Weakening technology and application of ultra-deep hole energy-gathering blasting in fault structure area
Li Jianguang 1, Cheng Zhibin 2
1. Shanxi Lingshi Huayuan Coal Industry Co., Ltd., Jinzhong 031302, China; 2. Henan Polytechnic Industry Technology Research Institute Co., Ltd., Jiaozuo 454000, China
Aiming at the engineering problems of difficult cutting and limited propulsion efficiency of shearer in hard rock stratum during the period of No.10 coal seam passing through DF5 fault in Huayuan Coal Industry, this paper puts forward the advanced weakening technology of hard rock in deep hole multi-directional energy-gathering blasting. Through theoretical analysis, the directional cracking mechanism is clarified, and the three-dimensional calculation model is established by using ANSYS/LS-DYNA dynamics software. The blasting parameters are optimized by numerical simulation, and the equipment conditions of field drilling rig, hole sealing process and drilling economic cost are comprehensively considered. Finally, it is determined that the single hole diameter is 94 mm and the hole spacing is 2.0 m staggered, and the advanced weakening effect of hard rock is better. The field test results show that after blasting, a penetrating crack is formed inside the hard rock, the wear of the shearer pick is reduced by more than 40%, the overall propulsion efficiency of the working face is increased by more than 30 %, and the roof stability is maintained.
