Coal seam permeability is one of the key factors influencing gas extraction efficiency, which great significance to reduce coal and dynamic disasters in gassy mines. Hydraulic slotting technique an effective method stimulate reservoir, but selection parameters has impact on efficiency. For this reason, hydraulic model was established by using FLAC3D software analyze stress distribution before a...

In view of the high gas pressure and low permeability deep coal seam, it is difficult to control gas, which affects safety production mine. The technical scheme hydraulic fracturing improve seam put forward, drainage technology used emission seam. effect under different water pressure, gradient times, in situ stress analyzed by using 3DEC (3-Dimensional Distinct Element Code) discrete element s...

Gas disasters, such as coal and gas outburst overflow, always occur during the mining of steep extra-thick seam in horizontal, fully mechanized, top slice caving (HFMTCSC) method. To solve these issues guarantee safe efficient Yaojie No. 3 mine, 3DEC software was used this work to investigate overburden movement collapse law well stress redistribution coal-seam deformation characteristics below...

Aiming at the problems of difficult support mining roadway under goaf close distance coal seam, obvious large deformation, and long-term continuous deformation surrounding rock, an advanced bolt-grouting system is proposed. The can effectively solve problem from design system, construction monitoring evaluation realize intelligent support. Based on actual engineering background 29204 working fa...