正断层下盘工作面煤柱尺寸效应及冲击危险性分析

Analysis of Size Effect and Impact Hazard of Coal Pillar in Working Face of Normal Faults

为了研究工作面沿断层走向布置,不同煤柱宽度条件下采动空间的冲击危险性。采用FLAC3D数值模拟的方法,研究了不同宽度断层煤柱应力及其稳定性、正断层活化及弹性能密度空间分布。结果表明:正断层下盘工作面开采当断层煤柱尺寸较小时,采空区断层煤柱发生塑性破坏,断层滑移范围从基本顶位置处延伸至高位岩层断层面处,断层滑移量大,采动应力集中及弹性能聚集区域位于断层侧工作面前方;当断层煤柱尺寸较大时,煤柱能有效控制基本顶位置处断层滑移,仅高位岩层处断层发生少量滑移,断层侧工作面前方采动应力集中程度与弹性能密度明显降低。因此在确定断层煤柱尺寸时,应避免断层煤柱发生塑性破坏。

In order to study the layout of the working face along the fault, the impact hazard of the mining space under different coal pillar width conditions. FLAC3 Dnumerical simulation method was used to study the stress, stability, normal fault activation and elastic energy spatial distribution of coal pillars with different widths. The results show that when the size of the fault pillar is small, the plastic failure occurs in the coal pillar of the goaf, and the fault slip extends from the basic top position to the fault plane of the high rock formation, and the fault slip is large. The mining stress concentration and elastic energy accumulation area is located in front of the fault side working face. When the fault pillar is large in size, the coal pillar can effectively control the fault slip at the basic top position, and only a small amount of fault slips at the high level rock fault. The concentration degree of mining stress and elastic energy density in front of side face are significantly reduced. Therefore, the plastic failure of fault pillars should be avoided when the size of fault pillars is determined.