聚能定向预裂爆破切顶卸压在坚硬顶板综放工作面的应用

Application of Directional Fracture Blasting to Cut and Relieve Pressure in Fully-Mechanized Top Coal Caving Face with Hard Roof

金辛达煤业11(9+10+11)#煤层顶板为坚硬的K2灰岩,平均厚度10 m左右。工作面回采期间,受临近工作面采空区侧向支承压力影响,工作面顺槽变形底鼓严重。通过现场应用定向预裂爆破切顶技术,回采前人为控制采空区K2灰岩顶板断裂位置,消除悬臂梁、三铰拱,使采空区侧向支承压力及应力集中系数大大减小,达到了保护临近巷道的目的。

The roof of 11(9+10+11)~#coal seam in Jinxinda Coal Industry,which is hard K2 limestone,of which average thickness is about 10m.During the mining,affected by the side abutment pressure of adjacent gob,tailentry deformation and floor heave were serious.By using the technology of directional fracture blasting to cut the roof,the fracture position of K2 limestone roof in gob was controlled artificially before mining,the cantilever beam or three hinged arch was eliminated,and the side abutment pressure of adjacent gob and stress concentration coefficient were greatly reduced,the aim of protecting the adjacent tailentry was achieved.