Abstract: Explosion effect on a structure can be considered as a corporate results from the force shock and the heat shock. Based on the Biot’s theory of thermodynamics, the dynamic response of tunnel lining embedded in saturated thermoelastic medium, due to an internal excitation (heat/mechanical shock), is investigated theoretically by using the presented coupling the thermo-hydro-elastodynamic model. Using Flügge theory of thin shell and the general solution of thermo-hydro-elastodynamic model, the motion equation of tunnel lining is obtained; and the solutions of stress, displacement and pore pressure are derived by using the consistency condition at the interface of lining and soil in the domain of Laplace transformation. Numerical results are obtained using inverse Laplace transform and are used to analyze the effect of the internal excitation on stress, displacement and pore pressure for different rigidities and thicknesses. The results show that, under shock of blast, the lining acted as a good barrier for the surrounding soil, and bigger rigidity have better protection effect; the stresses on the interface between lining and soil decreased with lining rigidity increase, and bigger rigidity lead to faster stresses decrease; the rigidity and thickness of lining influence the displacement response evidently, but influence temperature response lightly.

Key words: thermo-mechanical shock, tunnel structure, coupling thermo-hydro-mechanics, dynamic response