槽墩高度对渡槽结构水平地震响应的影响

Eeffect of the height of pier on horizontal seismic responses of aqueduct structure

为了研究槽墩高度对矩形渡槽结构系统的动力特性及水平地震动力响应的影响,本文采用Housner流-固耦合模型,提出了一种用于土-桩-渡槽-水体系统的有限元分析方法。以渡槽结构原理性拟动力试验结果为依据,对拟动力试验进行了有限元仿真计算,验证了本文所给出的计算模型的合理性。在此基础上,重点对不同槽墩高度的矩形渡槽结构系统进行了计算研究,结果表明:渡槽结构的基频随槽墩高变化显著,而其高阶模态频率则变化不大。在El Centro波及TAR波输入时,随着槽墩高的增大,渡槽结构关键部位的最大动应力等响应存在递减趋势;尤其在El Centro波输入时,递减趋势更为显著。人工波输入时,结构动力响应状况存在一定波动,但从总体而言志,矮墩渡槽的动力响应大于高墩渡槽的动力响应。

The purpose of this paper is to study the influence of the height of pier on the dynamic characteristics and horizontal seismic responses of rectangular aqueduct structure.A finite element method is developed for solving the horizontal seismic responses of aqueduct with fluid-structure coupling and pile-soil-structure interaction in this paper.Analysis is carried out by using this finite element model and the results are in good agreement with the pseudo-dynamic principle testing data.The proposed finite element method is verified.On this base,the rectangular aqueduct structures with different heights of piers are studied by using this method.Results show that the fundamental frequency of aqueduct structure model is significantly changed with the increase of the height of pier,however,the difference of high-order frequencies is not evident.In addition,under the excitation of El Centro earthquake ground motion and TAR earthquake ground motion,these is a decreasing trend of the maximum seismic responses of the key parts of aqueduct structure with the increase of the height of pier,especially for the El Centro earthquake ground.motion.Under the excitation of artificial earthquake ground motion,these is a certain fluctuation in the seismic responses of aqueduct structures with high piers,however,in general,the dynamic responses of low piers are larger.