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

Abstract

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.

Keywords

• oil shale working face
• protective seam mining
• strong mine earthquake
• rock burst
• rock structure