考虑渗透系数变化的地下结构温度-渗流耦合分析

Study on Thermo-Hydro Coupling Model of Underground Structure with Permeability Coefficient Changes

地下岩体的温度随着深度的增加呈逐渐上升的趋势,在地下水的作用下,岩体温度-渗流耦合作用明显。分析了地下岩体温度场与渗流场间的相互作用效应,考虑流体渗流和岩体骨架本身的热传导作用以及温度梯度所产生的渗流作用,并计入温度对水体运动粘滞系数及岩体渗透率的影响,给出了完整的基于连续介质模型的地下岩体温度-渗流耦合数学模型。借助多物理场耦合软件CM,运用该耦合模型对某核废料地质贮存模型进行了双场耦合分析,分析结果显示,考虑温度-渗流耦合作用后,对废料地质贮存区附近的围岩稳定性产生了不利影响,需引起足够的重视。

The temperature of underground rock rises gradually with the depth increases.The thermo-hydro coupling effect of the rock is obvious under the influence of groundwater.The interaction between temperature and seepage of underground rock was analyzed,the heat transfer effect of fluid and rock matrix and the flow effect generated by the temperature gradient were considered.The influence on viscosity of water sports and rock penetration rate caused by the temperature was taken into account and a complete underground rock thermo-hydro coupling model based on the continuum model was given.The temperature and seepage flow field coupling analysis for nuclear waste storage model was given with the soft ware of COMSOL Multiphysics and the result shows that a negative effect was caused on the stability of surrounding rock near the storage geological place of the waste,so enough attention should be paied.