采矿学王庄煤矿

目录一般部分TOC\o"1-3"\h\u306091矿区概述及井田地质特征 ②监测数据可作为修改、完善锚杆支护初始设计数据的依据之一。顶板离层指示仪实际上是两点巷道围岩位移计。在顶板钻孔中布置两个测点，一个在围岩深部稳定处，一个在锚杆端部围岩中。离层值就是围岩中两测点之间以及锚杆端部围岩与巷道顶板表面间的相对位移值，并可直观显示出相对位移值(离层量)的大小。（3）位移量监测，利用多点位移计来完成岩层深部位移监测，多点位移计是监测巷道在掘进和受采动影响的整个服务期间深部围岩变形随时间变化情况的一种仪器。安设多点位移计的目的：了解巷道围岩各部分不同深度的位移，岩层弱化和破坏的范围（离层情况、塑性区、破碎区的分布等）；判断锚杆与围岩之间是否发生脱离，锚杆应变是否超过极限应变量；为修改锚杆支护设计提供依据。

4煤巷锚杆支护技术在王庄煤矿的应用4.1王庄煤矿简介潞安集团王庄煤矿设计生产能力为4.0Mt/a，立井单水平开拓，准备方式为带区，煤层开采方法为大采高低位放顶煤工艺，主采煤层为3号煤层，其中运输大巷和辅助运输大巷布置与岩层中，回风大巷布置于煤层中，分带斜巷长度达到了2700m，煤巷锚杆支护技术对于矿井巷道支护安全显得尤为重要。4.2锚杆支护技术在王庄矿的应用4.2.1大巷支护王庄煤矿胶带运输大巷、辅助运输大巷及回风大巷支护方式均采用锚喷支护，即锚杆、喷射混凝土联合支护，其中胶带运输大巷和辅助运输大巷为半圆拱形断面，胶带运输大巷布置于岩层，设计掘进断面积为19.8m2，混凝土喷射厚度100mm，树脂锚固剂加固，锚杆排列方式为三花式，锚杆间距800mm，示意见图4-1；图4-1胶带运输大巷断面示意图回风大巷沿煤层顶板掘进，为矩形断面，净断面18.3m2，混凝土喷射厚度100mm，树脂锚固剂加固，锚杆长度2200mm，外露端100mm，锚杆排列方式为三花式，锚杆间距800mm，示意图见图4-2。图4-2回风大巷断面示意图4.2.2回采巷道支护王庄煤矿东一带区，各分带斜巷断面形状及支护特征均相同：为锚网索组合钢带支护，矩形断面。斜巷均宽4.8m，高为3.5m，掘进断面15.75m2。（1）顶板支护W钢带组合锚杆支护，并进行锚索补强。锚杆直径Φ20mm，长度2.2m，左旋无纵筋螺纹钢锚杆（高强度），树脂加长锚固，破断力230kN，锚杆间排距800mm；WX220/3.0型钢带宽为220mm，长4250mm，厚3mm；采用菱形金属网护顶；单根钢绞线锚索，长6.3m，首采面安设在巷道顶脊线处，间距1.6m。托盘：采用拱形高强度托盘，规格为150×150×8mm。锚杆角度：靠近巷帮的顶板锚杆安设角度与顶板垂线成30度角，其余与顶板垂直。网片规格：采用铁丝编织的菱形金属网护顶，规格型号50×50mm、5.5×1.1m。（2）巷帮支护锚杆直径Φ20mm，长度2.2m，左旋无纵筋螺纹钢锚杆（高强度），树脂加长锚固，破断力230kN，锚杆间排距800mm；锚杆角度：靠近顶板的巷帮锚杆安设角度与水平线成15°。帮支护最大滞后顶支护为3m，严禁空班支护。如出现帮破碎，帮锚杆必须跟顶支护。如图4-3所示。图4-3回采巷道断面支护示意图4.2.3矿区锚杆支护安全保障体系制度保障，依据《煤巷锚杆支护技术规范》，并结合王庄矿具体生产、地质条件，听取各方技术人员的意见制定《王庄煤矿锚杆支护技术规范》，在地质评估、支护设计、支护材料的选用、施工行为规范、施工质量验收标准、数据监测监控以及锚杆支护人员技术培训等方面都制定了严格的规定，用以规范锚杆支护施工措施。（2）管理保障，加强施工作业机械工具及材料的管理，组成检查小组，定期对井下采掘巷道进行支护质量检查，依据支护标准，如若发现问题或危险征兆，及时反馈至王庄矿安全部，采取相应措施，并提出相关处理整改建议。（3）技术保障，定期组织锚杆支护相关人员（操作工、安监员）进行培训，使得管理人员、施工人员具备可靠的锚网支护专业知识，提高技术水平。（4）矿压监测预警机制，建立可靠完善的矿压监测监控系统，吸收技术人员、管理人员，在回采、掘进巷道内矿压显现处安设矿压监测站，实时监测，及时反馈监测结果，并对检测结果进行分析、处理，与对巷道安全提供监测预防作用。

5煤巷锚杆支护技术的改进途径5.1发展现状伴随着技术发展，需求增加，开采深度也不断增加，巷道埋深也随之增加，地应力也相应加大，矿压显现明显增加，伴之而来的是地质条件的复杂和进一步的恶化，这就对巷道支护技术提出了更高的要求。同时，采煤机械的自动化与采煤方法的高效化发展，综采放顶煤、厚煤层一次采全高开采技术的快速发展和大面积应用，对煤巷锚杆支护技术提出更高要求。全煤巷道和半煤岩巷、大断面巷道、沿空掘巷及破碎围岩巷道所占的比重越来越大，支护难度显著加大，这无疑需要巷道支护技术作出更好更强的改变。5.2煤巷锚杆支护技术改进途径（1）增强锚杆的初锚力，跟据相关资料说明，国外煤巷锚杆初锚力在100kN以上，占锚杆极限载荷的一半以上，而我国煤巷锚杆的螺母安装多为人为操作，一般初锚力为30kN以下，占锚杆极限载荷的五分之一。初锚力相对过小，降低了对围岩的支护效果，不利于维持巷道围岩的长期稳定。（2）加强煤层巷道巷帮支护是维持巷道围岩稳定的重要步骤。煤巷两帮煤体一般较松散破碎，如果两帮支护效果一般，常引起两帮煤体发生松动掉落，加大悬顶面积，易导致顶板破损，甚至冒落。因此，加强对巷道煤帮的支护显得尤为重要，通常可以采取的技术措施有：采用强力锚杆，锚喷支护，配合网、梁形成联合支护等。（3）研发新型高强度锚杆也是增强煤巷锚杆支护效果的有效途径。（4）采用小孔径锚索，提高锚固效果。当顶板岩层比较破碎的情况下，采用小孔径锚索对其进行支护，可有效的对顶板进行加固支护，保持顶板岩层的长期稳定。（5）推广以锚杆支护为主的联合支护形式，随着开采深度的加深，动压影响对处于软岩层的围岩影响较大，易发生变形，单一的锚杆支护已无法完全满足巷道支护要求，所以对于地压大的不稳定的围岩，联合支护必不可少。（6）加强顶板动态检测监控，确保煤巷锚杆支护安全。根据国外经验要制定相应的检测监控规范，对锚杆支护状态下的巷道顶板进行准确的实时监控，及时掌握巷道围岩的变形数据，一方面可以分析判断围岩动态，发现异常及时采取加强支护措施，避免危险发生；另一方面统计反馈信息，依据数据修改设计参数，使巷道锚杆支护参数选择更加科学合理。

6结论锚杆支护技术是煤炭开采过程中的一项重要技术，具备大量的理论依据和实践经验，经过50多年的发展逐步成熟。锚杆支护技术为一种主动支护形式，具有支护速度快、支护效果好、材料成本低、工作人员劳强度小等优点，并且可以与混凝土喷射、钢带（W型、M型）、金属网、工字钢梁、锚索等联合使用，它的广泛使用可以给煤矿企业带来有效的安全支护保障和显著的经济效益。安全有效的巷道支护是矿井安全生产、高产高效的重要保证，经过多年发展实践证明，煤巷锚杆支护技术是煤矿安全高效生产不可或缺的，普遍应用于国内外矿井支护行业，是煤矿巷道的主要支护形式，代表了煤矿巷道支护技术的发展方向。目前，随着矿井开采深度增加，围岩条件变得愈发复杂，支护也相对困难，这需要在熟练应用传统锚杆支护工艺的基础之上，不断开发推广新技术、新设备，才能保障矿井生存和安全生产。

参考文献[1]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.[2]康红普,王金华.煤巷锚杆支护理论与成套技术[M].北京:煤炭工业出版社.2009.[3]马念杰,侯朝炯.采准巷道矿压理论及应用[M].北京:煤炭工业出版社,1995.[4]陆士良,汤雷,杨新安.锚杆锚固力与锚固技术[M].北京:煤炭工业出版社,1998.[5]程良奎,范景伦,韩军等.岩土锚固[M].北京：中国建筑工业出版社,2003.[6]何满朝,袁和生,靖洪文.中国煤炭锚杆支护理论与实践[M].北京:科学出版社,2004.[7]范明建.锚杆预应力与巷道支护效果的关系研究[D].北京:煤炭科学研究总院,2007.[8]陈东印.地下工程预应力锚杆支护数值模拟分析[D].山东青岛:山东科技大学,2005.[9]康红普,姜铁明,高富强.预应力在锚杆支护中的作用[J].煤炭学报,2007,32(7):673-678.[10]康红普.软岩回采巷道锚杆支护技术的发展[A].软岩工程专业委员会第二届学术会议论文集[C].北京:1999.[11]康红普.高强度锚杆支护技术的发展与应用[J].北京:煤炭科学技术,2000,28(2):1-4.[12]侯朝炯.煤巷锚杆支护[M].徐州:中国矿业大学出版社,1999.[13]鞠文君,王泽进.测力锚杆研制与应用技术[J].煤矿开采,1997,增刊:54-57.[14]鞠文君.全长锚固锚杆工况监测方法[J].煤炭科学技术,1998,(6):15-18.[15]孔恒,马念杰.锚固技术及其理论研究现状和方向[J].中国煤炭,2000,(4).英文原文InvestigationintothedeformationofalargespanroadwayinsoftseamsanditssupporttechnologyFuJianqiua,b,FengChaoc,ShiJianjuna,*aSchoolofCivilandEnvironmentalEngineering,UniversityofScienceandTechnology,Beijing100083,ChinabGuangdongHongdaBlastingEngineeringCo.,Ltd.,Guangzhou510623,ChinacCrecElectrificationBureauXi’anRailwayEngineeringCo.,Ltd.,Xi’an710032,ChinaAbstract:Weinvestigatedthedeformationfailuremechanismofsurroundingrockfromtheaspectofengineeringsupportforaroadwayinseamswithsoftroofsandsoftfloorsandobservedthelargedisplacementoftheroadwayinthesesoftseams.Theresultshowsthatthedeformationareaisquitelarge,andsettlementoftheroofisevidentanddisplacementofthesidewallsisalsoobvious.Weconsideredrockbolt-cablecouplingforroadwaysupportinseamswithsoftroofsandfloors,inwhichthecableshouldbefixedatkeypositions.Aswell,wedesignedanoptimalschemetosupportaroadwayinsoftseamsoftheShizuishanSecondMineinNingxia,China.Fieldmonitoringresultsshowthatbolt-cablecouplingsupporthasachievedtheaimsofroadwaystabilitycontrolandminimizesdeformation.Keywords:Seamswithsoftroofsandfloors,Roadwaydeformation,Bolt-cablecouplingsupport,Fieldmonitoring1.IntroductionCoalprovidesmostoftheenergyforChina’seconomicgrowth.Buttheincreasingdemandforcoalaroundtheworldleadstoacontinuousdecreaseofthisresourcenearoronthesurfaceoftheearthwhichcanbeextractedeconomically.Hence,thetrendindevelopingminingtechnologyshouldbefocusedondeepmining,whichhasalreadybeenanimportantresearchfieldfortheinternationalminingindustry[1,2].Especially,softroadways,encounteredindeepminingtechnology,arebecomingoneofthemainchallengesrestrictingseriouscoalexploitation[3-7].Problemscausedbyroadwaysinseamswithsoftroofsandfloorshavebecomeprominentwithinsoftrockissues.Onceexcavated,thestabilityofroadwaysinsoftrockishardtomaintainduetoconstantdeformation,wheresecondarydeformationmayoccureventhoughtheroadwayitselfisstable[8].Forexample,intheXieyiMineadisplacementof800mmoccurredintherockofthemainroadway.Withhighinsitustress,themaximumdeformationofanundergroundpower-houseoftheErtanhydraulicpowerstationreached180mm.TheroadwayinamineoftheChenghecompanyisofatypicalsoft-rockroadwaywhereadeformationof300mmwasobserved.Inthesecases,hugerepairsandmaintenanceofroadwayswererequiredtosustainproduction.InordertocontrolroadwaydeformationintheChengheMine,aspecialsupportwasdesignedforalarge-spanroadwayinseamswithsoftroofsandfloors.Weinvestigatedtheapplicationofthisdesignandtheeffectofthissupportandtrustthatwehaveprovidedacontributiontocoalminesafety.2.Roadwaydeformationinsoftseamswithsoftroofsandfloors2.1.SoftseamswithsoftroofsandfloorsNormally,a“three-softroadway”referstoroadwaysinmineswithsoftroofs,softcoalandsoftfloors[4].AsoftroofisclassifiedasaI-typeunstableroof.Therockoftheimmediateroofshowsfeaturessuchasconsiderablefracturedevelopment,brokenrockmassandlowcompressionstrength.Thisleadstothecollapseofroofsshortlyafterexcavation.Thecompressionstrengthofasoftfloorisverylow(lessthan4MPa),expandsandsoftenswhenitencounterswaterandheavesfrequently.SoftcoalreferstotheProtodyakonovscaleofhardness,rangingonlyfrom0.3to1.0,showingcharacteristicsofmanyjoints,instabilityandfragility.2.2.TheoryofsurroundingrockdeformationAstableandsaferoadwayisexcavatedinsoftseamsineitherofthefollowingtwoconditions:(1)nodeformationoccursinthesurroundingrock,or(2)smalldeformationoccursbutshowslittledamageinitsapplicationandtheprojectissafe.Hence,thestabilityofundergroundroadwaysinsoftseamsisdeterminedbytheinteractionoftwofactors:rockmassstrengthanditsdeformationcharacteristicsandthestressredistributioninthesurroundingrockafterexcavation.Thus,theprojectremainsstablewhenthefirstfactorprevailsoverthesecond.Changesinthestateofstressofprimaryrockafterexcavationcanbedescribedby:（1）whereσristheradialstressoftheroadwayafterexcavation;γtheunitweightofthesurroundingrock;Hthedepthoftheroadway;randr1arethelanewayradiusandinfluencedistancerespectively(theequivalentradiuscanbeusedastheinfluencedistance).AsshowninEq.(1),theradialstressnearthesidewallsisclosetozeroafterexcavation,whichresultsinvariationoftheelasticvolumetricstrainandrockcreepage.Withlowconfiningpressure,thestructuralplaneinthesoftrockexpands,whichchangesthehydro-geologicalconditionsofthesurroundingrock.Meanwhile,seepagewithinthefractureweakenstheintensityoftherockandacceleratesdilatationandsofteningoftherock.Asaresult,largeconvergencedisplacementappearsinthesurroundingrock.Roadwaysthereforeshowavarietyofdisplacements,e.g.roofsettlement,floorheave,vaultdisplacementandsidewallheaves.Furtherdeformationcanleadtoinstabilityoftheroadway,suchastensilefailureofroofsandsidewalls,shearcracksinroofs,floorheaveandrooffalls.Itshouldbeemphasizedthatseriousdeformationusuallyoccursattheintersectionofroofandsideswalls,whereroadwayfailureismostlikelywithouttimelysupport.2.3.DeformationofsurroundingrockinseamswithsoftroofsandfloorsFrominvestigatingextensiveprojects,theconclusionisreachedthatsurroundingrockdeformationinseamswithsoftroofsandfloorsshowsthefollowingfeatures:(1)largedisplacementsofrock,rapiddeformation,largeareaswithdeformationand(2)continuousdeformation.Rockrheologybecomesthedominantfeatureofroadwaydeformationwiththefollowingcharacteristicsinthesurroundingrock.(1)Temporarynaturalstabilizationandfastcompression;(2)Large,fastandcontinuousdeformation;(3)Hoopandasymmetricalcompressionandviolentfloorheave;(4)Normalrigidsupportbecomessusceptible.3.SupportofroadwayinsoftseamsPlasticdeformationusuallyresultsincertaindiscordantareaswithinthesurroundingrock.However,couplingsupportcaneffectivelyreinforcesupportforanchormeshappliedtothesurroundingrockandforrockboltsatkeypositions.Thus,deformationcanbereducedconsiderablywherethesupportisloadeduniformly.Forourstudy,wedesignedareinforcedsupportschemewithacombinationofrockbolts,rebarnet,shotcrete,rebarjoistsandanchorcables.3.1.SupportmechanismThesupportmeasureshadthefollowingresults.(1)Couplingsupportbyrockboltsandcablespro-activelyprovidedconsiderablepreloadaswellasaxialandlateralresistancetothesurroundingrock.Thesupportingresistanceincreasedquicklyasthedeformationinthesurroundingrockdeveloped.(2)Reinforcementwassuppliedwhentheintensityofthesurroundingrockslightlydecreased.Therefore,thecompressionstrengthofthesurroundingrockwasmaximized.Asaresult,theconversionoftheloadingbodytothesupportbodyeffectivelycontrolledthedeformation.(3)Theanchorcablesprovideddeepsupport.Theroofreinforcementintrudedorextrudedtheserocksandthenformedacombinedbeam.Simultaneously,thearchspringofthereinforcementexpandedintothedeepercoalrip,whichloweredistheshallowfloorstress,reducedtheplasticdepthoftheripandintheendlimitedtheripdisplacementandfloorheave.3.2.SupportprinciplesCompressionminimizationrequirestherelaxationofhugeaccumulatedplasticenergywithinthesurroundingrock.Lithologytheoryandengineeringpracticesuggeststhatsurroundingrockdeformationwouldgraduallyincreaseafterexcavation.Giventhespeedofdeformation,deformationisgenerallydividedintoadeceleratingphase,anapproximatelylinearconstantphaseandanacceleratingphase.Whentherockfallsduringtheacceleratingphase,itsstructureisrebuilt,developsfissuresandlowersitsintensity.Inthiscase,theresistancecanbemaximizedduetodeformationconversion,whileitsabilitytosupplysupportdecreasessharply.Thus,itiscriticaltoselecttheoptimalreinforcementareasandtimberingtime.Duringcouplingsupport,advancedpracticesofanchorcablesalwaysleadstosnappingofsteelstrandsduetothelargedeformation;however,itshystereticsupportresultsintheseparationoflayersbetweendifferentsectionsofrockbolts.Therefore,anoptimalsecondarycouplingsupportisconsideredfollowingtheselistedprinciples.Inthecaseofprimaryrockboltsupportforlooseandbrokensurroundingrock,stressconcentrationzonescanbefixedbynumericalsimulationandreinforcedsupportofanchorcablescanbetimelyconstructed.3.3.NumericalsimulationofcouplingsupportAccordingtothecouplingsupportprinciplesofsoftrock,anchorcablesaremosteffectivewhentheyarefixedatkeypositionsinroofs.Inourstudy,weoptedfortheFLAC3Dsoftwarepackagetosimulatethedynamicstateofthefirstcouplingsupport(Fig.1,referstoacombinationofanchorgroutingandagroutinglayer),inordertofixtheoptimumpositionforthesecondarycouplingsupport.Fig.1.GeneralsituationofnumericalsimulationwithsoftwareFLAC3DThefinite-differencenumericalFLAC3Dpackageisdeemedtobesuitableforgeotechnicalengineering[10].UsingaLagrangianmethod,itisespeciallyusefulinsimulatingmaterialdeformationandtwists.Aswell,thissoftwareusesanexplicitalgorithmtoobtainatimestepsolutionofthekineticequationsofmodelsandthentrackstheirgradualfailuresandcollapse.TheMole-Coulombintensitylawwasselectedforthissimulation.Fig.2.PartiallyenlargedfigureofshearstressstateintheroofoftheroadwayFig.2presentsapartiallyenlargedfigureofournumericalsimulation.Itshowsthatstressconcentrationoccurredattheshouldersoftheroofoftheroadway,wherethemosturgentanchorcablesupportisneeded.Thesimulationalsoshoweditwascriticaltodesignasecondarycouplingsupport.Fig.3ashowsthatafterthefirstcouplingsupport,theplasticzonehasbecomecomparativelyenlargedintheroof,whereastheplasticzone,especiallyontheroofshoulders,hadsharplydecreasedafterthesecondarycoupling(Fig.3b).Theresultssuggestacorrectreinforcementofthesecondarycouplingwithanchorcables.Fig.3.Plasticzoneofsurroundingrockwithdifferentsupport4.AtypicalroadwaysupportinsoftseamsGiventheprinciplesenunciatedearlier,itisimportanttouseseveralkindsofsupportingschemesfortheroadwaysinseamswithsoftroofsandfloors.Torealizethis,wedesignedatargetedsupportforthe#2336transportationroadwayinthesecondShizuishancollieryinNingxia,China.Thetransportationlanewaywaslocatedthroughoutthelengthoftheseam,4.5mwideand3.0mhigh.Alongtheentirelanewaythecoalandroofaresoft,henceitwasdifficulttosupportalargespanlanewayinthistypeofseam.Onaveragetheseamwas7.79mthick,withamaximumof9.69mandaminimumof6.31m.Theupperpartoftheseamisbrightcoal(f=1.2),thelowerpartisdullcoal(f=0.8)andinbetweenarethreelayersofdirt0.12-0.70mthick.Theroofconsistsofsequentialkaolin(onaverage0.62mthick),carbonaceousshale(onaverage0.25mthick)andarenaceousshale(onaverage0.18mthick)fromthebottomup.Thefloorconsistsofsequentialclay(onaverage0.18mthick)andarenaceousshale(onaverage1.5mthick).4.1.FirstcouplingsupportofrockboltsThelengthofeachrockboltwasclosetotheloosecircleofitssurroundingrock.Accordingtoelastic–plastictheoryweestimatedthemostfrequentlyoccurringrangeofloosecircles.Thetransportationlanewaywasdesignedinarectangularfashionasrequiredanditsequivalentradiuswascalculatedtobe2.7musingEq.(2).（2）WhereBisthewidthofthelaneway;htheheightandr0theequivalentradius.Sincethelanewaywastemporaryunsupportedafterexcavation,itssupportcapacitywasnil.Thus,theradiusofthemaximumplasticcirclewithinthelanewaywas3.88m(60%ofthetrialdata),calculatedwithEq.(3).（3）WhereR0istheradiusofthemaximumplasticcircle;r0theradiusofthecavern;σ0=10.58MPaistheprimarygroundpressureanddependsontheweightstressoftheupperrock,C=2.0MPaisthelithologicalcohesionwithintheplasticcircleandu=35.0°istheinternalfrictionangleoftheplasticcircle.Thus,theloosecircleoftheroofandthesidewallswere1.98and2.13masdescribedbyEqs.(4)and(5),respectively.（4）（5）Thetheoreticaldataobtainedwasestimatedbasedontheassumptionthatthestressoftheprimaryrockwasunderhydrostaticpressure.Similarly,theloosecirclerangedfrom200to300cmandthereforethesurroundingrockwasclassifiedasaI-type.Length(L),interval(M)anddiameter(d)oftherockboltscanbedeterminedbyEqs.(6)-(8)[9].（6）（7）（8）WhereListhelengthoftherockbolt;Mtheintervalbetweentherockbolts;dthediameteroftherockbolt,N=1.2,i.e.thecoefficientofrockclassificationandWthespanofthelaneway,4.5m.Basedontheroadwayprojectinthemine,thelengthoftherockboltsintheroofwasdesignedtobe2.4mlong.Theboltsinthesidewallswereas2.0mlong,withboltspacingof800mmandarraypitch800mm.4.2.SecondarycouplingsupportofanchorcablesAccidentshappenwhenrockboltsandanchorcablesarenotsuccessfullycoupled.Inordertoachieveabettercouplingsupport,therockbolts,ontheonehand,shouldbeexactlyembeddedatthelanewayshoulderswherestressconcentrationoccurs;ontheotherhand,anchorcablesshouldbedesignedaccordingtothecouplingeffectofthetwosupportmethods.SimulationwascarriedoutwithparametersofanchorcablesassuggestedbyEqs.(9)and(10).（9）（10）WhereLa,la1andla3areoveralllength,exposurelengthandanchorlengthoftheanchorcablesrespectively,m;la2istheeffectivelengthoftheanchorcables,m;andatheequivalentwidthofthelaneway,m.Intheend,wedesignedthefinalsupportschemeemphasizingthecouplingeffectofrockboltsandanchorcables(Fig.4).ThecorrespondingsupportparametersareshowninTable1.Table1ParametersofacouplingsupportdesignforlanewayinatypicalsoftseamComponentComponenttypesLength(m)Interval(m)Arraypitch(m)RockboltsintheroofTwistedsteelΦ182.40.70.7RockboltsinthesidewallsTwistedsteelΦ1620.80.7AnchorcablesSteelstrainΦ15.246.21.62.4RebarjoistsRebarΦ14Length×width=2600mm×50mmFig.4.Couplingsupportdesignforlanewayinatypicalsoftseam5.FieldmonitoringofcouplingsupportThemainobjectofinsitumonitoringistorevealtheevolvementofthesurroundingrock,aswellasthestabilityandthereliabilityofthesupportsystem[11-15].Hence,theresultsofmonitoringprovidereferencesforlaterdesignsandconstruction.Asuitableschemewasthereforeimportantforinsitumonitoringandactedasavaliditycheckofthesupportscheme.5.1.MonitoringschemeSincethesurroundingrockinthiscollieryexertslowstrengthandissensitivetoexcavation,itisadifficultenvironmentfortheoperationofrockbolts.Themonitoringschememusttobeconstructedstrictlyaccordingitsdesigninordertoguaranteetheefficacyoftheconstructionandfieldmonitoring.Fig.5showsthefieldmonitoringsectionarrangementintermsofthecurrentsituationinthemine.Onsitemonitoringmainlyinvolvedthefollowingobjects:(1)Surfacedisplacementofthesurroundingrock(relativedisplacementofroofandfloor,relativedisplacementofsidewallsandroofsettlement);(2)Separationlayeroftheroof;(3)Stateofstressoftherockbolts.Inourstudy,wemonitoredsurfacedisplacementofthesurroundingrockwithaJSS30Aconvergencemeter,theseparationlayerdeepinthesurroundingrockwithaDDW-4multi-pointextensometerandthestateofstressoftherockboltswithaYJK4500Bdigitalstaticresistancestrainmeter.Monitoringdevelopedaccordingtothevariationintheseparameters.Monitoringfrequenciesofcircleconvergencedisplacementandroofsettlementweredeterminedbydisplacementvelocityanddistancefromtheexcavationface.Ingeneral,thisrequiredintensivemonitoring,especiallyatthebeginningoftheexcavationuntilthesurroundingrockstabilized.Monitoringwasconductedonceadaywhentheexcavationlengthwaslessthan50mandeverytwodayswhenexcavationextendedfurtherthan50m.Fig.5.FieldmonitoringsectionarrangementoflanewayinatypicalsoftseamInthemonitoringtimeframe,roofsettlementofthetransportationroadwayandtherelativeconvergenceofthesidewallswerecontrolledwithinlessthan120and110mm,respectively.5.2.ResultsoffieldmonitoringThemonitoringresultoftheobviousdeformationinthe#1roadwaysectionisshowninFig.6.Fig.6.Fieldmonitoringofacouplingsupportinatypical3SseamThemaximumsettlementoftheroofinthe#1sectionwas98mmanditsmaximumspeedis28mm/d(Fig.6a).Withinthemonitoringperiod,theminimumsettlementspeedoftheroofwasnomorethan0.1mm/dandaveraging1.02mm/d.Wefoundthatthemaximumrelativeconvergenceofthesidewallswas72mmandculminatedatlessthan0.08mm/d.Boththesettlementandconvergencestabilizedafter2months.Themaximumseparationoftherooflayerwas65mm,whichoccurredapproximatelyonday15anddecreasedgraduallyfromdeepsectionstoshallowones(Fig.6b).Theseparationlayerthereaftersettledataplateaudespitedifferentdepths.Everyanchorrodsharedacompressionofabout34kNafterday15(Fig.6c).Variationinloadingvelocityoftheanchorrodwasnomorethan0.4kN/d.Intheend,thedesignedcouplingsupporthadefficientlycontrolledthedeformationofthesurroundingrockinthissoftseam.6.ConclusionsOnthebasisofthedeformationofthesurroundingrockandlaneway,thetheoryofsupportinseamswithsoftroofsandfloorsandoursimulationandfieldmonitoringofanoptimalcouplingsupport,wedrawthefollowingconclusions.(1)Forroadwaysinseamswithsoftroofs,coalandfloors,deformationanditsrangeinthesurroundingrockislarge,roofsettlementisdistinctanddisplacementofthesidewallssevere.(2)Theproposedoptimumsupportisimportantforlanewaysupportinsoftseams.Itconsistsofafirstcouplingsupportwithrockboltsandsecondaryreinforcementwithanchorcables,whichweintroducedtimelyatkeypositions.Numericalsimulationimpliedthatstresswasconcentratedatroofshouldersoftheroadway,whichwereinthegreatestneedforurgentsupportofanchorcables.Theplasticzonedecreasedafterthesecondcouplingsupportwasinstalled,comparedtothesituationwithonlythefirstsupport.(3)Awellcoupledsupportofrockboltsandcablesisimportantforlanewaysupport,especiallyforlargespanroadwaysinsoftstrata.Theefficacyofanchorcablescanbemaximizedonlyiftheyarefixedatkeypositionsinroofsandfloorsandthereforecontrolthedeformationinordernottoendangerroadways.(4)Thefieldmonitoringshowsthattheoptimalcouplingsupportschemecanreducethedeformationofthesurroundingrockconsiderablyandguaranteethestabilizationoftheroadwayinsoftstrata.

References[1]BaiJB,HouChJ.Controlprincipleofsurroundingrocksindeeplanewayanditsapplication.JChinaUnivMiningTechnol2006;35(2):145-8.[2]ZhaoShC.Resourceminingandundergroundengineeringindeephighstressthe175thsummarizeofXiangshanmeeting.ChinJGeosciEvol2001;15(4):295-8.[3]PangLX,YaoDQ,JingChSh.Probeandpracticeofsupportingtechnologywithshotcreteandboltingwiremeshforlargesectioncoallanewaysinsoftseamsbetweensoftroofandsoftfloor.CoalMiningTechnol2002(1):40-3.[4]WeiShL,WangJL,ZhuJX,LiuDL,ZhangDM,HeMF,etal.Floorheavemechanismandsupporttechnologyofgoaf-sidegatewayforre-mininginseamwithsoftroof,softcoalandsoftfloor.CoalSciTechnol2009;37(5):9-12.[5]WangJL,WeiShL.Researchonlanewaysupporttechniqueforcoalpillarminingintheoldminingareaknownforweakseams.JShanxiDatongUniv2009;25(4):51-4.[6]LiJK,LiXB,LiuDSh,ZhengXJ.Numericalsimulationforboltingnetspraycompositesupportofthreesoftcoalseamtunnel.JXi’anUnivSciTechnol2009;29(3):270-2.[7]ZhangN,HouChJ,WangPR.Onboltingsupportoflanewayindeepmine’ssoftcoalseam.ChinJRockMechEng1999;18(4):437-40.[8]LiLF.Lanewaysupportingtechnologyofcoallanewaywithsoftroof,softcoalandsoftfloor.CoalMiningTechnol2007;12(3):59-62.[9]HeMCh,ZhouZhSh,ZhouYF.Surveyofsoftrocktunnelengineering.Xuzhou:ChinauniversityofMiningandtechnologypress;1993.[10]LiXH,WangWJ,HouChJ.Controllingfloorheavewithstrengtheningroofingatewaybynumericalanalysis.JChinaUnivMiningTechnol2003;32(4):436-9.[11]XuJH,ZhuHK,ShiBH,FengMM.Analysisofsupportwaysofroadwayanditssurrounding’scontroleffectinthree-softcoalseam.JChinaUnivMiningTechnol2004;33(1):55-8.[12]XuLM.Discussiononlowcostsupportmethodforgob-sideentrydrivinginseamwithsoftroof,floorandcoal.CoalSciTechnol2001;29(12):23-7.[13]ZhuShY,JuYJ,ZhaoZhZh,LiuDQ.Sitemeasurementonfloordeformationandfailureofmininggatewaysforfullymechanizedtopcoalcavingminingfaceinseamwithsoft,coalandfloor.CoalSciTechnol2008;36(10):10-3.[14]WangShY,ZhangY.Fullymechanizedtopcoalcavingminingtechnologyincombinedseamswithclosedistanceandwithsoftroof,softcoalandsoftfloorinGuobeiMine.CoalSciTechnol2009;37(7):24-7.[15]HeChL.Thecontroltechnologyandengineeringpracticeofthesurroundingrockindeepmine’ssoftcoalseam.JHunanUnivSciTechnol2006;21(3):9-12.

中文翻译软岩煤层大跨度巷道的变形研究及其支护技术摘要：我们研究了具有软弱顶底板的巷道支护工程方面的围岩变形破坏机理，并观测到了软岩煤层中巷道的大跨度偏移。结果表明，变形面积越大，顶板垮落和侧向位移也就越明显。我们考虑在软弱顶底板的煤层中采用锚索耦合支护巷道，这样锚索就可以固定在关键层中。与此同时，我们设计了一套针对中国宁夏石嘴山二矿软岩煤层巷道支护的最佳方案。现场监测结果表明，锚索耦合支护已经达到了巷道稳定性控制和最大限度地减少变形量的目的。关键词：软岩煤层；巷道变形；锚索耦合支护；现场监测1引言煤炭为中国的经济增长提供了大部分的能量。但世界各地对煤炭需求的不断增加导致了在邻近或在地球表面上能够被经济地提取的煤炭资源的持续下降。因此，发展采矿技术的趋势应该集中在深部开采，这已是国际采矿业一个重要的研究领域[1,2]。尤其，在深部开采技术中遇到的软岩巷道，正在成为严重制约煤矿开采的主要挑战之一[3-7]。由具有软弱顶底板的煤层巷道所导致的问题已经在中软岩问题