主讲曾绍武陕西铁路工程第讲预应力混课件讲解

第20讲预应力混凝梁桥后张法施工主讲：曾绍武

陕西铁路工程职业技术学院2能够掌握后张法的施工过程。目标1能够绘制后张法施工工艺流程图。目标2能够模拟组织后张法施工。目标3能力目标target1objective2objective3Canmastertheconstructionprocessoftheposteriortensionmethod.Abilitytodrawthepostconstructionprocessflowchart.Cansimulatetheorganizationafterthetensionmethodofconstruction.任务导入：大中跨径的预应力混凝简支梁整孔预制，一般都采用后张法施工。中铁十八局西潼高速改扩建工程尤河大桥项目部，引桥15孔30米简支箱梁为工程实例，介绍后张法是要点。Taskintroduction:thewholeholeoftheprestressedcoagulationsimplesupportbeamwithlargeandmediumspanisprefabricated,whichisgenerallyconstructedbythepost-tensionmethod.InYouxiBridgeprojectdepartmentofXitongExpresswayreconstructionandexpansionprojectofChinaRailway18thBureau,the15holesand30metersoftheapproachbridgeistheprojectexample,andtheZhangmethodisthekeypointafterintroduction.预应力混凝土后张法施工项目任务

1后张法施工工艺--主线3后张法施工过程所用设备后张法施工工艺实施方法123Post-tensionmethodconstructiontechnology--themainlineEquipmentusedinthepost-tensionconstructionprocessImplementationmethodofposttensionconstructiontechnology后张法箱梁制造工艺

一、制梁台底模准备Manufacturingprocessofbacktensionboxbeam1.Beammakingstagebottomformworkpreparation二.底腹板钢筋绑扎

任务1钢筋和预应力筋报检内容？任务1解析：钢筋规格、间距、尺寸、

数量、弯曲形式，位置。BindofbottomreinforcementTask1reinforcementandprestressedreinforcementinspectioncontent?Task1analysis:reinforcementspecification,spacing,size,quantity,bendingform,position.任务2：怎么保证预应力位置？任务2解析：定位钢筋，最少每50cm

要求和钢筋笼焊接牢固Task2:Howtoensuretheprestressedposition?Task2analysis:positioningsteelbar,atleastevery50cmrequirementsandsteelcageweldingfirmly123任务3：通过图片分析抽拔式和埋置式制孔器区别？任务3解析：形状、工作原理、材质Task3:Analyzethedifferencebetweendrawingtypeandburiedholemakerthroughpictures?Task3analysis:shape,workingprinciple,material三、内模安装

打磨清理内模、安装3.InternalmodeinstallationGrindingandcleaningtheinternalmoldandinstallation四、模板安装：端模板安装

4.Templateinstallation:terminaltemplateinstallation模板安装：侧模板安装，模板安装调整，检查轴线、标高，接缝、预埋件、连接件Templateinstallation:sideformworkinstallation,formworkinstallationandadjustment,checktheaxis,elevation,joints,embeddedpartsandconnections五、顶板钢筋安装

5.Installationofroofsteelreinforcement六、浇筑混凝土

混凝土运输、振捣

注意采用抽拔式制孔器时间。Six,pouringconcreteconcretetransportation,vibrationpayattentiontotheuseofdrawingtypeholemakertime.蒸汽养护篷布遮盖温度计锅楼蒸汽锅炉七、养护：薄膜洒水、喷雾、蒸汽养护Seven,maintenance:filmsprinklingwater,spray,steamcuringsteam-curedthermometerThepotfloorsteamboilerClosurecover八、拆模Eight,moldremoval卷扬机穿钢束穿束机械穿钢束九、穿预应力筋：任务1穿束前清孔、穿束方法和设备？任务1解析：空压机，卷扬机，穿束机

9.Wearprestressedtendons:Task1:Clearholes,piercingmethodandequipmentbeforepiercing?Task1analysis:aircompressor,winist,throughmachineThehoistpassesthroughthesteelbeamMechanicalmechanicalthroughsteelharness穿束二期张拉锚环钢绞线十、张拉：任务1设备选用、双控含义、安全？任务1解析：设备：穿心式千斤顶，设备标定双控：应力控制、伸长量控制安全：张拉速度，不能超过张拉控制应力人不能在设备后，夹片安装牢靠Task1Analysis:Equipment:piercingjack,equipmentcalibrationdoublecontrol:stresscontrol,elongationcontrolSafety:thetensionspeed,cannotexceedthetensioncontrolstresspersoncannotbeinstalledaftertheequipment,theclipisfirmlyTask1Equipmentselection,doublecontrolmeaning,safety?十一、清孔、压浆：压浆泵压浆压浆头任务1注意所用的设备，要求？任务1解析：压浆泵、压接管头浆体膨胀，饱满流出Task1analysis:pressureslurrypump,pressurecontrolheadslurryexpansion,fulloutflowTask1Notetheequipmentused,requirements?Xi.Holecleaningandgrouting:封锚前封端十二、封端：stopend后张法施工工艺实施方案后张法施工工艺后张法施工过程所用设备

13123小结：Post-tensionmethodofconstructiontechnologyEquipmentusedinthepost-tensionconstructionprocessPost-tensionconstructiontechnologyimplementationplan(1)桥墩施工情境：10*25m简支梁桥，双柱桥墩，柱高12-30m，矩形柱为1.4*1.8m，桥下无水。要求编制后张法施工方案，制定相应的实施方案。(2)教材P199，5.21，5.23

作业卡片关键：根据桥梁施工情境和施工单位的人员、材料、设备条件来选择经济合理的施工方法。(1)Pierconstructionsituation:10*25msimplysupportedbeambridge,doublecolumnpier,columnheight12-30m,rectangularcolumnis1.[]4*1.[]8m,nowaterunderthebridge.Itisrequiredtopreparethepost-methodconstructionplanandformulatethecorrespondingimplement