预应力效应对自复位高墩地震反应的影响

摘要

In order to investigate the influence of prestress effect on the seismic response of self-centring tall pier ,arrangement of prestressed reinforcement in self-centring tall pier was presented .The action mechanism of prestressed reinforcement was analyzed .The restoring force model of a reinforcement element was estab-lished considering the loss of prestress caused by the reinforcement yield .The method of simulating the initial force of prestressed reinforcement by using the initial strain was presented .The analysis model for the seismic response of the self-centring tall pier was established based on OpenSees program package to investigate the in-fluence of prestressed reinforcement ,initial prestressing force and prestressing loss on the seismic response of the pier .The results show that the prestressed reinforcement and its initial prestressing force will increase the seismic moment at the pier base ,and can control the lift off of the pier .The prestressing loss can reduce the seismic moment at the pier base .%为探讨预应力效应对自复位高墩地震反应的影响,本文给出自复位高墩中预应力钢筋的布置,分析预应力钢筋作用机制,建立考虑了钢筋屈服引起的预加力损失的预应力钢筋单元恢复力模型,给出通过初应变模拟预应力钢筋中初始预加力的方法.基于OpenSees(地震工程模拟的开放体系)建立自复位高墩地震反应分析模型,探讨预应力钢筋、初始预加力及预加力损失对桥墩地震反应的影响.结果表明:预应力钢筋及其初始预加力会增大墩底的地震弯矩、控制桥墩的竖向提离,预加力损失可以减小墩底的地震弯矩.