非煤保护层工作面能量应力演化规律及顶底板结构对强矿震的影响

Study on energy stress evolution law of non-coal protective layer working face and effect of roof and floor structure on strong mine earthquake

保护层开采作为一种有效的冲击地压区域防治手段被广泛应用,而保护层本身也存在强矿震和冲击地压风险。以海石湾煤矿油页岩工作面保护层开采过程中发生的强矿震事件为工程背景,通过数值模拟、理论分析等方法,对强矿震的震源机制和主控因素进行了分析。结果表明:油页岩工作面强矿震多以应力集中下的压缩剪切破坏为主;被保护层工作面回采对保护层工作面底板区域的应力和能量分布影响更为显著;工作面坚硬顶板岩层、底板薄岩层、保护层与被保护层间岩层厚度变化等对强矿震事件发生存在显著影响。

Protective seam mining is widely used as an effective method for preventing and controlling rock burst,the protective layer itself also has the risk of strong mine earthquake and rock burst.Taking the protective seam of the oil shale working face in Haishiwan Coal Mine,which encountered with the strong mining earthquake during the mining process,as the engineering background,the focal mechanism and main control factors of the strong mining earthquake were analyzed through numerical simulation and theoretical analysis.The research results show that the strong mining earthquake in the oil shale working face are mainly caused by compression shear failure under stress concentration.The mining of the protected coal seam working face has a more significant impact on the stress and energy distribution in the floor strata of the protected seam.There are significant influences on the occurrence of strong mine earthquake events,such as hard roof strata,thin rock strata on floor and thickness variation between protective layer and protected layer.