爆炸应力波作用下岩体破碎特性数值模拟分析

Numerical Simulation on the Rock Fragmentation Characteristic Under Explosion Stress Wave Disturbance

孔内爆破作为一种常用的破岩手段,广泛的用于岩体工程中。充分认识岩体的破碎特征是岩体工程中高效破岩的基础。通过采用RFPA^(2D-Dynamic)数值分析软件,建立岩体孔内爆破数值模型,分析岩体在爆炸应力波作用下的破碎特征。数值模拟结果表明,随着爆炸应力波峰值的增大,裂纹扩展距离随之增加。细观非均匀程度越大的岩体,在爆炸应力波的作用下,离散的破坏越多,萌生裂纹的数量越少,裂纹传播距离也越短。另外,岩石节理对爆炸应力波的削弱作用随着节理间距的增加呈现先增加后减小的特征。同时,节理的存在极大程度上削弱了岩体的破坏程度。

Hole-blasting,as one of the most commonly used rock fragmentation methods,has been widely utilized in rock engineering. Sufficiently understanding of the rock fragmentation characteristic could provide a good guidance for efficient rock breaking in rock engineering. In this study,the hole-blasting model of rock masses is established using the numerical code RFPA-（2D-Dynamic） to investigate the fragmentation characteristic of rock masses under the disturbance of the explosion stress wave. Simulation results demonstrate that the length of the cracks is determined by the explosion wave magnitude. With increasing wave magnitude,the length of the cracks increases. In addition,numerous discrete failures are captured inside rock masses with relatively low heterogeneity index. And the number and length of the cracks are increased with increasing rock heterogeneity index. Moreover,the rock joint significantly influence the propagation of the explosion stress wave. With increasing rock joint spacing,the weakness of the stress wave energy by rock joint gradually decreases before notably increasing.