铁路连续刚构桥合龙顶推力分析  

Jacking Force Analysis for Closure of Continuous Rigid Frame Railway Bridge

作　　者：胡平 杜钊 陈家龙 刘纲[2] HU Ping;DU Zhao;CHEN Jia-long;LIU Gang(The Fifth Engineering Co.,Ltd.,China Railway Eleventh Bureau Group,Chongqing 400037,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]中铁十一局集团第五工程有限公司,重庆400037 [2]重庆大学土木工程学院,重庆400045

出　　处：《世界桥梁》2020年第2期61-65,共5页World Bridges

基　　金：国家自然科学基金项目(51578095);重庆市自然基金项目(cstc2019jscx-msxmX0313);中铁十一局集团公司课题(2015c-9)。

摘　　要：针对铁路桥梁合龙大吨位顶推力理论分析及顶推力作用下结构力学性能研究不足,以某4跨连续刚构铁路桥为对象,考虑施工因素、合龙温度、混凝土收缩徐变等对桥墩水平位移的影响,拟合顶推力与桥梁水平位移的关系,推导基于水平位移的顶推力计算公式,并分析顶推力作用下桥梁结构不同阶段变形与受力。结果表明:在桥墩受力不超过规范允许条件下,顶推力与桥墩水平偏位成线性关系;施加计算顶推力下实桥的顺桥向位移与计算值偏差小于5%,公式拟合良好;施加顶推力将增加成桥阶段桥墩的拉应力;施加顶推力运营10年后,大桥的主梁下挠、桥墩顺桥向水平偏位将得到有效控制,桥梁结构安全。To work out the proper jacking and pushing force for the closure of continuous rigid-frame railway bridge and study the mechanical property of bridge structure under the large-tonnage jacking and pushing force,a four-span continuous rigid-frame railway bridge is taken as an engineering example.Based on the consideration of the effects of construction factors,closing temperature,concrete shrinkage and creep on the horizontal displacement of piers,the relation between jacking and pushing force and the bridge horizontal displacement was fit,the calculation formula for jacking and pushing force based on horizontal displacement was deduced and the effect of jacking and pushing force on the deformation and load bearing behaviors of the bridge in different stages was analyzed.The results show that when the loads on the piers do not exceed the allowable values in the code,the jacking and pushing force and the horizontal displacement of piers are in linear relation.When the calculated jacking and pushing force is applied,the deviation of the displacement along the length of the real bridge is 5%smaller than the calculated value,the fitted formula is effective.To apply jacking and pushing force will increase the tensile stresses in the piers in the completed bridge stage.The example bridge was tuned with jacking and pushing force,and after 10 years of service,the down warping of the main girder and the displacement of the piers along the bridge length have been under effective control,and the bridge structure is safe.

关 键 词：铁路桥 大吨位 合龙 墩顶位移 顶推力 理论分析 收缩徐变 效应分析 

分 类 号：U448.13[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]