地下结构抗震设计方法整体强制反应位移法

Integral Forced Displacement Method for Seismic Design of Underground Structures

摘要:

基于地震作用下地下结构主要受周围土层变形控制这一基本思想，在地下结构抗震设计方法强制反应位移法的基础上，探讨了一种新的抗震设计方法——整体强制反应位移法.新方法将土层变形施加到计算模型的整个土层有限元上以模拟地震作用，避免了原方法所施加土层变形传递到远离模型边界位置会发生衰减的现象.结合上海市某地铁车站的计算实例，详细介绍了该方法的具体实施步骤、基本特点.同时以动力时程法为基准，分析了该方法在不同地震动强度下的计算效果.研究表明,整体强制反应位移法的计算结果与动力时程法符合较好，设计理念体现了地下结构的震害机制，是一种方便有效的抗震设计方法.

Abstract:

The internal forces of underground structures in an earthquake are controlled by the seismic deformation of surrounding soils. Based on the forced displacement method for seismic design of underground structures, a novel seismic design method, named the integral forced displacement method, was proposed. The ground response deformation was applied to the finite element model of integral soil in this method to simulate seismic loading. Taking a subway station in Shanghai as an example, the implementation procedure and special features were introduced. By comparing with dynamic time history analysis results，the validity and accuracy of the proposed method was verified. The results show that the design concept of integral forced displacement method well agrees with the earthquake damage mechanism of underground structures, and the method is suitable for seismic analysis and design of underground structures in practice.