多跨连续刚构桥合龙顶推方案优化  

An Optimization on Closure Jacking Scheme for Multi-span Continuous Rigid Frame Bridge

作　　者：胡志坚[1] 王智康 李玉生 HU Zhi-jian;WANG Zhi-kang;LI Yu-sheng(School of Transportation and Logistics Engineering,Wuhan University of Technology,Wuhan,Hubei 430063,China;Jiangxi Communications Investment Group Co.,Ltd.,Nanchang,Jiangxi 330025,China)

机构地区：[1]武汉理工大学交通与物流工程学院,湖北武汉430063 [2]江西省交通投资集团有限责任公司,江西南昌330025

出　　处：《公路交通科技》2024年第8期137-145,共9页Journal of Highway and Transportation Research and Development

基　　金：国家重点研发专项资助项目(2017YFC0806000);江西省创新驱动“5511”项目(20165ABC28001)。

摘　　要：为了能更好地减少多跨连续刚构桥成桥后期各个桥墩墩顶的纵桥向水平位移和结构附加内力,提出由中到边合龙依次顶推的优化方案,作出了相应的计算图示且推导了相关的理论计算公式,同时根据顶推力理论计算公式的需要,推导了变截面的主梁和桥墩的抗弯惯性矩的理论计算公式,以某六跨连续刚构桥为例,建立有限元模型,通过理论计算公式和有限元模型分别计算了优化方案的顶推力数值并进行了对比分析,验证合龙优化方案顶推力理论计算公式的有效性,然后将由边到中的原合龙顶推方案和先中后边的优化合龙顶推方案作对比,验证合龙优化方案的合理性。结果表明:相较于原方案,使用优化方案虽然增加了顶推次数,但是其每次顶推力的数值较原方案中一次顶推力的数值都有大幅减少,从而能够有效地减少顶推处的局部应力水平;优化方案能更好地调控各个墩的变形,尤其是距离主梁中点较远的桥墩,因此优化方案对墩顶的纵向水平位移和墩底的弯矩改善效果更加明显;优化方案理论计算公式计算得到的顶推力数值相比于使用有限元模型推算的顶推力数值偏大,但总的来说相差不大,满足实际工程的要求;不同的顶推方案主要的影响是桥墩的变形与内力,顶推施工对成桥后主梁的收缩徐变以及线形的影响不大。In order to effectively reduce the longitudinal horizontal displacement and additional internal force on the top of each pier of multi-span continuous rigid frame bridge at later stage,the optimized scheme for sequential jacking from the middle to the side closure is put forward,and the corresponding calculation diagrams are given and the relevant theoretical calculation formulas are deduced.Simultaneously,according to the needs of theoretical calculation formula of jacking force,the theoretical calculation formula of bending moment of inertia of the main beam and pier with variable cross-section is derived.Taking a six-span continuous rigid bridge for an example and establishing a FEM,the theoretical calculation formula and the finite element model are used to calculate the jacking force of the optimized scheme and carry out comparative analysis to verify the effectiveness of the theoretical calculation formula of the jacking force belong to optimized scheme.Subsequently,the original jacking scheme from side to middle and the optimized jacking scheme from middle to side to verify the rationality of the optimized jacking scheme are compared.The result shows that(1)compared with the original scheme,the optimized scheme increases the number of jacking,but the value of each jacking force is substantially reduced compared with the original scheme,that effectively reducing the local stress level at the jacking position;(2)the deformation of each pier is better controlled with the optimized scheme,especially the pier far from the midpoint of the main beam,therefore,the optimized solution is more effective in improving the longitudinal horizontal displacement of the pier top and the bending moment at the bottom of pier;(3)the jacking force calculated with the theoretical calculation formula of the optimized scheme is larger than that with the FEM,but the difference is small in general,that meeting the requirements of the actual project;(4)the main impact of different jacking schemes is the deformation and internal force

关 键 词：桥梁工程 顶推方案优化 数值模拟 连续刚构桥 墩变形 

分 类 号：U445.462[建筑科学—桥梁与隧道工程] U448.23[交通运输工程—道路与铁道工程]