隧道施工项目六支护施工43课件

任务二衬砌施工Task2Liningconstructio——仰拱施工UpwardarchconstructionTunnelconstruction

隧道施工

项目六支护施工Project6Supportconstruction学习目标Learningobjectives知识目标Knowledgeobjectives能力目标Competencyobjectives通过本任务的学习，学生应理解仰拱的概念、掌握仰拱的作用、掌握仰拱施工流程、掌握仰拱施工质量控制要点。Throughthestudyofthistask,studentsshouldunderstandtheconceptofthearch,mastertheroleofthearch,mastertheconstructionprocessofthearch,andmasterthekeypointsofthequalitycontrolofthearch.通过本任务的学习，学生应能初步具备组织仰拱施工及控制拱墙施工质量的能力。Throughthestudyofthistask,studentsshouldbeabletoinitiallyhavetheabilitytoorganizetheconstructionofthearchandcontroltheconstructionqualityofthearchwall.1.仰拱的概念Theconceptofthesupinearch仰拱是为改善上部支护结构受力条件而设置在隧道底部的反向拱形结构，是隧道结构的重要组成部分之一，它是隧道结构的基础。它一方面要将隧道上部的地层压力通过隧道边墙结构或将路面上的荷载有效的传递到地下，而且还有效的抵抗隧道下部地层传来的反力。Thebackarchisareversearchstructuresetatthebottomofthetunneltoimprovethestressconditionsoftheuppersupportstructure,whichisoneoftheimportantcomponentsofthetunnelstructure,whichisthefoundationofthetunnelstructure.Ontheonehand,itmusteffectivelytransmittheformationpressureoftheupperpartofthetunnelthroughthetunnelsidewallstructureortheloadontheroadsurfacetotheground,andalsoeffectivelyresistthereactionforcetransmittedbythelowerformationofthetunnel.1.仰拱的概念Theconceptofthesupinearch实际上他是能承受地层永久荷载和路面临时荷载（动荷载）的一种地基梁。仰拱与二次衬砌构成隧道整体，增加结构稳定性。Infact,itisafoundationbeamthatcanwithstandpermanentloadsontheformationandtemporaryloadsontheroadsurface(dynamicloads).Thebackarchandsecondaryliningformthewholeofthetunnelandincreasestructuralstability.1.仰拱的概念Theconceptofthesupinearch2.仰拱的作用Theroleofthearch1、解决基础承载力不够，减少地表下沉，防止底鼓的隆起变形，调整衬砌应力；Solvetheinsufficientbearingcapacityofthefoundation,reducethesurfacesinking,preventtheupliftdeformationofthebottomdrum,andadjusttheliningstress;

2、封闭围岩，阻止围岩过大的变形，提高结构整体的承载力；2.Closethesurroundingrocktopreventtheexcessivedeformationofthesurroundingrockandimprovethebearingcapacityofthestructureasawhole;3、增加底部和墙部的支撑抵抗力，防止内挤而产生剪力破坏。Increasesthesupportresistanceofthebottomandwallstopreventsheardamagecausedbyinternalsqueezing.3.仰拱施工工艺流程Upwardarchconstructionprocess1.搭建仰拱栈桥Erectanarchedtrestle栈桥的搭建要注意安设的平整及安设宽度，保证车辆行车安全及不同施工车辆顺利通过。Theconstructionofthetrestleshouldpayattentiontotheflatnessandwidthoftheinstallationtoensurethesafetyofvehiclesandthesmoothpassageofdifferentconstructionvehicles.栈桥一侧搭设在已完成仰拱回填和底板施工部位，另一侧搭设在原地面上，栈桥搭设应考虑栈桥承载力，根据不同地质条件对栈桥基础进行加固。

Onesideofthetrestleiserectedinthecompletedarchbackfillandthebottomplateconstructionsite,andtheothersideiserectedonthegroundsurface,andthetrestleerectionshouldconsiderthebearingcapacityofthetrestle,andthetrestlefoundationshouldbereinforcedaccordingtodifferentgeologicalconditions.3.仰拱施工工艺流程Upwardarchconstructionprocess2开挖Excavation仰拱土质地层开挖应以辅以机械配合，人工开挖为主；对土石开挖，必须控制开挖长度，爆破作业时避免开挖震动对已形成的衬砌等结构物造成影响，并尽可能的控制超挖和欠挖，仰拱断面开挖后应立即检查，不足部分需重新开挖，以保证仰拱厚度；隧道仰拱开挖应平顺，避免引起应力集中。Excavationofthearchsoiltextureshouldbesupplementedbymechanicalcooperation,andmanualexcavationisthemainstay;Forsoilandstoneexcavation,theexcavationlengthmustbecontrolled,andtheexcavationvibrationmustbeavoidedduringtheblastingoperationtoaffecttheformedliningandotherstructuralobjects,andasfaraspossibletocontrolover-excavationandunder-excavation,thearchsectionshouldbecheckedimmediatelyafterexcavation,andtheinsufficientpartneedstobere-excavatedtoensurethethicknessofthearch;Tunnelarchexcavationshouldbesmoothtoavoidcausingstressconcentration.3.仰拱施工工艺流程Upwardarchconstructionprocess3初期支护及二衬钢筋预埋Initialsupportandrebarembedding（1）仰拱开挖和仰拱初期支护应衔接紧密，在设置钢拱架前，应在基地铺设5-10cm低标号混凝土垫层，再安装仰拱钢架，然后喷射混凝土或采用模筑混凝土，便于进行仰拱钢筋安装及安装模板等工序；Theexcavationofthebackarchandtheinitialsupportofthebackarchshouldbecloselyconnected,beforesettingupthesteelarchframe,a5-10cmlow-gradeconcretecushionshouldbelaidonthebase,andthenthesteelframeofthebackarchshouldbeinstalled,andthentheconcreteshouldbesprayedormoldedconcreteshouldbeusedtofacilitatetheinstallationofthebackarchsteelbarandtheinstallationoftheformwork;3.仰拱施工工艺流程Upwardarchconstructionprocess3初期支护及二衬钢筋预埋Initialsupportandrebarembedding（2）仰拱钢支撑安装必须符合设计及规范要求，且与边墙拱架焊接畅牢固；(2)Theinstallationofthebackarchsteelsupportmustmeetthedesignandspecificationrequirements,andtheweldingwiththesidewallarchframeissmoothandfirm;（3）仰拱两侧二衬边墙部位的预埋钢筋伸出长度应满足与环向二衬钢筋焊接的要求，且将接头错开，使同一截面的钢筋接头数不大于总数的百分之五十，仰拱二衬钢筋的绑扎必须保证间距，通过焊接定位钢筋来保证层间距。(3)Thelengthoftheembeddedreinforcementextensionofthetwo-linedsidewallonbothsidesofthearchshouldmeettherequirementsofweldingwiththeannulartwo-linedsteelbar,andthejointsshouldbestaggered,sothatthenumberofsteeljointsinthesamesectionisnotmorethan50%ofthetotal,andthelashingofthetwo-linedsteelbarofthearchmustensurethespacing,andthelayerspacingisensuredbyweldingandpositioningthesteelbar.3.仰拱施工工艺流程Upwardarchconstructionprocess3.仰拱施工工艺流程Upwardarchconstructionprocess4仰拱浇筑Arched仰拱浇筑前应严格论证混凝土配合比，使用预留振捣孔的顶模施工以保证混凝土振捣密实，仰拱混凝土可采用泵送混凝土浇筑；Beforetheconstructionofthearch,thepositionoftherecessedsettlementjointshouldbedesignedinadvance,andthesettlementjointshouldensurethatthetwo-linedconcrete,thearchwall,andthearcharedisconnectedinthesameverticalstraightplane,andthesettlementjointshouldbetreatedaccordingtotherequirementstoensurethequalityoftheconstruction,andintheareawherethesurroundingrockdoesnotchangemuch,aslittleornoexpansionjointaspossibletoensurethattheliningdoesnothaveanti-drainageproblems.3.仰拱施工工艺流程5.仰拱填充浇筑Upwardarchfillingpouring仰拱回填应在仰拱混凝土达到设计值得70%后开始施工。Thebackslidingofthearchshouldbeginafterthebacksliderconcretereaches70%ofthedesignvalue.3.仰拱施工工艺流程Upwardarchconstructionprocess6施工缝及变形缝处理Constructionjointsanddeformationjointstreatment施工缝应将其表面浮浆和杂物清楚干净，刷不低于结构混凝土强度等级的净浆或涂混凝土截面处理剂，及时浇筑混凝土，施工缝应用模板或者其他措施，形成预定的形状，以保证后续工程紧密连接Theconstructionjointshouldbeclearandcleanofthesurfacefloatingslurryanddebris,brushthenetslurryorcoattheconcretesectiontreatmentagentthatisnotlowerthanthestrengthlevelofthestructuralconcrete,pourtheconcreteintime,andapplytheformworkorothermeasurestoformapredeterminedshapetoensurethatthefollow-upprojectiscloselyconnected3.仰拱施工工艺流程Upwardarchconstructionprocess6施工缝及变形缝处理Constructionjointsanddeformationjointstreatment4.仰拱施工注意事项Precautionsfortheconstructionofthearch仰拱应及时尽早施工，以实现支护结构早闭合；Thearchshouldbeconstructedintimeandasearlyaspossibletoachieveearlyclosureofthesupportingstructure;仰拱施工时必须使用模板，保证混凝土的浇筑质量；Formworkmustbeusedduringtheconstructionofthearch