爆炸应力波作用下的凿岩爆破破岩模拟

爆破破岩是爆炸应力波和爆生气体载荷共同作用的结果,本文采用改进的DDA方法模拟爆炸应力波作用下的爆破破岩过程. 采用Hopkinson层裂算例验证了DDA方法对应力波传播和动态断裂破坏问题模拟的准确性. 通过在炮孔壁上施加三角冲击载荷,模拟再现了凿岩爆破中爆炸应力波作用下的孔周破坏、自由表面剥落、碎裂漏斗区域形成、较远区裂纹的扩展,以及岩体的抛掷,结合应力波传播模拟结果对破岩过程与机理进行了分析. 研究为进一步采用DDA模拟两种形式爆破载荷共同作用下的凿岩爆破创造了条件.

Numerical Modeling of Rock Failure in Drilling Blasting Under the Effect of Explosion-Induced Stress Waves

Blasting-induced rock failures are resulted from the loading effects of explosion-induced stress waves and explosion gas pressure. In this paper, rock failure under the former effect was numerically modeled by the discontinuous deformation analysis (DDA). Firstly, the DDA was verified by the simulation of a Hopkinson spalling model. It shows that wave propagations in rock and the resulted rock dynamic fracturing can be accurately modeled. Thereafter, drilling blasting simulations were conducted by applying triangular shock loads on the borehole walls. Rock failures including the fracturing surrounding boreholes, the spalling near the free surface, the formation of the crater-shaped fragmentation domain, the crack evolution in the relatively far region, and the cast of rock were numerically reproduced. The failure process was analyzed combining the simulated stress wave propagation process. This work is the basis for the further simulation of rock blasting considering both blasting loading effects.