岩浆岩床下伏短壁综放面集中静载荷型冲击启动原理

Start-up principle of concentrated static load type rockburst in short wall work face under magmatic rocks roof

为了探索没有动载荷源的冲击地压发生原理,以平庄某矿为例,采用数值分析、理论分析结合现场实测的方法,研究了巨厚岩浆岩床下伏短壁综放面回采前冲击启动原理。结果表明,巨厚岩浆岩床下伏短壁综放面开始推进前、后,下巷冲击启动都不需要动载荷源,难垮岩浆岩顶板的悬臂为冲击启动提供了足够的集中静载荷;短壁工作面开采使得下巷处于高位高应力区中,加剧了下巷冲击危险性;倾斜煤层巷道冲击时,围岩主应力方向大致与煤层倾向正交,使围岩冲击、鼓出非对称局部化,并且大致位于煤层倾向面的法线方向,这一认识为倾斜煤层冲击地压巷道支护与卸压实行非对称性提供新论点。

This paper aims to explore the mechanism ofrockburst occurrence without dynamic loading. Taking a mine of Pingzhuang Region as an example, the start-up mechanism of rockburst in short wall work face under magmatic rocks roof is studied by employing numerical analysis, theoretical analysis and field measurement method. The results show that, when the work face under magmatic rocks roof moves forwards or backwards, the lower roadway start-up occurs without dynamic loading, since the hard diabase roof provides sufficiently concentrated static load. Due to short wall mining, the lower roadway is brought into a high position and high stress area, which exacerbates the risk of rockburst occurrence. When bursting of the lower roadway happens in inclined coal seam, the principal stress of the surrounding rock is perpendicular to the dip direction of coal seam. Therefore, the burst and bulge of surrounding rock are asymmetric and localized and even its direction is corresponding to the normal direction of seam inclined plane. This study provides a new argument that asymmetrical method should be adopted to prevent rockburst in roadway support and pressure relief in the inclined coal seam.