节理岩体爆破破坏过程数值模拟

Numerical Simulation of Blasting Failure Mode of Jointed Rock Mass

针对目前常用的有限元和离散元等数值方法难以客观反映岩体中存在的大量断续节理和在外力作用下岩体破碎及块体运动的不足,提出采用最近新出现的数值方法——数值流形方法以解决目前岩体爆破中存在的上述问题。数值流形方法采用数学网格与物理网格以形成求解流形单元,很容易反映岩体中存在的众多初始节理,本文采用断裂力学准则模拟岩石节理和裂纹扩展,采用DDA中的块体运动学理论模拟块体运动,并通过算例对比分析了完整岩体和节理岩体爆破破坏模式的差异。模拟结果表明,节理存在对岩体爆破破坏模式有着重要影响,且其影响程度与节理的几何分布和物理力学性质有着密切关系。

The finite element method and the discrete element method widely used in practice can not adequately deal with lots of intermittent joints, the fragmentation of rock mass and the rock block movement. Therefore, a new numerical method, the numerical manifold method, is developed for that purpose. In the numerical manifold method, the mathematical mesh and the physical mesh are used to form a manifold element, which can very easily be used to deal with the lots of original joints in the rock mass. Meanwhile, the fracture mechanics principle is used to simulate the propagation of the joint and the crack, and the block movement theory in DDA is used to simulate the block movement. Finally, a calculation example is taken to analyze the difference of failure modes between the intact and jointed rock masses, and the results show that the existence of joints would greatly affect the rock mass blasting failure mode, and its effect is closely related to the joint＇s geometry distribution and physical and mechanical properties.