巨厚岩浆岩失稳导致的冲击地压灾害严重威胁着煤矿的安全生产。以王楼煤矿巨厚岩浆岩下孤岛工作面开采为工程背景,采用理论分析、数值模拟和现场实测等方法研究巨厚岩浆岩失稳的孤岛工作面防冲,得出如下主要结论:(1)巨厚岩浆岩失稳导致的孤岛工作面冲击地压类型为自发型和诱发型,自发型冲击机制为巨厚岩浆岩失稳导致自身及其上覆载荷层重力向下传递,使得被影响区域煤岩应力逐渐集聚到冲击的应力水平,诱发型冲击机制为巨厚岩浆岩断裂强动载使得被影响区域煤岩应力突跃至冲击的应力水平;(2)提出巨厚岩浆岩失稳的孤岛工作面整体失稳冲击判断准则,根据准则将王楼煤矿12310孤岛工作面设计成大宽度孤岛工作面开采可使其由整体失稳冲击向局部冲击转化,并得到了现场验证;(3)针对巨厚岩浆岩失稳时大孤岛工作面局部冲击类型提出了保持低应力的防治措施,微震、应力监测结果验证了措施的有效性。研究成果为巨厚坚硬岩层下工作面冲击地压灾害的防治提供了一种新方法。
Rockbursts induced by instability of super-thick magmatic strata presents a serious threat to mine safety and production. This paper investigates the rockburst mechanism induced by instability of super-thick magmatic strata in Wanglou coal mine using field monitoring, numerical simulation and theoretical analysis. The main results are as follows (1) The rockbursts in island longwall panels induced by instability of super-thick magmatic strata can be classified into two types, spontaneous type and induced type. Spontaneous rockbursts occur due to the overstressing of the instable super-thick magmatic strata and the overburden. Induced rockbursts occur due to the dynamic loading from the movement of super-thick magmatic strata. (2) The criterion for overall burst instability of island longwall panels was proposed. Using the criterion, LW12310 at Wanglou coal mine was designed into large-width island longwall panel to transform the overall rockbursts into local rockbursts. (3) Corresponding measures were developed according to local rockburst mechanism, which agreed well with microseismic and stress monitoring results. The research results provide a practical approach for rockburst prevention of island longwall panels under super-thick magmatic strata.