简支变连续法加固双T形铁路桥梁的力学性能  

Mechanical properties of double-T railway bridges by transforming simply supported into continuous system

作　　者：周长东[1] 马欣 张许[1] 田苗旺 王朋国[1] ZHOU Changdong;MA Xin;ZHANG Xu;TIAN Miaowang;WANG Pengguo(School of Civil Engineering,Beijing Jiaotong University,Beijing100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《中南大学学报（自然科学版）》2018年第3期703-710,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51478033;51678039)~~

摘　　要：针对既有铁路桥梁承载力以及横向刚度不足造成的振动响应过大问题,提出一种联合使用改变结构支承体系、体外预应力和增加横隔板的加固方法。采用有限元软件ANSYS和多体动力学软件Universal Mechanism对加固前后的桥梁进行数值模拟和动力分析。研究结果表明:重力式桥墩对于梁体性能的影响很小,因此可以建立无桥墩的桥梁有限元模型以提高计算效率;增设预制横隔板可以增加梁体的刚度和承载力,但数量和厚度超过一定程度则会削弱加固效果;简支变连续的纵向加固法对提高刚度和承载力效果显著,而纵向和横向联合加固效果更佳;联合加固方案可以有效减小横向振幅,这与梁体刚度的增加程度密切相关。To solve the problems such as the weak transverse stiffness,excessive deflection and so on,one composite strengthening method for railway bridges was proposed which includes changing the support system,adding external pre-stressed strands and precast concrete transverse diaphragms.The finite element software ANSYS and the multi body dynamic software UM were used for numerical simulation and dynamic analysis.The results show that solid gravity piers have little influence on performance of bridge.To increase computational efficiency,the analytical model of bridge without piers should be taken.Adding precast concrete transverse diaphragms can improve stiffness and bearing capacity of bridge,but they also have a negative effect when the number and thickness exceed some certain extent.The method transforming simply supported into continuous system shows beneficial to increase stiffness and bearing capacity,and a combination of transverse and vertical strengthening method is more prominent.The transverse amplitude of bridge is decreased more obviously than that of vertical when using proposed composite strengthening method,because it is directly related to the extent of the stiffness increase.

关 键 词：双T形铁路桥梁 简支变连续 体外预应力 预制横隔板 车桥耦合分析 振幅 加速度 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]