近直立煤层水平分段开采夹持煤体型冲击机理及防治

针对目前近直立特厚煤层水平分段开采条件下动力灾害发生的现状，综合运用理论分析、数值模拟等研究方法，分析了顶底板和煤体3者形成的结构并建立力学模型，认为近直立煤层在顶底板两侧均受到支承压力的夹持挤压，正是这种夹持力构成了冲击力源，经过力学推导，得出表征力源集中程度和发展趋势的关系式。采用数值模拟方法分析了开采后夹持煤体的应力分布特征，对理论分析进行了验证。结果表明:从工作面水平直至下方约70 m深度的煤体出现了应力集中现象，夹持煤体的增压区才是发生动力灾害的直接危险源。基于分析结果，在工作面巷道进行顶底板预裂和煤体卸压爆破等原有卸压措施的基础上，提出在夹持煤体中掘进爆破卸压巷的防治方案，为近直立特厚煤层水平分段开采冲击灾害防控提供借鉴。

Rock-burst mechanism and prevention of clamping coal in mining near-vertical coal seam with horizontal slice method

According to the present situation of dynamic disaster under the conditions of horizontal slice mining of near-vertical and extremely-thick coal seam,the structures of roof,floor and coal were analyzed,and the mechanical model was established.The near vertical coal seam is clamped by the support pressure on both sides of roof and floor,the force source of clamping pressure which might result in rock burst was analyzed,and its expression of concentration degree and development trend was obtained by mechanical model solution.The stress distribution characteristics of the clamping coal were analyzed by numerical simulation and the theoretical analysis was verified.The results show that the stress concentration phenomenon occurs in the coal body from the level of the working face to about 70 m depth below.The pressurized area of the clamping coal is the direct hazard of rock-burst.Based on the analysis results,the prevention and control scheme of the rock-burst was put forward,which is to develop a heading for blast de-stressing.