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HomeMy WebLinkAboutParcel Map 8595 Parcel 4 Geotech Feasibility (May14,2003) I /~ -).. I ~b:t::l-IL-~--EnGEN Coq~oration . Soil Engineering and Consulting Services e EngineeringGeology. CompaclionTesting -Inspections- ConstrudionMalerialsTesting. LaboratoryTestinge PercolalionTesting . Geology. Water Resource Stm:lies . Phase I & II Environmental Site Assessments ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK I I I I I I I I I I I I I I C"" ", " ,_.___-c_. \ ~I(r ' ~.,~".. , ' GEOTECHNICAL FEASIBILITY STUDY Dods Residence Assessor's Parcel Number: 945-140-008 Parcel 4 of Parcel Map 8595, Lolita Road City of Temecula, County of Riverside, California Project Number: T2771-GFS May 14, 2003 Prepared for: Mr. and Mrs. Stephen Dods 30984 Lolita Road Temecula, California 92592 -\ . ,,/ , .' I' / '- ~,.- -' \ - - - \ I "" \ _ _ _ \ ~ -... '- " - '.- " , .' --- I " -- I , I I I ~,I) \ I: I \ I ''" I __-......___-' :'_ '. ........>---..1I COR ATE 0E6CE..4..160 ~_"':-o"f'O"'-: ".,.~.='--'-'._~"..'-'- '-'ORANGE COUNTY'n ~,.. '- r / " / / " r ~ I _ "/" I.... / /.... /" F / 1-, \_ .__ " \..-" -' 1/ __ \..-' " I" '- _ -' '- _ '- '- / _ _' '- - ," -.---.........:..~ J" _ I - _ " - \ F \__ I ,,', \ I I I " _~_J"-'~'--- . - . --;r-'----'-'"-------- _t-~=,;-.IL_.....<..... ,\,._~J ':-_~.----:.lr=---_r.-:- . - Ii P ~I . II U - . !I I! E terprige Circi,,,N rt ,Suite.l..TemecOla;C;o;JJ2590,.-!phone:J9091 296aiio,"_faJ<: (909),296'2231 ~,=' "~~, _ _" ".~- . _.c,_'_ ___', " "'::--~~;;-'~::O-'-- -,. I E2615 Orange A e ue, Santa Ana, CA 92101 "phone: (714) 546,4051 "fax: (714) 546.4052 B~-SftE:'VVwW:en e c'orp:com"'-e:=MAlL:"engencorp@engencorp:'"com-, - -~ ~._----- .:.. I I I I I I I I I I I I I I I I I I I Mr. and Mrs. Stephen Dads Project Number: T2771-GFS TABLE OF CONTENTS Section Number and Title Page 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 Site History ...,.......... .... .......... ................. ,............ ...... .... ... ............ .............. .......... 2 2.3 Laboratory Testing.....,......,..............,...........................,........................................ 2 2.3.1 General.......................................................,.........,.............,.......,........... 2 2.3.2 Classification...............,.............................,...........,..........".........,.......... 3 2.3.3 Maximum Dry Density/Optimum Moisture Content Relationship Test.... 3 2.3.4 Expansion Potential.......................,............,.........,.,.........,..................... 3 2.3.5 Soluble Sulfates.....................,..,............................................,.......,........ 3 2.3.6 Direct Shear TesL.. ........ ................ ...:........ ........ ...." ,............... .............4 2.4 Excavation Characteristics .......,..... .,.............. ... ....... ... ....,..,............. ......,... ........ ,.4 3.0 ENGINEERING GEOLOGY/SEISMICITY ........ .............. .,............. ............ ,..... .... ,...........4 3.1 Geologic Setting ............................ ..... ........... .......... ............ .................... ...........,. 4 3.2 Seismic Hazards....,.....,..............................................,................,...................,.... 4 3.2.1 Surface Fault Rupture ..............................................,....................,........5 3.2.2 Liquefaction....................".......,.................,...........,.........,.,.......,............ 5 3.2.3 Seismically-Induced Landsliding................ .......... ...... ......... ... ......... ........5 3.2.4 Seismically-Induced Flooding, Seiches and Tsunamis........................... 5 3.3 Earth Materials .. ,....... .............. ......... ......... ...... ......................... ......... ,.. .... ..... ......, 5 3.3,1 Existing Fill........,......... ......... ,....,...,.............. .... ...... ... ...,..... ...,...... ........... 5 3.3.2 Colluvium.,................,.............................,.... .,....,...........,.......,.,..............5 3.3.3 Pauba Formation ................... .............. ....... ............ .................... ............ 5 4.0 EARTHWORK RECOMMENDATIONS ... ,..........................., ............. ................. .......... ... 6 4.1 All Areas .... ,......... ........................................ ............................. ........... ..... ..... ....... 6 4.2 Oversize Material...................................................".,............................,...........,.. 7 4.3 Structural Fill,..............,..............................................................,.......................... 7 5.0 CONCLUSIONS AND RECOMMENDATIONS ...............................................................7 5.1 Foundation Design Recommendations .............................................,..................7 5.1.1 Foundation Size...............................................,......................................8 5.1.2 Depth of Embedment ..............................................,............,...........,..... 8 5.1.3 Bearing Capacity .............,...............................................,........".......,....8 5.1.4 Seismic Design Parameters ......,............................................................ 8 5.1.5 Settlement ................................,.............,...............................................8 5.2 Lateral Capacity. ...,... .............. ....................... ,.. .... ...... .............. ......... ,..,.... ,.... ...... 9 5.3 Slab-on-Grade Recommendations.. .... .... .... ................ ......, ....... ...... ..... ,.... ,.... ......9 5.4 Exterior Slabs ....................,...........................................,...........,...............,....,...1 0 EnGEN Corporation \ I I I I I I I I I I I I I I I I I I I Mr. and Mrs. Stephen Dods Project Number: T2771-GFS TABLE OF CONTENTS (Continued) Section Number and Title Page 6.0 RETAINING WALL RECOMMENDATIONS ...............................................,.................10 6.1 Earth Pressures........ ..................... ............. ...... ...... ............. ,..... ............. ,...... ..... 10 6.2 Retaining Wall Design ...,.........................................,..........................................10 6.3 Subdrain ............. .... ................ ,....... .......................... ........ ... ........ ........... ............ 11 6.4 Backfill... .............. ....... ,..... ............... .......,..... ...... ...................... ......, ....... ...... ...,..11 7.0 MISCELLANEOUS RECOMMENDATIONS ............................,................,.............,......12 7.1 Utility Trench Recommendations................................................,..............,........12 7.2 finish Lot Drainage Recommendations ...................,.............,...........................12 7.3 Planter Recommendations ................. ....., ,............... .....,........,.. ... ......................12 7.4 Supplemental Construction Observations and Testing .........................,............12 7.5 Plan Review........,..,.............................................,..,................,......,............,..,... 13 7.6 Pre-Bid Conference ............... ........ ....... ...................... ... ........... ........ ......... ,........13 7.7 Pre-Grading Conference ...............................................,......................,.............13 8.0 CLOSURE..,.,..,.....,....................,.......................................".,..,........,............,............. 14 APPENDIX: TECHNICAL REFERENCES LABORATORY TEST RESULTS DRAWINGS 2... 1 ") ~' /'''J\, -"'~,,-. // I ~.d:lJ..,.,-,~:EnGEN ~,--,,~- I I 1 I 1 1 1 1 1 1 1 I 1 I r'1;;:-":\ / .-" / .... "" / I '- ,~I --. ~\-~._- .::\~~-_\/ \" \ /, \ \ I " -- I "" "-- I \ - .... ~ I - ..... ~ I ~..;...:._~_..;. :, ,.l..~.u--'1r .,' COR ATE~QEElCE..4..160 =~=, -''''ORANGE-COUNTY'O - , -Soil EngineeringandConsullingSel'lices- EnllineeringGeology. Compaction Testing -Inspections- ConstrllCllonMalerialsTesting. Laboratory Testmg . PercolallOnTesling . Geology-WaterResourceSludl€s . Pl1ase 1& II Envlronmenlal Sile AsssssmenlS Cor~oration ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK May 14, 2003 Mr. and Mrs. Stephen Dods 30984 Lolita Road Temecula, California 92592 (909) 694-5901 I FAX (909) 694-5911 Regarding: GEOTECHNICAL FEASIBILITY STUDY Dods Residence Assessor's Parcel Number: 945-140-008 Parcel 4 of Parcel Map 8595, Lolita Road City of Temecula, County of Riverside, California Project Number: T2771-GFS Reference: L South Coast Civil Engineering, Additional Pad Grading, Dads Residence, 30984 Lolita Road, Parcel 4 of Parcel 8595, Temecula, California, Order No, 95-155, report dated August 25, 1995. 2, Temecula Engineering Consultants, Inc., Grading Plan, Parcel 4, Parcel Map 8595, plans dated March 26, 2003, Dear Mr. and Mrs. Dods: In accordance with your request and signed authorization, a representative of this firm has visited the subject site on April 28, 2003, 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 minor cut and fill type grading will take place for the proposed structural development Footings are planned to be excavated into either compacted fill or competent bedrock, but not a combination of both, Grading for hardscape improvements will accompany the structural development and we have included appropriate recommendations, Based on this firm's experience with this type of project, our understanding of the regional geologic conditions surrounding the site, and our review of in- house maps, published and unpublished reports, deeper subsurface exploration was not considered necessary, However, in lieu of subsurface exploration, additional grading beyond that anticipated in this report may be necessary depending on exposed conditions encountered during grading, / \ >:,~ ..,J' ". ,.-;.~; --~---'--'~~'T~-'''' '/ " ~,,/ _ ' , '/ " ~ ~ I _' _ ~ / '- J / _" _ '/" F' / _" _ ' J / "" - - - \ __ " / i ,,- - - \ " " / I -- \ - - \ 'J;t' / --, I,.. \_ _._ '. \. " ~ _" ~ : ~ \ ~ \~- ~; \ ...." \ " \_-- i ,,~~ \ '/'~- ~~~=:- -~-~j.lr~'::~-:"~~;r--~'~~~--- :, .. , .. ,.. , ~ ~-~-~-'II ' II Ii ii ~---.- --'-., . '-- - ., . ,..... . ~' ..Jl E !erprise~i~'N rt,.S1Yt9,I,je\\,elJula;'CA'92596)bh6neL(~Q~}~,9~'1M~iE~IillPf~i~1' .. ,'~~~-. I E2S"50range A e ue, Sahta Ana. CA 92707 . phone: (714) 546.4051 . fax: 1714} 546.4052 B-:SfrE: WWw;en e corp.colTl; -., E;:M)\lE:~enge-ricorp'@en:genc(frp~.com---:--'."""~ ~...............___c_ . I I I 1 1 1 I 1 I I 1 1 1 1 I I I 1 1 Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 2 1.0 SITE/PROJECT DESCRIPTION 1.1 Site DescriDtion: The subject site is comprised of a 4.7 -acre parcel with vertical relief of roughly 45-feet. The site occupies a northwest trending ridge with site drainage towards the north. Access to the site is by the existing Lolita Road (Figure 1). The site appears to have been previously graded and consists of a bedrock knob mantled by fill and minor amounts of colluvium. Based on our site review, the existing structures appear to be located primarily in cut, while the northwest facing slope and easterly yard areas appear to be primarily in fill.. 1.2 Proiect DescriDtion: Based on our review of the grading plans, the proposed development will consist of one to two-story additions to the existing single family wood- framed home, with a slab-on-grade foundation. We are providing general grading and minimum footing recommendations for the proposed structures. Any changes to the plans should be reviewed by this office so that additional recommendations can be made, if necessary. 2.0 FINDINGS 2.1 Site Review: Based on our site visit, it appears that existing fill, colluvium and Pauba Formation underlie the site. Since no deeper subsurface exploration was performed for this investigation, the thickness and condition of the existing fill or colluvium is unknown, Based on our experience in this area, we anticipate a 1 to 2-foot thick blanket of colluvium to mantle the bedrock. Based on our conversations, the existing structural footings are founded entirely into bedrock. 2.2 Site History: Based on our review of the Referenced No. 1 Report, a residential structure was present prior to the 1995 investigation. No grading reports or maps other than those referenced were presented for our review. 2.3 Laboratory Testing 2.3,1 General: 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, EnGEN Corporation L\. I 1 I I 1 I 1 I 1 I I 1 1 I 1 1 1 1 I Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 3 2.3.2 Classification: 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 2488-93, Standard Practice for Determination and Identification of Soils (Visual-Manual Procedures). The final classification is shown in the Moisture Density Test Report presented in the Appendix. 2.3.3 Maximum Dry Density/Optimum Moisture Content Relationship Test: Maximum dry density/optimum moisture content relationship determinations were performed on samples of near-surface earth material in general accordance with ASTM 1557-00 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 specimens is constructed and the maximum dry density and optimum moisture content determined from the plot. The plot is shown in the Moisture Density Test Report presented in the Appendix. 2.3.4 Expansion Potential: Preliminary Expansion Index testing was performed on a mixture of the import stockpiles, yielding an Expansion Index (EI) of 3. This is classified as a very low expansion potential. At the conclusion of grading, our firm should perform sampling and Expansion Index testing of the soils at final pad grade as well as at footing grade. Those results should be forwarded and incorporated into the final foundation design by the Project Structural Engineer. The Project Structural Engineer should determine the actual footing width and depth to resist design vertical, horizontal, and uplift forces based on the final Expansion Index test results. The recommendations for concrete slab-on-grade reinforcement and thickness, both interior and exterior, excluding PCC pavement, should be provided by the Project Structural Engineer based upon the information provided at the conclusion of grading, and considering the expansion potential for the supporting material as determined by Chapter 18 of the California Building Code. The Expansion Test Results Sheet is presented in the Appendix. 2.3,5 Soluble Sulfates: Based on our visual inspection of the site and of the samples collected during our site. visit, our experience with this type of project, and test results from similar sites in the immediate vicinity, testing for the presence of soluble sulfates was not performed. In our opinion, the near-surface soils do not contain excessive amounts of EnGEN Corporation ~ I I I 1 I 1 I I I I 1 I I I 1 1 1 I I Mr. and Mrs. Stephen Dods Project Number: T2771-GFS May 2003 Page 4 soluble sulfates. As a result, normal Type II cement may be used for all concrete in contact with native soils at the site. 2.3.6 Direct Shear Test: Direct shear tests were performed on select samples of near-surface earth material in general accordance with ASTM D 3080-98 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), The Direct Shear Test Results Sheets are presented in the Appendix. 2.4 Excavation Characteristics: Excavation and trenching within the colluvium is anticipated to be relatively easy, The Pauba Formation bedrock is expected be rippable to the desired depths with typical earth working equipment. 3.0 ENGINEERING GEOLOGY/SEISMICITY 3.1 Geoloaic Setting: 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 and Mann, 1955). The Peninsular Range is characterized by large Mesozoic age intrusive rock masses flanked by volcanic, metasedimentary, and sedimentary rocks. Various thicknesses of colluvial/alluvial sedirnents 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 section of this report. 3.2 Seismic Hazards: 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 surface rupture and/or 9round shakin9, or secondary, such as liquefaction or dynamic settlement. EnGEN Corporation G:. 1 1 I I I I I I I 1 I 1 I I 1 I I I I Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 5 3.2.1 Surface Fault Rupture: No known active faults exist on the subject site, The nearest State designated active fault is the Elsinore Fault (Temecula Segment), located approximately 0,5 miles (0.8 Km) southwest of the subject site. This conclusion is based on literature review (references) and EnGEN Corporation's site visit Accordingly, the potential for fault surface rupture on the site is very unlikely. 3.2.2 Liauefaction: Based on a preliminary screening for liquefaction hazard potential performed for the subject site as outlined in Division of Mines and Geology Special Publication 117, and the dense formational Paliba Formation bedrock underlying the subject site, it is our opinion that the potential for hazards associated with liquefaction are considered low. 3.2.3 Seismically Induced Landsliding: Due to the overall relatively horizontal geologic structure of the Pauba Formation in the vicinity of the site, the probability of seismically induced landsliding is considered low. 3.2.4 Seismically Induced Floodina. Seiches and Tsunamis: Due to the absence of a confined body of water in the immediate vicinity of the project site, the possibility of seismically induced floodin9 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 Earth Materials 3.3.1 Existing Fill: Areas of existing fill were observed during our site visit No compaction reports of the existing fill areas were provided for our review. It is our understanding that all footings for the proposed additions will be founded entirely into existing bedrock. 3.3.2 Colluvium: Colluvium mantled the bedrock across the undeveloped portions of the site, The colluvium consists of red brown to brown porous silty clayey sand, Since no deeper subsurface exploration was performed for this investigation, the depth and condition of the colluvium is unknown. Based on our experience in the area and the visible exposed bedrock outcrops, we anticipate the colluvium to range in thickness form 1 to 2-feet with local pockets up to 3-feet thick. 3,3.3 Pauba Formation: Pauba Formation was observed along slopes across the site and in nearby road cuts. The Pauba Formation consists of a dense, weakly to moderately EnGEN Corporation 1 I 1 I 1 I 1 I I I 1 I 1 I I 1 1 I I I 4.0 4,1 Mr. and Mrs. Stephen Dods Project Number: T2771-GFS May 2003 Page 6 cernented silty sand, tan to red brown, dry to moist and medium dense to very dense in place. Regional geologic maps (Kennedy, 1977) indicate that the Sandstone Member of the Pauba Formation underlies the site. Regional bedding orientations indicate an overall northwest trend with a dip to the northeast of 50 or less, The Pauba Formation at the site constitutes bedrock. EARTHWORK RECOMMENDATIONS All Areas: 1. All vegetation should be removed from areas to be graded and not used in fills. 2. All undocumented fill must be removed from proposed cut or fill areas. Existing fills that were engineered and documented may be left in place, provided appropriate documentation is available and the current condition and competency of the fill is verified and meets current industry standards. 3. In the structural areas, removals should extend to bedrock. Removals should extend a minimum of 5-feet outside the structure. Removals in the hardscape areas should extend to bedrock or to a minimum depth of 2-feet below the existing grades where bedrock is not encountered, to or 2-feet below proposed grades, whichever is deeper. Hardscape removals should expose competent colluvial or bedrock bottoms. The material generated during removals should be cleared of any debris, and may then be placed as engineered fill. Competent bottoms shall be defined as undisturbed removal bottoms which exhibit a minimum relative compaction of 85 percent. Deeper removals may be required depending upon exposed conditions encountered. Bedrock bottoms should be probed to verify competency. 4. All exposed removal and overexcavation bottoms should be inspected by the Geotechnical Engineer and/or Engineering Geologist's representative prior to placement of any fill. All removal bottoms should be probed to verify competency. 5. 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 EnGEN Corporation g. 1 1 I 1 I I 1 1 I 1 1 1 1 1 1 1 1 I 1 4.2 43 5,0 5.1 Mr. and Mrs. Stephen Dods Project Number: T2771-GFS May 2003 Page 7 optimum moisture content for compacted materials should be determined according to ASTM D 1557-00 procedures. 6. A keyway excavated into competent bedrock should be constructed at the toe of all fill slopes that are proposed on natural grades of 5: 1 (horizontal to vertical) or steeper. 7. All fill slopes should be constructed at slope ratios no steeper than 2:1 (horizontal to vertical). Oversize Material: We anticipate that no oversize material will be encountered during the grading for the proposed development. Should oversize material be encountered, please contact our office for further recommendations. Structural 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 uniformity of soil moisture. Structural fill should meet a minimum relative compaction of 90 percent of maximum dry density based upon ASTM D 1557-00 procedures. Moisture content of fill materials should not vary more than 2.0 percent of optimum, unless approved by the Project Geotechnical Engineer. CONCLUSIONS AND RECOMMENDATIONS Foundation Desil"n Recommendations: Foundations for the proposed structures may consist of conventional column footings and continuous wall footings founded in properly compacted fill or competent bedrock, but not a combination of both. The recommendations presented in the subsequent paragraphs for foundation design and construction are based on geotechnical characteristics and upon an assumed 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 EnGEN Corporation \0 I I 1 1 1 1 1 I I 1 I 1 1 1 1 I I I 1 Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 8 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. 5.1.1 Foundation Size: 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 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. 5.1.2 Depth of Embedment: Exterior and interior footings founded in properly compacted fill should extend to a minimum depth of 12-inches for single story structures and 18-inches for two story structures below lowest adjacent finish grade, 5.1.3 Bearing Capacity: 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 1,500 psf for footings in properly compacted fill and 2,500 psf for unweathered bedrock. 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. 5.1 A Seismic Design Parameters: The following seismic parameters apply: Seismic Source: Seismic Source Type: Distance to Source: Maximum Historical Event: Soil Profile Type: Elsinore Fault - Temecula Segment Type B Less than 2 Km 6.8Mw SD 5.1.5 Settlement: Footings designed according to the recommended bearing values and the maximum assumed wall and column loads are not expected to exceed a maximum EnGEN Corporation \\ 1 I 1 1 1 1 I I I 1 I 1 1 I 1 1 I I 1 5.3 Mr. and Mrs. Stephen Oods Project Number: T2771-GFS May 2003 Page g settlement of 0.75-inch or a differential settlement of 0.50-inch in properly compacted fill under static load conditions. 5.2 Lateral Capacity: Additional foundation design parameters based on compacted fill for resistance to static lateral forces, are as follows: Allowable Lateral Pressure (Equivalent Fluid Pressure), Passive Case: Compacted FiII- 250 pcf 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 undisturbed, properly, compacted fill material. 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 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. Slab-on-Grade Recommendations: 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 crackin9 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-9rade 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 nominal in EnGEN Corporation \;L I I 1 I 1 I 1 I I I I I I I 1 1 1 1 1 Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 10 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. 5.4 Exterior Slabs: 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 should be moisture conditioned to at least optimum moisture content to a depth of 12-inches immediately before placing the concrete. 6.0 RETAINING WALL RECOMMENDATIONS 6.1 Earth Pressures: Retaining 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: Condition Level Backfill 2:1 Slope Active 30 pcf 45 pcf At Rest 60 pcf - 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 are not capable of this 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. 6.2 Retaining Wall Design: Retaining wall footings should be founded to the same depths into properly compacted fill, or firm, competent, undisturbed, natural soil as standard foundations and may be designed for an allowable bearing value of 1,500 psf (as long as the resultant force is located in the middle one-third of the footing), and with an allowable static lateral bearing pressure of 250 psf/ft and allowable sliding resistance coefficient of friction of 0,35. Footings in sound bedrock may be designed for 2,500 psf. When using EnGEN Corporation \.3 I 1 1 1 I I 1 I 1 I 1 1 1 I 1 1 1 I I 6.3 6.4 Mr. and Mrs. Stephen Dads Project Number; T2771-GFS May 2003 Page 11 the allowable lateral pressure and allowable sliding resistance, a Factor of Safety of 1,5 should be achieved. Subdrain: 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 4-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. It is our understanding that a basement might be constructed. It such an arrangement, proper waterproofing and either a sump pump drainage system or drainage to daylight need to be designed. Low point of the drainage system .should be at least 18-inches below finished basement floor. Backfill: 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 jetting, mechanical methods will be required. If other types of soil or 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 \4 1 I 1 1 I 1 1 1 1 1 1 1 1 1 I 1 1 1 1 7.2 7.3 7.4 Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 12 system. Maximum dry density and optimum moisture content for backfill materials should be determined in accordance with ASTM D 1557-00 procedures. 7.0 MISCELLANEOUS RECOMMENDATIONS 7.1 Utility Trench Recommendations: 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 1557-00 procedures. Finish Lot Drainage Recommendations: 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 2.0 percent away from the structures and tops of slopes for a minimum distance of 5.0-feet and a minimum of 1.0 percent pad drainage off the property in a non- erosive manner should be provided, Planter Recommendations: 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. Supplemental Construction Observations and Testing: Any subsequent grading for development of the subject property should be performed under engineering observation and testing performed by EnGEN Corporation. Subsequent 9rading includes, but is not EnGEN Corporation IS 1 1 I I I 1 1 I I I I I I I I I I I I 7.6 7.7 Mr. and Mrs. Stephen Dods Project Number: T2771-GFS May 2003 Page 13 limited to, any additional overexcavation of cut and/or cuUfill 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. 7.5 Plan Review: 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 conformance 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 recomrnendations presented in this report. Pre-Bid Conference: 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 Pre-Grading Conference: 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 engineering report. Any special grading procedures and/or difficulties proposed by the contractor can also be discussed at that time. EnGEN Corporation \tP I 1 1 I 1 I 1 I I I I 1 1 1 I I I 1 I 8.0 Mr. and Mrs. Stephen Dads Project Number: T2771-GFS May 2003 Page 14 CLOSURE 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 information regarding the geotechnical and subsurface conditions of the 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 information 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 \ l 1 1 I 1 1 I I I I I 1 1 1 1 1 I 1 I 1 Mr. and Mrs. Stephen Dods Project Number: T2771-GFS May 2003 Page 15 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. Respectfully submitted, EnGEN Corporation ~~ Ernest W. Roumelis Staff Geologist EWRlOB:hh Distribution: (4) Addressee FilE: EnGEN\Reporting\LGS\T2771-GFS Stephen Dods, Geotechnical Feasibility EnGEN Corporatioo \g I I 1 I 1 I I I I I I I I I I I I I I 13. 14. 15. 16. Mr. and Mrs. Stephen Dads Project Number: T2771-GFS Appendix Page 1 TECHNICAL REFERENCES 1. Bartlett and Youd, 1995, Empirical Prediction of Liquefaction-Induced Lateral Spread, Journal of Geotechnical Engineering, Vol. 121, No.4, April 1995. Bowles, Joseph E., 1996, Foundation Analysis and Design, 5th Edition. California Building Code, 1998, 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. California Department of Conservation, Geology Map of the Santa Ana 1: 1 00,000 Quadrangle, California Division of Mines and Geology Open File Report 91-17. California Division of Mines and Geology, 1997, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117. Hart, Earl W, and Bryant, William A., Revised 1997, 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 /c9slrghm/apl Map_indexlF4E.htm#SW Hull, A. G., 1990, Seismotectonics of the Elsinore-Temecula Trough, Elsinore Fault Zone, Southern California, Ph.D. Dissertation, University of California, Santa Barbara. 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. Mann, J.F" Jr., October 1955, Geology of a Portion of the Elsinore Fault Zone, California: State of California, Department of Natural Resources, Division of Mines, Special Report 43. 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, Riverside, County of, 2000, Transportation and Land Management Agency, Technical Guidelines for Review of Geotechnical and Geologic Reports, 2000 Edition. Riverside, County of, 1978, Seismic Safety/Safety Element Policy Report, June 1978, by Envicorn. Riverside County Planning Department, January 1983, Riverside County Comprehensive General Plan - County Seismic Hazards Map, Scale: 1 Inch = 2 Miles. Riverside County Planning Department, February 1983, Seismic - Geologic Maps, Murrieta - Rancho California Area, Sheet 854B, Scale 1" = 800'. Rogers, T.H., 1966, Geologic Map of California, Olaf P. Jenkins Edition, Santa Ana Sheet, California Division of Mines and Geology, Scale: 1 :250,000. Southern California Earthquake Data Center (SCEDC), 2002, Southern California Earthquake Data Center Website, http://www.scecdc.scec.org, 2. 3. 4, 5. 6. 7. 8. 9. 10, 11. 12, EnGEN Corporation \Q, I I I 1 1 I I 1 I I I I 1 I 1 I I 1 I 17. 18, 19. Mr. and Mrs. Stephen Oods Project Number: T2771-GFS Appendix Page 2 TECHNICAL REFERENCES (Continued) 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. Temecula, City of, 1993, General Plan, adopted November 9, 1993. Uniform Building Code (UBC), 1997 Edition, by International Conference of Building Officials, 3 Volumes. EnGEN Corporation Y:> 1 I I I I I I 1 I 1 I I 1 1 I 1 1 I I LABORATORY TEST RESULTS Mr. and Mrs. Stephen Dods Project Number: T2771-GFS Appendix Page 3 EnGEN Corporation :2..\ I 1 1 I I 1 1 1 I 1 1 I 1 1 I 1 I 1 I UBC Laboratory Expansion Test Results Jdb ilium""". T2n1-GFS Job Name: OOOS RESIDENCE Location: LOLITA RD.,TEMECULA Sample Source: A (ADDITIONS AREA) Sampled by: ER (4-28-03) Lab Technician: PB Sample Descr: SAND, LIGHT BROWN 5/1/03 Wet Cornpilcted \lilt:. 585,9 RingWt.: 185:9 Net Wet Wt.: 400.0 Wet Density: 120.8 Wet Soil: 209,1 Dry Soil: 187.7 Initial Moisture (%); 11.4% Initial Dry Density: 108.4 % Saturation: 55.6% Final \11I1. & Ring WI.: Net Final Wt.: Dry Wt.: Loss: Net Dry Wt.: Final Density: Saturated Moisture: Dial Chan e Time Reading 1: 0.100 N1A 2:25 Reading 2: 0.100 0.000 2:40 Reading 3: 0.099 -0.001 2:55 Reading 4: 0,098 -0.002 1-Ma 603.0 417.1 359.1 58.0 354.4 107.0 16.4% Expansion Index: o Adjusted Index: (ASTM D 4832-95) 2.2 .ii EnGEN Corporation 41607 Enterprise Circle North Temecula, CA 92590 (909) 296-2230 Fax: (909) 296-2237 22..- I I I I 1 1 1 1 1 1 1 1 1 I 1 1 1 1 I MOISTURE - DENSITY TEST REPORT 'l3 a. ;i- 'ill c Q) ." ~ o 1\ \ \ /' r-... \ 1/ " \ J " 1\ I \ " / .. '\ \ II I\. I\. \ / '\ \. \ / \. - 1\ / J \ I- \ 1\ 120 118 116 114 112 110 6 ZAV for Sp.G.= 2.6 18 8 10 12 Water content, % 14 16 Test specification: ASTM D 1557-00 Method A Modified Elevl Depth Classification uses AASHTO Nat. Moist. %> No.4 %< No.2Oll Sp.G. LL PI SP 8.1 TEST RESULTS Maximum dry density = 118.1 pcf Optimum moisture = 12.1 % Project No. T2771-GFS Client: SlEPHEN DaDS Project: DaDS RESIDENCE MATERIAL DESCRIPTION SAND,LlGHT BROWN Remarks: SAMPLE A ADDffiON AREA CaLL BY ER CaLL ON 4-28-03 _ LocatIon: LOLITA ROAD MOISTURE - DENSITY TEST REPORT ENVIRONMENTAL AND GEOTECHNICAL ENGINEERING NETWORK CORPORATION Plate '2:3 I 1 I 1 1 1 1 1 I I 1 1 I 1 1 1 1 1 1 (J) (J) QJ L ~ if) L o QJ .L if) 3000 o ~ (J) Q. 2000 if) if) w n:: I- if) W n:: ::0 ...J ~ 1000 RESULTS C. pst cI>, de9 TAN ~ 404 40.7 0.86 2000 o o 0.1 0.2 0.3 0.4 SPECIFIC GRAVITY= 2.6 REMARKS: SAMPLE A ADDITIONS AREA COLL BY ER COLL ON 4-28-03 Fig. No_: 3000 2500 .... (J) Q. 2000 1500 1000 o o 1000 Horiz. Displ., in SAMPLE TYPE: DESCRIPTION: SAND.LIGHT BROWN 500 3000 4000 Normol Stress. pst SAMPLE NO. : WATER CONTENT. % ~ DRY DENSITY. pet ~ SATURATION, % !;i VOID RATIO H DIAMETER. in HEIGHT. in WATER CONTENT. % I- DRY DENSITY. pet if) W SATURATION. % l- I- VOID RATIO <( DIAMETER. in HEIGHT. in NORMAL STRESS, pst FAILURE STRESS. psf DISPLACEMENT, in ULTIMATE STRESS, psf DISPLACEMENT. in Strain rate. in/min CLIENT: STEPHEN ODDS PROJECT: DODS RESIDENCE 13.3 106,2 65.2 0.529 2.42 1.00 0.0 106.2 0.0 0,529 2.42 1.00 1000 1223 0.11 0.2000 5000 13.3 106.2 65.2 0.529 2.42 1.00 0.0 106.2 0.0 0,529 2.42 1.00 2000 2211 0.13 0.2000 2 SAMPLE LOCATION: LOLITA ROAD. TEMECULA PROJ. NO.: T2771-GFS DATE: 5-1-03 DIRECT SHEAR TEST REPORT 6000 3 13.3 106.2 65.2 0.529 2.42 1.00 0.0 106,2 0.0 0,529 2.42 1.00 3000 2944 0.10 0.2000 EnGEN Corporation '21\ I I I 1 1 1 I I I 1 1 I 1 1 1 1 1 I 1 Mr. and Mrs. Stephen Dods Project Number: T2771-GFS Appendix Page 4 DRAWINGS EnGEN Corporation ~ I 1 1 1 1 I I 1 I 1 1 I 1 1 1 1 1 I 1 BASE MAP: Thomas 8ros., Riverside and San Bernardino Counties, 2002, page 959 & 979 EnGEN Corporatl'on G.otoeh,;,'" ",."..ri,. Engineering Geology SITE LOCATION MAP PROJECT NAME: DODS RESIDENCE DATE: MAY 2003 PROJECT NUMBER: T2771-GFS N I -@- , Special Inspection Material Environmental Testing Asses'sments SCALE: 1"=2400' FIGURE 1 Zb