凉水井煤矿6.0Mt-a新井设计-岩巷快速施工技术现状与支护趋势

本科生毕业设计（论文）题目：凉水井煤矿6.0Mt/a新井设计岩巷快速施工技术现状与支护趋势大学毕业论文任务书毕业论文题目：凉水井煤矿6.0Mt/a新井设计毕业论文专题题目：岩巷快速施工技术现状与支护趋势毕业论文主要内容和要求：根据采矿工程专业毕业设计大纲，本毕业设计分为一般部分、专题部分和翻译部分，具体包括：1、一般部分：凉水井煤矿6.0Mt/a新井设计，主要内容包括：矿井概况、矿井工作制度及设计生产能力、井田开拓、首采盘区设计、采煤方法、矿井通风系统、矿井运输提升等。2、专题部分：岩巷快速施工技术现状与支护趋势3、翻译部分：完成近3~5年国外期刊上与采矿或煤矿安全有关的科技论文翻译一篇，要求不少于3000字符。大学毕业论文答辩及综合成绩答辩情况提出问题回答问题答辩委员会评语及建议成绩：答辩委员会主任签字：年月日学院领导小组综合评定成绩：学院领导小组负责人：年月日

摘要本设计包括三个部分：一般部分、专题部分和翻译部分。一般部分为凉水井煤矿6.0Mt/a新井设计，共包括10章：1.矿区概述及井田地质特征；2.井田境界和储量；3.矿井工作制度及设计生产能力；4.井田开拓；5.准备方式-盘区巷道布置；6.采煤方法；7.井下运输；8.矿井提升；9.矿井通风与安全技术；10.矿井基本技术经济指标。凉水井矿井位于陕西省榆林市神木县境内，井田走向长约7.9km，倾向长约11.0km，面积约69.4km2。主采煤层为4-2、5-2煤层，平均倾角0~3°，平均厚度2.98m。井田工业储量为747.5Mt，可采储量590.72Mt，矿井服务年限为75a。矿井正常涌水量为100~150m3/h，最大涌水量为450m3/h；矿井相对瓦斯涌出量为1.01m3/t，属瓦斯矿井。根据井田地质条件，设计采用双斜井两水平开拓方式，井田采用盘区式布置方式，共划分为四个盘区，辅运大巷、胶运大巷和回风大巷皆为煤层大巷，布置在4-2煤层中。考虑到本矿井为低瓦斯矿井，经过方案比较矿井通风方式采用中央并列式通风，由于工作面推进长度较大，需风量较多在井田开采后期通风较困难，因此在后期在井田两翼设置两个回风斜井，满足井田后期开采需风量。针对42101工作面进行了采煤工艺设计。该工作面煤层平均厚度为3.2m，平均倾角1°，顶板岩性以粉砂岩、细粒砂岩为主，局部为中粒砂岩和泥岩。工作面采用长壁一次采全高综合机械化采煤法。采用双滚筒采煤机割煤，往返一次割两刀。采用“三八制”工作制度，截深1.0m，每天8个循环，循环进尺16m，月推进度440m。大巷采用可伸缩式胶带输送机运煤，辅助运输采用无轨胶轮车。专题部分题目为《岩巷快速施工技术现状与支护趋势》，介绍了矿井岩巷快速施工的现状与支护的趋势，经过查阅大量资料和结合国内外现场应用分析，认为发展快速掘进技术对煤矿经济持续增长有着非常大的意义。翻译部分为《\o"GotoMiningScienceandTechnology(China)onSciVerseScienceDirect"MiningScienceandTechnology》中的一篇题目为《Discriminationconditionsandprocessofwater-resistantkeystrata》的论文。关键词：凉水井矿；双斜井；盘区布置；一次采全高综合机械化采煤；中央并列式；岩巷快速施工与支护；隔水关键层ABSTRACTThisdesignincludesofthreeparts:thegeneralpart,specialsubjectpartandtranslatedpart.Thegeneralpartisanewdesignof6.0Mt/aforLiangShuijingmine,itincludestenchapters:1.Anoutlineoftheminefieldgeology;2.Boundaryandthereservesofmine;3.Theservicelifeandworkingsystemofmine;4.developmentengineeringofcoalfield;5.Thelayoutofpanelen;6.Themethodusedincoalmining;7.Transportationoftheunderground;8.Theliftingofthemine;9.Theventilationandthesafetyoperationofthemine;10.Thebasiceconomicandtechnicalnorms.LiangShuijingmineislocatedinYuLin,Shanxiprovince.It’sabout7.9kmonthestrikeand11.0kmonthedip,withthe69.4km2totalhorizontalarea.Theminablecoalseamis4-2、5-2withanaveragethicknessof2.98mandanaveragedipof0-3°.Theprovedreservesofthiscoalmineare747.5Mtandtheminablereservesare2590.72Mt,withaminelifeof75a.Thenormalmineinflowis100-150m3/handthemaximummineinflowis450m3/h.Theminegasemissionrateis1.01m3/twhichcanberecognizedaslowgasmine.Basedonthegeologicalconditionofthemine,thisdesignusesaduel-verticalslopedouble-leveldevelopmentmethod,andfullstrippreparation,whichdividedintofourbands,beltconveyorroadwayandreturnairwayareallcoalroadways,arrangedinthefloorrockof4-2coalseam.Takingintoaccountofthelowgasemission,mineventilationmethodusethecentralparatactictypeventilation,Becauseworkingfaceimpellinglargelength,needtoairvolumeinminingfieldlatemoredifficultventilation,thereforeinthelaterinthefieldsettworeturnairshaftswings,meetlatertorunminingairvolume.Thedesignconductedcoalminingtechnologydesignagainstthe42101face.Thecoalseamaveragethicknessofthisworkingfaceis3.2mandtheaveragedipis1°,theimmediateroofismudstoneandthemainroofissandstone.Theworkingfaceappliesfullymechanizedlongwallfull-heightcoalcavingmethod,andusesdoubledrumshearercuttingcoalwhichcutstwiceeachworkingcycle."Three-Eight"workingsystemhasbeenusedinthisdesignandthedepth-webis1.0mwitheightworkingcyclesperday,andtheadvanceofaworkingcycleis16mandtheadvanceis440mpermonth.Specialsectionentitled《RapidConstructionofRocksituationandsupporttrends》;aftertheaccesstolargeamountsofdataandanalysisoffieldapplicationathomeandabroad,thedevelopmentofrapidexcavationtechniquesthatsustainedeconomicgrowthincoalmineshasaverylargesignificance.Translationpartfor"theMiningScienceandTechnology"inthetitlefortheDiscriminationconditionsandprocessofwater-resistantkeystrataofthewaterofthekeystratumdiscriminantrecognitionconditionsandsteps.Keywords:LiangsShuiJingcoalmine;DoubleverticalDoubleslope;Plateareadecorate;Inonetimesthecomprehensivemechanizedmininghigh;Thecentralparatactictype;Rockfastconstructionandsupporting;Waterproofkeylaye一般部分专题部分第页参考文献[l]王金华.我国煤巷机械化掘进机现状及锚杆支护技术.煤炭科学技术，2004，32(l)[2]李跃宇，吴志海.我国煤矿掘进装备技术发展的思路.煤炭科学技术，2000，28(9)：46~47[3]ROBINHILL.适用于所有开采的机器-连续式采煤机.WORLDCOAL.1998(8)[4l朱昊.振动截割式掘进机的研制.煤矿机电，1999(2)[5]涂兴子，康全玉，翟新献等.厚煤层分层综采技术.北京：煤炭工业出版社，2002[6]张宝明，陈炎光，涂永沂.中国煤矿高产高效技术.徐州：中国矿业大学出版社，2001[7]《综采技术手册》编委会.综采技术手册.北京：煤炭工业出版社，2001[8]曹催晨，孟晋忠.TBM在国内外的发展及其在万家寨引黄工程中的应用.水利水电技术，2001，32(4)[9]丁录仕.炮掘巷道快速掘进技术.煤矿开采，2004，9(4)：50~51[10]沈季良等编.建井工程手册.北京：煤炭工业出版社，1985[11]路耀华，崔增祁主编.中国建井技术.徐州：中国矿业大学出版社，1995[l2]闫日武，王高.大断面岩巷快速掘进技术.建井技术，2002，23(l)[13]张卫斌.煤巷快速掘进技术初探.采矿技术，2003，3(4)[14]尚立斌.隧道掘进技术在斜井井筒施工中的应用.山西科技，2004(5)：76~78[15]牛宝玉.采掘锚与掘锚一体化快速掘进成巷技术.煤炭工程，2003(l1)9~12[16]崔增祁，李树青.岩巷施工技术的回顾与展望.建井技术，N.o5~6，1996[17]刘其兴著.现代凿井技术研究.西安矿业学院.陕新出批字第95157号，1995[18]董方庭、姚玉煌、黄初主编.井巷设计与施工.徐州：中国矿业学院出版社，1986[19]赛云秀编著.现代矿山井巷施工技术.陕西：陕西科学技术出版社，2000[20]DongFangting，etc.DesignandConsrtuctionofMineShaftandDritf，ChinaUniversityofMiningandTechologyPress，1991[21]Per-AndersPersson、RogerHolmberg、JaiminLee.RoekBlastingandExplosivesEngineeringCRCPress，1994[22]FrankHarris，GroundEngineeringEquipmentandMethods，McGRAW-HILLBookCompanyLimitedNEWYORK，1983[23]姜彦忠编.爆破技术基础.北京：中国铁道出版社，1992[24]王树仁.我国煤矿岩巷爆破技术的回顾与展望.建井技术，1996[25]戴光林，林东才编著.光爆锚喷施工技术.北京：煤炭工业出版社，1992[26]胡坤伦，杨仁树等.淮南煤矿深部岩巷掘进用爆破器材优化.中国矿业，2005，14(3)[27]周昌达等编.井巷工程.北京：冶金工业出版社，1993[28]孙执书.采掘机械与液压传动.徐州：中国矿业大学出版社，1991[29]白杰平.液压传动与采掘机械.北京：煤炭工业出版社，1995[30]程居山主编.矿山机械.徐州：中国矿业大学出版社，1997[31]张卫斌.煤巷快速掘进技术初探.采矿技术2003，3(4)[32]陈光寒，庞景波.浅谈提高矿井综合单进的几个途径.鸡西大学学报，2005，5(4)：25~27[33]王建军，林在康.掘进保证系数-一种衡量采掘平衡的新指标.辽宁工程技术大学学报(自然科学版)，1992，18(6)：593一595[34]中国矿业学院等编.井巷工程.北京：煤炭工业出版社，1980[35]董方庭.巷道围岩松动圈支护理论，1997[36]A.WahabKhair.HowtocopewithcutterroofProblem.11thInternationalConferenceonGroundControlinMining.TheUniversityofOollongong，NSW，July1992[37]HeManchao，WangHongmei.MiningTrendofChineseCoalResourcesinthe2lstCenturyandthePredicting，SystemforEnvironmentalDamageduetoMining.ProceedingsoftheJapan-ChinaJointForumonEnvironmentalGeomechanics.KyushUniversityPress，1994：29~34[38]侯朝炯，郭励生，勾攀峰.煤巷锚杆支护[M].徐州:中国矿业大学出版社，1999英文原文：Discriminationconditionsandprocessofwater-resistantkeystrataWANGLianguo*,MIAOXiexing,WUYu,SUNJian,YANGHongboStateKeyLaboratoryofGeomechanics&DeepUndergroundEngineering,ChinaUniversityofMining&Technology,Xuzhou221008,ChinaAbstract:Water-preservationminingisoneofthemostimportantpartsofthe‘GreenMining’technologysystem,whichcanrealizetheeffectiveregulationofgroundwaterresourcesbycontrollingstratamovement,changingpassivepreventionandgovernanceofwaterdisasterstoactiveconservationandutilizationofgroundwaterresourcesandthusobtainingcoalandwatersimultaneouslyinmining.Theconceptofwater-resistantkeystratafurtherenrichesthecontentofthekeystratumtheoryandprovidesatheoreticalbasisforwater-preservationmining.Inordertorealizetheideaofwater-resistantkeystrataasaguidelineinthedesignofwater-preservationminingandengineeringapplications,theconditionsfordiscriminationintheprocessofwater-resistantkeystrata,wehavepresentedamechanicalmodel,aswellasitscorrespondingcomputerprogram,basedonalargenumberoftheoreticalanalysesandfieldmeasurements,aswellasonacomprehensiveconsiderationoftheposition,structuralstabilityandseepagestabilityofkeystrata.Practicalengineeringapplicationsindicatethatthisdiscriminationmethodanditscorrespondingcomputerprogramonwater-resistantkeystrataareaccurateandreliableandcansatisfytheactualdesignneedsofwater-preservationminingandthushaveinstructionalimportanceforwater-preservationmininginminingareaslackingwater.Keywords:water-resistantkeystratum;water-preservationmining;structuralstability;seepagestability1IntroductionThekeystratumtheoryofstratacontrolproposedbyQianetal.hasbeenwidelyappliedintheidentificationofsuitablestratigraphichorizonsofbedseparationgrouting,inthedesignofdrillingholearrangementsofgroundgasdrainage,inthecontrolofoverlyingstrataandsurfacesubsidenceandelsewhere[1].The‘keystrata’inthiskeystratumtheoryofstratacontrolarereferredtoasstructuralkeystrata,bearingthemaineffectofrockmassmovementsduringmining,whichcontrolsthestructuralshapeofrupturedrockmasses.Givengroundpressurecontrolproblemsinwater-preservationmining,Miaoetal.have,inthelastfewyears,presentedtheconceptofwater-resistantkeystrata[2-5].Awater-resistantkeystratuminwater-preservationminingisdifficulttodefinebutcanbedescribedasfollows:providedthattheupperaquiferofacoalseamisabovethestructuralkeystratum,ortheloweraquiferofacoalseamisbelowthestructuralkeystratumandifthestructuralkeystratumcannotbreakundermining,thenthestructuralkeystratumhasawater-resistantfunctionandiscalledthewater-resistantkeystratum.Ifthestructuralkeystratumcanbreakundermining,butthebrokenfissurescanbefilledwithweakrockstrataandaseepagewater-inrushchannelcannotbeformed,thenacompoundwater-resistantkeystratumisformedbycombiningthestructuralkeystratumwithaweakrockstratum.Fromthisdescription,onecanseethatthewater-resistantkeystratumcanconsistofonlyonesinglerockstratum,orbycompoundingseverallayersofweakrockstratawithhardrockstrata.Therockstrataofthewater-resistantkeystratummustincludehardrockstratawhichcanbearthestrainofrockmassmovementduringmining.Thatistosay,awater-resistantkeystratummustbeformedbystructuralkeystratumorbycompoundingweakrockstratawithhardrockstratathatcanbearacertainamountofstrainofrockmassmovementduringmining.Theconceptofawater-resistantkeystratumfurtherenrichesthecontentofthekeystratumtheoryandprovidesatheoreticalbasisforwater-preservationmining.However,distinguishingwater-resistantkeystratalargelydependsonfieldexperienceandisstillshortofascientificbasis.Inordertorealizetheideaofwater-resistantkeystrataasaguidelineinthedesignofwater-preservationminingandengineeringapplications,inthisstudy,wepresenttheconditionsfordiscriminationandprocessofwater-resistantkeystrataandtheircorrespondingcomputerprogramsbasedonalargenumberoftheoreticalanalysesandfieldmeasurements.Inthismethodofdiscrimination,theposition,structuralstabilityandseepagestabilityofkeystrataareconsideredcomprehensively.Wealsoprovideforacorrespondingforceanalysismodel.Ourpracticalapplicationssuggestthatthediscriminationmethodanditscorrespondingcomputerprogramsofwater-resistantkeystrataareaccurateandreliable,whichshouldsatisfytheactualdesignneedsofwater-preservationminingandarethusofinstructionalimportanceforwater-preservationmininginminingareaslackingwater.2ConditionsfordiscriminationAccordingtoourdescriptionofawater-resistantkeystratum,weseethatthedecisionofwhetherthereisawater-resistantkeystratumintheoverlyingstratashouldbeconsideredfromtwosides.First,weneedtodecidewhetherthereisarockstratumthatcancontrolthemovementoftheoverlyingstrataabovethecoalseam(roof)orbelowthecoalseam(floor).Rockstratacanconsisteitherofasinglerockstratumcalledthestructuralkeystratumorisacompoundstratumwhichcancontrolthemovementoftheoverlyingstratainaparticularcombinationofseverallayersofweakandhardrockstrata.Theserockstratahavethecapacityofwater-resistancewhentheirstructureremainstableanddonotbreak.Secondly,theriskofwater-inrushcanbejudgedbytheabruptchangesinthecharacteristicsofbrokenrockseepageastherockstratabreakwhenmining.Ifnowater-inrushfromthebrokenrockstrataoccurs,wecanconcludethattheserockstrataarewater-resistantkeystrata.Therefore,thediscriminationofwater-resistantkeystratacanbeclassifiedintothreesteps:2.1DiscriminationbasedonpositionThebasisfortheformationofwater-resistantkeystrataisthattherearestructuralkeystrataintheoverlyingstrata.Wemustfirstidentifythepositionofstructuralkeystrataandthenidentifywhetherthesestructuralkeystratacanformwater-resistantkeystrata[1].Thepositionofastructuralkeystratumcanbeidentifiedbycombiningthedrillingdataandtheminedgeologicalconditionswiththekeystratumtheory.ProvidedthattherockstratumS1isthelowestkeystratumasshowninFig.1,whichcontrolsnlayersofrockstrata(S2,…,Sn,SmarerefertorockstrataaboveS1,and1,2,…,nandmarethelayernumber,wheren<m),thentheloadq1ofnlayersofrockstrataactingonrockstratumS1canbeexpressedasfollows:whereEi,iandhiaretheelasticmodel,thebodyforce,andthethicknessofeachrockstrata(i=1,2,…,n,s,m).Ifaspecificrockstratumisakeystratum,itshouldsimultaneoussatisfytheconditionsofdiscriminationbasedonstiffness(deformation)andstrength,whichcanbepresentedasfollows:whereliindicatesthefirstintervalofroofbreakingoftheithrockstratum.Giventheconditionofafixed-fixedbeam,thefirstintervalofroofbreakingofthe1strockstratumcanbeexpressedasfollows:whereisthelimitofthecompressivebearingcapacity.2.2DiscriminationbasedonstructuralstabilityThestructuralstabilityofakeystratumintheoverlyingstrataisveryimportantforcontrollingwaterinrushunderminingconditions.Ifakeystratumdoesnotbreakduringmining,water-inrushwillnotoccur.Takingacompoundwater-resistantkeystratumoftheoverlyingstrataasanexample,itslowerrockstratummustbeahardrockstratumnomatterwhetheritismadeupofseverallayersofrockstrata.Inordertocarryoutastrengthanalysisofarepresentativecompoundwater-resistantkeystratum,westudiedacompoundwater-resistantkeystratummadeupoffourrocklayers,similartothestructuralprocedurefollowedbyMiaoetal[4].ItsmechanicalmodelisshowninFigs.2and3,wherelistheadvancingdistanceoftheminingworkface,4histheheightofthecrosssectionanditswidthisunitlength.Accordingtothemechanicalmodelofacompoundwater-resistantkeystratum,thenormalstressandshearstressofeachrockstratuminacompositerockbeamcanbecalculatedbyusingEqs.(4)and(5),respectively.Otherwise,theintervalofroofbreakingofthecompositerockbeamcanbeanalyzedbytheMohr-Coulombfailurecriterion,wherethefirstintervalofroofbreakingl1canbecalculatedbyusingEq.(6).Hence,wecandistinguishthestructuralstabilitycharacteristicsofkeystrataintheoverlyingstrata[4].2.3DiscriminationbasedonseepagestabilityAccordingtotheseepagetheoryofaminedrockmass,wecantheoreticallydecidewhetherabrokenstructuralkeystratumintheoverlyingstratastillhastheabilityofwater-resistance,orstillisawater-resistantkeystratum[6-11].Wehaveusedthenrocklayers(includingthekeystratum)betweenthekeystratumandthemainaquifertoanalyzeitspermeabilityandtheseepagecatastrophecoefficientoftheroof(floor)todeterminetheseepagestabilityofthekeystratumintheoverlyingstrata[8-9],whichcanbecalculatedasfollows:whereisthemassdensityofwater;p0–pnthedifferenceinpressurebetweenroof(floor)andaquifer;anon-Darcyflowfactor;μthedynamicviscosity;hjthethicknessofthejthrocklayer;iactheaccelerationcoefficientandkithepermeability.When<1,thecompositerockstratabetweenthekeystratumanditsoverlyingstratastillhastheabilityofwater-resistance,whichcanformacompoundwater-resistantkeystratum,wherewater-inrushaccidentsdonotoccur.When,thecompositerockstratabetweenthekeystratumanditsoverlyingstratadoesnothavetheabilitytoresistwaterandthereforecannotformacompoundwater-resistantkeystratumandwater-inrushaccidentsmayoccur.Accordingtothisthree-stepdiscriminationmethod,wecansolvetheproblemsofwhetherthereisawater-resistantkeystratumintheoverlyingstrataandwhatkindofrockstratumcanformawaterresistantkeystratum.3DiscriminationprocessGivenouranalysisofthedeterminationandconditionsofwater-resistantkeystrata,itcanbeseenthatthedeterminationofwater-resistantkeystrataisacomparativelycomplexsystem.Ourproposedmethodofathree-stepdeterminationisalsoacomparativelycomplexcalculationinpracticeandmaybedifficultinpracticalengineeringapplications.Forconveniencetherefore,wedesignedaspecialprogramforthedeterminationofwater-resistantkeystrataandacorrespondingcomputerprogramforthedeterminationprocessofwater-resistantkeystrataasshowninFig.4.Inputforthecomputerprogramisgeometric,physicalandmechanicalparameters,seepagepropertiesofeachrockstratumintheoverlyingstrata,hydrogeologicalconditionsandotherproperties.Theoutputparametersofthecomputerprogramarestructuralstabilityandseepagestabilityofwater-resistantkeystrata.Elsewhereacorrespondinginterpretationandfeasiblecountermeasuresaregiven.Thedeterminationprogramofthewater-resistantkeystrataincludesfiveparts:astructuralcalculationmoduleofthekeystratum,ananalyticalseepagecharacteristicsmodule,adatabasemodule,afuzzyreasoningmoduleandaninterpretationmodule.Thestructuralcalculationmodulelargelycalculatesstructuralstabilityofthekeystratum,includingaforcedstateandthefirstintervalofroofbreakingofthekeystratum.Theseepagecharacteristicmodulemainlycalculatestheseepagestabilityofthebrokenkeystratum.Thedatabasemodulepreservesthephysicalandmechanicalcharacteristicparametersandseepagepropertiesofeachrockstratumandapartoftheexpertknowledgethatcanbeusedbyfuzzyreasoning.Thefuzzyreasoningmoduledeterminesthedeletedparametersbasedonreasoninggivenaconditionofscarcityofdata.Theinterpretationmodulemainlyinterpretstheobtainedresultsandpresentsexpertopinionsandsuggestions,inaccordancewithmanytypesofconditions.4ExampleanalysisThestrikelengthofthe12610fully-mechanizedworkfaceintheDaliutacoalmineoftheShendongminingareais5293.4mandthelengthofitsinclination239.8m,sotheareaoffully-mechanizedworkfaceis1269357m2.Thecoalseampitchisaround1°~5°anditsaveragethickness5.19m.Thegeologicalreservesareabout8498474tandtherecoverablereservesapproach7903581t.Giventhecapacityofthemine,thiscanbeminedoveraperiodof10months.The12610fully-mechanizedworkfacehas141setsofJOY8670installedforsupportandisequippedwithasetofJOY7LSshearers.The12610workfacebelongstothespringareaofHalagouandSanbulago,andthereisaQuaternaryloosebedandYananformationbedrockintheoverlyingstratumofthe2–2-coalseam.Loosesoilsarefrom10~100mthick,withanaverageof67m.Thereisasandygravellayeratthebottomofthisloosebed,0~15mthick,withanaverageof6.3m(thesandygravellayerintheBaijiaquditchis2.4~9.6mthick).ThethicknessoftheYananformationbedrockintheoverlyingstratumis27.5~65.0m,withanaveragethicknessof48m(theYananformationbedrockintheBaijiaquditchis27.5mthick).Onthefirstcavingsegmentofthecut-hole,theYananformationbedrockisabout60mthick,theloosebed50m,theweatheredbedrock22mandthesandygravellayerbetween0~5m.Thefirstcavingsegmentofthecut-holebelongstotheareaofloosebedswithlotsofwater.Thephysicalandmechanicalparametersoftheroofrockstrataofthe12610workfaceareshowninTable1.Accordingtoourthree-stepdiscriminationmethodofthewater-resistantkeystrata,wemustfirstidentifythepositionofthestructuralkeystratumintheoverlyingstrata.Onthebasisofthephysicalandmechanicalparametersoftheroofrockstrataofthe12610workface,wedeterminedthatthemainroof,18mthick,isthestructuralkeystratumoftheminingoverlyingstratabasedonourtheoreticalcalculation,usingEq.(2).Thedeformationandmovementofthemainroofleadstothemovementofalloverlyingstrata.Sothemainroofcanformasinglewater-resistantkeystratumuntilitbreaks.Themainroofwillcausethemovementofalloverlyingstratawhenitbreaks.Secondly,wemustdeterminethestructuralstabilityofstructuralkeystrataintheoverlyingstrata.Wecalculatedthebearingload1qandthefirstbreakingintervall1ofthekeystratabasedonthephysicalandmechanicalparametersoftherockstrata,giveninTable1.Thecalculatedresultscanbeexpressedasfollows:Weknowfromthecalculatedresults,thatthekeystratamustbreakwhenthe12610workfaceispushed.However,fromTable1,wecanseethatthereisasoftclayeyrockbetweenthekeystratumandtheaquifer(betweenthefirstandthesecondaquifer)Weshouldalsodeterminefromtheseepagecalculationwhetherthecompoundwater-resistantkeystratum,acombinationofthekeystratumandthesoftclayeyrock,hasawater-resistantfunction.So,inathirdstep,wemustidentifythepermeabilityperformanceofthecompoundkeystratathatcombinesthekeystratumandthesoftclayeyrock.Thereare10layersofrockstrataabovethe12610workface.Themassdensityofwateris1000kg/m3anditsdynamicviscosityTheaveragepressuredifferencebetweenthe12610workfaceanditsupperaquifer,i.e.,p0–pnis0.8MPa.Basedontherockstratastrainfields,calculatedbyRFPAsimulation,wecanobtaintheseepagepropertiesofeachlayerwhentheworkfaceadvances50m,asshowninTable2.Accordingtotheseepagepropertiesofeachlayer,asshowninTable2andEq.(7),wecancalculatetheseepagecatastrophecoefficientasfollows:Fromthisresult,weseethattheseepagecatastrophecoefficientwhentheworkfaceadvances50mandtheoverlyingstratacannotformacompoundwater-resistantkeystratum,sothataccidentsofwater-inrushwilloccur.Therefore,wemusttakemeasurestopreventwater-inrushandtoensuresafeminingattheworkface.5Conclusions1)Whetherthereisawater-resistantkeystratumintheoverlyingstratashouldbeconsideredfromtwosides.Infirstinstance,weshouldconsiderwhetherthereisarockstratumcontrollingthemovementoftheoverlyingstrataabovethecoalseam(roof)orbelowcoalseam(floor).Thisrockstratumcanbeeitherasinglerockstratumcalledthestructuralkeystratumoracompoundstratumwhichcancontrolthemovementoftheoverlyinginaspecialcombinationofseveralweakrocklayersandahardrockstratum.Theserockstratahavetheabilitytoresistwaterwhentheirstructureremainsstableanddoesnotbreak.Secondly,theriskofwater-inrushcanbejudgedbytheabruptchangesinthecharacteristicsofthebrokenrockseepage,whentherockstratumbreaksdurinmining.Ifthereisnowater-inrushfromthebrokenrockstratum,wecanconcludethattheserockstrataarewater-resistantkeystrata.2)Wehavepresentedathree-stepdiscriminationmethodofwater-resistantkeystrata.Wefirstidentifiedthepositionofthestructuralkeystratumintheoverlyingstrata.Secondly,weidentifiedthestructuralstabilityofthisstructuralkeystratumintheoverlyingstrata.Finally,weidentifiedtheseepagestabilityofstructuralkeystratum,alsointheoverlyingstrata.Weoutlinedthecorrespondingdiscriminationconditionsandthecalculationformulaforthewater-resistantkeystratum.3)Basedonthethree-stepdiscriminationmethodofthewater-resistantkeystratum,wehavepresentedthediscriminationprocessofthewater-resistantkeystratumanditscorrespondingcomputerprogram.4)Practicalapplicationsindicatethatthisdiscriminationmethodanditscorrespondingcomputerprogramofwater-resistantkeystrataareaccurateandreliable,whichcansatisfytheactualdesignneedsofwater-preservationminingandarethereforeofinstructionalimportanceforwater-preservationmininginareasshortofwater.References[1]QianMG,MiaoXX,XuJL,MaoXB.TheoryofKeyStratainStrataControl.Xuzhou:ChinaUniversityof[2]QianMG,MiaoXX,XuJL.Resourcesandenvironmentharmonics(green)mining.JournalofChinaCoalSociety,2007,32(1):1-7.(InChinese)[3]QianMG,MiaoXX,XuJL.Resourcesandenvironmentharmonics(green)mininganditstechnologicalsystem.JournalofMining&SafetyEngineering,2006,23(1):1-5.(InChinese)[4]MiaoXX,ChenRH,BaiHB.Fundamentalconceptsandmechanicanalysisofwater-proofkeystratainwater-keepingmining.JournalofChinaCoalSociety,2007,32(6):561-564.(InChinese)[5]MiaoXX,PuH,BaiHB.Principleofwater-resistingkeystrataanditsapplicationinwater-preservedmining.JournalofChinaUniversityofMining&Technology,[6]PuH,MiaoXX,YaoBH,TianMJ.Structuralmotionofwater-resistingkeystratalyingonoverburden.JournalofChinaUniversityofMining&Technology,[7]FengMM,MaoXB,BaiHB,MiaoXX.Analysisofwaterinsulatingeffectofcompoundwater-resistingkeystrataindeepmining.JournalofChinaUniversityof[8]MiaoXX,LiuWQ,ChenZQ.SeepageTheoryofMinedRockMass.Beijing:SciencePress,2004.(InChinese)[9]ChenZQ,MiaoXX,LiuWQ.Analysisonstabilityofparametricsystemofseepageflowinwallrockaffectedbymining.JournalofCenterSouth[10]KongHL,MiaoXX,WangLZ,ZhangY,ChenZQ.Analysisoftheharmfulnessofwater-inrushfromcoalseamfloorbasedonseepageinstabilitytheory.JournalofChinaUniversityofMining&Technology,2007,[11]WangLG,MiaoXX.Cuspcatastrophemodelofrelationsamongpermeability,stressandstrainofrocks.ChineseJournalofRockMechanics&Eng