外文翻译--关于倾角煤层挖掘巷道的锚杆支护的研究.docVIP

中国矿业大学2007届本科生毕业设计第66页Where,1listhelengthofboltedend；2listhelengthofouterpart.Boltspacingacanbederivedbythecriteriathatnoslipoccursalongbeddingplanes.Besidestheabove-mentionedconditions,thesafetyofthecombinedbeammustbecheckedtopreventitfromlongitudinalinstability.Whenalltheconditionsaresatisfied,roofboltparameterscanreadybedetermined.Asforsidewallbolts,theirlengthandspacingcanbederivedbysoilbracingtheoryinsoilmechanics.Itshouldbenoticedwhenroofiscomposedofweakandloosestrata,somebracingmeasuresmustbetakentoprotecttheintegrityofthefragileroof.1.Boltingofthegatewayanditsassessment1.1SupportassessmentbydiscreteelementmethodWeconsidertwocaseinordertocompare,firstcase:onlytheroofisbolted；secondcase:bothroofandsidewallarebolted.Havingbeenboltedinthefirstcase,theroofhasaobvioushigherstiffnessandstrength,intheinitialstage,onlyslightdeflectionoccurs.However,withthesidewallcoalfailingandcaving,thefreespanoftheroofincreases,theroofgraduallyentersunstablestage,subsidingandbeddingseparatingasshowninFig.5.Comparedwiththeunsupportedgateway,thegatewaywithroofboltedcankeepstabilityformuchlongertimeevenitdestabilizesfinally.Inthesecondcase,thesidewallcoaldeformationandfailurearestrictlycontrolledbythesidewallbolts,thesidewallsarestable.Roofdeflectsonlyasmallamount.Displacementcanbehardlyseenintheblockdiagram(Fig.6).中国矿业大学2007届本科生毕业设计第67页Theoverallsurroundingstrataareinstableconditions.Eveninfluencedbyminingactivitythegatewayonlyfailslocally,theroofis,howeverratherstable.Itis,thusimportanttoadoptacomprehensiveboltsupportpatternincludingthesidewalls.1.2BoltingschemeanditsimplementationBasedontheinclinedcombinedbeamtheory,gatewayloosedzonemeasurementanddiscreteelementanalysis,fourbolts1.6mlongareinstalledintheroof.Attheouterendofeachbolt,atestingdeviceisinstalled(5patentofNationalBureauofChina)toensurethatatleast20kNpretensionisexerted.Boltspacingis0.75m,arraypitchis1.0m.Duetoratherdevelopedjoints,steelbendsareusedtogetherwithroofbolttoensuresupporteffectivenessandpreventlocalroofcaving.Thesteelplateis0.01mthick,0.89mlongand0.1mwide.Thecoalsidewallisreinforcedbytimberboltwithspacing1.0m,timerboltforuppersidewallis2.0mlongand1.0mforthelowersidewall.Thetimberboltisinstalledwithnoless7.5kNpretension.Intheinfluencezoneoffrontabutmentpressure,strengthenedsupportsareadded.Metalfrictionalpropwithtimbercapissetastemporaryreinforcement.Thereinforcementdistanceis25maheadoftheworkingface.Thereinforcedpropsarearrangedinthecenterlineofthegateway.Moreattentionsshouldbepaidtogatewayexcavationprocedure.Theroofboltsshouldbeinstalledassoonaspossibleaftertheroofisexposed,thenthesidewallbolt.Themaximumdelayedtimeshouldbelessthan6hours,whichcanmaketheroofdeformexceedinglyandintegrityworsening.Aftereachconstructioncycle,theboltsnearthedrivingfaceshouldberefastenedtoassuretheiranchorageforce.1.3MeasurementofgatewayclosureInordertoassesstheeffectivenessofthesupportscheme,thegatewayclosureismonitoredduringitsdrivingandworkingfaceretreating.Theclosureofroofvsfloor,sidewallsandroofsubsidingvelocityareshowninFig.7.中国矿业大学2007届本科生毕业设计第68页Itcanbeseenthatwhentheworkingfaceisfarawayfromthemonitoringarea,thedeformationofthesurroundingrocksisverysmall,indicatingthatthegatewayisnotinfluencedbyfacedynamicpressure,thesupportsystemcaneasilybearthestaticloadofgatewayitself.Withtheworkingfaceadvancing,thegatewaybegintosensethedynamicactionoftheworkingface.Whenthedistancebetweenthefaceandmonitoringareaisaround20meters,thedeformingvelocityofsurroundingisincreasingobviouslyandthestrataismovingremarkably,suchresponseofthegatewayisthedynamicactionoftheworkingface.Thetestingresultsshowthatthereinforceddistanceshouldbemorethan20meters.However,fromtheoverallstatusofthesurroundingrock,thegatewayisinstableconditionsandcansatisfythedemandofcoaltransportation,airintakeandotherengineeringfunction.Inspiteofthefactthatthereare23groupsofjointsdistinctivelyshowniftheroof,theroofis,howeverstableunderthecombinedactionofroofboltsandsteelbens.Theuppersidewallcoalfailsandfallsinsomeplaces,butthedepthislimitedwithin0.6m.Basedonthefactsinfield,inbrief,thesupportschemeisrationalandeffective.Goodeconomicandrechnicalbenefitwereobtained.2.ConclusionThefailurepatternofgatewayininclinedseamisremarkablyanisotropic.Thefailurezoneisnotonlyrelatedtothemechanicalpropertiesofstrata,butalsocloselytothestabilityofsidewallcoalbody.Thesidewallcoalfailurecausestheabutmentpointstotransferintodeepsolidcoal,increasethefreespanoftheroofandthereforeworsentheroofintegrity.Itis,thusakeytasktokeepthegatewaysidewallsoundingatewaymaintenance.Bygatewayloosedzonetesting,combinedwiththeinclinedcombinedbeammodel,boltparameterscanbereadilydetermined.Discreteelementmethodcanbeadoptedtoverifytherationalityandmakesomeamendment.Asfortheroofwithmultiplesoftandlooselayers,ensuringboltpretensionandinstallingroofboltsasearlyaspossiblearethekeystomaketheroofstable.Meanwhile,tokeeproofintegritywithsteelbends(sometimesmetalnetisneeded)isanotherimportantmeasure.Itisprovedthatboltingcanbeuseingatewaywithfragileandweakroofaslongasnecessarymeasuresaretaken,considerableeconomicbenefitcanbeobtained.中国矿业大学2007届本科生毕业设计第69页References1.陶连金.大倾角煤层开采矿山压力显现及其控制学位论文.沈阳：东北大学.1996。70792.候朝烔.郭宏亮.我国煤巷锚杆动手术的发展方向：煤炭学报，1996，21（2）：1131183.陈炎光主编.中国煤矿巷道围岩控制.徐州：中国矿业大学出版社，1995（34）：67704.陶连金.宝山煤矿巷道围岩松动范围测试.建井技术,1993(34):67705.刘明远，陶连金，李芳成等.锚杆预紧力标示圈.1993,国家专利号：93208997.6中文译文关于倾角煤层挖掘巷道的锚杆支护的研究摘要一种典型的巷道是使用完全可变形的离散元素法。巷道周围的断裂区域是有规则的。在测量结果和理论分析的基础上，一种全新的使用锚杆和铁板的支护方案被提出。离散元素法被用于评估锚杆支护方案，并且取代了在现场上经常采用的监测手段。自从投入到实际应用以来，这种方案被证实是成功的和正确的。对于理论分析和现场的监测，一些在巷道螺栓连接的实践中必须被注意的关键点最好还是总结一下。关键词倾