桥梁上部结构抗震性能研究

Research on Seismic Performance of Bridge Superstructure

依托河北省某三跨预应力混凝土连续箱桥梁开展Midas Civil有限元抗震性能研究,重点对不同曲率半径下上部结构的自振特性及E1反应谱下上部结构的内力变化进行分析,得到以下结论:上部结构设计曲率半径增大会导致自身柔度增大;不同曲率半径主梁主振型以竖向弯曲为主;E1地震反应谱作用下,考虑恒载、顺横桥向荷载同时作用下的上部结构关键节点内力随曲率半径增大而减小。

Based on a three-span prestressed concrete continuous box bridge in Hebei Province,Midas Civil finite element seismic performance research was carried out,focusing on the natural vibration characteristics of the superstructure under different curvature radius and the change of internal force of the superstructure under E1 response spectnum.The following conclusions were drawn:the increase of the design curvature radius of the superstructure will lead to the increase of its own flexibility;the main vibration modes of beams with different curvature radius are mainly vertical bending.Under the action ofE1 seismic response spectrum,the internal forces of key nodes of superstructure under both dead load and transverse bridge load decrease with the increase ofcurvature radius.