EI、Scopus 收录
中文核心期刊

考虑局部场地效应的土-结构动力相互作用SEM-FEM耦合模拟方法

SEM-FEM coupled simulation method for soil structure dynamic interaction considering local site effects

  • 摘要: 考虑局部场地影响的结构地震反应分析中,合理有效的地震动输入非常关键。本文基于分区计算思想,发展了一种谱元和有限元耦合的两步模拟方法。首先,采用谱元法(SEM)结合多次透射公式(MTF),模拟平面波入射下仅含局部场地模型内部缩减计算域边界区节点的位移时程。其次,将上述位移时程直接施加于土-结构计算域的边界区节点完成地震动输入,采用有限元法(FEM)模拟土-结构系统的动力反应,基于MTF实现结构引起的外行散射波的吸收。相比传统域分解法(DRM),本文方法省去了地震动输入所需的人工边界处等效节点力的计算而直接实现位移时程输入,且对不同属性介质可采用相同的计算式而无需修改。基于均匀半空间模型、盆地场地模型和地表局部凹陷模型验证了本文方法的精度和有效性。最后通过考虑盆地效应与否时地铁车站和地上框架结构地震动反应的对比,验证了进行结构地震反应模拟时考虑局部场地影响的重要性。

     

    Abstract: In the analysis of structural seismic response considering the influence of local site, reasonable and effective seismic input is crucial. Based on the domain reduction theory, a two-step simulation method coupling the spectral element method (SEM) and the finite element method (FEM) is developed in this study. Firstly, SEM combined with MTF is used to simulate the displacement response of the model with structures being removed under plane wave incidence, and the responses of the boundary zone nodes defining the localized soil-structure calculation domain is directly used as the input for the soil-structure region. Secondly, the FEM is used to simulate the dynamic response of the soil-structure system, and the scattered waves caused by the structure is absorbed by the MTF. Compared with traditional DRM method, this method avoids the calculation of equivalent node forces at artificial boundaries, and the same calculation scheme can be used for different attribute medium. The accuracy and effectiveness of the proposed method were verified based on the uniform half space model, the basin model and the local canyon model. Finally, by comparing the seismic responses of a subway station and a frame structure with and without considering the basin effect, the importance of considering local site effects in simulating structural seismic response was verified.

     

/

返回文章
返回