To investigate the influence of strike-slip faults on the seismic responses of underground structures, based on the single-layer potential theory of the boundary element concept and the fault-site-underground structure coupling mechanisms, we proposed a hybrid indirect boundary element-finite element numerical method (IBE-FEM) to simulate efficiently the seismic response of the entire process from the near seismogenic-fault to the underground structure. Initially, based on the kinematic finite-fault model, the seismic wavefield of an overlying soft-soil sedimentary-layer site subjected to strike-slip faults with source parameters, such as rupture velocity, dip-angle, and upper-boundary burial depth, was solved using the indirect boundary element method (IBE). Subsequently, the accuracy of the IBE-FEM in predicting the site seismic wavefield was verified. On this basis, the influence laws of the source parameters and the fault-site coupling effects on the seismic performance of the structure were preliminarily investigated by establishing a numerical model of the nonlinear dynamic interaction system of a soil-underground structure. The results showed that the seismic responses of the underground structure located in the footwall far-fault region were more strongly affected by variations in the rupture velocity. The lateral deformation of the structure under the rupture velocity condition of bedrock shear-wave velocity () was dramatically increased compared to sub-, and the lowest amplification is 59 %. Furthermore, the hanging wall and seismic damage concentration effects significantly impacted the structure located in a strike-slip fault site with a shallow-burial. This study provides a reliable and efficient analytical method for the seismic design of underground structures in complex near-fault regions.

中文翻译：

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利用IBE-FEM混合方法研究走滑断层附近地下地铁车站结构的抗震性能


为了研究走滑断层对地下结构地震响应的影响，基于单层势理论的边界元概念和断层-场地-地下结构耦合机制，提出了一种混合间接边界元-有限元模型。单元数值方法（IBE-FEM）有效模拟从近震源断层到地下结构的整个过程的地震响应。首先，基于运动学有限断层模型，研究了受走滑断层影响的上覆软土沉积层场地的地震波场，其震源参数包括破裂速度、倾角和上边界埋藏深度，使用间接边界元法（IBE）进行求解。随后验证了IBE-FEM预测现场地震波场的准确性。在此基础上，通过建立土-地下结构非线性动力相互作用系统数值模型，初步研究了震源参数和断层耦合效应对结构抗震性能的影响规律。结果表明，位于下盘远断层区域的地下结构的地震响应受破裂速度变化的影响更为强烈。基岩剪切波速()破裂速度条件下结构的侧向变形较亚显着增大，最低增幅为59%。此外，上盘和地震损伤集中效应对位于浅埋藏走滑断层部位的结构影响显着。 该研究为复杂近断层地区地下结构的抗震设计提供了可靠、高效的分析方法。