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建立了一种饱和-非饱和的双重孔隙-裂隙介质热-水-应力-迁移耦合三维模型,其特点是应力场和温度场是单一的,但具有不同的孔隙渗流场、裂隙渗流场和孔隙浓度场、裂隙浓度场,以及可考虑裂隙的组数、间距、方向、连通率和刚度对本构关系的影响,并研制出相应的三维有限元程序.通过与已有算例的对比,验证了该模型和程序的可靠性.针对一个假定的高放废物地质处置库,就岩体和缓冲层均为非饱和介质和放射性核素泄漏的情况进行了数值分析,考察了岩体中的温度、负孔隙水压力、地下水流速、核素浓度和正应力的状态.结果显示,缓冲层中的温度、负孔隙水压力及核素浓度呈现非线性的变化、分布;尽管裂隙水饱和度平均仅为孔隙水饱和度的1/9,但因裂隙的渗透系数比孔隙的渗透系数大4个数量级,故裂隙中地下水的流速约是孔隙中相应值的6倍;应力分布集中的区域位于缓冲层和处置孔壁交界两侧附近.
A three-dimensional model of saturated-unsaturated dual pore-fracture medium coupled with thermo-hydro-stress-migration is established, which is characterized by a single stress field and a temperature field, but with different pore fluid seepage fields, fractured seepage fields and pores Concentration field and fracture concentration field, and the influences of group number, spacing, direction, connectivity rate and stiffness on the constitutive relationship can be considered and the corresponding three-dimensional finite element program has been developed. By comparing with the existing examples, The reliability of the model and the procedure was evaluated.According to a hypothetical high-level waste disposal geological repository, the rock mass and buffer layer were both numerically analyzed for unsaturated medium and radionuclide leakage, and the temperature in the rock mass , Negative pore water pressure, groundwater flow rate, nuclide concentration and normal stress.The results show that the temperature, negative pore water pressure and the concentration of the radionuclides present a nonlinear change and distribution in the buffer layer. Although the average fissure water saturation is only Pore water saturation of 1/9, but the fracture permeability coefficient than the pore permeability coefficient of 4 orders of magnitude, so the fissure groundwater flow rate is about 6 times the corresponding pore value; stress distribution set In the area is located near the interface between the buffer layer and the disposal hole wall.