渡槽拟动力试验仿真分析

Simulation analysis of aqueduct pseudo-dynamic testing

建立了一种可以同时考虑流-固耦合与桩-土-结构相互作用的渡槽结构水平地震响应的有限元计算模型,该模型通过等效线性化方法考虑土体非线性,以自由场计算结果为依据,确定黏-弹性人工边界的参数及进行相应的地震动输入。建立了渡槽结构拟动力试验模型的整体有限元计算模型,进行了试验地震波作用下的有限元仿真计算,并与拟动力试验结果进行了比较,计算结果与试验结果基本一致,说明了建立的有限元计算模型的有效性。同时,拟动力试验及有限元计算结果表明,水体对渡槽结构地震响应有一定影响,有水工况时,结构的基频降低,可能较无水工况与输入地震波能量主频段偏离更远,从而起到一定的减震作用。

A finite element model was developed for solving horizontal seismic response of aqueduct with fluid--structure cou- pling and pile--soil--structure interaction in this paper. Equivalent linearization principle was employed to deal with the nonlin- ear characteristics of the soil. Based on the analysis results of free filed, the parameters of viscous-elastic artificial boundary and the input method of earthquake wave were given. Analysis was carried out by using this finite element model, the results were in good agreement with the pseudo-dynamic testing data. At the same time, the results of the pseudo dynamic test and finite el- ement calculation show that water has a certain effect on the earthquake response of the aqueduct structure. On the water con- dition, the fundamental frequency of the aqueduct structure decreases and deviates from the energy basic frequency of the input seismic wave farther than that on the water-less condition. In this case, it has certain damping effect.