为模拟天然岩体中裂隙对渗流的影响,基于裂隙的空间形态及分布的统计特性,应用裂隙网络随机模拟技术,采用Matlab程序生成二维裂隙网络。由此裂隙网络生成包含裂隙的有限元计算网格。考虑到渗流场数值模拟分析时步多、计算量大的问题,采用基于element-by-element策略的有限元并行计算方法进行数值模拟。该方法不集成整体刚度矩阵,可有效节省存储量,同时可降低共轭梯度法中的迭代次数,提高收敛性。编制相应的模拟分析并行程序,并在分布存储的并行机上实现。分别对包含1,2组裂隙的岩体进行渗流场的数值模拟。计算结果表明,该方法能够较真实地反映裂隙岩体的实际状态,对于模拟岩体中的裂隙是很有效的;同时,并行计算可有效降低数值模拟的计算时间。
To simulate the fractures in natural rock, the fracture network has been formed with Matlab based on statistical parameters of fracture shapes and random distribution of fractures. Then finite element mesh has been generated with fracture network. Considering enormous time steps and huge workload in the numerical analysis, the element-by-element(EBE) finite element parallel computation method is adopted for numerical simulation. This algorithm does not generate global stiffness matrix and only stores element stiffness matrices, which can reduced the number of iteration in preconditioning conjugate gradient method and improve the convergence of calculation. Corresponding parallel program for numerical analysis is developed and then implemented on cluster of workstation. Numerical analysis of seepage is conducted for two examples, which include separately one set fracture sets and two different strikes of fractures. Computational results show that the numerical analysis model is effective for the fractured rock mass.