大吨位钢桁梁步履式顶推滑移施工力学行为分析  

Mechanical Analysis of Walking-Type Incremental Launching and Sliding Construction of Large-Tonnage Steel Truss Girder

作　　者：娄松 吴芳 江湧 王戒躁 LOU Song;WU Fang;JIANG Yong;WANG Jie-zao(Wuhan Bridge Special Technology Co.,Ltd.,China Railway Major Bridge Engineering Group,Wuhan 430205,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China)

机构地区：[1]中铁大桥局武汉桥梁特种技术有限公司,湖北武汉430205 [2]桥梁结构健康与安全国家重点实验室,湖北武汉430034

出　　处：《桥梁建设》2021年第1期66-73,共8页Bridge Construction

基　　金：中国中铁股份有限公司科技研究开发计划课题(2012-重点-10)。

摘　　要：某公铁两用大桥主桥为主跨1260m的双塔连续钢桁梁斜拉桥,结合该桥地理环境,提出边跨斜拉索区钢桁梁采用步履式顶推滑移方案施工,最大顶推重量约35700t。顶推跨度为75m,顶推支架上设3道凸形滑道梁,凸形滑道梁一端布置1台450t限压步履机(限定压力4000 kN,顶推水平力1200kN),另一端布置6台450t竖向千斤顶,利用限压步履机和竖向千斤顶的组合动力进行顶推施工。为了分析该方案的合理性及可行性,采用MIDAS Civil软件建立三跨钢桁梁结构有限元模型,分析最大悬臂和非悬臂工况下钢桁梁下弦杆剩余承载能力、顶推水平力及支点承载能力。结果表明:钢桁梁下弦杆承载能力满足要求;顶推水平力及支点承载能力均满足设计要求,顶推跨度及顶推设备布置合理,顶推过程结构安全可控,该方案合理可行。The main bridge of a rail-cum-road bridge is a two-pylon continuous steel truss girder cable-stayed bridge with a main span of 1260m.To suit the geological conditions at the bridge site,a walking-type incremental launching and sliding construction solution was selected for the steel truss girders in the cable-stayed regions of side spans.With maximum launching weight of about 35700t,the incremental launching covered a distance of 75m,with three protruding beams bearing sliding rails.There was a 450t-capacity compression-controllable crawler crane(with a limited compression force of 4000kN and horizontal pushing force of 1200kN)installed on one end of the three beams,and six 450t-capacity vertical jacks on the other end,to carry out the incremental launching construction.To analyze the rationality and feasibility of this solution,a finite element model of a three-span steel truss girder structure was established by MIDAS Civil,based on which the residual load bearing capacity of the lower chords of the steel trusses,horizontal pushing force and supporting capacity of the piers in the longest cantilever stage and non-cantilever stages were calculated.The results show that the load bearing capacity of lower chords of the steel trusses can meet the requirements.The horizontal pushing force and supporting capacity of the piers can also meet the design requirements.The incremental launching distance and the arrangement of the incremental launching facilities are rational.The incremental launching process is safe and controllable,proving that the solution is reasonable and feasible.

关 键 词：公路铁路两用桥 斜拉桥 钢桁梁 下弦杆 步履式顶推滑移 承载能力 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.462[交通运输工程—道路与铁道工程]