Loading...
HomeMy WebLinkAboutTract Map 4059 Lot 8 Geotechnical Feasibility I /~'~. Ht'"Wn,\...f. ."~","!:~,..~~.... ;.GEN '. t~' .~~" .....~ '.~'"'' '-. 0:.:: ~'"''"'-~~:,:~'''\i,-- ,./_-:;~. j""~"'-'~ ~ '" .....""'"'._....~.:- ~--' / '\ I I Coq~oration -Soil Engineering and Consulting Services e Engineering Geology .CompaclionTesting -Inspections- Construction MalerialsTesting-laboratoryTesting. Percolation Testing _Geology.WalerResourceStudies .Phasel&IIEnvironmentaISiteAssessments ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NElWORK I I I GEOTECHNICAL FEASIBILITY STUDY Torrales Residence Assessor's Parcel Number: 919-210-002 Lot 8 of Tract 4059 Via Norte and Calle Fiesta City of Temecula, County of Riverside, California Project Number: T3456-GFS I I November 2, 2005 I 'I I I !I I I I Prepared for: I Sugarberry Properties, LLC 28924 Old Town Front Street "Temecula, California 92590 , ,,- .,,,,--~ .., .. / , " I" / ~ "" - - :1, -- , . - . , -- , , , - - \ / I ' , I .. ; / ' - ,-, ':"~~~:--":~W';':~:7,,",;""":-=--:-'':''~:'':;'''~ / -- i '-.~..J" ..':' -.- "-":_::._~.;L~;;-;_~",__:::;::::::;;;;:==::":: ~ L~ ' " '_I .: --'---'-JI . "if: -- :_><;:~t?:tjif(tffiH!!;.:II~..IS '/'> ;,:,.,,;.ij&, ',' ;', ',';' I,.. ",:.:' ,,' ::",','''' ...:' ",I; ..e;'\,":,x:"i'....::i'nf\:>jpr:lX'i/f.,'>;'ctJ)it: *_!Q~ -1P.il~1i!r~rij f,! SQrt,Li,1emecula,c:A !Y.1SW:"phon",J!l.51) 29.6-2i:l0:."fBX:-(95.1g9fi!~;" .. - ~ ;:;~.. FI -~~~~Z:, e "ii~ila'\1a\ ~A -92707 'Jlf(:012e::(114} 54f~405j 'I...; 17'jA~54ttA~~;;'~ ~J; B SITE: www.en' e COJP.COO:L:.e-MAIL: engencorp@engencorp.c6m ,'-,' ,. ,M.. M~ ..j:~ .. ,:'](''2 .-----.~......I. , ~ - -- I ~ iiil"' ~ ~. I II I I I I I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS TARI F OF CONTFNTS S.."tinn Numh.., "nd Tit'.. eage 1.0 SITE/PROJECT DESCRIPTION ... ................. ..........,... ........,...... ... .......... .... ............... ...,.2 1.1 Site Description ..............,...........,..."...,.."............................................,......"....... 2 1.2 Project Description...... ............., ... .... ... ........ .... ........................,...... ...................".2 2.0 FINDINGS...,.......... ...,...,........... ,....... ........ ..... .... ...... ........,..,...... ........... ......,.... .... ....,.....2 2.1 Site Review, ..............,... ............ .............. ...... ,........... ....................,... .... ........... .....2 2.2 Laboratory Testing..... ................. ........ ..................................................................2 2.2.1 General......................, ...........,......................, ,..,......... ,..........,................2 2.2.2 Classification ... ..... ..........................,........ ...............................................2 2.2.3 Maximum Dry Density/Optimum Moisture Content Relationship TesL.3 2.2.4 Expansion Potential.....,...........,......................... .....................,............... 3 2.2,5 Direct Shear Test......,...........,................................................................. 3 2.3 Excavation Characteristics .........................................,......................................... 3 3.0 ENGINEERING GEOLOGY/SEISMICITY .........................................................,.......,.....4 3.1 Geologic Setting ...,.......................................................,............,..........................4 3.2 Seismic Hazards......... .........,.... ............................................................................4 3.2.1 Surface Fault Rupture ............................................................................4 3.2.2 Liquefaction .................................................,.................... ...................... 4 3.2.3 Seismically-Induced Landsliding.,........................................................... 4 3.2.4 Seismically-Induced Flooding, Seiches and Tsunamis........................... 5 3,3 Earth Materials..... ....... ............. ..........................................................,................. 5 3.3.1 Road Fill, By Others (Afo).......................................................................5 3.3,2 Alluvium (Qal) ................,......,.......................................,...,......,.............. 5 3.3.3 Pauba Formation Sandstone (Qps)........................................................5 4.0 EARTHWORK RECOMMENDATIONS ..........................,........................................,.......5 4.1 All Areas .................................................,......................,...........................,.......... 5 4.2 Oversize Material..,..., '"'''''' ......,.......,.... ,.............,.......,...........................,.......,....7 4.3 Structural Fill............... ......... ....... ......... .............. ....,.......,............,......................... 7 4.4 Soil Expansion Potential.............................................,......................................... 7 4.5 Soluble Sulfate................ ..................................................................................... 8 5.0 SLOPE STABILITY - GENERAL ....................................................................................8 6.0 CONCLUSIONS AND RECOMMENDATIONS.............................,.......,..........................8 6.1 Foundation Design Recommendations ................................................................8 6.1.1 Foundation Size...................................................................................... 8 6.1.2 Depth of Embedment .............................................................................9 6.1.3 Bearing Capacity ....................................................................................9 6.1.4 Seismic Design Parameters ...................................................................9 6.1.5 Settlement .....................................,........................................................ 9 6.2 Lateral Capacity........... ..........................................,..........,................................... 9 EnGEN Corporation z. I I I I I I I I !I ! I II I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS TARlF OF CONTFNTS Sp-r.:tinn Nllmh9r ::Inn TitlA. 2aga 6.3 Slab-on-Grade Recommendations...,....,......... .......,...... ....... ............. ..........,...... 10 6.4 Exterior Slabs ................."............."......................."................................"........1 0 7,0 RETAINING WALL RECOMMENDATIONS.................................................................. 11 7.1 Earth Pressures......,...........................................................................,...............11 7.2 Retaining Wall Design ........................................................................................11 7,3 Subdrain ...,.,...... ......., ...............,.............. .......,...,............."... .........,.... ....... ........ 12 7.4 Backfill... ....... .................. .... ........,....... ..........,...,... .... ......,... ... ......"... .... .... .... ...... 12 8,0 MISCELLANEOUS RECOMMENDATIONS,.................,..........,..,.............,..............,....13 8.1 Utility Trench Recommendations........................................................................ 13 8.2 Finish Lot Drainage Recommendations .............................................................13 8.3 Planter Recommendations .................................................................,...............13 8.4 Supplemental Construction Observations and Testing ......................................13 8.5 Plan Review..... ... .... ... ..... .......,.... .........."...... ...........,... .......,.. ...........,... .... .......... 14 8.6 Pre-Bid Conference ........,..., .... .......,.... .... ... ......., .... ... .......... ........... ....... ...., ... ..... 14 8.7 Pre-Grading Conference .....................,............................,.............,...................14 9.0 CLOSURE........ ............ .... ................ .... '... ..... ... ......,.... ........... ..........,... .... ........ .... .......,15 APPENDIX: TECHNICAL REFERENCES LABORATORY TEST RESULTS DRAWINGS 3> I ,', /' , ~~~ GEN I .. L~., _.",d ",-.,w,c,,' :;":,,,<c;~""t; .... -",..~,.. 0: I [' ~~~"'lJ"'?~"""'T-'II_ I I I I I I I I I I I I I I COfl~oration ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NElWORK -Soil EngineerinllandConsulting 5ervices . EngineeringGeology. Compaction Tesling .lnspeclions-ConstructlonMaterialsTesling. LaboraloryTestlng-PercolallOnTesling . Geoloqy-WaterResourceStudies .Phasel&IIEnvilOnmenlaISiteAssessments . November 2, 2005 . Sugarberry Properties, LLC 28924 Old Town Front Street Temecula, Califomia 92590 (951) 693-9060 I FAX (951) 693-9061 Attention: Mr. Rober Torrales, Jr. . Regarding: GEOTECHNICAL FEASIBILITY STUDY T orrales Residence Assessor's Parcel Number: 919-210-002 Lot 8 of Tract 4059 Via Norte and Calle Fiesta City of Temecula, County of Riverside, California Project Number: T3456-GFS Reference: 1. SB & 0, Inc., Precise Grading Plan, Torrales Residence, Lot 8, Tract 4059, 30865 Via Norte, City of T emecula, plans dated September 6, 2005. Dear Mr. Torrales: In accordance with your request and signed authorization, a representative of this firm has visited the subject site on October 24, 2005, to visually observe the surficial conditions of the subject lot and to collect samples of representative surficial site materials. Laboratory testing was performed on these samples. Test results and preliminary foundation recommendations for the construction and grading of the proposed development are provided. It is our understanding that cut and fill type grading will take place for the proposed structural development Based on this finm's experience with this type of project, our understanding of the regional geologic conditions surrounding the site, our review of in-house maps, and both published and unpublished reports, subsurface exploration was not considered necessary. However, in lieu of subsurface exploration, additional grading beyond that anticipated in this report may be necessary dependin9 on the exposed conditions to be encountered durin9 grading. If any changes are made to the Referenced No. 1 Plans, they should be reviewed by this office so additional recommendations, if necessary, can be prepared. Keystone wall plans were not available for review. The Keystone wall designer should determine if the minimum setback shown on the Referenced No, 1 plans is appropriate and will provide adequate support for the structure, and will not have a detrimental effect on the Keystone wall. ''"' " I' . I . ..,. - - - - \ / ~ ~ ! " , " l .~I~. I; u, \ -,' __ I -,_.::...~~...._,.J_ , - / .-, - :..-1--- " , '--.......- ::':~iE\:fjr~I..'N ~ Sutte::ij~ecul., CA ~2590. PhbJ1e:1ll~;l2~Q,~:lo~ fall: (~ FI ~i:~f.(1j'g,j; e~~~;'a, CA 92707 . plione:\71/1J(54Sz4Q51 ~. la":;(75':" B.. SITE: www.en e corp;collJ~ E-MAIL: engencorp@)engencorp.com ~ I I. I I I I . I I I . I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 2 1.0 SITF/PRO.lFr.T OFSr.RIPTlON 1.1 Sit" O".."riptinn" The subject site consists of approximately 1. 61-acres located on the south side of Via Norte between Calle Torcida and Calle Fiesta, in the City of Temecula, County of Riverside, California. The lot surface is situated 10 to 20-feet below street level at the toe of the Via Norte fill slope. Topography on site, below the fill slope, is gently sloping to the south at gradients of approximately 5 to 10 percent. Vegetation on site consists of native weeds and grasses. No structures are located on site. 1.2 Prnj"r.t O".."riptinno It is our understanding that the proposed development will consist of a one or two story, wood-framed single family residence with a slab-on-grade foundation. A Keystone wall is proposed along the eastern, western, and southern sides of the residence. We are providing general grading and minimum footing recommendations for the proposed development. 2.0 FINOINGS 2.1 Sit" R"vi"w" Based on our field reconnaissance, it appears that alluvium, and Pauba Formation Sandstone underlie the site. Artificial fill associated with the construction of Via Norte is located along the northern portion of the site. Documentation of the fill is not present at this time. The condition of the road fill is not known. Pauba Formation Sandstone constitutes bedrock at the subject site. The alluvium exposed at the ground surface was found to be dry and loose. Since no subsurface exploration was performed for this study, the thickness and condition of the alluvium is unknown. 2.2 I ahnratn-:y TAsting" 2.2.1 G"n"...t" The results of laboratory tests performed on samples of earth material obtained during the site visit are presented in the Appendix. Following is a listing and brief explanation of the laboratory tests performed. The samples obtained during the field study will be discarded 30 days after the date of this report. This office should be notified immediately if retention of samples will be needed beyond 30 days. 2.2.2 Cla....ifi""tinn" The field classification of soil materials encountered during our site visit were verified in the laboratory in general accordance with the Unified Soils Classification System, ASTM D 2488-00, Standard Practice for Determination and Identification of Soils (Visual-Manual Procedures). ~ EnGEN Corporation I I I I I I I I I I I I I I , I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 3 2.2.3 May;mllm DQI DAn"ity/Optimllm Mni"tllrA CnntAnt RAlatinn"hip TA"t. Maximum dry density/optimum moisture content relationship determinations were performed on samples of near-surface earth material in general accordance with ASTM 1557-02 procedures using a 4.0-inch diameter mold. Samples were prepared at various moisture contents and compacted in five (5) layers using a 10-pound weight dropping 18-inches and with 25 blows per layer. A plot of the compacted dry density versus the moisture content of the specimen is constructed and the maximum dry density and optimum moisture content determined from the plot. 2.2.4 Fypan"inn PntAntial' Laboratory expansion tests were performed on samples of near- surface earth materials in general accordance with CBC 18-2 procedures. In this testing procedure, a remolded sample is compacted in two (2) layers in a 4.0-inch diameter mold to a total compacted thickness of approximately 1.0-inch by using a 5.5 pound weight dropping 12-inches and with 15 blows per layer. The sample should be compacted at a saturation of between 49 and 51 percent. After remolding, the sample is confined under a pressure of 144 pounds per square foot (pst) and allowed to soak for 24 hours. The resulting volume change due to the increase in moisture content within the sample is recorded and the Expansion Index (EI) is calculated. 2.2.5 DirAd ShA"r TA"t (RAmnldAd)' Direct shear tests were performed on select samples of near-surface earth material, which had been remolded to 90 percent of the maximum density, in general accordance with ASTM D 3080-03 procedures. The shear machine is of the constant strain type. The shear machine is designed to receive a 1.0-inch high, 2.416-inch diameter ring sample. Specimens from the sample were sheared at various pressures normal to the face of the specimens. The specimens were tested in a submerged condition, The maximum shear stresses were plotted versus the normal confining stresses to determine the shear strength (cohesion and angle of internal friction). 2.3 Fyr.avatinn CharadAri"tir.,,' Excavation and trenching within the alluvium is anticipated to be relatively easy. Excavation and trenching in the bedrock will be more difficult due to the higher bedrock densities typically encountered in the area. A rippability survey was not within the scope of our investigation. Based on our experience on similar projects near the subject site, the bedrock is expected to be rippable with conventional grading equipment. ~ EnGEN Corporation I !. I I I I I I ! I I I I I . I I I I I Sugarberry Properties. LLC Project Number: T3456-GFS . November 2005 Page 4 3.0 FNC::INFFRINC:: C::FOI OC::Y/SFISMICITY 3.1 C::"nlngi" S"tt;ng' The site is located in the Northern Peninsular Range on the southern sector of the structural unit known as the Perris Block. The Perris Block is bounded on the northeast by the San Jacinto Fault Zone, on the southwest by the Elsinore Fault Zone, and on the north by the Cucamonga Fault Zone, The southern boundary of the Perris Block is not as distinct, but is believed to coincide with a complex group of faults trending southeast from the Murrieta, California area (Kennedy, 1977). The Peninsular Range is characterized by large Mesozoic age intrusive rock masses flanked by volcanic, metasedimentary, and sedimentary rocks. Various thicknesses of alluvial and colluvial sediments derived from the erosion of the elevated portions of the region fill the low-lying areas. The earth materials encountered on the subject site are described in more detail in subsequent sections of this report. 3.2 S";..mi,, H"7"rd... Because the proposed development is located in tectonically active southern California, it will likely experience some effects from earthquakes. The type or severity of seismic hazards affecting the site is mainly dependent upon the distance to the causative fault, the intensity of the seismic event, and the soil characteristics. The seismic hazard may be primary, such as ground surface rupture and/or ground shaking, or secondary, such as liquefaction or dynamic settlement. 3.2.1 SlIrf""" F'lIJlt RI,ptllr,,' The site is not located within a State of California designated Alquist-Priolo Earthquake Fault Zone. No faulting was observed during our site reconnaissance. The nearest State designated active fault is the Elsinore Fault (Temecula Segment), located approximately 4.0 kilometers (2.5 miles) to the southwest of the subject site. This conclusion is based on literature review (Kennedy, 1977) and EnGEN Corporation's field reconnaissance. Accordingly, the potential for fault surface rupture on the site is very unlikely. 3.2.2 I iqll"f"clinn' Based on Section 4.0, Earthwork Recommendations, of this report, and the dense nature of the underlying bedrock, the potential for liquefaction at the site is considered very low. 3.2.3 S";..mi",,lIy Indll""d I "nd..liding' Due to the overall massive and dense nature of the bedrock, and the low topographic relief on site, the probability of seismically induced landsliding is considered very low. 1 EnGEN Corporation I I ~ I I I I I I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 5 3.2.4 ~";,.ml"ally Indll""d Flnnding ~"i"h,,!': and T!':lInami!':" Due to the absence of a confined body of water in the immediate vicinity of the project site, the possibility of seismically induced flooding or seiches is considered nil. Due to the large distance of the project site to the Pacific Ocean, the possibility for seismically induced tsunamis to impact the site is considered nil. 3.3 F,uth Mat"rial!':" 3.3.1 Rnad Fill F\y nth"r!': (Afn)" Existing road fills lie on the northern side of the site, along Via Norte. The existing fill slope is inclined at approximately 2:1 (horizontal to vertical) with a vertical height of approximately 10 to 20-feet. The condition and thickness of the road fill is not known. 3.3.2 Allllvillm (Pal)' Alluvium exists in the lower elevations on the southern end of the site. The alluvium consists of silty fine- to medium-grained sand and was found to be moist in- place. .Since no subsurface exploration was performed for this investigation, the condition of the alluvium is unknown, The thickness of the alluvium is unknown. 3.3.3 Pallha Fnrmatinn ~and!':tnn" (Op!':)" Pauba Formation sandstone constitutes bedrock at the subject site. The Pauba Fonmation is generally massive with near horizontal bedding. On site the Pauba Formation consists of silty medium-grained sand, and was found to be moist and medium dense in-place. 4.0 FARTHWORK RFCOMMFNnATION~ Keystone wall plans were not available for review. The Keystone wall designer should determine if the minimum setback shown on the Referenced No.1 plans (approximately 8-feet from the top of the wall) is appropriate and will provide adequate support for the structure, and will not have a detrimental effect on the Keystone wall. 4.1 All Ar..a!':" 1. All vegetation should be removed from areas to be graded and not used in fills. Any undocumented fill should be removed and recompacted. 2. Removals of the alluvium in the vicinity of the proposed fill slopes should be performed to competent Pauba Formation bedrock, Actual removal depths should be detenmined during grading under exposed conditions. ~ EnGEN Corporation I I I I I I I I I I I I I I I I I I I Sugarbeny Properties. LLC Project Number: T3456-GFS November 2005 Page 6 3. Removals of the road fills should be performed to competent Pauba Formation sandstone in the building pad area beyond the perimeter of the building. Keying and benching should be performed in the remainder of the proposed areas. 4. Any earthwork performed within the S.C.E. and MW.D, easements will require the same earthwork recommendations set forth in paragraph 2 and 3. It is our understanding that permission to perform earthwork in these areas is in progress. 5. Based on the Referenced NO.1 plan, the structure appears to straddle a shallow to deep fill transition. The shallow fill portions should be overexcavated to a depth equal to at least half the maximum fill thickness. The fill in the deep portion is approximately 25-feet, therefore, the overexcavation should be performed to a minimum depth of 12.5-feet. The overexcavation should extend beyond the perimeter of the structure a distance equal to the overexcavation depth. 6. All exposed removal and overexcavation bottoms should be inspected by the Project Geologist or his representative prior to placement of any fill. Road fills should be removed to competent bedrock. Alluvium should be removed to competent bedrock. Any residual soils and weathered bedrock must be removed to competent bedrock. Bedrock bottoms should be probed to verify competency. 7. The approved exposed bottoms of all removal areas should be scarified 12-inches, brought to near optimum moisture content, and compacted to a minimum of 90 percent relative compaction before placement of fill. Maximum dry density and optimum moisture content for compacted materials should be determined according to ASTM D 1557-02 procedures. 8. A keyway should be constructed at the toe of all fill slopes that are proposed on natural grades of 5: 1 (horizontal to vertical) or steeper. Keyways should be a minimum of fifteen (15) feet wide (equipment width) and tilted a minimum of two percent into the hillside. A series of level benches should be constructed into competent bedrock on natural grades of 5: 1 (horizontal to vertical) or steeper prior to placing fill. 9. All fill slopes should be constructed at slope ratios no steeper than 2: 1 (horizontal to vertical). All cut slopes should be inspected by the Project Geologist to verify stability. q, EnGEN Corporation I I I I II I I I I I I I I I I I I I I I 4.3 4.4 Sugarbeny Properties, LLC Project Number: T3456-GFS November 2005 Page 7 Cut slopes exposing loose soils may be considered unstable. Unstable cut slopes may require flattening or buttressing. 4.2 Ov.m<i7A MatAri,'" Oversize material is defined as rock, or other irreducible material with a maximum dimension greater than 12-inches. Oversize material shall not be buried or placed in fill unless location, materials, and placement methods are specifically accepted by the Project Geotechnical Engineer. Placement operations shall be such that nesting of oversize material does not occur, and such that oversize material is completely surrounded by compacted fill (windrow). Alternative methods, such as water jetting or wheel rolling with a backhoe may be required to achieve compaction in the fill materials immediately adjacent to the windrow. Oversize material shall not be placed within ten (10) vertical feet of finish grade, within fifteen (15) lateral feet of a finished slope face, or within two feet of future utilities, ~trlldllral Fill' All fill material, whether on-site material or import, should be accepted by the Project Geotechnical Engineer and/or his representative before placement. All fill should be free from vegetation, organic material, and other debris. Import fill should be no more expansive than the existing on-site material, unless approved by the Project Geotechnical Engineer. Approved fill material should be placed in horizontal lifts not exceeding 6.0 to 8.0-inches in thickness, and watered or aerated to obtain near-optimum moisture content (within 2.0 percent of optimum). Each lift should be spread evenly and should be thoroughly mixed to ensure unifonmity of soil moisture. Structural fill should meet a minimum relative compaction of 90 percent of maximum dry density based upon ASTM D 1557-02 procedures. Moisture content of fill materials should not vary more than 2.0 percent of optimum, unless approved by the Project Geotechnical Engineer. ~nil Fypano::inn PntAntial' Preliminary Expansion Index testing was performed, yielding an EI of O. This is classified as a very low expansion potential. Import soils or soils used near finish grade may have a different EL The bedrock can potentially contain significant amounts of expansive silts or clays. Mixing of these silts and clays during grading could affect the overall EI of the fill. If selective grading is desired in order to ensure that expansive soils are not used near pad grade, this option should' be discussed with this firm and the grading contractor prior to grading the site. Final foundation design parameters should be based on EI testing of near-surface soils and be performed at the \0 EnGEN Corporation I I I I I I I I I I I I I I I I I I I Sugarbeny Properties, LLC Project Number: T3456-GFS November 2005 Page 8 conclusion of rough grading. Those results should be forwarded and incorporated into the final design by the Project Structural Engineer, 4.5 Snlllhl.. SlIlfat..". Based on this finm's familiarity with the on-site soils, it is our opinion that soluble sulfates are not a concern, and as a result, nonmal Type II cement may be used in concrete that will come in contact with native soils. 5.0 SI OPF STARIIITY _ GFNFRAI It is our professional opinion that cut or fill slopes no taller than 30-feetand inclined at 2:1 (horizontal to vertical) or flatter, will possess gross and surficial stability in excess of generally accepted minimum engineering criteria (Factor of Safety at least 1.5) and are suitable for their intended purpose, provided that proper slope maintenance procedures are maintained. These procedures include but are not limited to installation and maintenance of drainage devices and planting of slope faces to protect from erosion in accordance with County of Riverside Grading Codes. 6.0 CONCI IISIONS ANn RFCOMMFNnATIONS 6.1 Fnllndatinn n.."ign R.."nmm..ndatinn,,' Foundations for the proposed structure may consist of conventional column footings and continuous wall footings founded in compacted fill. The recommendations presented in the subsequent paragraphs for foundation design and construction are based on geotechnical characteristics and upon a very low expansion potential for the supporting soils and should not preclude more restrictive structural requirements. The Structural Engineer for the project should determine the actual footing width and depth in accordance with the latest edition of the California Building Code to resist design vertical, horizontal, and uplift forces and should either verify or amend the design based on final expansion testing at the completion of grading. 6.1.1 Fnllndatinn Siz..' Continuous footings should have a minimum width of 12-inches, Continuous footings should be continuously reinforced with a minimum of one (1) NO.4 steel reinforcing bar located near the top and one (1) NO.4 steel reinforcing bar located near the bottom of the footings to minimize the effects of slight differential movements which may occur due to minor variations in the engineering characteristics or seasonal moisture change in the supporting soils, Column footings should have a minimum width of EnGEN Corporation \\ I I I I I II I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 9 18-inches by 18-inches and be suitably reinforced, based on structural requirements. A grade beam, founded at the same depths and reinforced the same as the adjacent footings, should be provided across doorway and garage entrances. 6.1.2 np.pth nf Fmhp.dmp.nt. Exterior and interior footings founded in compacted fill should extend to a minimum depth of 12-inches below lowest adjacent finish grade for single story structures and 18-inches below lowest adjacent finish grade for two (2) story structures. 6.1.3 Rp.arlng C",pacity. Provided the recommendations for site earth work, minimum footing width, and minimum depth of embedment for footings are incorporated into the project design and construction, the allowable bearing value for design of continuous and column footings for the total dead plus frequently-applied live loads is 2,000 psf for compacted fill. The allowable bearing value has a Factor of Safety of at least 3.0 and may be increased by 33.3 percent for short durations of live and/or dynamic loading such as wind or seismic forces. 6.1.4 ~p.;"mi" np."lgn Paramp.tp.r,,' The following seismic parameters apply: Name of Fault: Elsinore Fault (Temecula Segment) Type of Fault: Type B Fault Closest Distance to Fault: 4.0 Kilometers (2.5 miles) Soil Profile Type: SD 6.1.5 ~p.ttlp.mp.nt. Footings designed according to the recommended bearing values and the maximum assumed wall and column loads are not expected to exceed a maximum settlement of 0,75-inch or a differential settlement of 0.5-inch. 6.2 I atp.ral Capa,,;ty. Additional foundation design parameters based on competent engineered fill. for resistance to static lateral forces, are as follows: Allowable lateral Pressure (Equivalent Fluid Pressure), Passive Case: Compacted Fill- 250 pet Allowable Coefficient of Friction: Compacted Fill - 0,35 Lateral load resistance may be developed by a combination of friction acting on the base of foundations and slabs and passive earth pressure developed on the sides of the footings and stem walls below grade when in contact with compacted fill. The above values are allowable design values and may be used in combination without reduction in evaluating the resistance to lateral loads. The allowable values may be increased by EnGEN Corporation ~~ I . I :1 I I I I ,I I ;. i :1 i ,I I I I II I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 10 33.3 percent for short durations of live and/or dynamic loading, such as wind or seismic forces. For the calculation of passive earth resistance, the upper 1.0-foot of material should be neglected unless confined by a concrete slab or pavement. The maximum recommended allowable passive pressure is 5.0 times the recommended design value. 6.3 SI"h-nn-Gr"rte Rer.nmmenrt"tinn,,' The recommendations for concrete slabs, both interior and exterior, excluding PCC pavement, are based upon the anticipated building usage and upon a very low expansion potential for the supporting material as determined by Chapter 18 of the California Building Code. Concrete slabs should be designed to minimize cracking as a result of shrinkage. Joints (isolation, contraction, and construction) should be placed in accordance with the American Concrete Institute (ACI) guidelines. Special precautions should be taken during placement and curing of all concrete slabs. Excessive slump (high water/cement ratio) of the concrete and/or improper curing procedures used during either hot or cold weather conditions could result in excessive shrinkage, cracking, or curling in the slabs. It is recommended that all concrete proportioning, placement, and curing be performed in accordance with ACI recommendations and procedures. Slab-on-grade reinforcement and thickness should be provided by the structural engineer based on structural considerations, but as a minimum, it is recommended that concrete floor slabs be at least 4-inches in nominal thickness and reinforced with at least No.3 reinforcing bars placed 24-inches on center, both ways, placed at mid-height of the slab cross-section. Final expansion testing at completion of grading could cause a change in the slab-on-grade recommendations, In areas where moisture sensitive floor coverings are anticipated over the slab, we recommend the use of a polyethylene vapor barrier with a minimum of 10.0 mil in thickness be placed beneath the slab. The moisture barrier should be overlapped or sealed at splices and covered top and bottom by a 1.0 to 2,0-inch minimum layer of clean, moist (not saturated) sand to aid in concrete curing and to minimize potential punctures. 6.4 Frier;nr S/"h,,' All exterior concrete slabs cast on finish subgrade (patios, sidewalks, etc., with the exception of PCC pavement) should be a minimum of 4-inches nominal in thickness. Reinforcing in the slabs and the use of a compacted sand or gravel base beneath the slabs should be according to the current local standards. Subgrade soils EnGEN Corporation '$ II I I I I I I I I . :1 II I I I I '. I I 7.2 Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 11 should be moisture conditioned to at least optimum moisture content to a depth of 12-inches immediately before placing the concrete. 7.0 RFTAININ~ WAil RFCOMMFNnATIONS Keystone wall plans were not available for review. The following general retaining wall recommendations are given for design purposes which may be used at the discretion of the Keystone wall designer. With respect to typical Keystone design parameters, the following is provided for the native soils: Soil Type Unit Weight Internal Angle of Friction (degrees) The wall designer may wish to use more conservative values for the reinforced and retained soils since it may be difficult t control imported soils to match the above values. 7.1 F"rth Pr....""r..". Retainin9 walls backfilled with non-expansive granular soil (EI=O) or very low expansive potential materials (Expansion Index of 20 or less) within a zone extending upward and away from the heel of the footing at a slope of 0,5:1 (horizontal to vertical) or flatter can be designed to resist the following static lateral soil pressures: c~:~~::n Lev~~ ~~~i11 2:~5s~~~e Further expansion testing of potential backfill material should be performed at the time of retaining wall construction to determine suitability. Walls that are free to deflect 0,01 radian at the top may be designed for the above-recommended active condition, Walls that need to be restricted from this amount of movement should be assumed rigid and designed for the at-rest condition. The above values assume well-drained backfill and no buildup of hydrostatic pressure. Surcharge loads, dead and/or live, acting on the backfill behind the wall should also be considered in the design. R..t"ining W"II n.."ign' Retaining wall footings should be founded to the same depths into firm, competent, compacted fill as standard foundations and may be designed for an allowable bearing value of 2,000 psf when founded in compacted fill (as long as the EnGEN Corporation ~~ I I I I I I I .1 I I I I I I I I I I I 7.4 Sugarberry Properties, llC Project Number: T3456-GFS November 2005 Page 12 resultant force is located in the middle one-third of the footing). Allowable static lateral bearing pressure of 200 psflft may be used in compacted fill. An allowable sliding resistance coefficient of friction of 0.35 is applicable for compacted fill. When using the allowable lateral pressure and allowable sliding resistance, a Factor of Safety of 1,5 should be achieved. 7.3 SlIhrlr..in" A subdrain system should be constructed behind and at the base of retaining walls equal to or in excess of 5-feet in height to allow drainage and to prevent the buildup of excessive hydrostatic pressures. Gravel galleries and/or filter rock, if not properly designed and graded for the on-site and/or import materials, should be enclosed in a geotextile fabric such as Mirafi 140N, Supac 4NP, or a suitable substitute in order to prevent infiltration of fines and clogging of the system. The perforated pipes should be at least 4.0-inches in diameter. Pipe perforations should be placed downward. Gravel filters should have volume of at least 1.0 cubic foot per lineal foot of pipe. For retaining walls with an overall height of less than 5-feet, subdrains may include weep holes with a continuous gravel gallery, perforated pipe surrounded by filter rock, or some other approved system. Subdrains should maintain a positive flow gradient and have outlets that drain in a non-erosive manner. R.."kfill' Backfill directly behind retaining walls (if backfill width is less than 3-feet) may consist of 0.5 to 0.75-inch diameter, rounded to subrounded gravel enclosed in a geotextile fabric such as Mirafi 140N, Supac 4NP, or a suitable substitute or a clean sand (Sand Equivalent Value greater than 50) water jetted into place to obtain proper compaction. If water jetting is used, the subdrain system should be in place. Even if water jetting is used, the sand should be densified to a minimum of 90 percent relative compaction. If the speCified density is not obtained by water jettin9, mechanical methods will be required, If other types of sailor gravel are used for backfill, mechanical compaction methods will be required to obtain a relative compaction of at least 90 percent of maximum dry density. Backfill directly behind retaining walls should not be compacted by wheel, track or other rolling by heavy construction equipment unless the wall is designed for the surcharge loading. If gravel, clean sand or other imported backfill is used behind retaining walls, the upper 18-inches of backfill in unpaved areas should consist of typical on-site material compacted to a minimum of 90 percent relative compaction in order to prevent the influx of surface runoff into the granular backfill and into the subdrain EnGEN Corporation \6 I I I I I I I I I I I I I I I I I I I I 8.2 8.3 8.4 Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 13 system. Maximum dry density and optimum moisture content for backfill materials should be determined in accordance with ASTM D 1557-02 procedures. 8.0 MISCFI I AN FOilS RFCOMMFNDATIONS 8.1 IItility Tr"nr.h R"r.nmm"ndatinn.." Utility trenches within the zone of influence of foundations or under building floor slabs, hardscape, and/or pavement areas should be backfilled with properly compacted soil. .It is recommended that all utility trenches excavated to depths of 5.0-feet or deeper be cut back to an inclination not steeper than 1: 1 (horizontal to vertical) or be adequately shored during construction. Where interior or exterior utility trenches are proposed parallel and/or perpendicular to any building footing, the bottom of the trench should not be located below a 1:1 plane projected downward from the outside bottom edge of the adjacent footing unless the utility lines are designed for the footing surcharge loads. Backfill material should be placed in a lift thickness appropriate for the type of backfill material and compaction equipment used. Backfill material should be compacted to a minimum of 90 percent relative compaction by mechanical means. Jetting of the backfill material will not be considered a satisfactory method for compaction. Maximum dry density and optimum moisture content for backfill material should be determined according to ASTM D 1557-02 procedures. Fini..h I nt Drainag.. R"r.nmm"ndatinn.." Finish lot surface gradients in unpaved areas should be provided next to tops of slopes and buildings to direct surface water away from foundations and slabs and from flowing over the tops of slopes. The surface water should be directed toward suitable drainage facilities. Ponding of surface water should not be allowed next to structures or on pavements. In unpaved areas, a minimum positive gradient of 4.0 percent away from the structures and tops of slopes for a minimum distance of 3.0-feet and a minimum of 1.0 percent pad drainage off the property in a non- erosive manner should be provided. Plant"r R"r.nmm"ndatinn.." Planters around the perimeter of the structure should be designed with proper surface slope to ensure that adequate drainage is maintained and minimal irrigation water is allowed to percolate into the soils underlying the building. SlIppl..m..nta' Cnm:trudinn Oh.."rvatinn..and T..<:fing" Any subsequent 9rading for development of the subject property should be performed under engineering observation and testing performed by EnGEN Corporation" Subsequent grading includes, but is not EnGEN Corporation fro I I I I I I I I I I I I II I I I I I I 8.6 8.7 Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 14 limited to, any additional overexcavation of cut and/or cut/fill transitions, fill placement, and excavation of temporary and permanent cut and fill slopes. In addition, EnGEN Corporation, should observe all foundation excavations. Observations should be made prior to installation of concrete forms and/or reinforcing steel to verify and/or modify, if necessary, the conclusions and recommendations in this report. Observations of overexcavation cuts, fill placement, finish grading, utility or other trench backfill, pavement subgrade and base course, retaining wall backfill, slab presaturation, or other earthwork completed for the development of subject property should be performed by EnGEN Corporation. '. .If any of the observations and testing to verify site geotechnical conditions are not performed by EnGEN Corporation, liability for the safety and performance of the development is limited to the actual portions of the project observed and/or tested by EnGEN Corporation. 8.5 PI,," Rp.vip.w' Subsequent to formulation of final plans and specifications for the project but before bids for construction are requested, grading and foundation plans for the proposed development should be reviewed by EnGEN Corporation to verify compatibility with site geotechnical conditions and confonmance with the recommendations contained in this report. If EnGEN Corporation is not accorded the opportunity to make the recommended review, we will assume no responsibility for misinterpretation of the recommendations presented in this report. Prp..Rid Cn"fp.rp.""p.' It is recommended that a pre-bid conference be held with the owner or an authorized representative, the Project Architect, the Project Civil Engineer, the Project Geotechnical Engineer and the proposed contractors present. This conference will provide continuity in the bidding process and clarify questions relative to the supplemental grading and construction requirements of the project, Prp..Gr"ding Cn"fp.rp.""p.' Before the start of any grading, a conference should be held with the owner or an authorized representative, the contractor, the Project Architect, the Project Civil Engineer, and the Project Geotechnical Engineer present. The purpose of this meeting should be to clarify questions relating to the intent of the supplemental grading recommendations and to verify that the project specifications comply with the recommendations of this geotechnical en9ineering report. Any special 9rading procedures and/or difficulties proposed by the contractor can also be discussed at that time. EnGEN Corporation \1 I I I I I I I II I I I ,I I I I I I I I I 9.0 Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 15 CLOSIIRF This report has been prepared for use by the parties or project named or described in this document. It mayor may not contain sufficient information for other parties or purposes. In the event that changes in the assumed nature, design, or location of the proposed structure and/or project as described in this report, are planned, the conclusions and recommendations contained in this report will not be considered valid unless the changes are reviewed and the conclusions and recommendations of this report are modified or verified in writing, This study was conducted in general accordance with the applicable standards of our profession and the accepted soil and foundation engineering principles and practices at the time this report was prepared. No other warranty, implied or expressed beyond the representations of this report, is made. Although every effort has been made to obtain infonmation regarding the geotechnical and subsurface conditions of ~he site, limitations exist with respect to the knowledge of unknown regional or localized off-site conditions that may have an impact at the site. The recommendations presented in this report are valid as of the date of the report. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or to the works of man on this and/or adjacent properties. If conditions are observed or infonmation becomes available during the design and construction process that are not reflected in this report, EnGEN Corporation should be notified so that supplemental evaluations can be performed and the conclusions and recommendations presented in this report can be modified or verified in writing. Changes in applicable or appropriate standards of care or practice occur, whether they result from legislation or the broadening of knowledge and experience. Accordingly, the conclusions and recommendations presented in this report may be invalidated, wholly or in part, by changes outside of the control of EnGEN Corporation which occur in the future, EnGEN Corporation ~ I I I I I I I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS November 2005 Page 16 Thank you for the opportunity to provide our services. Often, because of design and construction details which occur on a project, questions arise concerning the geotechnical conditions on the site. If we can be of further service or should you have questions regarding this report, please do not hesitate to contact this office at your convenience. Because of our involvement in the project to date, we would be pleased to discuss engineering testing and observation services that may be applicable on the project. CM/OB:II Distribution: (4) Addressee FILE: EnGEN\Reporting\GFS\T3421-GFS Tonales Residence, Geotechnical Feasibility Study EnGEN Corporation \C\. I I I I I II I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS Appendix Page 1 TFCHNICAI RFFFRF'NCFS 1. California Building Code, 2001, State of California, California Code of Regulations, Title 24, 1998, California Building Code: International Conference of Building Officials and California Building Standards Commission, 3 Volumes. 2. California Division of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117. 3. Hart, Earl W" and Bryant, William A., 1997, Revised 1999, Fault-Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zone Maps: State of California, Department of Conservation, Division of Mines and Geology, 38 Pages reviewed at the California Geological Survey's web page: http://www.consrv.ca.gov /cgs/rghm/ap/ MapjndexlF4E.htm#SW. 4. Kennedy, M.P., 1977, Recency and Character of Faulting Along the Elsinore Fault Zone in Southern Riverside County, California: California Division of Mines and Geology, Special Report 131,12 p., 1 plate, scale 1:24,000, 5. Morton, D. M., 1999, Preliminary Digital Geologic Map of the Santa Ana 30' x 60' Quadrangle, Southern California, version 1.0, Open File Report 99-172. 6. Riverside, County of, 2000, Transportation and Land Management Agency, Technical Guidelines for Review of Geotechnical and Geologic Reports, 2000 Edition. 7. Riverside, County of, 1978, Seismic Safety/Safety Element Policy Report, June 1978, by Envicom. 8, Riverside County Planning Department, January 1983, Riverside County Comprehensive General Plan - County Seismic Hazards Map, Scale 1 Inch = 2 Miles. 9. Southern California Earthquake Center (SCEC), 1999, Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Liquefaction Hazards in California, March 1999. 10. Southern California Earthquake Data Center (SCEDC), 2004, Southern California Earthquake Data Center Website, http://www.scecdc.scec.org. 11. Tan, S,S., and Kennedy, M.P., 2000, Geologic Map of the Temecula 7.5' Quadrangle, San Diego and Riverside Counties, California: A Digital Base Map, Version 1.0: California Division of Mines and Geology and United States Geological Survey, Southern California Aerial Mapping Project. 12. Uniform Building Code (UBC), 1997 Edition, by International Conference of Building Officials, 3 Volumes. EnGEN Corporation 2D I I !I , II I I I I I I I I I I I I I I I LABORATORY TEST RESULTS Sugarberry Properties, LLC Project Number: T3456-GFS Appendix Page 2. EnGEN Corporation I I , I I I , I i I , I I il I I I I I I I I I COMPACTION TEST REPORT 130 \ 1\ \ \ \ \ \ '" - .... ...... \ 1/ ". ...... \ "- / '" \ I...... I\.. \ .... \ \ 1\ \ \ \ \ 1\ 128 126 '0 c. ;3 'iij c: Q) " ~ 0 124 122 120 4 ZAV for Sp.G. = 2.67 16 12 14 6 8 10 Water content, % Test specification: ASTM D 1557-02 Method A Modified Elevl Depth %> No.4 %< No.200 Classification USCS AASHTO Nat Moist Sp.G. LL PI SM 6.6 TEST RESULTS MATERIAL DESCRIPTION SILTY SAND, BROWN Maximum dry density = 126.0 pcf Optimum moisture = 9.6 % Project No. T3456-GFS Client: ROBERT TORRALES Project: TORRALES RESIDENCE Remarks: SAMPLE A UPPER CUT AREA COLLECTED BY RW COLLECTED ON (10/24/05) . .Location: VIA NORTE COMPACTION TEST REPORT ENVIRONMENTAL AND GEOTECHNICAL ENGINEERING NETWORK CORPORATION Figure zA I I I I I I I I I I I I I I I !I I I I use Laboratory Expansion Test Results Job Number: T3456-GFS Job Name: TORRALES RESIDENCE Location: VIA NORTE Sample Source: A (UPPER CUT AREA) Sampled by: RW (10-24-05) Lab l1echnlcian: AJ Sample Oescr: SIL TV SAND, BROWN :JJJ.'::::.V:::: Wet Compacted Wt: 591.7 RingWt.: 199.3 Net Wet Wt.: 392.4 Wet Density: 118.5 Wet Soil: 224.0 Dry Soil: 205.0 Initial Moisture (%): 9.3% Initial Dry Density: 108.5 % Saturation: 45.2% Final Wt. & Rin9 Wt.: 615.4 Net Final Wt.: 416.1 DryWt.: 359.1 Loss: 57.0 Net Dry Wt.: 356.0 Final Density: 107.5 Saturated Moisture: 16.0% 011 c T a hanDe ime Reading 1: 0.100 N/A 2:05 Reading 2: 0.099 -0.001 2:20 Reading 3: 0.099 -0.001 2:35 Reading 4: 0.099 -0.001 26-Oct Expansion Index: o Adjusted Index: (USe 18-2) 0.0 EnGEN Corporation 41607 Enterprise Circle North Temecula, CA 92590 (951) 296-2230 Fax: (951) 296-2237 I 6000 II ,I ft 4000 - I ~'ti uic. '" - ., '" ~'" Ci5~ I .,(1) 2000 (ijtij .~ ., ",a. => Peak Ultimate I C, pst 23 0 ~,deg 46 41 0 Tan 1.03 0.85 I 0 2000 4000 6000 8000 10000 12000 Normal Stress, pst I 6000 Sample No. 1 2 3 Water Content, % 10.5 10.5 10.5 I 5000 Dry Density, pet 113.3 113.3 113.3 7ii Saturation, % 59.4 59.4 59.4 :e 4000 .!; Void Ratio 0.4717 0.4717 0.4717 1;; I c. Diameter, in. 2.42 2.42 2.42 ui Hei ht in. 1.00 1.00 1.00 '" ~ 3000 Water Content, % N/A N/A N/A (I) I ~ '" 3 Dry Density, pet ., u; .<= Saturation, % en 2000 ., 2 l- I < Void Ratio Diameter, in. 1000 1 Hel ht in. I Normal Stress, pst 1000 2000 3000 0 Peak Stress, pst 1037 2103 3091 0 0.1 0.2 0.3 0.4 Displacement, in. 0.11 0.08 0.10 Hortz. Displ., in. Ultimate Stress, pst 919 1839 2455 I Displacement, in. 0.21 0.24 0.22 Strain rate, in.lmin. 0.20 0.20 0.20 I Sample Type: REMOLDED Client: ROBERT TORRALES Description: SILTY SAND, BROWN Project: TORRALES RESIDENCE I Specific Gravity= 2.67 Source of Sample: SHEAR Remarks: UPPER CUT AREA Sample Number: A I COLLECTED BY RW Proj. No.: T3456-GFS Date: 10/27/05 COLLECTED ON (10/25/05) DIRECT SHEAR TEST REPORT ,. ENVIRONMENTAL AND GEOTECHNICAL I Figure ENGINEERING NETWORK CORPORATION Tested By: AJ Checked By: JH ?;Z-' I I I I I I I I I I I I I I I I I I I I Sugarberry Properties, LLC Project Number: T3456-GFS Appendix Page 3 DRAWINGS EnGEN Corporation