Abstract: Slotted cartridge blasting improves the quality of roadway excavation and the stability of surrounding rock by directional control of blasting energy release path.Aiming at the problems of stress dispersion and surrounding rock damage in conventional blasting in the corner area of rectangular rock roadway excavation,based on the existing symmetrical slotted car tridge structure,a right-angle slotted cartridge structure suitable for blasting control in the corner area is proposed.Based on the LS-DYNA numerical simulation method,the energy propagation characteristics,surrounding rock damage evolution law and crack propagation form of the structure under single-hole and multi-hole blasting conditions are systematically analyzed.By comparing with the simulation results of different charging structures,the energy directional release and damage control effect are evaluated,and the field application verification is carried out in combination with the engineering practice.The results show that the right-angle slotted cartridge can realize the aggregation and synergistic release of blasting energy in the vertical orthogo nal two-way direction.The energy regulation mechanism is that the stress concentration effect in the slit direction is enhanced, and the stress response of the surrounding rock in the non-slit area is significantly weakened,so as to guide the stable expan sion of the crack along the preset path and inhibit the crushing failure of the non-slit area.The crack propagation influence in dex Ks and the crushing zone damage influence index Kc proposed in the study can effectively reflect the spatial distribution of blasting energy and the regulation ability of surrounding rock damage morphology by the slit structure,and provide a unified in dex for the quantitative evaluation of different slit charge structures.The engineering practice results further show that the ener gy directional release law of the right-angle slotted cartridge has good applicability in the actual rectangular and complex cross section rock roadway excavation,which can significantly improve the section forming quality and reduce the degree of over-ex cavation and surrounding rock loosening.The research results provide a theoretical basis and technical reference for the structural optimizationdesignof slottedcartridgeblastingandthedamagecontrol of complexsectionroadway.

Key words: slottedcartridge,numerical simulation,crackgrowth,surroundingrockdamage