Dynamic response of cylindrical deep buried tunnels in unsaturated soil under axisymmetric explosion loading

Abstract

This study established a calculation model for a cylindrical tunnel subjected to internal explosion loading in an unsaturated medium, assuming that the transient load exponentially decays along the tunnel direction. The governing equations for the lining tunnel and the surrounding unsaturated soil under explosion load were derived based on continuum mechanics and the theory of porous media mixtures. Laplace inverse transformation and Fourier inverse transformation were employed to derive the dynamic response of the lining and soil in the time-space domain. Furthermore, the effects of unsaturated medium saturation on the explosion response of the lining and the surrounding region were investigated. The results demonstrate that the analytical solution can be used to explain the dynamic response of an underground tunnel surrounded by unsaturated soil, during an internal explosion. The solutions can be extended to further advancements considering different boundary conditions.