外文翻译--关于倾角煤层挖掘巷道的锚杆支护的研究.doc

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。关键词倾斜地层巷道地层运动锚杆支护离散元素法概述倾角煤层一般是指煤层有一个25到45的下沉角度，这种煤层在中国的产量和储存量中占有相当大的比例。涉及到地层控制的问题，很少被研究，并且研究地层巷道的学者就更少了。维护倾斜煤层巷道的费用一般来说比近似平直和逐渐倾斜的煤层巷道的费用要高百分之三十。导致出现这种现象的原因一是自身的复杂情况，另一个是基本的地层运动理论。目前，关于煤层巷道的维护问题已经引起关注，并且许多关于地层运动和巷道的支撑的研究已经展开了。这些研究在巷道的维护过程中，起到了积极的作用。然而，大多数研究是围绕平直或者是逐渐倾斜的煤层展开的。由于他们是定位在非常特殊的各有异性的媒介和环境中的，而在倾斜煤层的巷道通常受到不利的载荷并且不均衡的产生变形，地层运动比逐渐倾斜的煤层要强烈，另外遭到破坏的区域也是很大的，这就造成了巷道的支撑更加困难。从以上提到的情况来看，我们在仿真倾斜煤层巷道的地层运动中使用了完全可变形离散元素法，并且在巷道的承载小的区域也被监控起来。基于这些监控结果，一种螺栓连接的方法被提出。等到付诸实践以后，这种方法被证明是有效的并且是合理的。1没有任何支撑的巷道的变形和实效特征1.1地质条件研究对象是宝山煤矿的第36号煤层，煤层的向下倾角是35度，煤层厚度是1米，地质条件是相当简单的。平均的埋藏深度是440米。巷道上紧接着的顶是2米厚的沙岩和页岩，施加全部的载荷是低的。再一层是比较硬的重要的顶。