Seismic Response Analysis of Shallow Tunnel Under Simultaneous Oblique Incidence of P and SV Wave

Abstract

The incident angle of seismic waves can significantly affect the seismic response of shallow tunnels. Based on wave field separation technology and equivalent seismic load method, a general 2D numerical model whose accuracy of the model is verified considering oblique incidence characteristics is established. A series of time-history analysis are conducted to study the influence law of P wave oblique incidence alone, SV wave oblique incidence alone and simultaneous incidence of P and SV wave (P-SV wave) on the dynamic response of shallow tunnels. The results show that (1) The seismic response of tunnels increases with the increasing of incident angle in small range. (2) For the same intensity level, the seismic response of structures under the obliquely incident SV wave is higher than that under P wave, while the vault and arch foot are vulnerable parts. (3) The seismic response resulted in the oblique incidence of SV wave alone is less than that under P-SV wave, which indicates the necessity of considering the simultaneous incidence of P and SV waves.