关键词: 坚硬顶板, 深浅孔, 水力致裂, 初采期

Abstract: Aiming at the problems of large overhanging roof area and serious air leakage in the goaf caused by the difficulty of the roof to collapse on its own in the initial mining stage of the working face under the hard roof, and the impact force caused by the sudden large-area collapse of the overhanging roof causes harm to equipment and personnel, etc, put forward a technical scheme of coupling three-dimensional directional hydraulic fracturing to weaken the roof at the initial mining depth and shallow hole. Through theoretical analysis, numerical calculation and field observation, etc., the first pressure data of the working face without hydraulic fracturing and the hydraulic fracturing of the new process were compared, the study revealed the control mechanism of the initial mining depth and shallow hole coupling 3D directional hydraulic fracturing technology on the hard roof structure of the fully mechanized caving face of the thick coal seam. The results show that the coupling of deep and shallow holes with three-dimensional directional hydraulic fracturing shortens the first pressure step of the basic roof of the 1012 working face from 58m to 16.3m, which greatly improves the safe production conditions during the initial mining of the hard roof.