大型地下工程三维弹塑性并行有限元分析

3D ELASTOPLASTIC PARALLEL FINITE ELEMENT ANALYSIS OF LARGE-SCALE UNDERGROUND ENGINEERING

有限单元法是岩土工程中最常用的一种数值计算方法,但是面对大型岩土工程,地质条件复杂、分析范围大,其计算精度往往不够,为了提高计算精度而细化计算网格,增加单元的数量,又会造成计算量大,单机计算能力不足的矛盾。针对以上问题,在区域分解和共轭梯度算法的基础上,采用VisualC++6.0开发基于Windows平台的三维弹塑性并行有限元程序ParallelGeoFEM3D,并在分布式网络环境中调试通过。对水布垭电站尾水洞阶段洞室的开挖过程进行详细的模拟,单元数量达到100×104个,开挖步为20步。计算结果表明,该程序可以对大型岩土工程施工方案进行快速准确的分析计算。

FEM is a numerical simulation method commonly used in geotechnical engineering. But for the large-scale problem with complex strata and large-scale region in geotechnical engineering, the calculation precision is not good enough. Refinement of finite element mesh causes element number increase greatly; and single PC computing capacity will be insufficient to accomplish the huge computing task. Based on the domain decomposition and precondition conjugate gradient methods, a ParallelGeoFEM^3D program is developed and implemented on cow duster of workstation（COW）. The construction sequence of the tail-tunnel excavation of Shuibuya Project is simulated with 100×10^4 elements and 20 excavation steps successfully showing the ParallelGeoFEM^3D can analyze construction options fast and accurately.