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HomeMy WebLinkAboutTract Map 9833-3 Lots 11 & 12 Limited Preliminary Soils I I I I I I I I I I I I I I I I I I I ~... CALIFORNIA GEO TEK, INC. 42030 Avenida Alvarado, Suite A . Temecula, CA 92390 . (714) 676-2782 June 10, 1991 Project No. BS2WRC-492 INTRODUCTION Prior to issuance of a grading permit, the City of Temecula has requested a Preliminary Soils Report be prepared for the two subject lots. The work was authorized by Mr. John McKinney, and included: (1) exploratory trenching and soil sampling, (2) laboratory testing and analysis, and (3) preparing this report presenting our findings, conclusions, and recommendations Plate 1 - Proposed Grading Plan/Trench Location Plan, Lot 11 (20-scale) Plate 2 - Proposed Grading Plan/Trench Location Plan, Lot 12 (20-scale) Plate 3 - Fill Slope Cross Section Plate 4 - Fill Slope Search Results Plate 5 - Cut Slope Cross Section Plate 6 - Cut Slope Search Results Appendix A - Trench Logs Appendix B - Laboratory Test Data Sheets Appendix C - Grading and Earthwork Specifications Appendix D - Reference 2. I I I I I I I I I , I I I I I I I I I I BS2WRC-492 Page 2 FINDINGS Proposed Development The two lots, 2f acres each, are proposed for grading and subsequent residential construction. The lots will be graded simultaneously. Site Conditions The site is located on the southeasterly side of Jedediah Smith Road, northeast of Ynez Road and southwest of Margarita Road in the Santiago Ranchos Tract. The terrain is gently rolling to moderately steep with gradients exceeding 50 percent in places. A northeast-southwest trending knoll extends across both lots. Drainage is directed as sheetflow into a southwesterly trending natural watercourse which flows along Jedediah Smith Road. The site supports a well established growth of sage, cactus, and annual grasses. A wet spot was observed near the terminus of a broad swale as it reaches the pad area. Plan Review The proposed Grading Plan, prepared by Lakeshore Engineering, Inc. indicates transition residential pads are to be graded on each of the two lots. Both pad elevations are equal (1150.0), therefore, the finished product will resemble one large pad extended across both lots. Lot 12 will require cut slopes to a maximum vertical height of 35 feet and fill slopes to 25 feet. A proposed 5 foot high retaining wall is indicated along a portion of the cut slope toe easterly of the proposed residence. Riprap is to be placed at the low points on the northerly and southerly ends of the pad. The pad is to be accessed via a fill driveway constructed from Jedediah Smith Road to the northwest. The driveway will require two 66 foot diameter CMP's where it crossed the natural watercourse. The maximum driveway gradient per plan is 15 percent. Lot 11 will be graded in conjunction with Lot 12. A 3:1 fill slope at a maximum vertical height of 25 feet will be required to construct the pad. Fill is also indicated to the southeast and will extend onto an adjacent lot (Plate 2). The cut slope on Lot 12 will be extended onto Lot 11 and will be at 2:1 in steepness and 30f feet in vertical height. The pad will be accessed via a fill driveway extended from Jedediah Smith Road along a 30 foot access easement. Two 66 foot diameter CMP's will be required where the driveway crosses the natural watercourse. The upstream side of the culvert crossing is to be grouted. Riprap is to be placed at low points to reduce erosion. Site InvestiQation Four exploratory trenches were excavated (May 29, 1991) to determine subsurface conditions (see Trench Location Plan). Two predominant units were observed. The lower portions of the site are underlain by poorly consolidated alluvium deposited by the natural watercourse. The remaining areas are underlain by residual soils (colluvium) which are in turn underlain by the Sandstone- Siltstone facies of the Pauba Formation. Representative soil samples were obtained at various depths for laboratory testing (see Trench Logs). 3 I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 3 GeoloQic SettinQ The site is located in a geologic province known as the Peninsular Ranges of Southern California which is characterized by fault controlled elongated northwest-southeast trending valleys and mountains. The property is situated on the southwesterly margin of the Perris Block approximately 2400 feet northeast of the Wildomar Fault (Elsinore Fault Zone). The Wildomar Fault forms the southwesterly boundary of the Perris Block and is considered active. The geologic unit underlying the subject site is known as the Pauba Formation. In this area the Pauba Formation consists of interbedded, slightly cemented siltstones and sandstones which resemble soil due to their young age (Late Pleistocene). The units are nearly flat lying with dips of less than 5 percent to the northeast. The Pauba Formation is overlain by alluvium of variable thickness on the lower portions of the site along the natural watercourse. Seismicitv See Appendix D - report by Shaefer Dixion Associates. laboratorv TestinQ Moisture Densitv Two moisture density determinations were made on materials in the upper 4 feet. Two methods were used. A ring sampler was used on the materials in Trench T3, and a Sand Cone Test was conducted in Trench T2. The results are tabulated below: Location T2 13 Depth 3 feet 4 feet Drv Densitv Moisture Content 111.4 pcf 113.9 pcf Maximum Density 11. 7% 10.8% One maximum density determination was conducted on the material encountered in Trench TI from a depth of three feet. The sample has a maximum dry density of 126.0 pcf with an optimum moisture content of 9.0 percent. Direct Shear Two direct shear tests were conducted to represent the soil stren9th parameters of the native materials encountered in the upper 4 feet. Both tests were performed under saturated conditions. The results (ultimate values) are tabulated below. Sample Location Tl 13 Depth 3 Feet 4 Feet Sample . Condit i on Cohesion. psf Angle of Internal Friction Remolded In-Situ 60 45 39' 43' " I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 4 Expansion Index One expansion index test was conducted to determine the expansion potential of the finer grained earth materials. The expansion index is 23 or a LOW EXPANSION POTENTIAL. Analvsis Soil Bearina Capacitv The ultimate bearing capacity for foundations is a function of the soil properties and characteristics of the foundation itself (size, depth, shape). We have assumed that square spread footings and continuous footings will be used for support of the structural loads The equation developed by Karl Terzaghi was used, which combines the effects of soil cohesion, internal friction, foundation size, and soil weight. Bearing values were determined for continuous footings 12 inches in width and 12 inches in depth and also for square footings 12 inches square and 12 inches in depth, measured below the lowest adjacent firm grade (in compacted native soils). The results are given below: Continuous Footings Square Footings Maximum Soil Bearing Value 2000 psf* 2075 psf** 4000 psf add 490 psf for each additional foot of width and 995 psf for each additional foot of depth ** add 415 psf for each additional foot of width and 665 psf for each additional foot of depth * Settlement ProYided structures are founded in properly placed fills compacted to a mlnlmum of 90 percent relative compaction, post construction settlement is expected to be less than 1/2 inch under loads of up to 2 kips per linear foot. Overexcavation The non-uniform, loose, porous nature of the underlying soils all indicate that overexcavation is required. To keep post construction settlement less than 1/2 inch, the cut portions of the slab areas extending at least 10 feet outside the building perimeter must be overexcavated in a manner which will provide a minimum of 3 feet of compacted material beneath the bottom of the proposed footings. Overexcavation will also be required where driveway fills are placed over alluvium in the watercourse areas. Proper processing of the bottom of the overexcavation areas prior to fill replacement is necessary to provide suitable bonding of the replaced fill and in-situ materials. s I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 5 Active and Passive Soil Pressure The Rankine equations were used to calculate the active and passive soil pressures. The values represent the on-site native material (recompacted to 93 percent relative compaction). Active Pressure . The equivalent fluid pressure for the earth materials with no surcharge is 30 pcf. Passive Pressure . The equivalent fluid pressure for the earth materials with no surcharge is 440 pcf. This may be combined with a soil to concrete friction coefficient of 0.40 to resist lateral movement provided the combined value does not exceed two-thirds of allowable lateral bearing. A one-third increase in frictional lateral bearing values may be used to resist wind load or earthquake forces. Slope Stabilitv Analvsis The Simplified Bishop method was used to determine the minimum Factor of Safety for fill and cut slopes. Fill slopes were evaluated to a maximum vertical height of 30 feet and cut slopes were evaluated to a maximum height of 40 feet. All slopes are to be at 2:1 or less in steepness. Fill strength parameters were obtained from the remolded direct shear test. Cut strength parameters were determined from the direct shear test conducted on an in-situ sample. The direct shear tests were conducted under saturated conditions. The analysis was performed utilizing computer software supplied by Von Gunten Engineering Software, Inc. (SB-Slope). An automatic search routine was used to determine the critical circle coordinates which were found to produce minimum Factors of Safety (see Plates 3 through 6). The seismic parameters used for the eyaluation are listed below: Horizontal ground acceleration = .20g Vertical ground acceleration = .05g The Slope Stability results are tabulated below: Slope 2:1 Fill slopes (30 feet) 2:1 Cut slopes (40 feet) Seismic Factor of Safety Static Factor of Safety Plate No. 1.29 1. 51 1. 98 2.32 3 & 4 5 & 6 Note: Adequate erosion control for the cut slopes should be provided in the form of well constructed brow ditches and terraces. Landscaping and planting of the fill slopes should be conducted after grading as soon as practical. " I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 6 CONCLUSIONS AND RECOMMENDATIONS Conclusions 1. Development of the site for residential construction is geotechnically feasible. 2. The in-situ earth materials consist of interbedded sands, silty sands and silty very fine sands with some clay. 3. Excavation was easy using a Ford 755B Backhoe to a maximum depth of 10 feet. 4. The site is not within any Special Studies Zone for faulting or liquefaction. 5. The in-situ dry densities were 111.4 pcf and 113.9 pcf in the upper 4 feet. The moisture contents were 11.7 and 10.8 percent, respectively. 6. The ultimate angles of internal friction (0) for an in-situ sample of silty sand is 43' with a cohesion (C) of 45 psf. 7. The ultimate angles of internal friction (0) for a remolded sample of silty sand is 39' with a cohesion (C) of 60 psf. 8. The allowable soil bearing value for footings 12 inches in width and 12 inches in depth, measured below the lowest adjacent firm grade, is 2000 psf. 9. Passive earth pressures are equivalent to the pressure created by a liquid weighing 440 pcf. The equivalent fluid pressure (active) with no surcharge is 23 pcf. 10. The expansion index of on-site materials is a 23 (LOW expansion potential). 11. Post construction settlement of the proposed structures is expected to be less than one-half inch with differential settlement up to one-fourth inch provided the structural loads do not exceed 2 kips per linear foot and the overexcavation recommendations are adhered to. 12. The allowable coefficient of friction between concrete and soil is 0.40. 13. The minimum static Factor of Safety for fill slopes to a maximum height of 30 feet and at a maximum slope ratio of 2:1 has been determined to be above the minimum allowable 1.5 (Factor of Safety =1.98). ~ I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 7 Conclusions (continued) 14. The minimum seismic Factor of Safety for fill slopes to a maximum height of 30 feet and at a maximum slope ratio of 2:1 has been determined to be above the minimum allowable 1.1 (Factor of Safety =1.29). 15. The minimum static Factor of Safety for cut slopes to a maximum height of 40 feet and at a maximum slope ratio of 2:1 has been determined to be above the minimum allowable 1.5 (Factor of Safety =2.32). 16. The minimum seismic Factor of Safety for cut slopes to a maximum height of 40 feet and at a maximum slope ratio of 2:1 has been determined to be above the minimum allowable 1.1 (Factor of Safety =1.51). Recommendations 1. The design for the proposed structures should be based on the Uniform 8uilding Code values for Seismic Zone 4 with a site coefficient of SI' 2. All grading shall be in accordance with applicable provisions of the Uniform Building Code as amended by County Ordinance 470 and the attached General Grading and Earthwork Specifications (Appendix C) except as modified herein. 3. A soil bearing value of 2000 psf may be used for the design of continuous and square footings 12 inches in width and 12 inches in depth, measured below the lowest adjacent firm grade. 4. The soil bearing values may be increased 490 psf per foot of additional width and 995 psf per foot of additional depth to a maximum value of 4000 psf. 5. The cut areas beneath the subject residences shall be overexcavated to a minimum depth of 3 feet beneath the proposed footings. The overexcavation shall extend a minimum of 10 feet outside the building perimeter. 6. Overexcavation depths and limits beneath driveway fills shall be determined at the time of grading by the soil engineer. 7. All overexcavation backfill shall be recompacted to a minimum of 90 percent relative compaction. 8. All areas to receive fill not overexcavated in accordance with Recommendation 5 or 6, above, shall be overexcavated to a minimum depth of 2 feet below existing grade. 8 I I I I I I I I I I I I I I I I I I I SS2WRC-492 Page S Recommendations (continued) 9. The exposed surface of all overexcavation areas shall be scarified a minimum of 6 inches, suitably moistened, and precompacted prior to replacement of the excavated material. 10. The following values may be used for design of retaining walls: 23 pcf (no surcharge) 440 pcf (no surcharge) 0.40 2000 psf (add 99S psf for each additional foot of depth and 490 psf for each additional foot of width) 4000 psf 127.7 pcf (93% relative compaction at optimum moisture) 11. If structural loads exceed the values in this report, a more detailed settlement analysis should be performed. Active Pressure Passive Pressure Soil:Concrete Friction Soil Bearing Maximum Soil Bearing Value Unit Soil Weight 12. All footings shall be designed to keep the structural loads less than the allowable soil bearing value. 13. All continuous footings shall be a minimum of 12 inches in width and 12 inches in depth, measured below the lowest adjacent firm compacted grade. 14. A moisture barrier, such as 6 mil Visqueen shall be placed beneath all structure slab-on-grade concrete where moisture sensitive floor coverings are proposed. The membrane shall be properly lapped and protected with a minimum of one inch of sand, above and below. IS. All util ity trenches, including those within the building envelope, shall be properly compacted prior to placing sand, Visqueen, concrete, etc. 16. A copy of the foundation plans should be submitted to this office for review prior to grading. 17. Any import material shall be approved by the Soil Engineer prior to use, and additional testing may be needed to determine bearing values, expansion potential, etc. IS. Any existing vegetation including tree root balls shall be removed from the site and shall not be blended into any of the fill materials unless approved by the Soil Engineer at the time of grading. q I I I I I I I I I I I I I I I I I I I 8S2WRC-492 Page 9 Recommendations (continued) 19. Relative compaction shall be determined in accordance with ASTM DI557-78. The minimum requirements shall be as follows: a. all fi 11 s. .. .. . .. . .. .. .. .. .. .. .. . .. . .. .. .. 90 percent b. precompacted areas........................90 percent c. recompaction of overexcavated areas.......90 percent d. trench backfill ...........................90 percent e. aggregate base............................95 percent f. subgrade for pavement.....................95 percent 20. The fill slope faces should be track rolled, or otherwise suitably compacted during the placement to reduce any potential "skin failures". 21. Cut slopes are to be free of any protruding rocks or boulders and protected from erosion by placement of adequate brow ditches. 22. All fill slopes are to be 30 feet or less in vertical height and at a slope ratio of 2:1 of less (unless a further, more detailed stability analysis is completed). 23. All cut slopes are to be 40 feet or less in vertical height and at a slope ratio of 2:1 of less (unless a further, more detailed stability analysis is completed). 24. All slopes shall be landscaped and planted as soon after grading as feasible. 25. Erosion Control should be provided in conformance with Uniform Building Code, Chapter 70, Section 13, and County Ordinance 460. 26. The "wet spot" in the pad area should be geotechnically inspected during grading to determine any remediation necessary. Respectfully submitted, ~~~-t Ed Lasater Staff Geologist Y:<<e 12 If{ Bruce R. Lee, P.E. GE 509 \0 EL/ks Distribution: Addressee (8) I I I I I I I I I I I I I I I I I I I S,mpl,f,ed Bishop Slope StaDllity Analysls PRO,JECT: 8S2WRC-492 (30 FT. 2 1 FILL SLOPE) LOCATION: LOT 12 TRACT 9B33-3 FILE: MCKINEY2 COMPLETE SLOPE CROSS SECTION CIRCLE 1 RADIUS 90 0 FS 1. 98 x 185.5 y 1210.3 1210 ~ 1200 !j90 1180 Z 1170 o f-- <( > llJ 1160 -.J W 1150 ~140 1130 1120 1110 1100 90 120 130 150 190 200 100 170 180 160 100 110 HORIZONTAL DISTANCE DATE: JUNE. 1991 PROJECT NO.: 8S2WI\( -492. SLOPE STABILITY ANALYSIS PLATE: 3 CALIFORNIA GEO TEK INC. 42030 AVENIPA ALVARAPO, SUITE A TEMECULA CALIFORNIA 92390 ~ LOTS 11 ~ 12., 111..(,C.T 9&33-3 CtTY OF TE.MEWLA C.ALlFOI\NII\ ~l I I I I I I I I I I I I I I I I I I I Simplifled BishOP Slope StaD,l,ty Analysls PRO,JECT: 8S2WRC-492 (30 FT. 2 1 FILL SLOPE) LOCATION: LOT 12 TRACT 9833-3 FILE: MCKINEY2 1235 ~- 1220 Z 1200 0 H f-- <( > 1180 AREA EXPANDED ABOVE W -.J ill 1160 1140 1120 1100 , 180 320 260 280 240 300 80 180 200 220 100 120 140 HORIZONTAL DISTANCE DATE: JUNE. 1'3~1 PROJECT NO.: 852IJRC.-'l-'l'L SLOPE STABILITY ANALYSIS PLATE' 4 CALIFORNIA GEO TEK INC. 42030 AVENIOA ALVARADO, SUITE A TEMECULA CALIFORNIA 92390 ~ LOTS 11 &, \2" TAAtT 9233-:=J CITY OF TI.MEL.UU\ C.AU FORNIA \2. I I I I I I I I I I I I I I I I I I I Slmpllfled B1ShOP Slope StaDlllty AnalyslS PRO,JECT: 8S2WRC-492 (40 FT. 2: 1 CUT SLOPE) LOCATION: LOT 12 TRACT 9833-3 FILE: MCKINNEY 1280 1265 1250 Z 1235 o ~ f-- <( > 1220 W -.J W 1205 1190 1175 1160 1145 1130 DATE: &s2WI\c'-"\9t PROJECT NO.' ~SZ.Wr..L-49t COMPLETE SLOPE CROSS SECTION CIRCLE 1 RADIUS 129 3 FS 2.32 x 167.6 y 1293 5 45 60 75 90 105 120 135 150 165 180 195 210 HORIZONTAL DISTANCE SLOPE STABILITY ANALYSIS PLATE: LOTS 11 R, 12.. TRAtT 9833-3 CITY OF TEMECULA CALlFORNl/l. -5 CALIFORNIA GEO TEK INC. 42030 AVENIDA ALVARADO. SUITE A TEMECULA CALIFORNIA 92390 ~.!> ~ I I Simplified B1ShOP Slope StaDllity Analysls PROclECT: 8S2WRC-492 (40 FT. 2: 1 CUT SLOPE) LOCATION: LOT 12 TRACT 9833-3 FILE: MCKINNEY ~ ~310 - . . . . . . . . . 2.50 2.,45 2.49 2..:15 2.42 2.48 2.<45 2 46 2.62 1305 -, . . . . . . . . . 2.47 2.44 2.47 2.45 2.48 2.47 2.45 2.49 2.70 i300 ~ . . . . . . . . . 2.4..:1 2.43 2.45 2.<117 2.47 2.46 2.45 2.5.11 2.79 1295 - CENTE.R OF CRITIU,L CIRClE . . . 2'f, . . . . . 2.,41 2.462.44 2. 2 2.48 2.416 2.47 2.59 2.89 1290 - . . . . . . . . . 2.38 2.47 2.44 2.40 2.49 2.46 2.50 2.65 3.00 1285 "' i . . . . . . . . . 2.36 2.45 2.46 2.48 2.48 2.47 2.50 2.72 3.09 I 1280 -' . . . . . . . . . 1 2.36 2.44 2.50 2.49 2.48 2.49 2.51 2.79 3.07 1275 ~ . . . . . . . . . 2.39 2.-44 2.50 2.51 2.48 2.50 2.52 2.86 2.96 , 1270 - , . . . . . . . . . 2.46 2.46 2.50 2.51 2.50 2.51 2.55 2.93 2,91 1265 -' 1<5 150 155 160 165 170 175 180 185 190 195 1300 1270 Z 0 AREA EXPANDED ABOVE H f-- <( 1240. > W -.J W 1210 1180 1150 1120 , , I I 300 30 60 90 120 150 180 210 2.0 270 330 360 HORIZDNTAL DISTANCE DATE: SLOPE STABILITY ANALYSIS PLATE: JUNE. 1991 b PROJECT NO.: LDTS 11&1'2-. TRALT '3833-3 CALIFORNIA GEO TEK INC. ~ 42030 AVENIDA ALVARADO, SUITE A 'Z\57JJRC-4'32- CITY OF TEMEC.ULA CALI FDP-N\I\ TEMECULA CALIFORNIA 92390 \,,\ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I GEOTECHNICAL TRENCH lOG Date May 29. 1991 Trench No. Project McKinney Equipment Company RB Backhoe Project No. 8S2WRC-492 Tl Type of Equipment Ford 755B Backhoe Elevation Logged by .JEL Sampled by Lot No. 11 Page 1 of 1 JEl - ... ~ Cl g" ~ ~ - ... ~ tJ Cl ... . Geotechnica 1 Description Cl ~ III >. . u.. Cl Cl VI .~ .... ... ... IIl- ... l- 0> VI 0 .~ III (Classification, moisture, c '" ... c . III Cl . "'VI .~ ~ ... 0 .~o c ~... ~ . tightness, color, etc. ) '" 0 III 0 III ~ '" c uu ~ c ~ IIlN '" ...Cl . ... '" Cl ... '" C Ill'" ~ VI "'- 0 "'- "'- ... ..~ >. .~ c .~ . ~ ~ ~ Cl o E! ~ :i3 .5l= '-" c ... z:~ c SM SILTY SAND, damp loose, light brown, medium fine 7.8 grained, subangular (colluvium) some clay micacious, occasional +4 quartz fragments MD DS 6 SP POORlY GRADED SAND, damp, moderately dense, 7.2 brown less damp, reddish brown very dense {Pauba} coarser grained light EOB TOTAL DEPTH 10 FEET NO GROUNDWATER NO REFUSAL A i \(S'" I I I I I I I I I I I I I I I I I I I GEOTECHNICAL TRENCH lOG Oate May 29, 1991 Trench No. T2 Project No. 8S2WRC-492 Project McKinney Type of Equipment Ford 755B Backhoe Equipment Company RB Backhoe Elevation Logged by JEl Sampled by JEL lot No. 12 Page 1 of 1 - I+- - ~ ClI lS. ~ - ~ - .... - t t~ t .... . Geotechnical Description ~ III >, . ... ClI ClI V'> ,~ " .... .. 1Il- .... ,... I::'lV'lO .~ III (Classification, moisture, e '" l+- e . III ClI . "'V'> .~ ~ I+- 0 '~8 e ~.... ~ . tightness, color, etc.) .., 0 III III ~ " e '-''-' ~ e ~ III N " ...ClI . .... " ClI .... '" e Ill.... ~V'> Q. 0 C. C. c... ...... ~ .~ e .~ . ~ ~ ~ ClI o E! :i8 o=> ~ Q ..z- Q V>- SM SILTY SAND, damp, loose, gray, some clay - - (co 11 uvi urn) - SC CLAYEY SAND, wet, moderately dense, reddish - - brown, (pauba) - - - - ? EI 11.7 SM SILTY SAND, damp, moderately dense, green-gray - some clay, blocky - - - - Ml SILT, damp, moderately dense, gray, some sand - - - 4 SM SILTY SAND, damp, moderately dense, gray, - - coarse-fine some clay, micacious - - - - - - - - - 6 16.9 EOB - - - - - - - - - - - - TOTAL DEPTH 6 FEET NO GROUNDWATER NO REFUSAL I" A ii I I I I I I I I I I I I I I I I I I I GEOTECHNICAL TRENCH lOG Date Mav 29. 1991 Trench No. T3 Project No. 8S2WRC-492 Project McKi nney Type of Equipment Ford 755B Backhoe Equipment Company RB Backhoe Elevation logged by JEl Sampled by JEL Lot No. 12 Page 1 of 1 ~ ... ~ ~ QI ~ ~ - ~ ~ ... - t ~~ QI ... . Geotechnical Description QI ... III >. . L.I.. QI QI Vl .~..... ... .. 11I- ... ... cnVl 0 .~ III . (Classification, moisture, c: '0 ... c: . III QI . 'OVl .~ ~ ... 0 .~o c: ...... ~ . '" 0 .&: 11I0 III ~ ::s c: <.J<.J tightness. color, etc.) .&: c: IIl""::S ...QI ... ::s QI ... '0 c: iii... ~Vl C. 0 C. C. .... ..~ ~ _c: .~ . QI ... ~ QI os i!8 0:::> 0 '" 0 ..:z:- 0 Vl~ SM SILTY SAND, wet, loose, dark gray, coarse-fine, - - some clay (colluvium) - - - - DS ~ 113.9 10.8 SC CLAYEY SAND, wet, loose, dark brown, coarse-fine - cohesive, occasional cobbles, micacious ( Paube:-) ~ - - - - 11.4 - - - EOB - - - - - - - .lD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TOTAL DEPTH 6.5 FEET NO GROUNDWATER NO REFUSAL \1 A iii I I I I I I I I I I I I I I I I I I I GEOTECHNICAL TRENCH LOG Date May 29. 1991 Trench No. T4 Project No. 8S2WRC-492 Project McKinney Type of Equipment Ford 555B Backhoe Equipment Company RB Backhoe Elevation Logged by JEL Sampled by JEl lot No. 11 Page 1 of 1 I - .... - - CII g, - - - - +> - t ~J CII +> . Geotechnical Oescription CII .. III >> . Ll. CII CII V'> ,~ .... +> .. ill- +> ... alV'>O ,~ III (Classification, moisture, c .. .... c . III III . ..V'> .~ . .... 0 '~8 c ..... - . tightness, color, etc.) 'Q 0 III III c8 " c '-''-' .s:. c .s:. IIlN::O +>11I . ... ::0 CII ... .. C Ill'" _V'> Q. 0 Q. Q. 0. ..~ t' .~ c ,~ . c8 .. ~ c8 0& i8 0:::> ., ..z- Q V'>- SM SILTY SAND. dry. loose. light gray. coarse-fine, - ~ damp more dense. wet porous (alluvium) - - - occasional cobbles and gravel - - - - ---5 SC ClA YEY SANO. wet moderately loose. brown. ~ micacious. cohesive - - ~ - SW WELL GRADED SAND. damp. moderately loose. reddish - ~ brown, coarse to fine - - dry. more dense (Pauba) - 10 5.4 - - EOB - - - - - - - - - - I-- - - f- - - I- - - f- - - f- - - TOTAL DEPTH 10 FEET NO GROUNOWATER NO REFUSAL I~ A iv -I -I -I ;j -I -I ;::! 8/J1l. / TKfNCf./ ~ w w '" .... h/J ~ FIELD BPR. / TREheH NO. - FINAL VI VI VI VI VI rG VI SAMPiF N/J. .... '" .... '" .... .... \0 C'l ~ C'l W co w /JurN) FT. .... .... :!) .... .... ~ !:> w .... ~~t> . . b \0 ~ ~::::~ .... ~ ""t '" -< C'l . ~ <:> .... .... .... .... :!) '" .... <:> C'l .... ..... ..... . . . . . . . :t! ~~ ~ ~ co \0 ..... '" co t:> ~~~ \0 ~ ~~ ..,~ <:> :'1 \0 co RELAnvE <:> co C/JMPACTI/JA/ . . ~ ~ % MINUS NO. lD/J (D.75M/'(] % LlrYUI/J LIMIT % fLAme LIMIT % VI VI VI ::!] !il! VI VI VI ~ ...., i i :IE: n n 3: .., 3: ...... !::> , , b ~ r--...: : ..... - .... ~ ~ ~ '" VI 5ANll E&UIVIlLENT ~ fXfANSIDN /N/JEX PENlTRdMlTEl. I<SF ~ :l:.~ "" 0 ~;:;; .....::j ~ w :::: ""~ w \0 :"'1 ~ ~ .- - - - - -- --.- - - -,- -. - - -"-- .' - -- - -. - " - .- --- - . -- ~ -~ --.... ~ . .,,~ ....,,,, ~ ~ :::: <::; '" :'1 <!:: ---..-- "" ~ .... ~ "" C ~ ::: ~ -. ~ co VI '" :IE: ;:c C"'l I ~ \0 '" ~ ..... ~ ~ ~ ~ ~ li: .... :0. "" ~ '< "" ~ ~. ~ ~ :.,;; i:;l :.::i "" i;:j V) "i ~ ~ - ....D I RI R2 R3 R4 I DRY DENSITY (lbs.lft.3) 101.6 109.6 113.4...ffiL TRENCH NO T' SATURATION (%) ~ ~ ~ --2L SAMPLE 5-1 NATURAL MOISTURE (%) JQ:.L ~ ~ --1Q!.. DEPTH 4' I FINAL MOISTURE (%) ~ ~ ~ ~ SOIL CLASS Si'\ ULT MAX. NATURAL MOISTURE D COHESION (IbsJft. ) = 45 I SATURATED . 00= 4.3 IN-SITU . I REMOLDED LU D (;i f::' 1800 LO I I 1500 I I ~ 1200 C\J +-' - ~ ...... I vi ..c ~ Z I 0 900 en ~ ~ w I I ~ I 0 u -, ~ 600 I I ~ I 300 I I I I 300 600 900 1200 1500 1800 II NORMAL LOAD (Ibs./ft.2) DATE: DI RECT SHEAR RESULTS APPENDIX: I JUNE. 1991 5ii PROJECT NO.' LDTS 1\ & 12., II\A('1 9833-3 CALIFORNIA GEO TEK. INC. tt_. '3S2.WRC-492. 42030 AVENIOA ALVARAOO. SUITE A CITY DF TEMECULII CALIFORNIA TEMECULA CALIFORNIA 92390 I -z,o I I I I I I I I I I I I I I I I I I I I RI R2 R3 R4 DRY DENSITY Obs./ft.3) ~.Jllil. 1m 1%.7 SATURATION (%).JQ!L. ~ ~ ~ NATURAL MOISTURE (%) ~ ..J,L ~ ~ FINAL MOISTURE (%) 114 1l'L...lbL ~ ULT MAX. COHESION Obs/ft. )= "0 00= 39 1800 ffi L() r--: @ 1500 ~ C\I ...: - ...... vi .c 1200 - z o 900 C/) W I o U 600 300 BORING NO. T.1 SAMPLE s-, DEPTH 3.5' SOIL CLASS SI"I NATURAL MOISTURE SATURATED IN-SITU REMOLDED o . o . I I -" -" ~ -I ~ 300 600 900 I 1200 1500 1800 DATE: JUNE. 19'31 PROJECT NO.' 8S2WRC.-4'l2. NORMAL LOAD <Ibs./ft.2) 01 RECT SHEAR RESULTS APPENDI~:ili OT" e CALIFORNIA GEO TEK INC. ~ L u 11 &. 12.. TRII."T '3&33-.3 42030 AVENIDA ALVARADO. SUITE A ClTY OF l'E.Mt.C.ULA c.AUrORNIA TEMECULA CALIFORNIA 92390 .1 ZJv II I I I I I I I I II I I I I I I I I I I!:Q LOCATION BORING/TRENCH NO. 145 BORING / TRENCH DEPTH SOIL CLASS 140 1\ ASTM D 698 METHOD \ ASTM D 1557 METHOD \ 1\ \ 135 \ Ibs/ft3 1\ MAXIMUM DENSITY \ OPTIMUM MOISTURE 0/. 1\ 1\ 130 \ :\ 1\ ~ r<'l. - ,..., 1\ - 125 " \ vi 'I " ..0 - ~ 1\ ~ >- 120 , I- \ (f) \. \ Z 1\ W \ 0 >- 115 1\ a: 0 \ \ 110 \ \ 1\ \ 105 \ \ \ 100 \ S,G.=2.50 l(- S.G=2.60 ZERO AIR S.G.=270 VOIDS CURVE 95 " 1'\ '\ " 90 '\ 0 5 10 15 20 25 30 35 MOISTURE CONTENT (% OF DRY WEIGHT) DATE: MAXIMUM DENSITY CURVE APPENDIX: JUNE. \.,91 Biv PROJECT NO.: LOIS 11 &. H, t II\I\CT 9K~):J-3 CALIFORNIA GEO TEK INC. ~ 42030 AVENIOA ALVARA002 SUITE A 8S'l.WI\C- 492. C.11'< OF 'TIM COLA Ci\L1FOmll\ TEMECULA CALIFORNIA 9 390 ?,-P I I I I I I I I I I I I I I I I I I I APPENDIX C GENERAL GRADING AND EARTHWORK SPECIFICATIONS 1. Scope a) This section contains general specifications for work relating to the following construction: Site Clearing and Grubbing Preparation of Subgrade in Areas to be Filled Placement of Fill Trench Backfi II b) The owner shall employ a qualified soil engineer to inspect and test the fill as placed to verify the uniformity of compaction to the specified density requirement. The soil engineer shall advise the owner and grading contractor immediately if any unsatisfactory soil related conditions exist and shall have the authority to reject the compacted fill ground until such time as corrective measures necessary are taken to comply with the specifications. It shall be the sole responsibility of the grading contractor to achieve the specified degree of compaction. 2. Clearinq, Grubbinq and Preparinq Areas to be Filled a) All brush, vegetation, rubbish and desiccated top clay soil shall be removed, piled, or otherwise disposed of so as to leave the areas to be filled free of vegetation, debris and desiccated top clay soil. Any soft and swampy spots in the canyon areas shall be corrected by draining or by removal of the unsuitable materials. b) The natural ground which is determined to be satisfactory for the support of the filled ground shall then be plowed or scarified to a depth of at least six inches (6") and until the surface is free from ruts, hummocks, or other uneven features which would tend to prevent uniform compaction by the equipment to be used. The scarified ground should be compacted to at least 90 percent of the maximum laboratory density. Where undisturbed bedrock is exposed at the surface, scarification and recompaction may not be required. c) Where fills are made on hillsides or exposed slope areas, the existing top unstable materials should be removed. If existing slopes are steeper than 5 horizontal to 1 vertical, horizontal benches shall be cut into firm and competent undisturbed soil or bedrock in order to provide both lateral and vertical stability. C i z.o I I I I I I I I I I I I I I I I I I I 3. d) All areas to receive controlled fill, including all removal areas and toe-of-fill benches and keys, shall be inspected and approved by the soil engineer and/or engineering geologist prior to placing controlled compacted fill. Fill Materials and Special Requirements The fill soils shall consist of select materials approved by the project soil engineer or his representative. These materials may be obtained from the excavation areas and any other approved sources, and by blending soils from one or more sources. The material used shall be free from organic vegetable matter and other deleterious substances, and shall not contain rocks or lumps of greater than eight inches in diameter within a distance of ten feet from any finished compacted surface. If excessive vegetation, rocks, or soil with inadequate strength or other unacceptable physical characteristics are encountered, these shall be disposed of. During the grading operation, if potential problem soils are found, these soils shall be tested to determine their physical characteristics. Any special treatment recommended shall become an addendum to these specifi- cations. Boulders greater than eight inches but less than or equal to two feet in diameter should be uniformly distributed in the compacted fill areas but no closer than ten feet from final grade and should be surrounded with sufficient amounts of compacted finer-grained materials. No nesting will be permitted. Boulders greater than two feet in diameter shall be placed in approved disposal areas no closer than ten feet from final grade and shall be placed in windrows in such a manner that voids will not exist around boulders. Continuous inspection by the project soil engineer is required during rock disposal operations. Placing, SpreadinQ and CompactinQ Fill Materials a) The suitable fill material shall be placed in approximately level layers which, when compacted, shall not exceed six inches (6"). Each layer shall be spread evenly and shall be thoroughly mixed during the spreading to insure uniformity of material and moisture in each layer. 4. b) When the moisture content of the fill material is below that specified by the soil engineer, water shall be added until the moisture content is near optimum as specified by the soil engineer to assure thorough bonding during the compaction process. c) When the moisture content of the fill material is above that specified by the soil engineer, the fill material shall be aerated by blending and scarifying or other satisfactory methods until the moisture content is near optimum as specified by the soil engineer. d) After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted to not less than 90 percent of maximum density in accordance with ASTM D1557-78 (five layers). Compaction shall be accomplished with sheepsfoot rollers, multiple wheel pneumatic-tired rollersor other approved types of compaction equipment. Rollers shall be of such design that they will be able to compact the fill material to the specified density. C ii ~ I I I I I I I I I I I I I I I I I I I e) Special mlxlng and watering effort may be required where diatomaceous materials are encountered to achieve the recommended moisture content and density. f) Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting of the slopes shall be accomplished by backrolling the slopes in increments of three to five feet in elevation gain or by other methods producing satisfactory results. Relative compaction shall be at least 90 percent to the finished slope face. g) The soil engineer and/or his designated representative shall observe the placement of fill and shall take sufficient tests to provide an opinion on the uniformity and degree of compaction being obtained. 5. Trench Backfills a) Trench excavations for utility pipes shall be backfilled under engineering supervision. b) After the utility pipe has been laid, the space under and around the pipe shall be backfilled with clean sand or approved granular soil to a depth of at least one foot over the top of the pipe. The sand backfill shall be uniformly jetted into placed before the controlled backfill is placed over the sand. c) The onsite materials, or other soils approved by the soil engineer, shall be watered and mixed as necessary prior to placement in lifts over the sand backfill. d) The controlled backfill shall be compacted to at least 90 percent of the maximum laboratory density as determined by the ASTM compaction method described above. e) Field density tests and inspection of the backfill procedures shall be made by the soil engineer during backfilling to see that proper moisture content and uniform compaction is being maintained. The contractor shall provide test holes and exploratory pits as required by the soil engineer to enable sampling and testing. z:D C iii I I I I I I I I I I I I I I I I I I I APPEND IX D Reference Schaefer Dixon Associates, Geological Evaluation, Santiago Estates, Portion of Tract No. 9833-3, Rancho California, California, November 30, 1988. ''If'p