寒区隧道围岩水热力耦合数值分析

利用“三区域”理论，建立考虑水分迁移和水冰相变的寒区隧道水热耦合问题的联合求解微分方程，然后采用 COMSOL Multi-physics 软件实现温度场和水分场耦合数值模拟，进而将数值模拟结果与土柱冻结试验的结果进行对比，验证水热耦合数值模拟模型的有效性.根据冻胀理论，着重对寒区隧道的应力场控制方程进行推导，利用孔隙冰与冻胀率之间的关系建立寒区隧道水热力三场耦合计算模型.最后以牡丹江到绥芬河区间的牡绥隧道为例，对温度场、水分场以及应力场进行了模拟分析.结果表明:外界温度的变化对开挖后的隧道会有很大影响.随着时间的增加，隧道洞口冻结圈厚度逐渐增加，在1月份达到最大冻深2m左右.

Numerical Analysis on Thermo-Hydro-Mechanical Coupling of Surrounding Rocks in Cold Region Tunnels

Based on the theory of “three regions”， a combined differential equation is established to solve the problems of hydro-thermal coupling in cold regions considering water transfer and water ice phase transition. The numerical simulation of temperature field coupled with water field was carried out by COMSOL multi-physics software， and the numerical simulation results were compared with the results of soil column freezing experiment to verify the effectiveness of the hydrothermal coupled numerical simulation model. By considering the theory of frost heave， the stress field governing equation of the tunnel in the cold regions is deduced， and the thermo-hydro-mechanical coupled model of the tunnel in the cold regions is established by using the relationship between pore ice and frost heave rate. Finally， the temperature field， humidity field and stress field were simulated by taking the Musui tunnel between Mudanjiang and Suifenhe as a case study. The results show that the change in external temperature has a great impact on the tunnel after excavation. The thickness of the freezing ring of the tunnel hole gradually increased with time and reached a maximum depth of about 2meters in January.