高速铁路填方路基粗粒土细观力学性质的离散元模拟

DEM Simulation on Micro-mechanical Behavior of Coarse-grained Soil of Filling Subgrade for High-speed Railway

基于离散元方法,建立一个表征填方路基粗粒土细观力学性质的颗粒流模型。同时,利用三维颗粒流程序PFC3D的内置FISH语言,进行二次开发,真实地模拟了粗粒土的颗粒级配曲线。通过大量的颗粒流数值模拟试验,准确地标定了表征粗粒土细观力学性质的相关细观参数。计算结果表明:离散元模拟结果和室内土工试验结果基本一致,粗粒土呈现出较大的体缩和体胀性,同时分别对比了不同围压下,路基粗粒土离散元模拟与室内三轴试验下的应力-应变曲线,其变化规律基本一致。

Based on discrete element method（DEM） mechanics properties of coarse-grained soil of , a particle flow code （PFC）model representing micro- filling subgrad program built in three-dimensional particle flow code PFC3D e was built. At the same time, FISH language was used to carry out secondary development and simulate the grading curve of the coarse-grained soil truly. This paper, through a large amount of PFC numerical simulation, calibrated the related micro parameters representing the micro-mechanical properties accurately. The result of calculation shows that the result from the DEM simulation agrees to that from indoor soil test substantially and the coarse-grained soil presents obvious under different confining pressure, the stress-strain curves of the indoor triaxial test were compared respectively and found to have shrinkability and expansibility; in addition, coarse-grained soil from DEM simulation and the consistent change rule basically