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【英文标准名称】:StandardTestMethodsforLaboratoryCompactionCharacteristicsofSoilUsingModifiedEffort(56,000ft-lbf/ft3(2,700kN-m/m3))
【原文标准名称】:用修正作用力56000ft-Ibf/ft(2700KN-m/m3)测量土壤实验室压实特性的标准试验方法
【标准号】:ASTMD1557-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【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】:D18.03
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:compactioncharacteristics;density;impactcompactionusingmodifiedeffort;laboratorytests;modifiedproctortest;moisture-densitycurves;soilcompaction;Compactionmeasurement--soils;Density--soil/rock/relatedmaterials;Dryunitweight;Ear
【摘要】:Soilplacedasengineeringfill(embankments,foundationpads,roadbases)iscompactedtoadensestatetoobtainsatisfactoryengineeringpropertiessuchasshearstrength,compressibility,orpermeability.Inaddition,foundationsoilsareoftencompactedtoimprovetheirengineeringproperties.Laboratorycompactiontestsprovidethebasisfordeterminingthepercentcompactionandmoldingwatercontentneededtoachievetherequiredengineeringproperties,andforcontrollingconstructiontoassurethattherequiredcompactionandwatercontentsareachieved.Note38212;Thedegreeofsoilcompactionrequiredtoachievethedesiredengineeringpropertiesisoftenspecifiedasapercentageofthemodifiedmaximumdryunitweightasdeterminedusingthistestmethod.Iftherequireddegreeofcompactionissubstantiallylessthanthemodifiedmaximumdryunitweightusingthistestmethod,itmaybepracticablefortestingtobeperformedusingTestMethodD698andtospecifythedegreeofcompactionasapercentageofthestandardmaximumdryunitweight.Sincemoreenergyisappliedforcompactionusingthistestmethod,thesoilparticlesaremorecloselypackedthanwhenD698isused.Thegeneraloverallresultisahighermaximumdryunitweight,loweroptimummoisturecontent,greatershearstrength,greaterstiffness,lowercompressibility,lowerairvoids,anddecreasedpermeability.However,forhighlycompactedfine-grainedsoils,absorptionofwatermayresultinswelling,withreducedshearstrengthandincreasedcompressibility,reducingthebenefitsoftheincreasedeffortusedforcompaction(2).UseofD698,ontheotherhand,allowscompactionusinglesseffortandgenerallyatahigheroptimummoisturecontent.Thecompactedsoilmaybelessbrittle,moreflexible,morepermeable,andlesssubjecttoeffectsofswellingandshrinking.Inmanyapplications,buildingorconstructioncodesmaydirectwhichtestmethod,D698orthisone,shouldbeusedwhenspecifyingthecomparisonoflaboratorytestresultstothedegreeofcompactionofthein-placesoilinthefield.Duringdesignofanengineeredfill,testingperformedtodetermineshear,consolidation,permeability,orotherpropertiesrequirestestspecimenstobepreparedbycompactingthesoilataprescribedmoldingwatercontenttoobtainapredeterminedunitweight.Itiscommonpracticetofirstdeterminetheoptimumwatercontent(wopt)andmaximumdryunitweight(x03B3;dmax)bymeansofacompactiontest.Testspecimensarecompactedataselectedmoldingwatercontent(w),eitherwetordryofoptimum(wopt)oratoptimum(wopt),andataselecteddryunitweightrelatedtoapercentageofmaximumdryunitweight(x03B3;dmax).Theselectionofmoldingwatercontent(w),eitherwetordryofoptimum(wopt)oratoptimum(wopt)andthedryunitweight(x03B3;dmax)maybebasedonpastexperience,orarangeofvaluesmaybeinvestigatedtodeterminethenecessarypercentofcompaction.Experienceindicatesthatthemethodsoutlinedin5.2ortheconstructionc..........
【中国标准分类号】:B11
【国际标准分类号】:93_020
【页数】:14P.;A4
【正文语种】:英语


【英文标准名称】:StandardforMetal-OxideSurgeArrestersforACPowerCircuits(1kV)-Amendment:Short-CircuitTestsforStation,IntermediateandDistributionArresters
【原文标准名称】:交流电源电路(大于1kV)用金属氧化电涌放电器的标准.修改件:电站、中间装置和配电放电器用短路试验
【标准号】:ANSI/IEEEC62.11a-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】:美国国家标准学会(US-ANSI)
【起草单位】:ANSI
【标准类型】:()
【标准水平】:()
【中文主题词】:电路;电气工程;额定电压装置;金属氧化物;电涌放电器
【英文主题词】:Circuits;Electricalengineering;Installationsforratedvoltages;Metallicoxides;Surgearresters
【摘要】:Newproceduresforshort-circuittestingofstation,intermediateanddistributionarresterswouldreplaceexistingpressure-reliefandshort-circuittestproceduresfortheseclassesofarrester.
【中国标准分类号】:K40
【国际标准分类号】:
【页数】:
【正文语种】:英语