主講曾紹武陜西鐵路工程第講支架現(xiàn)澆課件講解

主講：曾紹武

陜西鐵路工程職業(yè)技術學院第24講支架現(xiàn)澆法施工Lesson24Constructionwithcast-in-placesupportmethodSpeaker:ZengShaowuShaanxiRailwayEngineeringVocationalandTechnicalCollege任務導入

通過對現(xiàn)澆支架施工的學習，掌握現(xiàn)澆預應力混凝土梁的支架法施工工藝及注意事項．Bystudyingtheconstructionofcast-in-placebrackets,mastertheconstructionprocessandprecautionsofthebracketmethodforcast-in-placeprestressedconcretebeamsTaskImport能力目標能夠掌握支架類型適用條件目標１目標２能夠掌握支架施工工藝目標３能夠了解支架監(jiān)控要點支架現(xiàn)澆法施工CapabilityobjectivesAbletograsptheapplicableconditionsofbrackettypesAbletomastertheconstructionprocessofbracketsAbletounderstandthekeypointsofbracketmonitoringSupportcast-in-placeconstructionmethod任務1.支架現(xiàn)澆法適用條件任務2.支架的類型及適用條件任務3.支架法施工工藝及實施方案本節(jié)任務資訊Task1.Applicableconditionsforcast-in-placesupportmethodTask2.TypesandApplicableConditionsofSupportsTask3.Constructionprocessandimplementationplanofsupportmethod就地澆注施工是必須有的，在偏僻山區(qū)，大型吊裝設備不能就住的地方。變寬度橋、彎橋等復雜結構橋梁城市彎曲曲橋等不能用裝配法施工的，則采用支架現(xiàn)澆方法。非標準跨徑采用裝配法成本較高。Cast-in-placeconstructionisnecessary,asinremotemountainousareas,largeliftingequipmentcannotbeeasilyaccommodated.Forcomplexstructuralbridgessuchasvariablewidthbridgesandcurvedbridgesthatcannotbeconstructedusingassemblymethodsinurbancurvedbridges,thebracketcast-in-placemethodisused.Thecostofusingassemblymethodfornon-standardspansisrelativelyhigh.任務1.支架現(xiàn)澆法適用條件Task1.Applicableconditionsforcast-in-placesupportmethod

就地澆筑混凝土梁橋的上部結構，首先應在橋孔位置搭設支架，以支承模板、澆筑的鋼筋混凝土以及其他施工荷載的重力。Theupperstructureofcast-in-placeconcretebeambridgesshouldfirstbesupportedbybracketsatthebridgeopeningtosupportthegravityoftheformwork,pouredreinforcedconcrete,andotherconstructionloads.

支架support按其構造分Dividedbyitsstructure立柱式梁式梁式－立柱式按其材料分木支架鋼支架鋼木支架萬能桿件組拼支架

（備注：還應進行強度和穩(wěn)定性驗算）任務2.支架的類型及適用條件SPARTask2.TypesandApplicableConditionsofSupportsBeamtypeBeamcolumntypeAccordingtoitsmaterialclassificationsupportSteelBracketSteelandwoodbracketsUniversalrodassemblybracket任務2.支架的類型及適用條件子任務1.立柱式支架及適用條件子任務2.梁式支架及適用條件子任務3.梁柱式支架及適用條件Task2.TypesandApplicableConditionsofSupportsSubtask1.PillarSupportandApplicableConditionsSubtask2.BeamSupportandApplicableConditionsSubtask3.Beamcolumnsupportandapplicableconditions思考選擇合適的支架？

情境1（橋一）30+45+30m連續(xù)梁橋，雙圓柱橋墩柱高2-8m，直徑1.4m，橋下無水。

情境2（橋二15+25+15m連續(xù)梁橋，雙圓柱橋墩，墩高35-60m，直徑1.4m，橋下有水。情境3（橋三）：

45+80+45連續(xù)梁橋，雙柱矩形橋墩，墩高10-15m以上，直徑1.4m，橋下無水，主跨下有二級公路通過。Thinkaboutchoosingtheappropriatebracket?Scenario1(Bridge1)30+45+30mcontinuousbeambridge,doublecylindricalbridgeThepiercolumnis2-8mhighwithadiameterof1.4m,andthereisnowaterunderthebridge.Scenario2(BridgeII15+25+15mcontinuousbeambridge,doublecylindricalpier,Thepierhasaheightof35-60mandadiameterof1.4m,withwaterunderthebridge.Scenario3(Bridge3):45+80+45continuousbeambridge,doublecolumnrectangularBridgepier,withaheightof10-15mormoreandadiameterof1.4m,withoutwaterunderthebridge,Second-classhighwaypassesunderthemainspan.立柱式支架特點和適用條件：構造簡單，搭設拆卸均較方便。一般用于旱地或不通航河流及橋墩不高的情況。組成：支架整體由排架和縱梁組成，而排架由柱、樁和蓋梁組成。PillarbracketFeaturesandapplicationconditions:Simplestructure,easyinstallationanddisassembly.Generallyusedindryland,navigablerivers,andsituationswherebridgepiersarenothigh.Composition:Thebracketiscomposedofabentframeandlongitudinalbeams,whilethebentframeiscomposedofcolumns,piles,andcoverbeams.立柱式支架圖例:Legendofcolumnbracket:底座墊木和U型底托BasematandU-shapedbottomsupport特點和適用條件：根據跨徑的不同，梁可采用工字鋼、鋼板梁或鋼桁梁。組成：梁，預留托架。構造布置：工字鋼用于L≤10m，鋼板梁用于L≤20m，鋼桁梁用于L>20m。梁支承于墩旁支柱上，也可支承于橋墩的預留托架上。子任務2.梁式支架Characteristicsandapplicableconditions:Accordingtothedifferentspans,beamscanbemadeofI-beams,steelplatebeams,orsteeltrussbeams.Composition:beam,reservedbracket.Structuralarrangement:I-beamforL≤10m,steelplatebeamforL≤20m,andsteeltrussbeamforL>20m.Thebeamissupportedonthepillarnexttothepier,andcanalsobesupportedonthereservedbracketofthebridgepier.Subtask2.Beambracket梁式支架圖例:

Legendofbeambracket:特點和適用條件：當橋梁較高，跨徑較大或必須在支承下通航，排洪時應采用梁—柱式支架。組成：將梁支承于支柱或臨時支墩上，形成多跨的梁—柱式支架，落架一般用木楔、木馬或砂筒等。子任務3.梁柱式支架Subtask3.BeamcolumnsupportCharacteristicsandapplicableconditions:Whenthebridgeishigh,hasalargespan,ormustbenavigableundersupport,beamcolumnsupportshouldbeusedforflooddischarge.Composition:Thebeamissupportedonapillarortemporarypiertoformamultispanbeamcolumnsupport,whichisusuallyloweredusingwoodenwedges,woodenhorses,orsandcylinders.梁--柱式支架Beamcolumnsupport支架的布置根據梁截面大小并通過計算確定以確保強度，剛度，穩(wěn)定性滿足要求，考慮混凝土重量外，還需考慮模板及支架重量，施工荷載（人，料，機等），作用模板上，支架上的風力，其他可能產生的荷載。2.支架設計與搭設：2.Supportdesignandinstallation:Thelayoutofthesupportisdeterminedbasedonthecross-sectionalsizeofthebeamandcalculatedtoensurethatthestrength,stiffness,andstabilitymeettherequirements.Inadditiontoconsideringtheweightofconcrete,itisalsonecessarytoconsidertheweightoftheformworkandsupport,constructionloads(personnel,materials,machinery,etc.),thewindforceactingontheformworkandsupport,andotherpossibleloads.支架預壓加荷示意圖Schematicdiagramofbracketpreloadingandloading支架預壓整體圖示Overalldiagramofbracketpreloading

支架預壓示意圖Schematicdiagramofbracketpreloading5.預拱度設置及模板安裝支架受力后將發(fā)生彈性變形和非彈性變形，使還未生成強度的橋跨結構在自重作用下隨之發(fā)生變形，為使所施工梁體在卸模后能夠獲得較滿意的設計文件規(guī)定的外形，故應對支架設置預拱度。5.CambersettingandformworkinstallationAfterthesupportissubjectedtoforce,itwillundergoelasticandnonelasticdeformation,causingthebridgespanstructurethathasnotyet