节理岩体爆破的DDA方法模拟

Numerical simulation of rock blasting in jointed rock mass by DDA method

在非连续变形分析(DDA)方法中,通过跟踪炮孔扩张和炮孔周边裂隙的发展贯通求得爆腔的即时体积,进而根据爆生压力状态方程计算爆腔即时压力,并将爆生压力载荷作用到主炮孔内壁和贯通裂隙面上,实现了爆生产物作用下节理岩体爆破的DDA方法模拟。采用DDA方法模拟了节理岩体中的水平柱状炮孔抛掷爆破问题,得到了爆腔的体积扩张和压力衰减时间曲线,模拟很好的再现了岩石爆破过程中的炮孔扩张、岩体破坏、块体抛掷和爆堆形成过程。

By tracking borehole expansion and the propagation and coalescence of cracks in surrounding rock medium, calculating instant blasting chamber pressure based on the detonation pressure equation of state, and loading this pressure on the wall of the borehole and the surface of connected cracks, discontinuous deformation analysis （DDA） method to simulate the blasting process only considering the effect of explosion product in jointed rock mass is developed. A horizontal column borehole cast blasting case in jointed rock mass is simulated with this method. In the simulation, the chamber volume expanding and pressure attenuating histories are obtained. The process of borehole expansion, rock medium failure and movement, and blasting pile formation in rock blasting is well duplicated by the simulation.