Abstract: Based on the dynamic strata pressure accidents happening when the working faces passed gully terrain in Huojitu coal mine of Shendong mine area, this paper has researched the influence laws of depth of gully on dynamic strata pressure of working face in shallow coal seams with the methods of theoretical analysis and numerical simulation experiments. The result indicates that the deeper the depth of gully is, the greater the possibility of being eroded by the primary key strata (PKS) is. When the working face meets the gully terrain, because the eroded PKS block can not form the stable bond-beam structure but cause instability, which will make the sub-key strata (SKS) blocks support increase load rapidly, it will cause dynamic strata pressure disasters and accidents on the working faces. Conversely, if depth of gully is shallow and the PKS block is not eroded, dynamic strata pressure accidents will not happen on working faces. Theoretical analysis and simulation results fit the in-situ measurement well.

Key words: depth of gully, gully terrain, shallow coal seam, key strata, dynamic strata pressure