The dynamic response of a circular tunnel in the viscoelastic poroelastic soil was investigated using an analytical method to provide theoretical basis for antiblast protection design of tunnel. Assuming that the blast occured in the center of the circular tunnel, a model was established using decrease three-stage triangle loads. Biots theory was used to describe saturated soil and Kelvin-Voigt model was used for soil skeleton. The motions of the liner were considered specially based on Flügge theory. By introducing potential functions, numerical results were obtained in time-domain by using the Laplace transforms and inversion of Laplace transforms. The curves of displacement and hoop stress with time for different b*, which denotes the permeability of the soil, on the interface between the liner and soil were presented, and compared with those of the single-phase medium. The influences of viscous damping coefficient η on the displacement and stress response were emphatically analyzed in the viscoelastic saturated soil. The results show that the amplituds of displacement and hoop stress increase with the increasing parameter b*. The amplitudes of displacement and stress in the viscoelastic saturated soil are smaller than that in the viscoelastic medium. With the increasing of η, the amplitude of the wave attenuates fast, whereas the maximum the displacement and stress response get smaller.
CAI Yuan-qiang, CHEN Cheng-zhen, SUN Hong-lei. Dynamic response of tunnel in viscoelastic saturated soil subjected to blast loads. J4, 2011, 45(9): 1657-1663.
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