【英文标准名称】:StandardTestMethodsforDownholeSeismicTesting
【原文标准名称】:井下地震测试的标准试验方法
【标准号】:ASTMD7400-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D18.09
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:accelerometers;compressionwave;geophones;machinefoundations;seismicwaves;shearwaves;wavevelocity;Seismictesting
【摘要】:Theseismicdownholemethodprovidesadesignerwithinformationpertinenttotheseismicwavevelocitiesofthematerialsinquestion(1).TheP-waveandS-wavevelocitiesaredirectlyrelatedtotheimportantgeotechnicalelasticconstantsofPoissonx2019;sratio,shearmodulus,bulkmodulus,andYoungx2019;smodulus.Accuratein-situP-waveandS-wavevelocityprofilesareessentialingeotechnicalfoundationdesigns.Theseparametersareusedinbothanalysesofsoilbehaviorunderbothstaticanddynamicloadswheretheelasticconstantsareinputvariablesintothemodelsdefiningthedifferentstatesofdeformationssuchaselastic,elasto-plastic,andfailure.Anotherimportantuseofestimatedshearwavevelocitiesingeotechnicaldesignisintheliquefactionassessmentofsoils.Afundamentalassumptioninherentinthetestmethodsisthatalaterallyhomogeneousmediumisbeingcharacterized.InalaterallyhomogeneousmediumthesourcewavetraintrajectoriesadheretoSnellx2019;slawofrefraction.Anotherassumptioninherentinthetestmethodsisthatthestratigraphicmediumtobecharacterizedcanhavetransverseisotropy.Transverseisotropyisaparticularlysimpleformofanisotropybecausevelocitiesonlyvarywithverticalincidenceangleandnotwithazimuth.Byplacingandactuatingtheseismicsourceatoffsetsrotated90x00B0;inplanview,itmaybepossibletoevaluatethetransverseanisotropyofthemedium.Note18212;Thequalityoftheresultsproducedbythisstandardisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilities.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting/sampling/inspection/etc.UsersofthisstandardarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliableresults.Reliableresultsdependonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thesetestmethodsarelimitedtothedeterminationoftheintervalvelocitiesfromarrivaltimesandrelativearrivaltimesofcompression(P)andvertically(SV)andhorizontally(SH)polarizedshear(S)seismicwaveswhicharegeneratednearsurfaceandtraveldowntoanarrayofverticallyinstalledseismicsensors.Apreferredmethodintendedtoobtaindataforuseoncriticalprojectswherethehighestqualitydataisrequiredisincluded.Alsoincludedisanoptionalmethodintendedforuseonprojectswhichdonotrequiremeasurementsofahighdegreeofprecision.1.2Variousapplicationsofthedatawillbeaddressedandacceptableproceduresandequipment,suchasseismicsources,receivers,andrecordingsystemswillbediscussed.Otheritemsaddressedincludesource-to-receiverspacing,drilling,casing,grouting,aprocedureforboreholeinstallation,andconductingactualboreholeandseismicconetests.Datareductionandinterpretationislimitedtotheidentificationofvariousseismicwavetypes,apparentvelocityrelationtotruevelocity,examplecomputations,useofSnell''slawofrefraction,andassumptions.1.3Thereareseveralacceptabledevicesthatcanbeusedtogenerateahigh-qualityPorSVsourcewaveorbothandSHsourcewaves.Severaltypesofcommerciallyavailablereceiversandrecordingsystemscanalsobeusedtoconductanacceptabledownholesurvey.Specialconsiderationshouldbegiventothetypesofreceiversusedandtheirconfiguration.Heavily-dampedsensorsshouldnotbeusedsothatspectr......
【中国标准分类号】:E13
【国际标准分类号】:17_160
【页数】:11P.;A4
【正文语种】:英语