Mining-induced pressures caused by mining shallow buried coal seam in the gully terrain of Madiliang Coal Mine

To study the characteristics of mining-induced pressures of a shallow-buried coal seam in gully terrain mined using comprehensive mining method, a case study was performed at the 507 Longwall panel in Madiliang Coal Mine. The working resistance of the hydraulic yields in the longwall face was monitored by a dynamic monitoring system. The characteristics of mining-induced pressures were evaluated as the longwall face entered the shallowly buried deep area. The influence of gully dip depth, gully slope angle, and gully cutting coefficient on the working resistance were investigated. The research results show that:the 507 longwall face cycle pressure presents obvious zoning pattern, pressures mainly occurred in the central measurement area and not distinct in the upper and lower measurement area. With the reduction of overburden thickness, the periodic weighting distance increases, and the duration of the weighting is extended, the dynamic load coefficient also increased. In the gully terrain, the gully cutting coefficient is the dominant factor affecting the working resistance, followed by the gully slope angle. With the increase of both, the increment of working resistance increases. When the gully cutting factor is greater than 0.65, the increment of working resistance is more than 10%;when the gully cutting factor is 0.40-0.65, the increment of working resistance is 5%-10%;when the gully cutting factor is less than 0.40, the increment of working resistance is less than 5%. © 2021, Editorial Office of Journal of Mining and Strata Control Engineering. All right reserved.