隧道施工項目六支護施工43課件

任務二襯砌施工Task2Liningconstructio——仰拱施工UpwardarchconstructionTunnelconstruction

隧道施工

項目六支護施工Project6Supportconstruction學習目標Learningobjectives知識目標Knowledgeobjectives能力目標Competencyobjectives通過本任務的學習，學生應理解仰拱的概念、掌握仰拱的作用、掌握仰拱施工流程、掌握仰拱施工質量控制要點。Throughthestudyofthistask,studentsshouldunderstandtheconceptofthearch,mastertheroleofthearch,mastertheconstructionprocessofthearch,andmasterthekeypointsofthequalitycontrolofthearch.通過本任務的學習，學生應能初步具備組織仰拱施工及控制拱墻施工質量的能力。Throughthestudyofthistask,studentsshouldbeabletoinitiallyhavetheabilitytoorganizetheconstructionofthearchandcontroltheconstructionqualityofthearchwall.1.仰拱的概念Theconceptofthesupinearch仰拱是為改善上部支護結構受力條件而設置在隧道底部的反向拱形結構，是隧道結構的重要組成部分之一，它是隧道結構的基礎。它一方面要將隧道上部的地層壓力通過隧道邊墻結構或將路面上的荷載有效的傳遞到地下，而且還有效的抵抗隧道下部地層傳來的反力。Thebackarchisareversearchstructuresetatthebottomofthetunneltoimprovethestressconditionsoftheuppersupportstructure,whichisoneoftheimportantcomponentsofthetunnelstructure,whichisthefoundationofthetunnelstructure.Ontheonehand,itmusteffectivelytransmittheformationpressureoftheupperpartofthetunnelthroughthetunnelsidewallstructureortheloadontheroadsurfacetotheground,andalsoeffectivelyresistthereactionforcetransmittedbythelowerformationofthetunnel.1.仰拱的概念Theconceptofthesupinearch實際上他是能承受地層永久荷載和路面臨時荷載（動荷載）的一種地基梁。仰拱與二次襯砌構成隧道整體，增加結構穩(wěn)定性。Infact,itisafoundationbeamthatcanwithstandpermanentloadsontheformationandtemporaryloadsontheroadsurface(dynamicloads).Thebackarchandsecondaryliningformthewholeofthetunnelandincreasestructuralstability.1.仰拱的概念Theconceptofthesupinearch2.仰拱的作用Theroleofthearch1、解決基礎承載力不夠，減少地表下沉，防止底鼓的隆起變形，調整襯砌應力；Solvetheinsufficientbearingcapacityofthefoundation,reducethesurfacesinking,preventtheupliftdeformationofthebottomdrum,andadjusttheliningstress;

2、封閉圍巖，阻止圍巖過大的變形，提高結構整體的承載力；2.Closethesurroundingrocktopreventtheexcessivedeformationofthesurroundingrockandimprovethebearingcapacityofthestructureasawhole;3、增加底部和墻部的支撐抵抗力，防止內擠而產生剪力破壞。Increasesthesupportresistanceofthebottomandwallstopreventsheardamagecausedbyinternalsqueezing.3.仰拱施工工藝流程Upwardarchconstructionprocess1.搭建仰拱棧橋Erectanarchedtrestle棧橋的搭建要注意安設的平整及安設寬度，保證車輛行車安全及不同施工車輛順利通過。Theconstructionofthetrestleshouldpayattentiontotheflatnessandwidthoftheinstallationtoensurethesafetyofvehiclesandthesmoothpassageofdifferentconstructionvehicles.棧橋一側搭設在已完成仰拱回填和底板施工部位，另一側搭設在原地面上，棧橋搭設應考慮棧橋承載力，根據不同地質條件對棧橋基礎進行加固。

Onesideofthetrestleiserectedinthecompletedarchbackfillandthebottomplateconstructionsite,andtheothersideiserectedonthegroundsurface,andthetrestleerectionshouldconsiderthebearingcapacityofthetrestle,andthetrestlefoundationshouldbereinforcedaccordingtodifferentgeologicalconditions.3.仰拱施工工藝流程Upwardarchconstructionprocess2開挖Excavation仰拱土質地層開挖應以輔以機械配合，人工開挖為主；對土石開挖，必須控制開挖長度，爆破作業(yè)時避免開挖震動對已形成的襯砌等結構物造成影響，并盡可能的控制超挖和欠挖，仰拱斷面開挖后應立即檢查，不足部分需重新開挖，以保證仰拱厚度；隧道仰拱開挖應平順，避免引起應力集中。Excavationofthearchsoiltextureshouldbesupplementedbymechanicalcooperation,andmanualexcavationisthemainstay;Forsoilandstoneexcavation,theexcavationlengthmustbecontrolled,andtheexcavationvibrationmustbeavoidedduringtheblastingoperationtoaffecttheformedliningandotherstructuralobjects,andasfaraspossibletocontrolover-excavationandunder-excavation,thearchsectionshouldbecheckedimmediatelyafterexcavation,andtheinsufficientpartneedstobere-excavatedtoensurethethicknessofthearch;Tunnelarchexcavationshouldbesmoothtoavoidcausingstressconcentration.3.仰拱施工工藝流程Upwardarchconstructionprocess3初期支護及二襯鋼筋預埋Initialsupportandrebarembedding（1）仰拱開挖和仰拱初期支護應銜接緊密，在設置鋼拱架前，應在基地鋪設5-10cm低標號混凝土墊層，再安裝仰拱鋼架，然后噴射混凝土或采用模筑混凝土，便于進行仰拱鋼筋安裝及安裝模板等工序；Theexcavationofthebackarchandtheinitialsupportofthebackarchshouldbecloselyconnected,beforesettingupthesteelarchframe,a5-10cmlow-gradeconcretecushionshouldbelaidonthebase,andthenthesteelframeofthebackarchshouldbeinstalled,andthentheconcreteshouldbesprayedormoldedconcreteshouldbeusedtofacilitatetheinstallationofthebackarchsteelbarandtheinstallationoftheformwork;3.仰拱施工工藝流程Upwardarchconstructionprocess3初期支護及二襯鋼筋預埋Initialsupportandrebarembedding（2）仰拱鋼支撐安裝必須符合設計及規(guī)范要求，且與邊墻拱架焊接暢牢固；(2)Theinstallationofthebackarchsteelsupportmustmeetthedesignandspecificationrequirements,andtheweldingwiththesidewallarchframeissmoothandfirm;（3）仰拱兩側二襯邊墻部位的預埋鋼筋伸出長度應滿足與環(huán)向二襯鋼筋焊接的要求，且將接頭錯開，使同一截面的鋼筋接頭數(shù)不大于總數(shù)的百分之五十，仰拱二襯鋼筋的綁扎必須保證間距，通過焊接定位鋼筋來保證層間距。(3)Thelengthoftheembeddedreinforcementextensionofthetwo-linedsidewallonbothsidesofthearchshouldmeettherequirementsofweldingwiththeannulartwo-linedsteelbar,andthejointsshouldbestaggered,sothatthenumberofsteeljointsinthesamesectionisnotmorethan50%ofthetotal,andthelashingofthetwo-linedsteelbarofthearchmustensurethespacing,andthelayerspacingisensuredbyweldingandpositioningthesteelbar.3.仰拱施工工藝流程Upwardarchconstructionprocess3.仰拱施工工藝流程Upwardarchconstructionprocess4仰拱澆筑Arched仰拱澆筑前應嚴格論證混凝土配合比，使用預留振搗孔的頂模施工以保證混凝土振搗密實，仰拱混凝土可采用泵送混凝土澆筑；Beforetheconstructionofthearch,thepositionoftherecessedsettlementjointshouldbedesignedinadvance,andthesettlementjointshouldensurethatthetwo-linedconcrete,thearchwall,andthearcharedisconnectedinthesameverticalstraightplane,andthesettlementjointshouldbetreatedaccordingtotherequirementstoensurethequalityoftheconstruction,andintheareawherethesurroundingrockdoesnotchangemuch,aslittleornoexpansionjointaspossibletoensurethattheliningdoesnothaveanti-drainageproblems.3.仰拱施工工藝流程5.仰拱填充澆筑Upwardarchfillingpouring仰拱回填應在仰拱混凝土達到設計值得70%后開始施工。Thebackslidingofthearchshouldbeginafterthebacksliderconcretereaches70%ofthedesignvalue.3.仰拱施工工藝流程Upwardarchconstructionprocess6施工縫及變形縫處理Constructionjointsanddeformationjointstreatment施工縫應將其表面浮漿和雜物清楚干凈，刷不低于結構混凝土強度等級的凈漿或涂混凝土截面處理劑，及時澆筑混凝土，施工縫應用模板或者其他措施，形成預定的形狀，以保證后續(xù)工程緊密連接Theconstructionjointshouldbeclearandcleanofthesurfacefloatingslurryanddebris,brushthenetslurryorcoattheconcretesectiontreatmentagentthatisnotlowerthanthestrengthlevelofthestructuralconcrete,pourtheconcreteintime,andapplytheformworkorothermeasurestoformapredeterminedshapetoensurethatthefollow-upprojectiscloselyconnected3.仰拱施工工藝流程Upwardarchconstructionprocess6施工縫及變形縫處理Constructionjointsanddeformationjointstreatment4.仰拱施工注意事項Precautionsfortheconstructionofthearch仰拱應及時盡早施工，以實現(xiàn)支護結構早閉合；Thearchshouldbeconstructedintimeandasearlyaspossibletoachieveearlyclosureofthesupportingstructure;仰拱施工時必須使用模板，保證混凝土的澆筑質量；Formworkmustbeusedduringtheconstructionofthearch