Dynamic response of shallow-buried circular composite lining tunnel with imperfect interface under SV waves

Abstract

In this paper, the dynamic response of lined shallow-buried composite lining tunnel with imperfect interface in semi-infinite elastic medium under plane SV waves is studied, and the spring model is introduced to describe the imperfect interface relationship among the surrounding rock, the isolation layer, the primary support layer and main support layer. By using the wave function expansion method, the analytical solutions of displacements and stresses are presented. The interacting effects of the interface properties and the buried depth under different dimensionless frequencies are discussed. The results show that the peak values of the dynamic stress in the linings gradually shift to the upper part of the tunnel with the increase of dimensionless frequency, and the maximum dynamic stress in the linings also tends to decrease. The dynamic stress around the main and primary support layers increases when the interfaces are weakly bonded, and the effect of transverse springs is greater than that of normal springs. The tunnel with diminutive buried depth has a larger dynamic stress under the low-frequency SV waves. Reducing the stiffness in the isolation layer will lead to the increase of dynamic stress in the surrounding rock, while the dynamic stress in the main and primary support will be weakened.