS, CONSULTING ENGINEER 3 . . !Scott Householder, Lot 26 of Tract 9338-1, 31685 Pio Pico, Temecula Page: 4 'Project No: 06001"5 :Recommendations, continued : Concrete ,Concrete on this job may consist ofType II Portland cement. Type V cement will NOT be required. I Reinforcement : Continuous footings should be reinforced with a minimum of one number 4 steel bar placed at the top and one at the bottom. Slabs should be reinforced with a minimum of number 3 steel bars : placed atthe center ofthickness at 18-inch centers both ways or welded wire fabricequivalentto 6x6 '6/6 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. 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 at the back of the wall. The active pressures indicated in the table are equivalent 'fluid 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 Slooe'of adiacent qround Active Pressure Passive Pressure 2:1 35 pcf 45 pcf 250 pcf 175 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 , wali' backfill areas so as not to intrude into the backfill materials. W. C. HOBBS, CONSULTING ENGINEER t\ . . Scott Householder, Lot 26 of Tract 9338-1,31685 Pio Pico, Temecula Page: 5 Project No: 06001'5 :Recommendations, continued :Siesmic Considerations !This site is approximately 5 km from a Type B fault with a soil profile of So' ,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 ,footings or by friction along the bottom of concrete footings. The value of the passive resistance for !Ievel ground may be computed using an equivalent fluid density of 300 pcf for level ground. The ,total force should not exceed 3000 pst. A coefficient of friction of .40 may be used for the horizontal soil/concrete interface for resistance of lateral forces. If friction and passive forces are combined, jthen the passive values should be reduced by one third. :Fine Grading Fine grading of areas outside of the residence should be accomplished such that positive drainage :exists away from all footings. Run-off should be conducted off the property in a non erosive manner Itoward approved drainage devices at the street or the rear of the property per approved plans. W. C. HOBBS, CONSULTING ENGINEER 5' . . iScott Householder, Lot 26 of Tract 9338-1, 31685 Pio Pico, Temecula Page: 6 Project No: 06001'5 :Construction lit is advisable to have the foundation excavations observed by a soil engineer prior the placement :of construction materials in them as consequential changes and differences may exist throughout ithe fill and natural soils on the site. The ground left at the surface has very high erosion potential. It is strongly recommended that :erosion control measures be placed as soon as practical (in the rainy season) to minimize damage. The opportunity to be of service is appreciated. Should questions or comments arise pertaining to ithis document, please contact the undersigned, in writing, for clarification. Hespectfully Submitted, IW. C. HOBBS, CONSULTING ENGINEER !BiII Hobbs, RCE 42265 :Civil Engineer expo 3-31-2008 :Distribution: Addressee (4) !Attachments: Appendix A, Plate 1 W. C. HOBBS, CONSULTING ENGINEER ~ . APPENDIX A . SUMMARY OF LABORATORY TEST RESULTS Curve Soil Maximum Optimum Letter Descriotion Density ocf Moisture % A Silty SAND fn to 124.6 10.9 crs., Tan to Dark Gray(SM) With trace fines Maximl:lm density and optimum moisture determined in accordance with test method ASTM D 1557-78. W. C. HOBBS, CONSULTING ENGINEER 1 . . Appendix A Summary of Field Density Tests Project No: 06001-5 Report dated July 12, 2006 Project for Scott Householder Test # Qate Location Elevation Curve Max. (oct) M.C.% Dens. (oct) Como. % Remarks 1 Jul-06 PAD AREA 1086 A 124.6 10.5 120.4 97 FILL 2 Jul-06 PAD AREA 1088 A 124.6 11.7 115.7 93 FILL 3 Jul-06 PAD AREA 1090 A 124.6 10.1 117.8 95 FILL 4 Jul-06 PAD AREA 1094 A 124.6 9.2 118.4 95 FILL 5 . Jul-06 PAD AREA 1095 A 124.6 11.3 119.3 96 FILL 6 Jul-06 PAD AREA 1095 A 124.6 12.0 117.7 94 FILL 7 Jul-06 PAD AREA 1095.4fp A 124.6 11.5 116.2 93 FILL Field Density Tests were conducted in accordance with ASTM D 2937 and or 1556 fp Denotes finished pas test. e / Uti u/:;) r UKtftU AlitA ~ 2 2 _ _ ;;::11 11 __ l=m!!!fjj!jjffilLm . -1Il'-" , IIUI_ _ -__=!JT~ BERM "'=111=1'" $----~ ~ o ... PLA TEST LOCATION MAP PROJ NO. 06001-5 DA TE: JUL Y 12, 2006 APPROXIMA TE LOCA TION OF FIELD DENSITY TEST " /' t.ij -.J g~ ." :"6'. ~"'o. a ~.~ " " I ~ / / LIMITS OF GRAD. OR DISTURBED I //ITS! ------ ---- / / ~r "< // / // ~I~// -( ~~ ~ < ~