基于IDA的高墩容许位移研究

Research on Allowable Displacement of High Piers Based on Incremental Dynamic Analysis

为了研究高墩结构塑性铰的形成过程、长度分布以及墩顶容许位移大小,以一座连续刚构桥为研究对象,采用增量动力分析的方法,结合OpenSees分析软件,从PEER数据库中选取15条地震波,完成了一系列非线性分析,通过改变墩身高度,得到了不同墩高时墩身曲率分布规律,据此总结了高墩塑性铰的形成规律、长度及其与地震波的关系,推导了两端固定桥墩的容许位移计算公式。结果表明:高墩塑性铰形成过程与传统中低墩基本一致;塑性铰的长度与地震波频谱特性、地震强度均无关,仅与结构自身特性有关,所提出的墩顶位移计算公式适用于高墩容许位移的计算。

In order to study the length and forming process of the plastic hinge and the allowable pier displacement of bridge with high piers, a continuous rigid frame bridge is taken as an example. Using Incremental Dynamic Analysis method and OpenSees,a series of nonlinear analysis are carried out with the 15 seismic waves selected from the PEER database. By changing the heLght of the pier, the law of the curvature distribution of the piers is given, and then the length and forming process of the plastic hinge which varies with waves is summarized. On these basis, the allowable pier displacement of high piers fixed at both ends of the piers is derived. Results show that. the forming pro：ess of the plastic hinge to high piers is as same as the traditional low pier; the length of the plastic hinge is independent of the spectral characteristics and earthquake intensity, but only related to the structtLral characteristics; the formula given by this paper can be applied to calculate the allowable pier displacement.