稀疏非正交填充裂隙岩体水流—传热—应力模型与离散元模拟

为研究填充裂隙水流速度对岩体温度和应力的影响，选取甘肃北山地区的花岗岩，制作了稀疏非正交裂隙岩体模 型，采用河砂填充裂隙后进行模型试验；并对模型试验进行离散元数值模拟，分析了模型试验所测岩体温度和热应力与数 值模拟结果的差异和原因。结果显示：填砂裂隙强化了裂隙介质的热导能力，无填充时岩体温度和热应力比填砂时低；模 型试验和离散元模拟均表明，岩体温度和岩体应力随裂隙水流速度增大而减小，但是系统达到稳态所需要的时间变短；模 型试验中斜裂隙水流对温度场起主要作用；由于现有3DEC软件不能考虑水的热物性参数随温度的变化，进而产生自然对 流换热，斜裂隙水流和靠近热源侧的竖裂隙水流对温度场起主要作用。

Model Tests and Discrete Element Simulations for Water Flow,Heat Transfer and Thermal Stress in Sparsely Non-Orthogonal Sand-Filled Fractured Rocks

Model tests and discrete element simulation are conducted to study the effects of water velocity on temperature and stress in a physical rock mass model with sparse non-orthogonal sand-filled fractures，and the differences in temperatures and thermal stresses between the tests and the discrete element simulations are analyzed and attributed to mismatches between the test setups and the discrete model setups. The granite rocks in Beishan area in Gansu Province are studied. Results show that the filled sand fractures strengthen thermal conductivity of fractures media, and both temperature and thermal stress of rock mass without filling are lower than those with filling sand. Both the tests and discrete element simulations indicate that the rock mass temperature and stress decrease with increasing fracture water velocity, but the time required for the system to reach the steady state becomes shorter. The model test shows that oblique fracture water flow controls the temperature field. Because the existing 3DEC software does not take into account the changes of thermal property parameters of water with temperatures, thus generating natural convection heat transfer, oblique fracture water flow and vertical fracture water flow near the heat source control the temperature field.