Abstract: Considering the non-complete connection between nearly saturated soil and elastic lining of a tunnel, the dynamical responses of nearly saturated elastic soil with a deeply buried circle tunnel subject to an axisymmetrical blasting load are investigated based on the Biot model and elasticity. Analytical solutions of dynamical responses of nearly saturated soil and elastic lining coupled system in the Laplace transform space are derived with the potential function and Laplace transform. The time-history responses of the coupled system are obtained with a numerical Crump method of the inverse Laplace transform. The dynamical responses of nearly saturated soil with different tunnel lining models are analyzed. It is shown that the soil responses of nearly saturated soil and a shell lining system are minimal, while the soil responses of nearly saturated soil without lining are maximal. Influence of the degree of saturation on displacement and stress of the soil is weak, but has evident influence on pore water pressure. Furthermore, the magnitudes of radial displacement and circumferential stress increase as stiffness of the interface increases.

Key words: blasting load, dynamical response, Laplace transform, nearly saturated soil, tunnel lining