裂隙岩体的热-水-应力耦合模型及二维有限元分析

Model of thermo-hydro-mechanical coupling for cracked rock mass and its 2D FEM analysis

尝试将Barton—Bandis模型和Oda的裂隙张量理论结合起来应用于饱和-非饱和裂隙岩体中热-水-应力耦合过程的计算分析,研制了相应的二维有限元程序,并列举算例比较了无、有多组裂隙岩体中的应力场、渗流场和温度场的分布及变化情况。由此看到:由于不连续面的存在减弱了母岩的刚度和增大了其透水能力,使得裂隙岩体中的应力集中程度降低和渗流速度提高,从而热源产生的热量可较快地被水流传输到周围区域中去,岩体中的温度和负孔隙水压力量值也相对较低。

The Barton-Bandis model and the Oda＇s crack tensor theory were combined for application in computation and analysis of coupled thermo-hydro-mechanical processes in saturated-unsaturated cracked rock mass, and a 2D FEM program was developed. Through the computation examples the distributions and the variation of the stress fields, the pore pressure fields and the temperature fields of the rockmasses with and without cracks were compared. It was shown that because of existence of the discontinuities the stiffness of the original rockmass was weakened and the leakage of the rockmass raised, so that the stress concentration level in the cracked mass decreased and the flow velocities increased, therefore the heat from the heat source could be transferred to the surrounding zones by the water flow quickly, and the magnitudes of the temperature and the negative pore pressures in the rockmass were comparatively low.