Response of a tunnel in double-layer rocks subjected to harmonic P- and S-waves
Journal
International Journal of Rock Mechanics and Mining Sciences
Journal Volume
70
Pages
435-443
Date Issued
2014
Author(s)
Abstract
The combination of tunnel depth and incident wavelength has been numerically revealed as a key factor dominating seismic responses of a tunnel in a homogenous rock layer. To investigate further the seismic response of a tunnel in double-layer rocks and to clarify the effect caused by the layered rocks, this study applies the dynamic finite element method and investigates seismically induced stress increments in the lining of a circular tunnel subjected to an incident harmonic P- and S-wave. Analysis results reveal that the normalized seismically induced stress increments are maximal when normalized tunnel depth is 0.25 multiplying an odd number. Additionally, normalized seismically induced stress increments are minimal when normalized tunnel depth is 0.25 multiplying an even number. Further, the impedance ratio links the seismic responses of upper and lower rock layers subjected to incident harmonic waves, which may significantly amplify incident stress in the upper rock layer, thereby affecting the seismically induced stress increments in a tunnel lining. © 2014 Elsevier Ltd.
Type
journal article