Study on a new-styled measure for treating water leakage of the permafrost tunnels

摘要

The status of water leakage of Kunlun mountain tunnel on Qinghai-Tibet railway is introduced by the time step in this paper. Based on the status of water leakage, the reason of water leakage of the tunnel is analyzed. In the light of the principle of protecting the frozen soil layer from thawing, a new-styled measure for treating water leakage, filling the ripped stone layer, is presented, and the design of filling the ripped stone layer is made. According to the basic theories of heat transfer and seepage, considering the coupled effects of seepage field and temperature field, a three-dimensional calculational model of the coupled problem is given, the spatial domain finite element formulae of this problem are obtained by Galerkin method, the time domain finite element formulae are obtained by Crank-Nicholson method, the solution process is presented, and a computer program is written. Using this model and program, three-dimensional nonlinear analyses for the coupled problem of seepage field and temperature field of the flat buried part from DK977+578 to DK977+682 in Kunlun mountain tunnel on Qinghai-Tibet railway are made under the two conditions of filling the ripped stone layer and not filling the ripped stone layer. The results show that it is feasible that the ripped stone layer is used for preventing water leakage of the permafrost tunnels. So, a new-styled measure can be used for treating water leakage of the permafrost tunnels.