Single low permeability coal seam water coupling deep hole pre-splitting blasting
Han Xiwei 1, 2, Han Yanning 1, 2, Yang Yuqiang 1, 2, Yi Jiahui 3
1. The First Exploration Team of Shandong Provincial Bureau of Coal Geology, Zaozhuang 277100, China; 2. Shandong Provincial Gas Prevention and Control Engineering Center, Zaozhuang 277100, China; 3. Shanghai University of Applied Sciences, Shanghai 200000, China
Abstract： In order to solve the problems of poor gas permeability, difficult extraction and poor antireflection effect of traditional blasting methods in single low permeability coal seam, a method of replacing air decoupling with water coupling charge is proposed. The deep hole pre-splitting blasting model of water coupling charge was established by ANSYS/LS-DYNA software, and the effect of stress wave transmission and crack extension after blasting was analyzed. It was concluded that the water coupling charge method can better transmit the stress wave generated by blasting. The water-coupled deep-hole pre-splitting blasting test was carried out in the 14207 lower bottom drainage roadway of Xinzheng Coal and Electricity Co., Ltd.in Henan Province.After the blasting cracking, the coal seam gas concentration and the standard gas pure flow were greatly improved. The mutual verification with the numerical simulation results shows that this method can better increase the permeability of the coal seam and improve the difficulty of gas extraction in a single low-permeability coal seam.
