上承式大跨度钢管混凝土拱桥地震反应分析

Analysis of Seismic Response of Deck Type Long-span CFST Arch Bridge

为研究上承式大跨度钢管混凝土拱桥的地震反应性能,以大型有限元计算软件ANSYS为平台,分别以纵向+竖向和横向+竖向迁安波与EI Centro波作为输入地震波,对跨径为430 m的上承式钢管混凝土拱桥——支井河特大桥进行了地震反应分析。研究结果表明:前10阶振动以侧向振动为主,表明桥纵向刚度远大于侧向刚度;拱肋抗震设计最危险截面是拱脚截面,地震反应内力最大;横向+竖向地震动输入时拱肋轴力及弯矩略大于纵向+竖向地震动输入时,相差幅度不大,但横向+竖向地震动输入时弯矩My远大于纵向+竖向地震动输入;在横向+竖向地震动输入下最危险截面——拱脚处的地震反应轴力内侧拱肋大于外侧拱肋。

In order to study the seismic response of deck type long-span concrete filled steel tube （CFST） arch bridge, taking Qian＇an seismic wave and EI Centro wave were taken as the input waves, Zhijinghe Great Bridge, which is the deck type CFST arch bridge with 430 m span, was analyzed with computation program ANSYS. The results show that （ 1 ） most vibrations in the first 10 orders are in the transverse direction of the bridge which indicates that stiffness in longitudinal direction is larger than that in transverse direction; （2） the section at arch springing is the most dangerons section which has the largest seismic response member forces; （3） although the axial force and moment Mz of arch rib with transverse and vertical input seismic waves are a little larger than those with longitudinal and vertical input seismic waves, the moment My with transverse and vertical input seismic waves are more larger than those with longitudinal and vertical input seismic waves; （4） the axial forces of inside arch rib at arch springing, which is the most dangerous section, are larger than those of outside arch rib with lateral and vertical input seismic waves.