巖土工程錨桿中英文對照外文翻譯文獻

巖土工程錨桿中英文對照外文翻譯文獻巖土工程錨桿中英文對照外文翻譯文獻(文檔含英文原文和中文翻譯)Effectofgroutpropertiesonthepull-outloadcapacityoffullygroutedrockboltAbstractThispaperrepresentstheresultofaprojectconductedwithdevelopingasafe,practicalandeconomicalsupportsystemforengineeringworkings.Inrockengineering,untensioned,fullycement-groutedrockboltshavebeenusedformanyyears.However,thereisonlylimitedinformationabouttheactionandthepull-outloadcapacityofrockbolts,andtherelationshipbetweenbolt–groutorgrout–rockandtheinfluenceofthegroutpropertiesonthepull-outloadcapacityofarockbolt.Theeffectofgroutpropertiesontheultimateboltloadcapacityinapull-outtesthasbeeninvestigatedinordertoevaluatethesupporteffectofrockbolts.Approximately80laboratoryrockboltpull-outtestsinbasaltblockshavebeencarriedoutinordertoexplainanddeveloptherelationsbetweenthegroutingmaterialsanduntensioned,fullygroutedrockbolts.Theeffectsofthemechanicalpropertiesofgroutingmaterialsonthepull-outloadcapacityofafullygroutedbolthavebeenqualifiedandanumberofempiricalformulaehavebeendevelopedforthecalculatingofthepull-outloadcapacityofthefullycement-groutedboltsonthebasisoftheshearstrength,theuniaxialcompressivestrengthofthegroutingmaterial,theboltlength,theboltdiameter,thebondingareaandthecuringtimeofthegroutingmaterial.Keywords:Rockbolt;Groutingmaterials;Boltpull-outloadcapacity;Boltgeometry;Mortar1.IntroductionInrockengineering,rockboltshavebeenusedtostabiliseopeningsformanyyears.Therockboltingsystemmayimprovethecompetenceofdisturbedrockmassesbypreventingjointmovements,forcingtherockmasstosupportitself(Kaiseretal.,1992).Thesupporteffectofrockbolthasbeendiscussedbymanyresearchers(e.g.Hyettetal.,1992;Itoetal.,2001;Reichertetal.,1991andStillborg,1984).Rockboltbindstogetheralaminated,discontinued,fracturedandjointedrockmass.Rockboltingnotonlystrengthensorstabilizesajointedrockmass,butalsohasamarkedeffectontherockmassstiffness(Chappell,1989).Rockboltsperformtheirtaskbyoneoracombinationofseveralmechanisms.Boltsoftenacttoincreasethestressandthefrictionalstrengthacrossjoints,encouraginglooseblocksorthinlystratifiedbedstobindtogetherandactasacompositebeam(FranklinandDusseault,1989).Rockboltsreinforcerockthroughafrictioneffect,throughasuspensioneffect,oracombinationoftwo.Forthisreason,rockbolttechniqueisacceptableforstrengtheningofmineroadwayandtunnellinginalltypeofrock(PanekandMcCormick,1973).Generallyrockboltscanbeusedtoincreasethesupportoflowforcesduetothediameterandthestrengthoftheboltmaterials.Theyenablehighanchoringvelocitytobeusedatcloserspacingbetweenbolts.Theirdesignprovideseithermechanicalclampingorcementgroutingagainsttherock(AldorfandExner,1986).Anchoragesystemofrockboltisnormallymadeofsolidortubeformedsteelinstalleduntensionedortensionedintherockmass(Stillborg,1986).Rockboltscanbedividedintothreemaingroupsaccordingtotheiranchoragesystems(FranklinandDusseault,1989;AldorfandExner,1986;HoekandWood,1989;CybulskiandMazzoni,1989).Firstgroupisthemechanicallyanchoredrockboltsthatcanbedividedintotwogroups:slitandwedgetyperockbolt,expansionshellanchor.Theycanbefixedintheanchoringparteitherbyawedge-shapedclampingpartorbyathreadedclampingpart.Secondgroupisthefriction-anchoredrockboltsthatcanbesimplydividedintotwogroups:split-setandswellex.Friction-anchoredrockboltsstabilisetherockmassbyfrictionoftheoutercoveringofboltagainstthedrillholeside.Thelastgroupisthefullygroutedrockboltsthatcanalsobedividedintotwogroups:cement-groutedrockbolts,resingroutedrockbolts.Agroutedrockbolt(dowel)isafullygroutedrockboltwithoutmechanicalanchor,usuallyconsistingofaribbedreinforcingbar,installedinadrillholeandbondedtotherockoveritsfulllength(FranklinandDusseault,1989).Specialattentionshouldbepaidtocement-groutedboltsandboltsbonded(glued,resined)bysyntheticsresinsforboltadjustment.Groutedboltsfixtheusingofthecoherenceofthesealingcementwiththeboltrodandtherockforfasteningthebolts.Syntheticresin(resinedbolt)andcementmortar(reinforced-concretebolt)canbeusedforthistyperockbolt.Theseboltsmaybeanchoredinalltypeofrock.Anchoringrodsmaybemanufacturedofseveralmaterialssuchasribbedsteelrods,smoothsteelbars,cableboltsandotherspecialfinish(AldorfandExner,1986).Groutedboltsarewidelyusedinminingforthestabilisationoftunnelling,miningroadway,driftsandshaftsforthereinforcingofitsperipheries.Simplicityofinstallation,versatilityandrelativelylowcostofrebarsarefurtherbenefitsofgroutedboltsiscomparisontotheiralternativecounterparts(IndraratnaandKaiser,1990).Boltsareself-tensioningwhentherockstartstomoveanddilate.Theyshouldthereforebeinstalledassoonaspossibleafterexcavation,beforetherockhasstartedtodeform,andbeforeithaslostitsinterlockingandshearstrength.Althoughseveralgrouttypesareavailable,inmanyapplicationswheretherockhasameasureofshorttermstability,simplePortlandcement-groutedreinforcingdowelsaresufficient.Theycanbeinstalledbyfillingthedrillholewithlean,quicklysetmortarintowhichthebarisdriven.Thedowelisretainedinupholeseitherbyacheapformofendanchor,orbypackingthedrillholecollarwithcottonwaste,steelwool,orwoodenwedges(FranklinandDusseault,1989).Concretegroutedboltsusecementmortarasabondingmedium.Indrillholesatminimumof158belowthehorizontalplane,themortarcansimplypouredin,whereasinraisingdrillholesvariousdesignofboltsorotherequipmentisusedtopreventthepumpedmortarfromflowingout(AldorfandExner,1986).Theloadbearingcapacityoffullycement-groutedrockboltsdependsontheboltshape,theboltdiameter,theboltlength,rockandgroutstrength.Thebondstrengthoffullycement-groutedrockboltsisprimarilyfrictionalanddependsontheshearstrengthatthebolt–groutorgrout–rockinterface.Thusanychangesinthisinterfacesshearstrengthmustaffecttheboltbondstrengthandboltloadcapacity.Thislaboratorytestingprogramwasexecutedtoevaluatetheshearstrengtheffectonthebondstrengthofthebolt–groutinterfaceofathreadedbarandthelaboratorytestresultsconfirmthetheory.2.PrevioussolutionsTheeffectivenessofagroutedboltdependsonitslengthrelativetotheextentofthezoneofoverstressedrockoryieldzone.Theshearandaxialstressdistributionsofagroutedboltarealsorelatedtotheboltlengthbecauseequilibriummustbeachievedbetweentheboltandthesurroundingground(IndraratnaandKaiser,1990).Bearingcapacitiesofcement-groutedrockbolts(Pb)andtheiranchoringforcesareafunctionofthecohesionofthebondingagentandsurroundingrock,andtheboltingbar.Theultimatebearingcapacityofthebolt(Pm)isexpressedasfollows(AldorfandExner,1986): (1)wherekb,safetycoefficient(usuallykb=1.5);C1,cohesionofthebondingmaterialonboltingbar,ld,anchoredlengthofthebolt,ds,boltdiameter. (2)wheredv,drillholediameter；C2,cohesionofthebondingmaterialwithsurroundingrock(carboniferousrocksandpolyesterresinsC2=3MPa). (3)whereC3,shearingstrengthofthebondingmaterial.Themaximum(ultimate)bearingcapacityofthebolt(Pm)willbethelowestvaluefromP1toP111.Bearingcapacitiesofalltypeboltsmustalsobeevaluatedfromtheviewpointofthetensilestrengthoftheboltmaterial(Pms),whichmustnotbelowerthantheultimatebearingcapacityresultingfromtheanchoringforcesofboltsindrillholes(Pm).Itholdsthat(4)wherePms,theultimatebearingcapacityoftheboltwithrespectofthetensilestrengthoftheboltmaterial;Pm,theultimatebearingcapacityofthebolt.3.Laboratorystudy3.1.ExperimentsThepull-outtestswereconductedonrebars,groutedintobasaltblockswithcementmortarinlaboratory.Therelationsbetweenboltdiameter(db)andpull-outloadofbolt(Pb)(Fig.2),boltarea(Ab)andpull-outloadofbolt(Pb)(Fig.3),boltlength(Lb)andpull-outloadofbolt(Pb)(Fig.5),watertocementratio(w/c)andboltbondstrength(τb)(Fig.7),mechanicalpropertiesofgroutmaterialandboltbondstrength(τb)(Fig.9,Figs.10and11),andcuringtime(days)andboltstrength(Figs.12and13)wereevaluatedbysimplepull-outtestprogramme.Thesamplesconsistedofrebars(ranging10–18mmdiameterstwobytwo)bondedintothebasaltblocks.ThesebasaltblocksusedhaveaYoung’smodulusof27.6GPaandauniaxialcompressivestrength(UCSg)of133MPa.Drillingholeswhichwere10mmlargerthantheboltdiameter,havingadiameterof20–28mmforinstallationofbolts,weredrilledupto15–32cmindepth.Theboltwasgroutedwithcementmortar.ThegroutwasamixtureofPortlandcementwithawatertocementratioof0.34,0.36,0.38and0.40curedfor28days.Inordertoobtaindifferentgrouttypesthathavedifferentmechanicalproperties,siliceoussand<100μm;500μm>andflyash<10μm;200μm>wereaddedinaproportionof10%ofcementweightandwhitecementwithawatertocementratioof0.40.Thesandshouldbewellgraded,withamaximumgrainsizeofv2mm(Schacketal.,1979).TheYoung’smodulusofthegroutswasmeasuredduringunconfinedcompressiontestsandshearstrengthwascalculatedbymeansofringsheartests.Thetestset-upisillustratedschematicallyinFig.1andtheprocedureisexplainedbelow:1.Afterfillingpreparedgroutmortarintothehole,boltisinsertedtothecentreofdrillinghole.2.Aftercuringtime,therebarsintherockwereaxiallyloadedandtheloadwasgraduallyincreaseduntiltheboltfailed.3.Thebondstrength(τb)wasthencalculatedbydividingtheload(Pb)bysurfacearea(Ab)oftheboltbarincontactwiththegrout.4.Pull-outtestswererepeatedforvariousgrouttypes,boltdimensionsandcuringtimes.Theinfluenceoftheboltdiameterandthebondareaonthebondstrengthofarockboltcanbeformulatedasfollows(LittlejohnandBruce,1975):(5)whereτb,ultimateboltbondstrength(MPa);Pb,maximumpull-outloadofbolt(kN);db,boltdiameter(mm);lb,boltlength(cm);πdblb,bondedarea(cm2).3.2.Analysisoflaboratorytestresults3.2.1.Infl uenceoftheboltmaterialBoltdiametersof10,12,14,16and18mmwereusedinpull-outtests.TypicalresultsarerepresentedinTable1,Figs.2and3.Themostimportantobservationswere: (1)Themaximumpull-outload(Pb)increaseslinearlywiththesectionoftheboltwhileembedmentlengthwasconstant.(2)Boltsectiondependsuponboltdiameter.Therelationbetweenboltdiameterandboltbearingcapacitycanbeexplainedasfollowempiricformulae(Fig.2).(6)(3)Thevaluesofboltbondstrengthwerecalculatedbetween5.68and5.96MPa(Table1).Boltlengthsof15.0,24.7,27.0,30.0and32.0cmwereusedinpull-outtestsasseeninFig.4.TypicalresultsarerepresentedinTable2,andFigs.5and6.Themostimportantobservationswere:(1)Thepull-outforceofaboltincreaseslinearlywiththeembeddedlengthofthebolt.(7)(2)Maximumpull-outstrengthofaboltislimitedtotheultimatestrengthoftheboltshank.3.2.2.InfluenceofgroutingmaterialThewatertocementratioshouldbenogreaterthan0.40byweight;toomuchwatergreatlyreducesthelong-termstrength.Because,partofthemixingwaterisconsumedbythehydrationofcementused.Restofthemixingwaterevaporatesandthencapillaryporositiesexistwhichresultsinunhomogenitiesinternalstructureofmortar.Thus,thisstructurereducesthelong-termstrengthbyirregularstressdistribution(Neville,1963;Atis,1997).Toobtainaplasticgrout,bentonitclaycanbeaddedinaproportionofupto2%ofthecementweight.Otheradditivescanacceleratethesetting-time,improvethegroutfluidityallowinginjectionatlowerwatertocementratios,andmakethegroutexpandandpressurizethedrillhole.Additives,ifusedatall,shouldbeusedwithcautionandinthecorrectquantitiestoavoidharmfulsideeffectsuchasweakeningandcorrosion(FranklinandDusseault,1989).Thewatertocementratio(w/c)ingroutingmaterialsconsiderablyaffectspull-outstrengthofbolt.AsseeninTable3,UCSgandshearstrength(tg)ofgroutinhighw/cratioshowlowervalueswhereasinloww/cratiohighervalues.Theratiobetween0.34and0.40presentsquitegoodresults.Althoughthew/cratioof0.34givesthebestbondstrength,groutibility(pumpability)decreasesandanumberofdifficultiesinapplicationappear.Inhighw/cratio,thepumpabilityofgroutingmaterialsintothedrillingholeiseasybutthebondstrengthofboltdecreases(Figs.7and8).Thebondstrengthoffullycement-groutedrockboltsisprimarilyfrictionalanddependsontheshearstrengthatthebolt–groutorgrout–rockinterface.Thusanychangeinthisshearstrengthofinterfacesaffectstheboltbondstrengthandloadcapacity.Theinfluencesofmechanicalpropertiesofgroutingmaterialsonthebearingcapacityofboltcanbedescribedasfollows:(1)Theuniaxialcompressiveandshearstrengthofthegroutingmaterialshasanimportantroleonthebehaviourofrockbolts.ItwasobservedthatincreasingshearstrengthofthegroutingmateriallogarithmicallyincreasesboltbondstrengthasshowninTable4andFig.9.Therelationbetweengroutshearstrengthandboltbondstrengthwasformulatedasfollows:(8)(2)Table4andFig.10showthatincreasinggroutcompressivestrengthconsiderableincreasesthebondstrengthofthegroutedbolts.(9)(3)InFig.11andTable4showthatthereisanotherrelationshipbetweenYoung’smodulusofgroutandboltbondstrength.IncreasingtheYoung’smodulusincreasesboltbondstrength.(10)3.2.3.InfluenceofthecuringtimeAnimportantproblemintheapplicationofcementgroutedboltsisthesettingtimeofthemortar,whichstronglyaffectsthestabilizingabilityofbolt.Cementgrouteddowelscannotbeusedforimmediatesupportbecauseofthetimeneededforthecementtosetandharden(FranklinandDusseault,1989).Inthepull-outtests,eightgroupofboltshavingsamelengthandmortarwithawatertocementratioof0.4wereusedfordeterminingtheeffectsofcuringtimeontheboltbondstrength.Eachgroupofrockbolttestingwasperformedafterdifferentsettingtimes(Table5).AscanbeseeninFigs.12and13,thestrengthofboltbondincreasesrapidlyin7daysduetocuringtime.However,thebondstrengthofboltcontinuestoincreaseratherslowlyafter7days.Rockboltsmaylosetheirsupportingabilitybecauseofyieldingofboltmaterial,failureatthebolt–groutorgrout–rockinterface,andunravellingofrockbetweenbolts.However,laboratorytestsandfieldobservationssuggestthatthemostdominantfailuremodeisshearatthebolt–groutinterface(HoekandWood,1989).So,thislaboratorystudyfocussedontheinterfacebetweenrockboltandrockandthemechanicalpropertiesofgroutingmaterials.4.ConclusionsThelaboratoryinvestigationshowedthattheboltcapacitydependsbasicallyonthemechanicalpropertiesofgroutingmaterialswhichcanbechangedbywatertocementratio,mixingtime,additives,andcuringtime.Increasingtheboltdiameterandlengthincreasestheboltbearingcapacity.However,thisincreaseislimitedtotheultimatetensilestrengthoftheboltmaterials.Mechanicalpropertiesofgroutingmaterialshaveanimportantroleontheboltbearingcapacity.Itisofferedthattheoptimumwatertocementratiomustbe0.34~0.4andthemortarhavetobewellmixedbeforepouredintodrillhole.Improvingthemechanicalpropertiesofthegroutingmaterialincreasestheboltbearingcapacitylogarithmically.Thebestrelationshipwasobservedbetweengroutshearstrengthandboltbondstrength.Increasingthecuringtimeincreasestheboltbondstrength.Boltbondstrengthof19kg/cm2infirstday,77kg/cm2in7daysand86kg/cm2in35dayswasdeterminedrespectively.Theresultsshowthatboltbondstrengthincreasesquicklyinfirst7daysandthentheincreasegoesupslowly.Bondfailureinthepull-outtestoccurredbetweentheboltandcementgrout,ofwhichthemechanicalbehaviourisobservedbyshearspring.Thisexplainsthedevelopmentofboltbondstrengthandthefailureatthebolt–groutinterfaceconsideringthatthebondstrengthiscreatedasaresultofshearstrengthbetweenboltandgrout.Thismeansthatanychangeatthegroutstrengthcausestothechangingofboltcapacity.Thefailuremechanisminapull-outtestwasstudiedinordertoclarifythebondeffectofrockbolt.Thusonemainbondeffectwasexplainedfrombondstrengthofrockbolts.

中文翻譯水泥漿性能對充分注漿錨桿拉拔承載力的影響A.K?l?c,E.Yasar*,A.G.Celik摘要：本文代表了一項在安全、實用、經(jīng)濟的支持系統(tǒng)指導下的工程結果。在巖石工程中，沒有被拉緊的且被水泥充分注漿的錨桿已使用多年。然而，對錨桿的作用過程和其拉拔載荷的能力，以及錨桿注漿或注漿的關系，水泥性能對充分注漿錨桿拉拔承載力的影響研究卻很少。為了評估錨桿支護效果，我們開始對水泥性能對最終錨桿在拉拔試驗載荷能力的影響進行了研究。大約80個針對玄武巖塊的錨桿拉拔試驗實驗室已開始進行研究以用來解釋和發(fā)展注漿材料和松弛的充分注漿錨桿之間的聯(lián)系。這種注漿材料的力學性能對一個完全錨桿拉拔承載力的力學性能的影響已被數(shù)量化，而且，為了計算充分注漿錨桿的承載能力，在考慮剪切強度，注漿材料的單軸抗壓強度，錨桿長度，錨桿直徑，粘結面積及注漿材料固化時間的基礎上，一些經(jīng)驗公式已被提出和不斷的發(fā)展。關鍵詞：錨桿；注漿材料；錨桿拉拔承載能力；錨桿幾何形狀；砂漿1引言在巖土工程中，錨桿已多年被用來穩(wěn)定開口。該錨桿支護系統(tǒng)可通過阻止接縫處移動，迫使巖塊支持其本身來提高巖體抗擾動能力(Kaiseretal.,1992)。對這樣的巖錨支護效果已被許多研究者討論過(e.g.Hyettetal.,1992;Itoetal.,2001;Reichertetal.,1991andStillborg,1984)。巖錨和承受層壓的，不連續(xù)的，有裂隙和節(jié)理的巖體結合在一起。錨桿支護不僅加強或穩(wěn)定節(jié)理巖體，同時也對巖體剛度有著顯著的影響(Chappell,1989)。錨桿的支護效果一個或幾個機制相結合來實現(xiàn)的。錨桿通常作為一個組合梁來增加應力和節(jié)理處的摩擦強度，固定松散巖塊或分層巖床(FranklinandDusseault,1989)。錨桿加固巖石是通過巖石間的摩擦作用，懸吊形態(tài)，或摩擦作用和懸吊兩者兼有而實現(xiàn)的?；谶@個原因，錨桿技術在支護巷道方面的應用可以適用所有巖石類型的(PanekandMcCormick,1973)。一般來說錨桿可用于增加由于直徑低勢力的支持和錨桿材料的強度。它們使高速貼壁將在更緊密的錨桿間距使用。他們的設計可以用來機械夾緊或對巖石進行水泥注漿(AldorfandExner,1986)。錨桿錨固系統(tǒng)通常是指固體或管狀型鋼安裝在松散或堅實巖體中(Stillborg，1986年)。按照其錨固系統(tǒng)，錨桿可分為三個主要類型(FranklinandDusseault,1989;AldorfandExner,1986;HoekandWood,1989;CybulskiandMazzoni,1989)。第一類是機械巖錨，它可以分為兩類：楔縫式錨桿，外殼膨脹錨桿。它們被安裝在錨桿上的一部分，具體是在楔形夾緊的錨桿螺紋部分或者是夾緊部分。第二類是摩擦巖錨，它可以簡單地分為兩類：分節(jié)錨桿和膨脹錨桿分為錨桿。摩擦錨桿錨固巖體是由外露錨桿和鉆孔的摩擦力完成的。最后一類是充分注漿錨桿，它也可分為兩小類：水泥注漿錨桿，樹脂錨桿。注漿錨桿(樁)是一種無機械錨定，通常包括一個帶肋鋼筋，該鋼筋被安裝在一個鉆孔里面并和超過其全長的巖體結合(FranklinandDusseault,1989)。特別要注意的是水泥注漿錨桿和螺栓(膠合，樹脂)是根據(jù)合成樹脂錨桿適當調(diào)整固定的。錨固螺栓要與連桿螺栓和水泥的密封粘結以及用來拴緊螺栓的巖體相適應。合成樹脂(樹脂錨桿)和水泥砂漿(鋼筋混凝土錨桿)可以為這種類型的錨桿使用。這些錨定錨桿可以被固定在所有類型巖石中。錨定桿體可以用多種材料制造，如帶肋鋼筋，光面鋼筋，錨索和其他特殊處理的材料(AldorfandExner,1986)。注漿錨桿廣泛應用于礦井中的掘進，巷道，平巷和井筒的支護和加強其外圍的穩(wěn)定性。與其它替代品相比較，注漿錨桿安裝的簡單性，多功能性和相對低成本性則會取得更多的效益(IndraratnaandKaiser,1990)。當巖石開始移動和擴張時，錨桿會自動拉緊。因此，在開鑿巷道后，巖體開始變形和已經(jīng)失去聯(lián)動性和剪切強度之前要盡快安裝這些錨桿。雖然只有幾種水泥漿類型可以適用，但是在現(xiàn)場許多應用中這些類型水泥漿已經(jīng)足夠，例如在被測得有短暫穩(wěn)定期，用簡單的波特蘭水泥注漿加固銷釘措施的巖體中應用。通過傾斜著向鉆孔里面快速注滿灰泥漿，它們可以被安裝在已經(jīng)拉緊的桿體中。保留的銷子最終以簡單的形式形成了錨孔，或用棉花包裝廢棄物，鋼絲絨，或木楔子(FranklinandDusseault,1989)。混凝土錨桿是用水泥砂漿作為粘結介質。在最低低于水平面158的鉆孔里面，砂漿很容易注入，然而在逐漸升高鉆洞中，各種錨桿或其他設備的設計則會用來防止水泥砂漿流出的(AldorfandExner,1986)。充分水泥注漿錨桿承載能力取決于錨桿直徑，錨桿長度，巖石和水泥漿的強度。這種充分注漿錨桿的錨固強度最初是靠摩擦力的，因此是取決于錨桿和水泥，水泥和巖體兩個層面的剪切強度。因此，在這個界面的剪切強度的任何變化都將影響錨桿的錨固力和其承載能力。實施實驗室的測試方案的目的是評估在水泥注漿錨桿和錨桿界面上剪切強度的變化對錨固力的影響，并且該實驗測試結果證實了這一理論。2解決方案相對于過分受壓區(qū)或屈服區(qū)的巖體來說，一個錨桿的有效性取決于其長度。一個錨桿剪切應力和軸向應力的分布，也關系到有效錨桿長度，因為應力平衡必須由錨桿和圍巖共同實現(xiàn)的(IndraratnaandKaiser,1990)。水泥注漿錨桿(Pb)的承載能力，錨固力是其粘結劑的凝聚力，圍巖和錨桿桿體的函數(shù)。從而得到最終的錨桿(Pm)承載能力公式，表示如下(AldorfandExner,1986)：(1)式中kb是安全系數(shù)(通常取1.5)；C1作用在錨桿上的粘結材料的粘結力；ld，錨桿長度；ds錨桿直徑。(2)式中dv，鉆孔直徑，C2,粘合材料與圍巖之間的凝聚力(C2=3MPa)(3)式中C3為粘結材料的剪切強度。螺栓的最大承載能力將是從P1到P111的最低值所有類型的錨桿承載能力都必須從錨桿材料的拉伸強度(Pms)的角度進行評估，且由于錨桿在鉆孔中的錨固力，這種拉伸強度必須不得超過極限承載力。它認為：(4)式中Pms,考慮到錨桿材料抗拉強度時的極限承載能力；Pm，錨桿的極限承載能力。3實驗室研究3.1實驗拉拔試驗是在實驗室被水泥砂漿玄武巖塊注漿的鋼筋進行的。通過簡單的拉拔試驗方案我們評估了錨桿直徑(db)和錨桿拉應力(以Pb計)(圖2)，錨桿面積(Ab)和錨桿拉應力(Pb)(圖3)，錨桿長度(Lb)和錨桿拉應力(Pb)(圖5)，水灰比(w/c)和錨桿粘結強度(τb)(圖7)，注漿材料的機械性能和錨桿粘結強度(τb)(圖9，圖10和11)，固化時間(天)和錨桿強度(圖12和13)之間的關系。這些樣本包括了和玄武巖巖塊固結在一起的鋼筋(成對的直徑在10-18mm)。所用的這些玄武巖塊的楊氏模量是27.6GPa和單軸抗壓強度133兆帕(UCSg)。鉆孔的深度是15-32cm，并要求鉆孔的直徑是20-28cm，比錨桿直徑大10mm。錨桿被水泥砂漿注漿。該水泥漿是各種不同水灰比的硅酸鹽水泥混合組成的，不同的水灰比有0.34,0.36,0.38和0.40，凝結時間為28天。為了獲得具有不同的力學性能不同類型的水泥漿，將<500μm，>100μm的硅質砂；粉煤灰>10μm，<200μm加入到水泥重量占10%，水灰比為0.40的白水泥漿中。沙粒應很好的分級，最大晶粒尺寸為2毫米(施克等人，1979)。楊氏模量的測量是在無限壓縮試驗中進行，同時抗剪強度是由環(huán)刀試驗方法計算。該試驗的圖解說明如圖1。程序說明如下：(1)在將水泥砂漿注入鉆孔之后，錨桿被插入到鉆孔中心。(2)過了凝結時間后，在巖體中的鋼筋承受軸向載荷，逐漸加大載荷直到錨桿被拉斷(3)負載(Pb)除以注漿錨桿接觸表面積(Ab)計算得到粘結強度(tb)。(4)以不同類型的水泥漿，錨桿尺寸和固化時間重復拉拔試驗。錨桿直徑和粘結面積對錨桿粘結強度的影響可以公式化，公式如下(利特爾約翰和Bruce，1975)：(5)式中，τb為錨桿極限承載力(MPa)；Pb為錨桿承受的最大載荷(kN)；lb錨桿長度(cm