Elastic visco-plastic analysis for earthquake response of tunnels in cold regions

In this paper, in order to determine the initial stresses of tunnels in col d regions before earthquake occurs, a mathematical mechanical model and the governing differential equations of the coupled problem of temperature, se epage and stress fields, with phase change, are first derived from the theo ry of heat transfer, the theory of seepage and frozen soil mechanics. Then, the finite element formulae of this problem are obtained from Galerkin's m ethod. Secondly, the visco-plastic constitutive equations of frozen soil fo r dynamic computation are given. Finally, an illustrative example is provid ed. The example shows that the effect of seepage field and stress field on the frozen depth of cold region tunnels is large and the influence of frost -heaving force on the stresses of the tunnel lining is very large. This exa mple also indicates that the influence of initial stresses of tunnels in co ld regions on the time stress response of tunnels to earthquake is large. S o the effects of these factors on the tunnel lining should be taken into ac count in cold regions engineering design. (C) 2000 Elsevier Science B.V. Al l rights reserved.