一份美国地质勘察报告(GeotechReport)

REPORTGEOTECHNICALENGINEERINGSERVICES14THAVENUEFORCEMAINANDGRAVITYSEWEREXTENSIONOLYMPIA,WASHINGTONAPRIL13,2006FORHDR,INC.FileNo.11763-002-00TABLEOFCONTENTSPageNo.INTRODUCTIONANDPROJECTUNDERSTANDING...............................................................................1PURPOSEANDSCOPE..............................................................................................................................1GEOLOGYREVIEW.....................................................................................................................................1SITECONDITIONS.......................................................................................................................................2PROJECTLOCATION........................................................................................................................2SURFACECONDITIONS...................................................................................................................2SUBSURFACEEXPLORATIONS.......................................................................................................2SUBSURFACECONDITIONS............................................................................................................2CONCLUSIONSANDRECOMMENDATIONS.............................................................................................3GENERAL...........................................................................................................................................3SITEDEVELOPMENTANDEARTHWORK.......................................................................................3General......................................................................................................................................3TemporaryExcavationSupportandGroundwaterHandling.....................................................3FILLMATERIALS................................................................................................................................4General......................................................................................................................................4PipeBedding.............................................................................................................................4TrenchBackfill...........................................................................................................................4UseofOn-SiteSoilasFill..........................................................................................................4FILLPLACEMENTANDCOMPACTION............................................................................................5LIMITATIONS................................................................................................................................................5ListofFiguresFigure1.VicinityMapFigure2.SitePlanandCrossSectionAPPENDICESAPPENDIXA–SUBSURFACEEXPLORATIONSANDLABORATORYTESTING.......................A-1…A-2AppendixAFiguresFigureA-1.KeytoExplorationLogsFiguresA-2throughA-11.LogofBoringsFigureA-12.SieveAnalysisResultsFigureA-13.DIPRA(10-PointSoilEvaluation)APPENDIXB–REPORTLIMITATIONSANDGUIDELINESFORUSE.........................................B-1…B-4FileNo.11763-002-00PageiApril13,2006REPORTGEOTECHNICALENGINEERINGSERVICES14THAVENUEFORCEMAINANDGRAVITYSEWEREXTENSIONOLYMPIA,WASHINGTONFORHDR,INC.INTRODUCTIONANDPROJECTUNDERSTANDINGThisreportrepresentstheresultsofoursubsurfaceexplorationandgeotechnicalevaluationfortheinstallationofapproximately1,800linealfeetofsewerextensionalong14thAvenueinOlympia,Washington.TheprojectareaisapproximatelyasshownontheVicinityMap,Figure1.Weunderstandthatapproximately1,100linealfeetofforcemainand700linealfeetofgravitysewerareproposedalong14thAvenue.Thiswillextendeast/westalong14thAvenue,betweentheexistingKaiserRoadStationforcemain(tothewest)toconnectwithagravityinterceptorbeingconstructedalongCooperPointRoadtoitsintersectionwith14thAvenue.The1,100feetofforcemainwillbeapproximately12-inchdiameter,with5feetofcover.The700feetofgravitysewerwillbeapproximately12-inchdiameter,withapproximately8to12feetofcover.PURPOSEANDSCOPEThepurposeofourservicesistoperformlimitedsubsurfaceexploration,testingandanalysisasabasisforevaluatingpotentialgeotechnicalissuesandconstraintsthatshouldbeconsideredindesign.Ourscopeofservicesisasfollows:1.Reviewingselectedexistinggeologicandsoilreportsandin-housefilesavailableinourlibrary.2.Drilling10boringsalongtheproposed1,800feetofalignment.Theboringsweredrilledtodepthsof9to16-1/2feetbelowgroundsurface(bgs).3.Subcontractingtrafficcontrolservicesduringdrilling.4.Performinglaboratoryteststoevaluatepertinentengineeringpropertiesoftheencounteredsoils.Ourtestingincludesmoistureanddensitydeterminationsandsoilgradationanalysisofselectedsamples.WealsosubmittedfoursamplesforDuctileIronPipeResearchAssociation(DIPRA)soilevaluation(10-pointprocedure)toassesspotentialforpresenceofcorrosivesoils.5.Evaluatingpotentialgeotechnicalissuesandconstraintsforthep