设有限位墩的典型长联梁桥抗震性能分析

Seismic Analysis on Typical Long Bridges with Restrainer Piers

我国现存大量梁式桥,而梁桥在近几次大地震中均出落梁现象,对梁的有效控制是桥梁抗震的关键问题之一。从国内外震害来看,限位墩是解决梁桥落梁现象的有效手段。以设有限位墩的典型长梁为研究对象,运用有限元分析手段,通过分别考虑主梁碰撞、联数不同、联长不同等因素来分析桥梁的动力响应。结果表明:碰撞对桥梁结构的动力响应影响很大,设计如果不考虑碰撞作用,可能引起结构的不安全。联数和联长的增加也使最大墩梁相对位移有所增加,但当联数增加到6联以上时,最大相对位移基本不变,此时限位墩限制位移作用达到极限状态。

There are many beam bridges in China.However,this kind of bridges often has the phenomenon of unseating of bridge girders in recent earthquakes. Therefore,the effective control of beam is a key problem of anti-seismic bridge design.According to the seismic damages at home and abroad,restrainer pier is an effective measure to solve the above problem.Taking typical long bridges with restrainer piers as the research object,the dynamic response of the bridge was analyzed by means of finite element analysis,taking the below factors into consideration,such as main beam ponding,different joint number and different joint length. The results show that girder pounding has a great impact on dynamic response of bridge structure. Therefore,the design without considering the girder ponding may result in structure insecurity.The increase of joint number and length also increases the maximum relative displacement of pier and girder.But the maximum relative displacement remains almost unchanged when the joint number increases above six joints,for the restrainer pier reaches the limit state of displacement restrain.