Based on a rectangle underground station structure, two-dimensional finite element models are established in this study to explore the effectiveness of different seismic reduction and isolation measures for underground structure, where Davidenkov model is adopted to consider the soil nonlinearity and the underground structure is considered elastic. The performances of the seismic reduction and isolation measures are evaluated by assessing the structure internal force and deformation responses. Depending on the ratio of wave impedance between the isolation layer and the structure, the isolation layers are divided into rigid and flexible types. The effects of the length and elastic modulus of rigid isolation layer as well as that of the thickness and shear modulus of flexible isolation layer are investigated. The results show that the seismic reduction effect of rigid isolation layer is better with the increase of stiffness, and the effect of flexible isolation layer is more obvious with the decrease of stiffness, which are consistent with the classical impedance theory. Furthermore, the middle column of subway station is usually the most vulnerable during seismic shakings, and one viable way to improve its seismic behavior is to reduce the column end constraints. Therefore, different column constraints consisting of swing, hinge, sliding connection and isolation bearing are considered. The numerical results suggest that among the different column end constraints considered, the sliding connection is comparatively more favorable, which can effectively limit the lateral deformation of column while imposing no horizontal reaction force.

中文翻译：

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城市地下车站结构减震隔震措施研究

本研究以矩形地下车站结构为基础，建立二维有限元模型，探讨不同减震隔震措施对地下结构的有效性，其中采用Davidenkov模型考虑土体非线性，考虑地下结构松紧带。通过评估结构内力和变形响应来评估减震和隔震措施的性能。根据隔离层与结构之间的波阻抗比，隔离层分为刚性和柔性两种。研究了刚性隔振层的长度和弹性模量以及柔性隔振层的厚度和剪切模量的影响。结果表明，随着刚度的增加，刚性隔震层的减震效果更好，随着刚度的降低，柔性隔震层的减震效果更明显，这与经典阻抗理论是一致的。此外，地铁站的中柱通常在地震中最容易受到震动，改善其抗震性能的一种可行方法是减少柱端约束。因此，考虑了由摆动、铰链、滑动连接和隔震支座组成的不同柱约束。数值结果表明，在考虑的不同柱端约束条件下，滑动连接相对更有利，可以有效限制柱的横向变形，同时不施加水平反作用力。