外文翻譯--關于傾角煤層挖掘巷道的錨桿支護的研究.doc

中國礦業(yè)大學2007屆本科生畢業(yè)設計第66頁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).中國礦業(yè)大學2007屆本科生畢業(yè)設計第67頁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.中國礦業(yè)大學2007屆本科生畢業(yè)設計第68頁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.中國礦業(yè)大學2007屆本科生畢業(yè)設計第69頁References1.陶連金.大傾角煤層開采礦山壓力顯現(xiàn)及其控制學位論文.沈陽：東北大學.1996。70792.候朝烔.郭宏亮.我國煤巷錨桿動手術的發(fā)展方向：煤炭學報，1996，21（2）：1131183.陳炎光主編.中國煤礦巷道圍巖控制.徐州：中國礦業(yè)大學出版社，1995（34）：67704.陶連金.寶山煤礦巷道圍巖松動范圍測試.建井技術,1993(34):67705.劉明遠，陶連金，李芳成等.錨桿預緊力標示圈.1993,國家專利號：93208997.6中文譯文關于傾角煤層挖掘巷道的錨桿支護的研究摘要一種典型的巷道是使用完全可變形的離散元素法。巷道周圍的斷裂區(qū)域是有規(guī)則的。在測量結果和理論分析的基礎上，一種全新的使用錨桿和鐵板的支護方案被提出。離散元素法被用于評估錨桿支護方案，并且取代了在現(xiàn)場上經常采用的監(jiān)測手段。自從投入到實際應用以來，這種方案被證實是成功的和正確的。對于理論分析和現(xiàn)場的監(jiān)測，一些在巷道螺栓連接的實踐中必須被注意的關鍵點最好還是總結一下。關鍵詞傾