导向孔对两爆破孔间成缝过程影响的数值模拟

在爆破中，控制裂纹扩展的方法之一是在装药孔之间开挖导向孔，促使裂纹的扩展贯通。炸药在爆炸时，产生的载荷包括爆炸应力波和爆生气体压力。基于这一认识，研发了爆破损伤的数值模拟系统，并对有机玻璃试样中两炮孔同时起爆时孔周裂纹的萌生、扩展过程进行模拟，探讨了无导向孔、有一个圆形导向孔和有一个带切割槽的导向孔3种情况下裂纹的扩展规律。数值模拟结果与室内试验结果相吻合，这一方面证实了在装药孔之间开挖带切割槽导向孔对控制裂纹扩展的有效性，同时也验证了该文提出的爆破损伤模型的可行性。

NUMERICAL SIMULATION ON CONTRIBUTION OF GUIDE-HOLE TO CRACK COALESCENCE OF TWO BOREHOLES

One of the best ways to control the crack propagation during rock blasting is to drill a guide-hole between the charging boreholes. The blasting process is composed of two consecutive stages, i.e., the dynamic stage caused by the stress wave and the static stage caused by the explosion gas. Based on this cognition, a general damage model for blasting damage is established. The blasting-induced crack propagation around two boreholes in the PMMA (polymethyl methacrylate) when detonated simultaneously is numerically simulated. The different cracking patterns under the configurations of no guide-hole, an ordinary circular guide-hole and a notched guide-hole between two charging boreholes are examined. The numerical results agree well with the experiments in the laboratory, which verify the effectiveness of the configured guide-hole in controlling the crack coalescence between two boreholes and confirm the validity of the proposed model in predicting the blasting damage.