【astm標準】d 4729 - 08

1、Designation:D4729?08StardTestMethodfInSituStressModulusofDefmationUsingFlatjackMethod1ThisstardisissuedunderthefixeddesignationD4729thenumberimmediatelyfollowingthedesignationindicatestheyearofiginaladoptioninthecaseofre

2、visiontheyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperepsilon()indicatesaneditialchangesincethelastrevisionreapproval.1.Scope1.1Theflatjacktestmeasuresstressatarocksurface.Themodulusofdef

3、mationthelongtermdefmationalproperties(creep)mayalsobeevaluated.1.2AllobservedcalculatedvaluesshallconfmtotheguidelinesfsignificantdigitsroundingestablishedinPracticeD6026.1.2.1Themethodusedtospecifiyhowdataarecollectedc

4、alculatedrecdedinthisstardisnotdirectlyrelatedtotheaccuracytowhichthedatacanbeappliedindesignotherusesboth.Howoneappliestheresultsobtainedusingthisstardisbeyonditsscope.1.3Limitation—Theflatjacktestmeasurestheaveragestre

5、ssnmaltothesurfaceofthetestchamber.Undisturbedstresslevelsmustbedeterminedbytheeticalinterpretationsofthesedata.1.4AssumptionsFactsInfluencingtheData:1.4.1Thestressreliefisassumedtobeanelasticreversibleprocess.Innonhomog

6、eneoushighlyfracturedmaterialsthismaynotbecompletelytrue.1.4.2Theequationsassumethattherockmassisisotropichomogeneous.Anisotropiceffectsmaybeestimatedbytestingindifferentientations.1.4.3Theflatjackisassumedtobe100%effici

7、ent.Thedesignsizerequirementsof7.1weredeterminedtosatisfythisrequirementtowithinafewpercent.1.4.4Thejackisassumedtobealignedwiththeprincipalstressesonthesurfaceoftheopening.Shearstressesarenotcanceledbyjackpressure.ienta

8、tingthetestsinthreedirectionsineachplanetestedpreventsthemisalignmentfrombeingexcessivefatleastoneofthetests.1.5Thevaluesstatedininchpoundunitsaretoberegardedasstard.Thevaluesgiveninparenthesesaremathematicalconversionst

9、oSIunitsthatareprovidedfinfmationonlyarenotconsideredstard.1.6Thisstarddoesnotpurpttoaddressallofthesafetyconcernsifanyassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstardtoestablishappropriatesafetyhealthpract

10、icesdeterminetheapplicabilityofregulatyrequirementspritouse.2.ReferencedDocuments2.1ASTMStards:2D653TerminologyRelatingtoSoilRockContainedFluidsD2113PracticefRockCeDrillingSamplingofRockfSiteExplationD3740PracticefMinimu

11、mRequirementsfAgenciesEngagedinTestingInspectionofSoilRockasUsedinEngineeringDesignConstructionD5720PracticefStaticCalibrationofElectronicTransducerBasedPressureMeasurementSystemsfGeotechnicalPurposesD6026PracticefUsingS

12、ignificantDigitsinGeotechnicalDataD6027PracticefCalibratingLinearDisplacementTransducersfGeotechnicalPurposes(Withdrawn2013)33.Terminology3.1FterminologyusedinthistestmethodrefertoTerminologyD653.3.2DefinitionsofTermsSpe

13、cifictoThisStard:3.2.1cancellationpressure—thepressureintheflatjackrequiredtoreturntherocktoitsinitialposition.3.2.2skinstress—thetangentialstressatthesurfaceofanopening.3.2.3undisturbedstress—thestressfieldexistinginaro

14、ckmasspritoexcavationofanopening.1ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoilRockisthedirectresponsibilityofSubcommitteeD18.12onRockMechanics.CurrenteditionapprovedJuly12008.PublishedJuly2008.iginallyapp

15、rovedin1987.Lastpreviouseditionapprovedin2004asD4729–04.DOI:10.1520D472908.2FreferencedASTMstardsvisittheASTMwebsitewww.astm.gcontactASTMCustomerServiceat.FAnnualBookofASTMStardsvolumeinfmationrefertothestard’sDocumentSu

16、mmarypageontheASTMwebsite.3Thelastapprovedversionofthishisticalstardisreferencedonwww.astm.g.ASummaryofChangessectionappearsattheendofthisstardCopyright?ASTMInternational100BarrHarbDrivePOBoxC700WestConshohockenPA1942829

17、59.UnitedStates1vertically.Thejacksineachgroupshouldallbeplacedinonepartoftheaditwithin20ft(6.1m)ofeachotheralongthelengthoftheadit.8.2SurfacePreparation:8.2.1RockQuality—Theflatjackdefmationinstrumentationshouldnotbeins

18、talledinloosebrokendrummymaterial.Loosebrokendrummymaterialmaybedetectedbyadullhollowsoundwhenstruckwithahammersuchmaterialshouldberemoved.8.2.2Dimensions—Thepreparedsurfaceshallextendatleast1ft(0.30m)pasteitherendofthef

19、latjackslotatleast1ft(0.30m)pastthefurthestmeasuringpoints.Thetransducersflatjackshallbe1ft(0.30m)insidethepreparedsurfaceatanypoint(seeFig.1).8.2.3Method—Drillingtoaunifmdepthmayberequiredtopreparetherockface.Residualro

20、ckbetweenthedrillholesmayberemovedbymovingthebitbackfthuntilasmoothsurfaceisachieved.Alternativelyinhardcompetentrockcontrolledblastingwithverysmallgesmaybeusedtoremovetheresidualrock.Insoftermaterialcoarsegrindingchippi

21、ngcuttingdevicesmayberequired.8.2.4Smoothness—Ideallythepreparedsurfaceshallbeaplane.Thedifferencebetweenthehighestlowestpointsonthepreparedsurfaceshallbenotgreaterthan2in.(50mm).8.3TransducerMeasurementPointsInstallatio

22、n—TransducersmeasurementpointsshallbeinstalledonthecenterlinenmaltotheflatjackeitheratthesurfaceatdepthasshowninFig.1.TransducersfstressdeterminationshallbeinstalledwithinL2oftheflatjackslotwhereListhewidthoftheflatjack.

23、8.4SlotCutting—Theslotcanbefmedbysawingbydrillingoverlappingholesinweakhighlyfracturedmaterial.Vibrationshouldbeminimized.Theslotshallbenomethan3in.(74mm)wideextendnomethan3in.(75mm)pasttheedgesoftheflatjack.Itshallbedee

24、penoughthattheflatjackmaybeed3in.(75mm)beyondthelowestpointontherockfactadjacenttotheslot.Ifdrilledcareshallbetakenthattheholesarestraightparalleltokeepthebottomoftheslotopentoreceivethejack.Theslotshallbewashedcleanofal

25、ldirtcuttingsusingcleanwater.8.5RelaxationMeasurements—Defmationshallbemeasuredimmediatelyuponcompletionofslotcuttingagainimmediatelypritotesting.Iftherockundergoesstrainunderconstantloadoveraperiodoftimeseveralintermedi

26、atereadingsshallbetakentoevaluatethiseffect.8.6FlatjackInstallation—Flatjacksshallbecenteredintheslotrecessed3in.(75mm)fromthefaceoftheexcavationtominimizethepossibilityofruptureduringpressurization.Themtarifusedshouldsu

27、rroundthejackshallbefreefromvoids.Thejackshallbeinstalledtoallowsufficienttimefthemtartoattaincompressivestrengthgreaterthanmaximumanticipatedjackstress.8.7FlatjackTesting—Theflatjackpressureshallberaisedin100lbin.2(0.7M

28、Pa)incrementsuntilcancellationofallmeasuringpointshasbeenachieved.Defmationshallbereadaftereachpressureincrement.Thepeakpressureshallbemaintainedf15mintocheckftimedependentdefmationdefmationreadingsshallbetakenevery5min.

29、Thepressureshallbereducedin100lbin.2(0.7MPa)decrementstozerowithdefmationreadaftereverydecrement.Zeropressureshallbemaintainedf15mintocheckftimedependentdefmationdefmationreadingsshallbetakenevery5min.Thecycleshallberepe

30、atedatleasttwometimesusingequalpressureincrementsdecrements.Thepeakjackstressofthesecyclesshouldbeashighaspossiblebedeterminedbythetestengineerinthefielddependingonthejackrockstrengththecancellationpressure.8.8DataRecdin

31、gRequirements—ExamplesoftestdatasheetsthetypeofdatatorecdareshownonFigs.23.HoweverthedatarequirementsmaybesitespecificshallbedevelopedusingtheminimumrequirementsspecifiedinSection10Repts.FIG.1RecommendedFlatjackMeasureme