Defects in rock masses have a great influence on the propagation of explosion stress waves and crack propagation behavior. Combined with dynamic caustics experiments and ANSYS/LS-DYNA numerical simulations, the mechanical behavior of crack propagation and the distribution of the surrounding stress field at the end of defects are studied. In this paper, a front vertical filling defect with a length change and a rear horizontal defect with a fixed position were designed. We analyzed the influence of the length change of the front defect on the crack initiation time, propagation velocity, initiation toughness, stress intensity factor and final propagation length of the end of the two defects. The numerical simulation shows that, on the one hand, the front defect can attenuate the intensity of the explosion stress wave; on the other hand, the superposition of diffraction waves at the end of the front defect with a short length can promote the dynamic propagation of the crack at the end of the rear defect. In addition, the diffraction wave intensity of the front defect acting on the back-blasting end of the rear defect is higher than that of the end facing blasting, resulting in a higher peak value of the stress intensity factor of the back-blasting end. The numerical simulation provides a good explanation of the experimental phenomenon.

岩体中的缺陷对爆炸应力波的传播和裂纹的传播行为有很大的影响。结合动态碱度实验和ANSYS / LS-DYNA数值模拟，研究了裂纹扩展的力学行为以及缺陷结束时周围应力场的分布。本文设计了一个长度变化的前垂直缺陷和一个位置固定的后水平缺陷。我们分析了前缺陷长度变化对两个缺陷末端的裂纹萌生时间，传播速度，萌生韧性，应力强度因子和最终传播长度的影响。数值模拟表明，一方面，前部缺陷可以减弱爆炸应力波的强度；另一方面，前部缺陷可以减弱爆炸应力波的强度。另一方面，长度短的前缺陷末端处的衍射波的叠加可促进后缺陷末端处裂纹的动态传播。另外，作用在后部缺陷的后喷砂端上的前部缺陷的衍射波强度高于面向喷丸的端部的衍射波强度，导致后部喷砂端的应力强度因子的峰值更高。数值模拟为实验现象提供了很好的解释。导致爆破端应力强度因子的峰值更高。数值模拟为实验现象提供了很好的解释。导致爆破端应力强度因子的峰值更高。数值模拟为实验现象提供了很好的解释。