PC桥梁预应力和徐变耦合时变效应的数值模拟  

Numerical Simulation of Coupling Time-Varying Effect of Prestress and Creep of PC Bridge

作　　者：马诚[1] 陈惟珍[1] 

机构地区：[1]同济大学桥梁工程系,上海200092

出　　处：《桥梁建设》2013年第3期77-82,共6页Bridge Construction

基　　金：交通部西部交通建设科技项目(200831849404)~~

摘　　要：针对传统PC桥梁设计软件难以反映预应力和徐变耦合时变效应的情况,将空间嵌入式实体组合单元应用于该类桥梁的空间受力分析中。采用拟线性回归方法对现行桥规徐变系数进行拟合,推导预应力和徐变耦合时变效应有限元分析列式,并编制相应有限元分析程序。以一跨径为7.5m的预应力混凝土简支梁为例,检验编制程序的正确性,并采用编制程序分析该简支梁的徐变效应。分析结果表明:编制程序精确地考虑了混凝土徐变与钢筋预应力损失间的耦合效应,更能反映结构真实的力学状态;拟线性回归方法对现行桥规徐变系数的拟合公式精度较高,适于有限元编程。The spatial embedded solid combination element is applied to the analysis of the spatial force conditions of prestressed concrete （PC） bridge since it is difficult for the traditional PC bridge design software to represent the coupling time-varying effect of prestress and creep. The creep coefficients given in the current bridge design code are fitted, using the quasi-linear regression method, the finite element analysis formulation for the coupling time-varying effect of the prestress and creep is derived and the corresponding analysis program is complied. By way of example of a PC simply-supported beam with span length 7.5 m, the correctness of the complied program is checked and with the program, the creep effect of the bridge is analyzed. The results of the analysis show that the program can accurately consider the coupling effect between the creep of concrete and the prestress loss of prestressing bars and still more, can represent the real force conditions of the structure. The accuracy of the quasi-linear regression method for fitting the creep coefficients in the current bridge design code is high and the method is applicable to the compiling of finite element program.

关 键 词：预应力混凝土桥 嵌入式实体组合单元 预应力 徐变 耦合效应 数值模拟 有限元法 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]