滑坡过程数值模拟的三维距离势离散元法

Numerical simulation of landslides with the three-dimensional distance potential discrete element method

根据滑坡问题的普遍性与重要性,探讨了三维情况下滑坡体的运动路径及堆积范围等问题,提出了用于模拟滑坡体运动的三维距离势函数离散单元法.新方法利用任意形状多面体的最大内切球半径得到无量纲化的距离势函数,在此基础上推导出块体间法向及切向接触力的计算式.为验证算法的正确性,模拟了含节理边坡的倾倒、滑块的动力响应两个经典算例,计算结果与解析解、数值解吻合度高,说明新算法能够准确描述块体间及整体复杂的力学性质.最终,将该方法应用于唐家山滑坡运动的模拟,结果表明新算法能够模拟实际滑坡运动及反应其堆积特性.

Based on the universality and importance of landslides, the kinetic process of landslides was investigated, including the associated travel trajectory and the endangered area. A 3 D distance potential discrete element method for the movement process of landslides was developed. Benefited from a new definition of the distance potential function with a clear physical meaning, a holonomic system of the calculation algorithm for the contact interaction was established, accounting for the influence of the tangential contact force. Performance of the new approach was validated with well-known benchmark examples, which consist of a sliding/toppling test of a joint rock slope and the block response to the induced acceleration in the foundation. The results were compared against existing analytical solutions and numerical results. It is worthwhile noting that the proposed method has an excellent ability in capturing the complex mechanical properties among individual blocks. Finally, the Tangjiashan Landslide was simulated by the verified method. The results show that the proposed method can describe the travel trajectory and the endangered area of landslides in practical engineering projects.