The URL can be used to link to this page

Home My WebLink AboutTract Map 3929 Lot 159 Rough Grade Compaction ,. ~U-- ~ W. C. Hobbs, Consulting Engineer 22800 Cove View Street Canyon ~~~:) ~~~i~~~ia 925f!1ECE'/\l"b' Project No: 93067-3 MAR 0 9 1994 Date: March 3, 1991/- CITYOFTEM -1NEE.~I~~.n~A.~ .~...... .., Mr. Robert Golledge 27349 Jefferson Ave., Suite 209 Temecula, California 92590 Referenced Report: Report of Rough Grade Compaction Testing Proposed Residence, Lot 159, Tract 3929, Monte Verde Rd., City of Temecula, California APN 921-120-017 ... . .... __~r~;aluation, for Proposed Resi~enc~, . III _ ~_ , .6. " onte Verde Road, Temecula, California APN 921-120-017, by W. C. Hobbs, dated Jan. 22, 1994 Subject: Dear Mr. Golledge, Contained herein are the results of compaction testing conducted during rough grade operations for the rear yard pad area at the subject site. The tests are plotted on a portion of the 20-Scale Grading plan. The results of laboratory and field density testing are contained in the attached Appendix A. It should be noted that observation and testing for the pad area 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 Site Index Map, Page 2 Test Location Drawing, 20-Scale, Plate 1 Appendix A, Summary of Field Density and Laboratory Test Results \ \ ffE----ce. \ /~\~~'Xff? \~.., \" ) .' \ // \ \ '\ ~\ ~\ .' ~ ~ '&/' ::\ -\ !\ '~\ m'vI~WLA \ ,. " -'f - ,Mr. Robert Golledge, Temecula, California Project No: 93067-3 If:::. ~\? .-:..--- _ k.~ I ('Q.(Zl'> - _ A'VW:> .~~ '\,L1~'::. ./ ~/ --------- t t-Jt:(l.n\ Site Vicinity Map No Scale Page: 2 W. C. HOBBS, CONSULTING ENGINEER Z-- " " 'Mr. Robert Golledge, Temecula, California Project No: 93067-3 Page: 3 Summary of Earthwork i General ~ Site grading was conducted during the months of February and March, 1994. I Rough Grading , Areas to receive fill or to be processed were first stripped of vegetation that was disposed i of or otherwise removed from the site. The ground to receive fill was scarified to a depth I of six inches, brought to near optimum moisture content and compacted to the minimum I requirements prior to the placement of fill. Fill was placed in 8- to 10-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-6 size Dozer. Water was added when necessary with the use of a water hose attached to a meter. Compaction was achieved by repeated passes of the heavy equipment over each lift of fill. In areas where fill was placed against sloping ground, a key was excavated a minimum of two feet into competent soil. The key was sloped a minimum of 2 percent to the back and was a minimum of 12 feet in width. As fill was placed against sloping ground, the loose upper soils were benched to expose firm natural ground. The key location is noted on the Test Location Map. W. C. HOBBS, CONSULTING ENGINEER 2:> 7. ,M r. Robert Golledge, Temecula, California :Project No: 93067-3 Page: 4 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 6 tests were conducted and their results are tabulated at the back : of this report. The approximate location of the field density tests are indicated on the a : portion of the Grading Plan, Plate 1. : (2) Fill Materials consisted of onsite silty sands. ] (3) Based on observation and classification, the matrix soils appear to have an expansion I potential of Medium. I (4) Groundwater was not encountered in any of the excavations during rough grading I operations. RECOMMENDATIONS The recommendations contained in the referenced report are still considered appropriate. They will be repeated herein for ease of use and clarification. Bearing Value and Footing Geometry A safe allowable bearing value for foundations embedded into observed and competent ground a minimum of 12 inches and 18 inches for one and two story construction, respectively, is 2500 psf. This value may be increased at the rate of 200 psf per foot of depth and 100 psf per foot of width over the minimums, but should not exceed 4000 pst. Continuous footings should have a minimum width of 12 inches. The use of isolated column footings is discouraged, however, where utilized, should have a minimum embedment of 18 inches below lowest soil grade. Interior column footings need not be tied to perimeter footings, but should meet the minimum embedment criteria of 18". Exterior column footings should be tied to the building perimeter by grade beams if located out on a slope steeper than 3:1 (H:V). Settlement The bearing value recommended above reflects a total settlement of 0.5" and a differential settlement of 0.25". This settlement is expected to occur during construction and as the loads are being applied. W. C. HOBBS, CONSULTING ENGINEER L\ 7. 'Mr, Robert Golledge, Temecula, California Project No: 93067-3 Page: 5 I Recommendations, continued IConcrete Slabs ,All concrete slabs on grade should. be 4 inches thick. They should be underlain by 3 i inches of sand or gravel. Areas that are to be carpeted or tiled, or where the intrusion I of moisture is objectionable, should be underlain by 6 mil visqueen properly protected I 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, 3 inches I of sand, then the subgrade soil. Contractors should be advise that when pouring during I hot or windy weather conditions, they should provide large slabs with sufficiently deep . weakened plane joints to inhibit the development of cracks. 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 at the center of thickness at 18-inch centers both ways or . welded wire fabric equivalent to 10x10, 6/6 may be used. It is understood that the sectional values for the two schedules are different, and is of no design concern. The steel bars have been proven to have a better performance history and selection is up to the builder. 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 may be computed using an equivalent fluid density of 350 pet for level grade. 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, then the passive values should be reduced by one third. It should be noted that reduction factors should be applied to passive values on sloping grades. W. C. HOBBS, CONSULTING ENGINEER ,.. ::> <. I Mr. Robert Golledge, Temecula, California : Project No: 93067-3 Page: 6 I Recommendations, continued I Retaining Walls j Retaining walls should be designep to resist the active pressures summarized in the jfollowing 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 I 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 LEVEL 35 pcf 350 pcf 2:1 48 pcf 200 pcf . These pressures are for retaining walls backfilled with non- cohesive, granular materials i 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 retaining ,wall drain devices be unobstructed and function properly for the above values to be implemented in long term design of retaining walls. IFine Grading : Fine grading of areas outside of the residence should be accomplished such that positive , drainage exists away from all footings in accordance with the minimum standards of the : governing agency. Run-off should be conducted off the property in a non-erosive manner : toward approved drainage devices. W. C. HOBBS, CONSULTING ENGINEER " , . ... 'Mr, Robert Golledge, Ternecula, California : Project No: 93067-3 Page: 7 I Recommendations, continued Ie onstruction , Run-off water should be collected qnd disposed of into approved drainage devices and not allowed to :pond or flow directly over designated slope faces. ! Future foundations should be embedded into natural ground or properly compacted fill : and should be observed by a soil engineer to confirm embedment prior to the placement : of construction materials into them. The opportunity to be of service is appreciated. Should questions or comments arise : pertaining to this document, please contact the undersigned, in writing, for clarification. I Respectfully Submitted, .~. obbs, RCE 42265 Civil Engineer Distribution: Addressee (4) W. C. HOBBS, CONSUL TlNG ENGINEER 1 ;-. \ APPENDIX A SUMMARY OF FIELD DENSITY TESTS Test Date Location Elev, Typ Max M.C. Dry Rei Comments Num.of Test of Test (feet) Crv D.D. fQilll Dens. Com Remarks 1 2/94 PAD AREA 1118 A 125.5 14.5 116.0 92% Fill 2 ,2/94 PAD AREA 1120 A 125.5 13.0 114.091% Fill 3 .3/94 PAD AREA 1122 A 125.5 15.0 112.5 90% Fill 4 .3/94 PAD AREA 1124 A 125.5 12.5 113.5 90% Fill 5 .3/94 PAD AREA 1126 A 125.5 13.5 116.0 92% Fill 6 .3/94 PAD AREA 1126.7" A 125.5 12.5 114.5 91% Fill " denotes finished grade elevation at time of report Field Density Tests were conducted in accordance with ASTM D 1556-70. SUMMARY OF LABORATORY TEST RESULTS Curve Soil Maximum Optimum Letter Description Density pcf Moisture % A Silty SAND fn to med. 125.5 12.0 brown to gray (SM) Maximum density and optimum moisture determined in accordance with test method ASTM D 1557-78. W. C. HOBBS, CONSULTING ENGINEER B I ~ f -?_ ~. . ~ 40 _~_...,...J..'-N 01" 0'5,2-0 b . ___n '\ /e5O:J ' . . lC' / / ( I I - i -;"-T1'U Z flbH~_ ) ~ -5010D ~eo ___ ........- --- - /' --~ / -- r1 ;..;. -- --= % 0' -- ~ t(J} ~ -- _--~ -- --- ~\ "7j~- \,-....--.---.- / I ./ ~ ~n t ;)- :h, :-T 0 v--\l ~~ ~ ~'- % ~ \(f)' I / I , ~.Jr LiX;XVj0 l'\;U.'i . R/~a; I PN '17~7n3 Mt.:<2d\ 3 i (1" 'i LOT !~ -re 39 //24 . / II~~( ,lTJIf-. ~1 {ftfJrfP 1fJf' ~ ~ ' , "1-1;; '.0 fL- ,"l , ~ ~ olf\ ~ ~. ~" ,,< //32 /J~ - ,!)L) , ~ c,gra"^\ ''/.~ / ~'(' l _./ f. --- ~ oL0 . ____ 11,0/0 -4'~"'----:- --c,% -3'2'" .. '0 '03' ?' ~, / ~G'~SJ;< fi, ~ __I -ps W4~'O 110 ~ 1'. tl.O~D I . / / '. . ~~, 4 X4 f!!, fe.4P . . C' 0 . " -=--- ~ ~:' ~ /$-'~ <5.- rf:.l'"v Ch' Cd/~ 37'080/, \ ..tr~/ 6/",_ ..\ y~-.;..~...-(......,. \:<;lll(jll ~/" %~ c. . ~~~ ~. ~0R,q -=-p / ,!. <7?~ J'~j;:/;;r3. e ((.) f .~".. 2:C(q) O~ .0 _<S:.-.s~>? . ~,~ . 0;.;' ~ctiP (:y J 6'4/::..s- fj' . . ..-/ \ , \-. , o B ~~ -=r:;- ~ ~,= "15, /0 _ /9'c.~_ :5/06 / -\~ ~ -\>lI~l r cur ,D flfdfT IjAJ/J 113~ , ,- 111~