開発機械/岩盤工学/資源開発技術

[3K62501-09-05] Numerical study of seismic wave propagation and scattering around a circular tunnel buried at different depth

○Huatao Zhao^1,2, Ming Tao¹, Hitoshi Mikada², Shibo Xu², Junichi Takekawa² (1. Central South University, 2. Kyoto University)

Keywords:SEM, Underground tunnel, seismic wave propagation

The stability and safety of underground structures is becoming more and more important with the development of underground space, especially, in the areas with frequent seismic disturbance. Therefore, it is of great significant to investigate the seismic responses around the underground structures for the earthquake disaster prevention. As we all know, the excavation of underground structures will cause compressive and tensile stress concentration in surrounding rock mass, which can further influence the propagation and scattering of seismic wave in the vicinity of the underground structures based on the relationship between wave velocity and stress. In the presented work, we study the seismic responses of a circular tunnel, including seismic wave propagation, scattering and Peak Particle Velocity (PPV), buried at different depth using the Spectral Element Method (SEM) package SPECFEM2D. A series of 2D tunnel models embedded with high speed block and low speed block are employed to characterize the different stress conditions induced by the buried depth. In addition, the remote fault-slip source and source parameters are considered to investigate the influence of focal mechanism on seismic response of the circular tunnel. The results indicate that both the buried depth of the tunnel and the source parameters can have a significant impact on its seismic response.