砂墩子煤矿3.0Mt-a新井设计-浅埋深大采高工作面矿压显现规律研究

题目：砂墩子煤矿3.0Mt/a新井设计浅埋深大采高工作面矿压显现规律研究摘要本设计包括三个部分：一般部分、专题部分和翻译部分。一般部分为砂墩子矿3.0Mt/a新井设计。共分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、服务年限；4.井田开拓；5.准备巷道布置；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。砂墩子位于新疆哈密市三道岭矿区后窑井田西部，北距312国道约5km，东距三道岭矿区20km，哈密市124km，行政区划隶属于新疆维吾尔自治区哈密市。井田东西走向长7km，南北宽3.5～5.0km，井田面积约19.49km2。主采煤层为4号煤，平均厚12.55m，井田地质条件简单。矿井工业储量为317.33Mt，可采储量215.48Mt。矿井正常涌水量为747m3/d，最大涌水量为1416m3/d。矿井瓦斯涌出量低，为低瓦斯矿井。矿井为立井单水平开拓，大巷采用胶带输送机运煤，辅助运输采用齿轨卡轨车，矿井通风方式为中央并列式通风。一矿一面，矿井采用倾斜长壁综合机械化放顶煤开采法，一次采全高。矿井年工作日为330d，每天净提升时间16h。矿井工作制度采用“四六”制，三班生产、一班准备。专题部分题目是浅埋深大采高工作面矿压显现规律研究。主要是对当前我国浅埋深大采高综采工作面的矿压显现规律进行分析。翻译部分主要内容为高预应力强力支护系统的发展及其在煤矿巷道中的应用，英文题目为：Developmentofhighpretensionedandintensivesupportingsystemanditsapplicationincoalmineroadways。关键词：立井；单水平；带区；综合机械化放顶煤；中央并列式通风ABSTRACTThethreepartsareincludedinthisdesign,i.e.,thegeneralpart,specialsubjectpartandtranslatedpart.ThegeneralpartisanewdesignofShadunzimine.Thisdesignincludestenchapters.1.Anoutlineoftheminefieldgeology.2.Boundaryandthereservesofmine.3.Theservicelifeandworkingsystemofmine.4.developmentengineeringofcoalfield.5.Thelayoutofpanels.6.Themethodusedincoalmining.7.Transportationoftheunderground.8.Theliftingsystemofthemine.9.Theventilationandthesafetyoperationofthemine.10.Thebasiceconomicandtechnicalnorms.ShadunzimineliesinwestofSandaolingmine.Therunoftheminefieldisabout7km，thewidthis3.5～5.0km，minefarmlandtotalareais19.49km2.Thefouristhemaincoalseam，It’sthicknessisabout12.55m.Thecoalfieldgeologicalconditionissimple.Theprovedreservesofthecoalfieldare317.33milliontons.Therecoverablereservesare215.48milliontons.Thenormalflowofthemineis747m3percentdayandthemaxflowofthemineis1416m3percentday.Themineralgasgushesthedeallower，forlowgasmineralmine.Theminefarmlandinaninclinedminetoexpand.Themaintransportationusestheadhesivetapetransportationopporteunitycoal.Theworkingsystem“four-six”isusedintheShadunzimine.Itproduced330d/a.SpecialsubjectpartsoftopicsisStudyonundergroundPressureCharacteristicofShallowMiningFieldwithLargeMining-height.ThemaincontentsofthespecialsubjectisananalysisabouttheundergroundPressureCharacteristicofShallowMiningFieldwithLargeMining-heightinchina.Translationpartofmaincontentsisabout“Developmentofhighpretensionedandintensivesupportingsystemanditsapplicationincoalmineroadways”.Keywords:shaft;twomininglevels;stripdistrict;fullymechanizedminingwithtopcoalcaving;centralizedjuxtaposeventilation目录一般部分TOC\h\z\t"标题001,1,标题002,2,标题003,3"1矿区概述及井田地质特征 页英文原文DevelopmentofhighpretensionedandintensivesupportingsystemanditsapplicationincoalmineroadwaysKangHongpu,LinJian,WuYongzhengCoalMiningandDesigningBranch,ChinaCoalResearchInstitute,Hepingli,ChaoyangDistrict,Beijing100013,ChinaAbstract:Inviewofthefeaturesofcomplicatedanddifficultroadways,thepresentproblemsonrockboltingtechniquewereanalyzed,andthehighpretensionedandintensivesupportingtheorywasputforward.Theinitialsupportingstiffnessandstrengthofboltingsystemshouldbeincreasedlargelytocontrolthedilatantdeformationandmaintaintheintegrityofsurroundingrock.Thehighpretensionedandintensiveboltandcablesystemwasdeveloped,andthemechanicalpropertiesoftheboltingcomponentswereobviouslyimproved.Thissystemhasbeensuccessfullyappliedinthe1000mdeepentriesinXinwencoalfield,andtheentriesaffectedbyintenseminingactivitiesinLu’ancoalfield.Thedeformationoftheentrieswasreducedbyabigmargin.Thissystemprovidesaneffectivesupportingformforcomplicatedanddifficultroadways.Keywords:roadways;rockbolting;highpretensionedstress;intensivesupporting;undergroundapplications1IntroductionWiththeincreasesofcoalminingintensityandlimit,thedepthofroadwaysinundergroundcoalminesinChinaisgettinglargerandlargerwiththemaximumminingdepthupto1365m;geologicalconditionsoftheroadwaysbecomemoreandmorecomplicated;andthelocations,sectionsandstressstatesoftheroadwaystendtobeunfavourabletotheirstabilities.Thesetrendsoftheroadwaylayoutposehigherandstricterrequirementstoboltingtechnique.Forthispurpose,studyandtestingonthecompleteboltingtechniquehavebeencarriedoutinseveralcoalfields,andtheresearchresultshavebeenutilizedindifferentroadwayconditions,andimprovedthesupportingperformancesharply.Atpresent,inChina,therateofboltingaccountsfor60%intotalroadwaysinmanycoalfields,even100%insomecoalfields.However,someproblemsarestillpresentthoughgreatprogresshasbeenmadeinboltingtechnique.Thesupportingperformanceofhighstrengthboltingispoorindeepandcomplicatedroadways,andtheboltingcomponentsaredestructedseverely.Ingeneral,theproblemsaresummarizedasfollows:Lowsupportingstiffness.Thesupportingstiffnessisassociatedwithpretensionedstressandanchoragetypes,andthehighsupportingstiffnesscanonlybeachievedbycombinationofhighpretensionedstresswithfull-lengthanchorage.Thespinmomenttoinstallboltsonlyamountsto100-150N.m,orthepretensionedforceisupto15-20kNatmostcases.Lowtendonstrengthforboltsandcables.Forexistingtendonsusedforhighstrengthbolts,theyieldstrengthisaboutonly335-400MPa,whilethebrokenstrengthisabout500-600MPa.Thediameterofcablesis15.2-17.8mm,andthebrokenforceisabout260-350kN.Poorendthreadquality.Poorthreadqualitywillincreasethefrictionalforcesbetweenthenutsandthreads,andlowerthetransitingratefromthespinmomentofnutstopretensionedforceoftendons.Ontheotherside,thepoorthreadqualitywillalsoworsentherearstressstate,resultinshearing,bending,rupture.Devaluatingsurfaceproofcomponents,suchasplate,strap,andmetalmesh.Strapswithlowstrengthandstiffnessarecommonlyusedtolowerthecostofmaterial,decreasethecapabilityofsurfaceproofandaffectthetotalsupportingperformance.Highdensityofbolts.Moreboltspersquaremeterandmoreinstallingtime,willbringdowntherateofroadwayadvance.Tosolvetheaboveproblems,thehighpretensionedandintensivesupportingsystemwasdevelopedbasedontherelativesupportingtheory.2HighpretensionedandintensivesupportingtheoryAtpresent,thereexisttwodifferenttheoriesforsupportingcomplicatedanddifficultroadwayswithhighstressesandlargedeformation.2.1SecondarysupportingtheoryAccordingtosecondarysupportingtheory,supportingforroadwayswithhighstressesandlargedeformationshouldbedividedintotwophases.Thefirstsupportingshouldpermitthesurroundingrocktodeformandreleasethestresswhenthestabilityofroadwaysissecured;thesecondsupportingshouldbeinstalledtokeepthelongtermstabilityofroadwaysatadefiniteinterval.Thistheoryhasbeenwidelyacceptedandapplied,andverygoodperformancehasbeenobtainedinsomedefiniteconditions.Butthistheoryisfacingmoreandmorechallengeswiththeincreaseofminingdepth,andtheadditionalcomplicated,geologicalandminingconditions.Inroadwayswithdepthupto1000m,orroadwaysaffectedbyintenseminingactivities,orcutbygeologicaldiscontinuities,weakandbrokenrockzones,thedeformationhasbeenstillunacceptedaftersecondarysupporting,andthethirdorevenfourthsupportinghadtobeappliedinsometimes,butthedeformationcouldnotbecontrolledforalongperiod.2.2Highpretensionedandintensivesupportingtheory(primarysupportingtheory)Theessenceofthistheoryistoincreasetheinitialstiffnessandstrengthofboltingbyalargemagnitude,controlthedisplacementofsurroundingrock,keepitsintegrity,andrelievethedecreaseofrockstrength.Toavoidthesecondarysupportingandroadwaymaintenance,thehighpretensionedandintensivesupportingtechniqueisapplied,whichshouldmeettheconditionsasfollows:Theboltingsystemshouldhaveenoughinitialstiffnessandstrength.Thepretensionedstressanditsspreadingeffectwillplaythekeyrole.Ononehand,keeptheintegrityofthetotalboltingstructure;ontheotherhand,sustainthehighanchorageforcesinboltsandcables,moreover,spreadthecompressivestressintotherock.Thesupportingsystemshouldhavehighextensionrate,toallowthesurroundingrocktodeformtosomeextent,butthelimitofdisplacementcannotbeexceededduringtheservicetime.Undergroundsupportingpracticesshouldbereadilycarriedout,adaptingtothesitemanagementandfavouringrapidadvance.Thesupportingsystemcanlowerthetotalcostofsupportingandmakeiteconomicallyreasonable.Therefore,basedonpresentboltingtechnique,developinghighpretensionedandintensivesupportingsystemisaviableoptiontotackletheproblemsofhighstressandcomplicatedroadways.3MaterialsforboltsandcableswithhighpretensionedstressandstrengthCoalMiningandDesigningBranch,ChinaCoalResearchInstitute,developedthehighpretensionedandintensivesupportingsystem,includingintensivebolts,lowviscosityandhighstrengthresincapsule,highstrengthstrap,andintensivecables.3.1Intensivebolts3.1.1ShapeandsizeoftendonsThedesignoftendonshapeshouldfollowfourrules:first,reasonablemarginbetweenthetendonandboreholetoputtendonsintoboreholesreadily;second,favourableforthehighbondcapacityandperformance;third,spreadingtheforceevenlyalongthetendon;fourth,highpretensionedstresstobeeasilyexertedontherearpart.Atpresent,thetendon,withleft-spinthreadandwithoutraisedaxialridge,canmeettheabovefourrules,andbeanidealoptionforthecurrentsupportingsystem.Thetendonisabout22-25mminnominaldiameter,2.0-3.0mlong.3.1.2MaterialsfortendonsIngeneral,thematerialsfortendonsusedbyforeigncompanieshaveyieldstrengthabout400-600MPa,orevenmore,andbrokenforceabout200-300kN.IntheUS,theproductshaveyieldstrengthabout414-689MPaandbrokenstrengthabout621-862MPa.InUK,theproductshaveyieldstrengthabout640-720MPa.InAustralia,thehighstrengthtendonof22mmindiameterhasbrokenforceabout240kN,andthesuperstrengthtendonof22mmindiameterhasbrokenforceabout340kN.Toreachandexceedthestandardofforeignmaterials,thespecialsteelformulasforboltsweredevelopedtomeetthesupportingrequirementsofcomplicatedroadways,andsomeformulaslikeBHRB500,BHRB600canbeusedforintensivebolts(shownintable1).Fig.1showsthetensileloadanddisplacementcurveofφ25mmbolt.Table1MechanicalperformanceofsteelforintensiveboltsTypeNominaldiameter(mm)Yieldstrength(MPa)Tensilestrength(MPa)Extension(%)BHRB50022-2550067018BHRB60022-2560080018FortheBHRB600tendonwithdiameterof22mm,itsyieldforceamountsto228.1kN,anditsbrokenforceisupto304.1kN,about1.79and1.73timesofthecommoncivilsteelwiththesamediameter,respectively.Thepretensionedforcecanamountto100kNforintensivebolts.3.1.3AuxiliarypartsBesidesthetendons,nutsandplatesfittingforthetendonsweredeveloped.Toreducethefrictionalforcebetweentheplateandthenut,andtotransformspinmomentintopretensionedforceatmost,theanti-frictionwasherwasalsodeveloped.3.2LowviscosityandhighstrengthresincapsulesWiththefollowingcharacteristics:highstrength,shortcuretime,highreliability,resincapsuleshavebeenwidelyusedforrockbolts.Butthedefectsofexistingresincapsulesarealsoevident,suchashighviscosity,coarsegrain,highmechanicalresistance,unfitnessforfullencapsulation.Tothisend,lowviscosityandhighstrengthresincapsulesweredevelopedbyloweringtheresinviscosity,applyingthefinerockpowderasskeleton,andusinghighaggregatingresin,andsuchresincapsulescanreducefrictionalresistanceduringspinning,andsolvetheproblemsofinstallingtheboltswithextensiveorfullencapsulation.Thefastandslowcureresincapsulesshouldbeusedtogether.Thefastcapsulesolidifiesearlier,pretensionedforceisexertedimmediately,then,theslowcapsulessolidify,thefulllengthpretensioncanberealizedandthesupportingeffectscanbeimproved.3.3HighstrengthstrapStrapisakeypartinthehighpretensionedandintensivesupportingsystem,andplaysanimportantroletospreadthepretensionedforceandresistanceofbolts,expandthespanofactionofboltsandincreasethetotalsupportingcapacity.Wstrapisformedbyseveralcoursesofrollingandcoldbending.Wstrapprotectslargersurfacearea,provideshighstrengthandstiffness,andshowsgoodperformanceasaboltingcomponent.ThemainshortcomingofWstrapisasfollows:whenWstrapisthinandthestressishigh,theplatesmayperforateWstrap,causingshearingfailureorruptureinit.Tomatchthemechanicalperformanceofintensivebolts,thehighstrengthWstrapwasdeveloped:oneapproachistoincreasethethicknessofstrap,from2.5-3mmto4-5mm,andincreasethebrokenloadto500kN;theotheristoselectsteelwithhigherstrengthwithoutchangingthedimensionsofthestrap.3.4Intensivecables3.4.1.StrandsforcablesStrandswithhighextensionrateandsuperstrengthweredevelopedforcoalmines,aimingattheproblemsofthecableswithsmallborehole.Thestrandsaremadefromanewtype:1×19form.Tomatchthesupportingstrengthandpracticearts,aseriesofstrandswithdifferentdiameters,φ18mm,φ20mm,andφ22mm,weredeveloped,andthelasttwotypesbelongtointensivecables.ThemechanicalperformancesarelistedinTable2.Thelaboratoryload-displacementcurveofφ22mmcableisshowninFig.2.Table2.MechanicalperformanceofcablesNominaldiameter(mm)Brokenload(kN)Extension(%orthestrandwithdiameterof22mm,thebrokenloadisabove600kN,andtheextensionrateamountstoabout7%.Theseresultsareclearlybetterthanthatofthestrand(1×7form)withthesamediameter.Thepretensionedforcecanreach300kN.3.4.2PlatesforcablesThereareseveraltypesofplatesforcables.Flatplatesaremostcommonlyused,anothertypeofplatesismadeofchannelsteel(type12#,14#),butthesetwotypesofplateshavepoormechanicalperformances.Whenthepretensionortheloadoncablesishigh,flatplatesoftenwarparoundtheirperimeter,theloadcapacityreducessharply;theplatesmadeofchannelsteelreadilydeformanddistort,insomecasesareperforatedtocausethecablefailure.Toovercometheabovedefectsofplates,thedomed-shapeplate,withthreedimensionsof300×300×16mm,wasdeveloped,includingacenter-adjustedwasher.Ononehand,thisnewproductincreasestheloadcapacitytomatchtheintensivecables;ontheotherhand,theplateallowstheadjustmentofitscentertoimprovethemechanicalperformance,andfullyexercisethecapacityofcables.4SiteapplicationsofhighpretensionedandintensivesupportingsystemThehighpretensionedandintensivesupportingsystemwasappliedtosolvetheproblemsofdeepandminingaffectedentriesinXinwenandLu’ancoalfieldsincethesystemhasbeendeveloped.4.1Applicationofintensiveboltsin1000mdeepentryinXinwencoalfield4.1.1GeologyandproductionconditionsThetestsiteislocatedat1202EhaulageentryinXiezhuangcoalmine,Xinwencoalfield.TheentryrunsalongtheroofofthecoalseamNo.2,average2.4mthick,withuniaxialcompressivestrengthof12MPa,andadipof20°26°.Theimmediateroofissandyshale,2.4mthick,withuniaxialcompressivestrengthof35-40MPa.Thedepthoftheentryis1150-1200m.Themaximumhorizontalmainstressis34.60MPawiththedirectionofN12.5°E,andtheminimumhorizontalmainstressis17.89MPa.Thestresslevelishigh,andthehorizontalstresstakestheclearadvantage.Thesectionareaoftheentryis11.1m2withameanheightof3mandawidthof3.7m.4.1.2DesignofsupportingpatternThehighpretensionedandintensiveboltingsystemisapplied.Thebolt,withleft-spinthreadandwithoutraisedaxialridge,is25mmindiameter,2.4mlong,withabrokenlimitof400kN.Theboltisextensivelyencapsulated,withaninitialtensileforceof80kN.Wstrap,withthicknessof5mmandwidthof280mm,isapplied.Theroofandtwosidesarecoveredbysteelmeshes.Therowspacingis1.0m,with12boltsineachrow.Thespacingbetweenroofboltsis900mm,andthespacingbetweenboltsinupsideis1100mm,andthatbetweenboltsindownsideis800mm.4.1.3AnalysisonundergroundmonitoringdataAfterapplyingthenewsupportingpattern,theroof-to-floorconvergencewas281mm,andtheside-to-sideconvergencewas173mm;theroofsagwas40mm,andthefloorheavewas241mm.Theseresultsdecreasedby69.8%,77.8%,79.5%,67.2%respectively,comparedwiththemonitoringresultsfromtheoldsupportingpattern.Thedisplacementsofrocksurroundingtheentrydecreasedsharply.Theroofseparationfromthenewsupportingpatternwasabout5%oftheresultfromtheoldsupportingpattern.Itclearlyshowsthehighpretensionedandintensivesupportingsystemcaneffectivelycontroltheseveredeformationofrockaroundthedeepentry.4.2ApplicationofintensivecablesinentryaffectedbystrongminingactivityinLu’ancoalfieldBecauseoftherequirementsofcontinuousheavyminingproductioninZhangcuncoalmine,Lu’ancoalfield,someentriesfornextminingfacemustbepreparedbeforetheadjacentminingfacewasrecovered,andtheseentrieshavetorunintheoppositedirectiontotheactiveminingface,andwillbestronglyaffectedbytheminingactivity.Theseentrieswillbeaffectedbytheabutmentstressbeforetheadjacentandlocalminingface,thestresscausedbyheadingandmining,andthestressredistributedinthegobareas.4.2.1.GeologyandproductionconditionsThetestingentry,belongingtotheface2203,isusedforgasdischargewithdepthof325-396m.Theuniaxialcompressivestrengthofthecoalseamisabout8MPa.Theimmediateroofisalayerofmudstone,3.62mthick.Theadjacentactivefaceistheface2202,andmostpartofthetestingentryisexcavatedbeforetherecoveroftheface2202,andwillaffectedbytheminingoftheface2202andtheface2203inthenearfuture.4.2.2DesignofsupportingpatternThetotalsectionoftheentryisreinforcedbyintensivecables.Thecablesare1×19strandswiththediameterof22mmand4.3mlong.Assoonastheinnerendisanchoredwithresincapsules,thepretensionedforceshouldbeinstalledandthentherestpartofcableshouldbeencapsulatedwithcementslurry.Theplateforcables,center-adjustedanddesignedspeciallyforinfusingslurry,hasthedimensionsof300×300×16mm.Theroofandsidesarecoveredbysteelmeshes.Thespacingbetweenroofcablesis1.2m;5cablesareneededforeachrow;thespacingbetweencablesis900mmatthesamerow.Thecablesareinstalledverticaltotheroofsurface.Thespacingbetweensidecablesis1.2m;3cablesareneededforeachrow.Thecablesareinstalledverticaltothesidesurface.Thepretensionedforcetobeinstalledforcablesis200-250kN.4.2.3AnalysisontheundergroundmonitoringdataThemaximumside-to-sideconvergencewas260mm,andthemaximumroof-to-floorconvergencewas160mm,andnoobviousseparationwasshowninroof.Thestrongstresschangearoundtheentrywasshownintherearofface2202,andtheside-to-sideconvergencechangedsharply.ThesupportingstatusoftheentryisshowninFig.3.Ingeneral,thedisplacementsaresmall,andnewsupportingpatternreducesby90%ofthedisplacementscomparedwiththeoldone.Theintegrityandstabilityofsurroundingrockiskept,andtheperformanceofthenewpatternisgood.Thesidecablesbearmoreloadthantheroofcables,andthemaximumloadisupto512kN.Itisobviousforentriesaffectedbystrongminingactivities,thetotalsectionofentriesshouldbereinforcedbycables,i.e.,theroof,twosides,eventhefloorshouldbesupportedfullybycables.Fromthechangingtrendofthebearingloadmonitoredfromcables,itshowstheloadsofcablesdonotchangeobviouslywiththeheadingandadjacentminingactivityafterthehighpretensionedforceisinstalled.Therefore,thepretensionedforceof200-250kNisreasonable.5ConclusionsThedefectsofexistingrockboltinglieinlowstiffness,lowstrength,poorquality,andlittleattentionpaidtothecomponents,suchasplates,straps,andmetalmeshes,whichresultinhighboltingdensityandpoorsupportingperformanceincomplicatedroadways.Theinitialsupportingstiffnessandstrengthofboltingsystemshouldbeincreasedlargelytocontrolthedilatantdeformation,maintaintheintegrityofsurroundingrockandkeepthestrengthoftherockandcoalseam.Thehighpretensionedandintensivesupportingsystemisaviableapproachtosolvethesupportingproblemsofcomplicatedroadways.Comparedwiththeexistingboltsandcables,theintensiveboltsandcablesimprovethemechanicalperformancesharply.Theintensiveboltsandcables,lowviscosityandhighstrengthresincapsules,thehighstrengthstraps,andsteelmeshestogethermakeupthehighpretensionedandintensivesupportingsystem.Thehighpretensionedandintensivesupportingsystemhaseffectivelycontrolledthedisplacementsofsurroundingrockandroofseparationin1000mdeepentries,andtheentriesaffectedbystrongminingactivities.Thedisplacementscandecreaseby70-90%,andtheroofseparationcanbereducedtoonly5-10%oftheoriginalvalue,evennoseparationmonitoredandthesupportingstatushasessentiallychanged.References[1]H.KangandJ.Wang,Rockboltingtheoryandcompletetechnologyforcoalroadways,Beijing:ChinaCoalIndustryPublishingHouse,2007.[2]J.Wang,NewdevelopmentofrockboltingtechnologyforcoalroadwayinChina,JournalofChinaCoalSociety,32(2007)113–8.[3]X.HuandS.Fan,CompletedsettechnologyofboltsupportforseamgatewayappliedtoLu’anminingarea,CoalScienceandTechnology,31(2003)33–5.[4]H.Kang,J.LinandB.Zhang,Studyonsmallboreholepretensionedcablereinforcingcomplicatedroadway,ChineseJournalofRockMechanicsandEngineering,22(2003)387–90.[5]H.Kang,J.WangandJ.Lin,Highpretensionedstressandintensiveboltingsystemanditsapplicationindeeproadways,JournalofChinaCoalSociety,32(2007)1233–8.[6]H.Kang,T.JiangandF.Gao,Effectofpretensionedstresstorockbolting.JournalofChinaCoalSociety,32(2007)673–678.[7]F.GaoandH.Kang,Effectofpre-tensionedrockboltsonstressredistributionaroundaroadway—insightfromnumericalmodeling,JournalofChinaUniversityofMining&Technology,18(2008)509–515.[8]N.ZhangandM.Gao,High-strengthandpretensionboltingsupportofcoalroadwayanditsapplication,JournalofChinaUniversityofMining&Technology,33(2004)524–7.[9]S.GuoSandJ.Stankus.Controlmechanismofatensionedboltsysteminthelaminatedroofwithalargehorizontalstress,In:16thInt.Conf.OnGroundControlinMining.Morgantown,WestVirginia,1997.[10]E.Villaescusa,R.VardenandR.Hassell,QuantifyingtheperformanceofresinanchoredrockboltsintheAustralianundergroundhardrockminingindustry,InternationalJournalofRockMechanics&MiningSciences,45(2008)94–102.中文译文高预应力强力支护系统的发展及其在煤矿巷道中的应用康红普，林健，吴拥政中国煤炭科学研究总院开采设计研究分院，北京，朝阳区，和平里，100013摘要：针对复杂困难巷道条件，对锚杆支护技术存在的问题进行了分析，并提出高预应力、强力支护理论。大幅度提高支护系统的初期支护刚度与强度，保持围岩的完整性，减少围岩强度降低，开发出高预应力、强力支护系统，包括强力锚杆、强力钢带及强力锚索系列材料，力学性能得到显著提高。该系统已成功地应用于新汶矿区千米深井巷道，并通过了潞安矿区强烈的采矿活动影响，大幅度减小了围岩的变形程度，本系统提供了一个有效的复杂困难巷道的支护形式。关键词：巷道，锚杆支护，高预应力，强力支护，井下应用1简介随着煤炭开采强度和极限的增加，我国煤矿井下巷道的深度越来越大，最大挖掘深度可达至1365米，巷道的地质条件变得越来越复杂；巷道的位置、节点和应力状态是巷道稳定性的不利因素。这些巷道布置的趋势对锚杆支护技术提出了更高，更严格的要求。为此，完整的锚杆支护技术的研究和测试已经进行了几个矿区，并利用研究成果已在不同的巷道条件下，大幅度的完善了支护性能。目前，在我国许多矿区60％的巷道采用锚杆支护，甚至在一些矿区100％巷道采用锚杆支护。然而，虽然锚杆支护技术取得了很大进展，但一些问题仍然存在。在深部及复杂困难巷道，高强度锚杆支护效果差，锚杆支护组件严重破坏。在一般情况下，存在的问题归纳如下：支承刚度低，支承刚度是与预应力和锚固类型相关联的，只有全长锚固和高预应力组合才能实现高支撑刚度。锚杆安装扭矩仅达到100-150N.m，或大多数情况下张紧力是在15-20KN。锚杆和锚索的杆体强度低。对于高强度锚杆使用现有的杆体，屈服强度约只有335-400MPa，而断裂强度约为500-600MPa。锚索的直径是15.2-17.8mm，破碎力约为260-350KN。螺母和托板的质量差，会增加螺母和托板之间的摩擦力，降低锚杆安装扭矩转化为预力的中转率。另一方面，较差质量的托板恶化后的应力状态，也将导致出现剪切，弯曲，破裂现象。降低表面防爆性能的组件，如杆体，钢带，金属丝网。常使用低强度和刚度的杆体，以降低材料成本，降低了表面防爆的能力，影响总的支撑性能。高密度的锚杆。每平方米内锚杆增多需要的安装时间增加，将降低巷道掘进推进速度。为了解决上述问题，在相关理论的基础上，提出了高预应力、强力支护系统。2高预应力、强力支护系统目前，存在着两种不同的理论用于支护高应力和大变形的复杂、困难巷道。2.1二次支护理论根据二次支护理论，高应力、大变形巷道的支护应分为两个阶段：当巷道处于安全稳定时，初次支护应允许围岩变形和释放压力；二次支护应确保巷道在一定的时期内长期稳定。这一理论已被广泛接受和应用，已经在一定条件下获得很好的表现。但是，这一理论正面临着越来越多的挑战，随着开采深度的增加，以及额外复杂的地质和开采条件。在巷道深度可达1000米，或受到强烈的采场活动，或经过不连续的地质条件，软弱和破碎岩石区的巷道，二次支护后巷道变形仍然太大，，第三次甚至第四次支护可以支护一些时间，但无法在很长一段时间内控制变形。2.2高预应力、强力支护理论（主要支护理论）这一理论的精髓，是由大幅度增加的初始刚度和锚杆支护的强度，控制围岩位移，保持其完整性，减轻降低围岩强度。为了避免二次支护和巷道维修，高预应力强力支护技术的应用，应符合如下条件：锚杆支护系统应该有足够的初始刚度和强度。预应力和其扩散效果将发挥关杆体作用。一方面，保持总的锚杆支护结构的完整性;另一方面，维持高锚固力在锚杆钢带，而且将压力传递到围岩。支护系统应具有高延伸率，允许围岩变形到一定程度，但不能在服务时间内超过位移的限制。井下支护措施应随时进行，适应现场管理，有利于快速推进。支护系统可以降低支护的总成本，并使其经济合理。因此，目前锚杆支护技术的基础上，开发高预应和强力支护系统是一个可行的办法，以解决高应力和复杂巷道的问题。3高预应力和高强度的锚杆与锚索材料中国煤炭科学研究总院开采设计研究分院，开发了高预应力、强力支护材料，包括强力锚杆，低粘度，高强度树脂填充液，高强度钢带，和强力锚索。3.1强力锚杆3.1.1锚杆杆体几何形状与尺寸锚杆杆体形状设计应遵循四个原则：第一，在合理孔径差的条件下，保证杆体能顺利插入钻孔；第二，有利于提高锚固剂的黏结力与锚杆锚固效果;第三，尽量使杆体各个部位等强度；第四，杆体尾部有利于施加较大的预紧力。目前，左旋无纵筋螺纹钢杆体基本能满足杆体形状设计的四准则，是比较理想的锚杆杆体。锚杆杆体的公称直径约22-25mm，长2.0-3.0m。3.1.2锚杆杆体的材质在一般情况下，外国公司所使用的锚杆杆体屈服强度为400-600MPa左右，甚至更高，破断力约200-300KN。在美国，杆体的屈服强度约为414-689MPa，抗拉强度约621-862MPa[9]。在英国，杆体屈服强度约为640-720MPa。在澳大利亚，直径22毫米的高强度杆体破断力约240kN，直径22毫米的超强度杆体破断力约340kN。为了达到和超过国外杆体材料水平，开发锚杆专用钢材配方，以满足复杂的巷道支护要求，其中BHRB500，BHRB600类型钢材可用于生产强力锚杆（表1所示）。图1显示φ25毫米锚杆拉伸载荷和位移曲线。表1强力锚杆钢材的力学性能类型标称直径(mm)屈服强度(MPa)抗拉强度(MPa)延伸率(%)BHRB50022-2550067018BHRB60022-2560080018杆体直径22毫米的BHRB600，其屈服力为228.1kN，其破碎力是高达304.1kN，分别是相同直径的普通民用钢质的1.79和1.73倍。强力锚杆的预应力可达100KN。3.1.3附件除了杆体外，还开发了与强力锚杆相配套的螺母和托盘。为了减少托盘和螺母之间的摩擦阻力，将最多的安装扭矩转化为预紧力，还开发出高效减摩垫圈。3.2低粘度，高强度树脂填充液具有强度高，固化时间短，可靠性高等特点的锚杆树脂填充液已被广泛使用。但现有树脂填充液的缺陷也显而易见的，如高粘度，粗粮，高机械性，不适宜完全封装。为此，开发低粘度，高强度树脂填充液通过降低树脂粘度，应用为骨架的细岩粉，并采用高聚合树脂，这种树脂填充液可以减少摩擦阻力，在纺纱，解决安装的问题广泛或全封装锚杆。快速和慢速固化树脂填充液应一起使用。快速填充液凝固后，立即施加预紧力，然后慢速填充液凝固，就可实现全长预紧，也可以改善支护效果。3.3强力钢带钢带是高预应力、强力支护体系的重要组成部分，并起着重要的作用，能传递锚杆的预紧力和阻力，扩大锚杆的作用范围并提高整体支护能力。W型钢带是经过冷弯、滚压成型的型钢产品，W型钢带保护面积大、强度高、刚度大，是一种性能比较优越的锚杆组合构件。W型钢带主要缺点如下：当钢带较薄、巷道压力大时，与平钢带类似，易出现托板压入或压穿钢带，导致钢带发生剪切和撕裂破坏．。为了与强