大跨度钢管混凝土拱桥吊杆更换关键技术研究  

Research on the Key Technology of Suspender Replacement of Long-span Concrete-filled Steel Tubular Arch Bridge

作　　者：王菲 WANG Fei(China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308

出　　处：《铁道工程学报》2021年第12期61-67,共7页Journal of Railway Engineering Society

摘　　要：研究目的:我国20世纪90年代修建的拱桥已陆续服役20~30年,吊杆的更换问题已逐步提到管养部门日程上来。本文以3×168 m钢管混凝土拱桥为例,针对吊杆更换工程中的关键问题展开论述,以期对类似工程起到一定的借鉴作用。研究结论:(1)吊杆使用期大多小于规范规定的20年设计使用年限,吊杆的设计应为后期管养与更换预留充分的条件;(2)吊杆更换工程应采用桥梁建设年代的设计荷载,可遵循容许应力法按吊杆安全系数控制设计,或按承载能力法用结构重要性系数、作用分项系数、材料分项系数进行综合表达;(3)采用桥面相对高差作为桥面线形控制指标更为有效,其限值可通过使裂缝宽度达到极小值时反求桥面板内力,进而通过内力求得桥面变形限值的方法获得;(4)可采用桁架单元模拟临时吊杆和新吊杆,只受拉单元模拟旧吊杆,逐级加载、卸载可通过替换体外力的形式施加;(5)设计中尚应对未更换的旧吊杆和新吊杆进行受力检算,并控制索力偏差不大于20%,同时还需检算施工过程中的桥面变形;(6)本研究成果可应用于中、下承式拱桥吊杆的更换工程。Research purposes:The arch bridges built in the 1990s have been in service for 20〜30 years,and the replacement of suspenders have been gradually putting on the agenda of the management and maintenance department.Taking the 3×168 m span concrete-filled steel tubular arch bridge as an example,this paper discusses the key issues in the suspender replacement project,in order to provide some reference for similar projects.Research conclusions:(1)Service life of suspenders is mostly less than the 20-year design service life specified in the specification.The design of suspenders shall give full consideration for later suspender maintenance and replacement.(2)The suspender replacement project shall adopt the design load of the bridge construction age,which can be controlled by the suspender safety factor according to the allowable stress method,or comprehensively expressed by the structural importance coefficient,action factor and material coefficient according to the bearing capacity method.(3)It is more effective to use the relative height difference of the bridge deck as the control index of the bridge deck alignment.Its limit value can be obtained by reverse calculating the force of the bridge deck when the crack width reaches the minimum value,and then obtaining the deformation limit of the bridge deck through the force.(4)The truss element can be used to simulate the temporary suspender and the new suspender,and the tension only element can be used to simulate the old suspender.The graded load and unload force can be applied in the form of replacing the external force.(5)The old and new suspenders that have not been replaced shall be calculated,and the cable force deviation shall not be greater than 20%.At the same time,the bridge deck deformation during construction shall be checked and calculated.(6)The research results can be applied to the suspender replacement of half-though arch bridge and through arch bridges.

关 键 词：吊杆 荷载组合 容许应力法 承载能力法 只受拉单元 桁架单元 体外力 桥面线形 

分 类 号：U448.225[建筑科学—桥梁与隧道工程]