二氧化碳气爆致裂综放工作面上隅角顶煤技术应用

Application of top coal technology in the upper corner of CO_(2)gas explosion induced cracking fully-mechanized caving face

为解决三元煤业综放工作面上隅角悬顶带来的安全隐患,通过理论计算得到了二氧化碳气爆致裂工作面上隅角顶煤的影响半径,设计了相关爆破孔布置方案及参数,开展了数值模拟验证和现场工程应用。研究与应用表明,沿煤柱侧打设一列气爆孔对回采巷道煤柱侧顶煤进行液态二氧化碳相变气爆致裂后,气爆孔间的顶煤均进入塑性屈服状态,煤柱侧、跨中及回采侧巷道顶板的下沉变形不再呈现常规的下凸形式,临近工作面时回采巷道煤柱侧与跨中的顶煤下沉量基本相当且增加较明显;超前综放工作面回采巷道顶煤气爆致裂切顶技术较好地解决了上隅角顶煤悬顶问题。

In order to eliminate the safety hazards caused by the hanging roof at the upper corner of the fully-mechanized caving face in Sanyuan Coal Industry,the influence radius of the top coal at the upper corner induced by CO_(2) gas explosion was obtained through theoretical calculation,and the blasting layout scheme and its parameters for gas explosion to fracture coal at upper corner roof were designed.Numerical simulation verification and field engineering application were also carried out.Research and application have shown that after drilling a series of gas explosion holes along the side of the coal pillar to cause liquid carbon dioxide phase change gas explosion cracking of the top coal on the side of the coal pillar in the mining roadway,the top coal between the gas explosion holes enters a plastic yielding state,and the subsidence deformation of the top coal on the side of the coal pillar,the middle span,and the mining side of the roadway no longer presents a conventional downward convex form.When adjacent to the working face,the subsidence amount of the top coal on the side of the coal pillar and the middle span in the mining roadway is basically equal and increases significantly.The technology of gas explosion induced cracking and roof cutting at the top of the mining roadway in the advanced fully-mechanized caving face has effectively solved the problem of coal suspension at the upper corner.