高应力区分层开采冲击地压事故发生机理研究

Mechanical mechanism of rock burst accidents in slice mining face under high pressure

以某矿厚硬顶板条件下特厚煤层上分层开采发生的巷道与工作面同时冲击的事故为背景,研究事故发生的机理与治理方法。研究表明:引起事故的主要力源来自上层煤煤柱、不等宽区段煤柱、巨厚坚硬顶板和大断层等形成的集中应力;主要冲击灾害体是巷道和工作面内的底煤;底煤发生冲击的主要力学机理是底煤在水平应力突变条件下发生屈曲破坏,并在垂直应力作用下发生冲击性滑移。提出了上层煤柱对下层煤采动影响范围与冲击危险范围的评估方法,为制定恢复生产方案提供了科学依据。根据发生事故的机理,制定并实施了恢复生产的方案,通过实施危险区卸压措施和建立冲击危险实时监测预警体系,工作面恢复了生产,保障了安全开采。

The mechanism and prevention of rock burst are investigated based on a rare rock burst accident in which the rock burst around working face and roadway occur simultaneously in the upper slice mining face of extremely thick coal seam with thick and hard roof. The results show that the main cause is the concentrated stress from the top coal pillar, sectional coal pillar with different widths, thick and hard roof and large fault. The bottom coal under roadway and working face is the main hazard body of rock burst. The main mechanical mechanism of rock burst is that the bottom coal produces buckling failure under sudden horizontal stress, and then slips to roadway and working face under the vertical stress. An evaluation method for the influence scope of the top coal pillar and the danger scope of rock burst is proposed in order to provide a scientific basis for making programs to resume production. The relevant programs to resume production are developed and implemented based on the research achievements. Through the implementation of pressure relief in the danger area of rock burst and the real-time monitoring of pressure bumping risk, the production is resumed and the safe mining is ensured.