Study on ground pressure behaviors of working face in nearly shallow coal seam under gully terrain

In order to analyze the influence of gully terrain on ground pressure behavior in nearly shallow coal seam,the 20105 working face in Wangjialing coal mine is taken as the research object,and the working resistance characteristics of hydraulic support under different slopes are measured and analyzed by using the top dynamic monitoring system.The research shows that the pressure step distance,duration and pressure intensity are different in different regions along the working face.Compared with the vertical depth of gully and the angle of slope body,the gully cutting coefficient is the main factor affecting the appearance of ground pressure.When the gully cutting coefficient is greater than 0.4,the increment of support resistance exceeds 8%,and when the gully cutting coefficient is less than 0.17,the change of support resistance is not obvious.The influence of gully topography on the support resistance of near-shallow coal seam is relatively low.