Study on dumping mechanism of hydraulic powered support in fully mechanized wall of deep inclined soft coal seam

In the fully mechanized caving face of large inclination soft thick coal seam,there is a comparatively large gap between the articulated hydraulic front spar bracket,while the top coal in middle and upper part of the face crushing more fully and leak more easily.Top-bracket lost their jobs resistance and dump in the process of moving,which is more serious when roof pressure increases.Measures such as laying of metal mesh stents at the top of the frame,moving support with pressure on and rubbing the top,pseudo-helical arrangement of working face,moving support from the bottom of working face,controlling mining height,top-down one-way cutting coal,bottom-up and two mining caving with one leaking,increasing anti-inverted jack,can effectively prevent the occurrence of the dumping.