土-结构相互作用分析中几类地震输入方式的比较

Comparison of Earthquake Input Methods in Soil-structure Interaction Analysis

地震作用下土-结构动力相互作用的整体有限元分析需要在人工边界处输入地震动。目前可能采用的地震输入方法包括黏弹性边界自由场输入方法、自由场应力方法、自由场位移方法以及侧边界自由方法。由于采用近似人工边界条件或者未完全考虑地震自由场,上述地震输入方法均为近似方法。本文以大开地铁车站二维有限元分析为例,根据规范建议的边界位置,研究了上述地震输入方法的精度,研究成果可为土-结构相互作用分析的合理地震输入提供一定参考。

The earthquake input is required in the finite element analysis of the seismic soil-structure interaction. The earthquake input methods that can be used in engineering at present include the free-field input method based on viscous-spring boundary, the free-field stress method, the free-field displacement method, and the free lateral boundary method. The results from these methods are all approximate due to the approximate artificial boundary condition or no consideration of the seismic free field. In this paper, the accuracies of the results by these methods are compared by the 2-dimensional finite element analysis of the Daikai subway station where the artificial boundary position is determined according to the code. This work can give a reference on the earthquake input in the soil-structure interaction analysis.