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Home My WebLink AboutTract Map 9833-2 Lot 8 Limited Geotechnical Study I~ I .'.~ n,:. ..~e,_ EN CO!poration -SoilEngineeringandConsullingServices. EngineeringGeology.CompactionTesling .\nspoclions-ConstructionMalerialsTestino. LaboraloryTesling .PercolalionTestinc -Geology. Water Resource Sludies . Phasel& II Environmental Site Assessments ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK I I I I LIMITED GEOTECHNICAL STUDY Proposed Residential Structure Lot 8 of Tract 9833-2 Manzano Drive, County of Riverside, California Project Number: T1649-LGS February 18,1999 I I I I I I I I I Prepared for: \ Mr. Vito Bucaro ~ 43601 Manzano Drive Temecula, California 92592 ; , , '. , , , \ , ; / "' - ~ - I/" ,_ __ \ ,,- .-"- , " \ ,,\_-- ; ~:....-..~~.,..../ , ., ., . I " .-" I _' _ ".... ~ ~ / _" _ / "- ,., I ~~ _ / I " \ - _ _ \ .... " .' I ~ ,_ ~ _ \.r"" I "' \ _ \ "' " / I .... 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I I I I I I I I I I I I I I I I I I I Mr. Vito Bucaro Project No: T1649-LGS TABLE OF CONTENTS Section Number and Title Paae 1.0 GENERAL GEOLOGy.......................................................................................... 1 2.0 EARTHWORK RECOMMENDATIONS................................................................1 3.0 FOUNDATION DESIGN RECOMMENDA TJONS ................................................3 4.0 GENERAL RECOMMENDATIONS ..... ..... ............................. ...............................3 4.1 Utility Trench 4.2 Finish Lot Drainage 4.3 Planters 4.4 Supplemental Construction Observations and Testing 4.5 Pre-Grading Conference 5.0 CLOSURE ....................................................................................................... 6 EnGEN Corporation 1,.. II~ I ..... w .!I'" I.... .;_ EN I I I I I I I I I I I I I I /J ,/ ~? Cor.t~oration -SoilEngineeringandConsullingServices. EngineeringGeology.CompactionTesling -Inspections- Construction MalerialsTesling -LaboratoryTesting .PercolalionTesting -Geology-WalerResourceStudies . Phasel& II Environmental Site Assessments ENVIRONMENTAL & GEOTECHNICAL ENGINEERING NETWORK February 18, 1999 Mr. Vito Bucaro 43601 Manzano Drive Temecula, California 92592 (909) 693-2549 Regarding: LIMITED GEOTECHNICAL STUDY Proposed Residential Structure Lot 8 of Tract 9833-2 Manzano Drive, County of Riverside, California Project Number: T1649-LGS Reference: Manning Engineering, Grading Plan, Lot 8 of Tract 9833-2, plans undated. Dear Mr. Bucaro: EnGEN Corporation has been retained by you to perform the Geotechnical Engineering for the proposed grading on the referenced lot. A site reconnaissance was performed on February 17, 1999 as part of this study. 1.0 GENERAL GEOLOGY Based on the site reconnaissance, the earth materials underlying the proposed pad area most likely consists of a thin layer (1-2 feet) of slopewash overlying either Pauba Formation bedrock or Quarternary Terrace Deposits. The slopewash deposits probably thicken in the wash areas. No known landslides or active faults traverse the property or the immediate surrounding area. Based on the earth material type (Pauba Formation bedrock), the potential for hazards associated with liquefaction is considered low. The regional geology has been mapped by Kennedy, 1977 (CDMG Special Report 131). 2.0 EARTHWORK RECOMMENDATIONS Based on the relativelYS~Ple grading proposed for the site, no unusual conditions are anticipateCt,which cannot be mitigated during grading. The surficial materials at ; , ; r .' '. l"'SI!lf1lf1le~im81!1V-; ,I - ..... " - /,,' / - /.....,' - - '/ " , I / \ _ \" ~ i / _ _ \......, I -" ,_ . _ \ ....',-' ction pf ,the. uppers6U~jn"t~~PYUqLng -. '-:~i~ ~,~ .....,"'~ :~$:~'~j};~';{:b,:;; ,;:_- 2~;/i :-,:~~f -;~r.~~,~-;;:~ ;f'ii ~;"i t~ ~ ~si~. i~#~ ~i~ii: "/ '- /,' "- I " ,_ ~ _ \__ ~ / ..... - /' - I -" _ _ _ \ ctioq'.. ,'In- a ..... :: " ~ __ I . I I I I I I I I I I I I I I I i I ! I I I Mr. Vito Bucaro Project No. Tl649-LGS February 1999 Page 2 footprint areA will be necessary in order to reduce the fill depth differential across the pad, thereby reducing the potential for differential settlements. The following grading recommendations are presented based on our familiarity with the area and the earth materials expected to be encountered: 1. All vegetation should be removed from areas to be graded and not used in fills. Removals of slopewash and/or weathered bedrock should be performed in areas to receive fill and shallow proposed cut areas and should extend to competent bedrock or competent terrace deposits. Removal depths should be determined by a staff geologist from EnGEN Corporation during grading operations. The cut portion (and proposed shallow fill areas) below the proposed structure area should be overexcavated so that a minimum of 4 feet of compacted fill will exist below the bottom of the footings for the entire structure. Overexcavation should extend a minimum of 5-feet outside the perimeter footings. 2. An equipment width key shall be excavated a minimum of 2 feet into competent bedrock for fill slopes that are planned on natural grades that are steeper than 5:1 (Horizontal to Vertical). The keyway should be constructed at the toe of all fill slopes prior to placing fill. 3. Benches shall be cut into competent bedrock such that all fill is placed on level ground. 4. All exposed natural ground shall be scarified to a minimum depth of 12 inches, moisture conditioned as necessary, and recompacted prior to placement of fill. This requirement may be waived by the project geologist depending on conditions encountered. 5. All fill shall be brought to near optimum moisture content and shall be compacted to at least 90 percent of maximum density as determined according to ASTM Test Method D-1557-78 (90). EnGEN Corporation ~ I I I I I I HI I I I I I I I I I I I I 4.0 4.1 Mr. Vito Bucaro Project No. T1649-LGS February 1999 Page 3 6. Both cut and fill slopes should be constructed at angles no steeper than 2 (horizontal): 1 (vertical). All cut slopes should be inspected by the staff geologist during grading to check for stability. 7. An expansion test should be performed on a representative retrieved from the proposed pad subgrade so that recommendations can be verified. soil sample foundation 8. Our representatives will be on the site to perform density testing and inspection to assure that the above recommendations are adhered to and to verify that the grading is being performed in an acceptable manner. A report of Rough Grading will be prepared upon completion of the grading. If any design or construction recommendations are in order they will be made in the report and will be presented together with the results of density testing. 3.0 FOUNDATION DESIGN RECOMMENDATIONS Foundations for the proposed structure may consist of conventional column footings and continuous wall footings founded upon properly compacted fill. Recommendations for foundation design and construction should be provided by the Structural Engineer in accordance with the UBC and should be based on geotechnical characteristics for a silty sand (SM) and a low expansion potential for the supporting soils and should not preclude more restrictive structural requirements. GENERAL RECOMMENDATIONS Utilitv 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 EnGEN Corporation ~ I I I I I I I I I I I I , I II , I I I I I 4.3 4.4 Mr. Vito Bucaro Project No. T1649-LGS February 1999 Page 4 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 D1557 -78(90) procedures. 4.2 Finish Lot Drainaae 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 nonerosive manner should be provided. Planter Recommendations: Planters around the perimeter of the structure should be designed to ensure that adequate drainage is maintained and minimal irrigation water is allowed to percolate into the soils underlying the building. Suoolemental Construction Observations and Testina: Any subsequent grading for development of the subject property should be performed under engineering EnGEN Corporation Ce I :":1 . I I I I HI I I I I I I I I I I I I 4.5 Mr. Vito Bucaro Project No. T1649-LGS February 1999 Page 5 observation and testing performed by EnGEN Corporation. Subsequent grading includes, but is not limited to, any additional overexcavation of cut and/or cutlfill 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 so as 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. Pre-Gradinq 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 1 I I I I I I I I I I I I I I I 'I I I I Mr. Vito Bucaro Project No. Tl649-LGS Februal)' 1999 Page 6 5.0 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 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. EnGEN Corporation <6 I I;. I I I I I I I I I I I I I I I I I Mr. Vito Bucaro Project No. Tl649-LGS February 1999 Page 7 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. The opportunity to address this matter, and your consideration of this request, is greatly appreciated. If you have any questions regarding these issues, please do not hesitate to call. Respectfully submitted, EnGEN Corporation TD/OB:ch Distribution: (4) Addressee File: EnGENIReportin9IGSITl649LGS Vito Bucaro, Umited Geotechnical Study EnGEN Corporation '\