Abstract：In order to make further analysis of crack propagation for blasting fracture，the paper gives a method to research dynamic mechanical characteristics by the transmitted dynamic caustics. The results indicate that the zone of fracture shows typical tensile fracture. The experiment finds that the trend of the dynamic stress intensity factors，the crack expanding lengths and velocities is almost the same with time. The lengths of blasting main cracks are achieved during 60–200 μs. The ultimate values of dynamic stress intensity factors are smaller than 1.5 MN/m3/2. The tough value of blasting cracks is about 0.3 MN/m3/2. “Gas wedge effect”of the high-pressure gas jet is the main driving force of radial compression cracks，playing a key role in the crack propagation of the cumulative energy orientation cracks under the directional blasting，while restraining the development of the non-cumulative energy directional radial compression crack. It is analyzed the fracture characteristics of the double-point jet with the double-seam thread jet in further，and found that the results of directional fractures and the fine fracture surfaces both can be achieved. Technical ideas are brought forward that both the double thread jet and the multi-seam thread jet cumulative cartridge should be utilized in the directional fracture blasting. The multi-seam thread jet cartridge can be applied to deep-hole presplitting explosion，such as deep-hole presplit blasting，to improve the speed of seam gas drainage and prevent mine gas and coal outburst in high gassy and low permeability coal seam.
李清，梁媛，任可可，曾佳，张茜. 聚能药卷的爆炸裂纹定向扩展过程试验研究[J]. 岩石力学与工程学报, 2010, 29(08): 1684-1689.
LI Qing，LIANG Yuan，REN Keke，ZENG Jia，ZHANG Xi. EXPERIMENTAL STUDY OF PROPAGATION OF DIRECTIONAL CRACKS WITH SHAPED CHARGE UNDER BLASTING LOAD. , 2010, 29(08): 1684-1689.
