连续刚构桥合龙顶推力的计算与优化研究——以S248天华大桥主桥为例  

Calculation and Optimization Research on the Closing Thrust of a Continuous Rigid Frame Bridge—Taking the main bridge of S248 Tianhua Bridge as an example

作　　者：谈亭 汪学明 Tan Ting;Wang Xueming(Anhui Hongtai Transportation Engineering Design and Research Institute Co.,Ltd.,Hefei,Anhui 230088)

机构地区：[1]安徽宏泰交通工程设计研究院有限公司,安徽合肥230088

出　　处：《现代工程科技》2024年第12期9-12,共4页Modern Engineering Technology

摘　　要：在混凝土收缩徐变作用下,连续刚构桥墩顶部会向跨中的顺桥向产生水平位移并在桥墩内引起附加弯矩,水平位移过大会降低桥墩稳定性,对结构受力不利。为减小这种水平位移,对连续刚构桥中跨合龙前施加水平顶推力,使墩顶预偏,从而减小桥梁运营阶段桥墩纵向位移对桥梁产生的不利影响。以S248天华大桥主桥为例,建立有限元模型,分析计算由钢束、混凝土收缩徐变、温度等因素产生的墩顶位移,以此来计算确定中跨合龙前顶推力理论值的大小,并分析施加顶推力对成桥阶段桥墩内力的影响。施工时结合具体的合龙温度,对顶推力进行修正,为该桥合龙顶推施工提供依据,并为同类桥型结构的合龙顶推设计提供参考。Under the action of concrete shrinkage and creep,the top of a continuous rigid frame bridge pier will generate horizontal displacement towards the mid span direction and cause additional bending moments inside the pier.Excessive horizontal displacement will reduce the stability of the pier and be detrimental to the structural stress.To reduce this horizontal displacement,a water level top thrust is applied before the closure of the mid span of the continuous rigid frame bridge,causing the pier top to be pre biased,thereby reducing the adverse effects of longitudinal displacement of the bridge piers on the bridge during the operation phase.Taking the main bridge of S248 Tianhua Bridge as an example,a finite element model is established to analyze and calculate the displacement of the pier top caused by factors such as steel strands,concrete shrinkage and creep,temperature,etc.,in order to calculate and determine the theoretical value of the jacking force before the mid span closure,and to analyze the effect of applying the jacking force on the internal force of the bridge piers during the completion stage.During construction,based on the specific closure temperature,the jacking force is adjusted to provide a basis for the closure jacking construction of this bridge and a reference for the closure jacking design of similar bridge structures.

关 键 词：连续刚构桥 合龙顶推力 抗推刚度 合龙温度 收缩徐变 墩顶水平位移 

分 类 号：U448.23[建筑科学—桥梁与隧道工程]