Research on Movement Characteristic of Surrounding Rock in Full-mechanized Mining Face with Large Mining Height

For geological condition of a colliery,this paper applied FLAC3D and 3DEC to researching coal failure area ahead of face and movement range of overlying rock under condition of different mining heights and face lengths.Results are as show.With increase of mining height and face length,failure area increases obviously and this will result in coal slide and roof fall.With increase of mining height,roof broken line advances and separation of strata increases.Roof instability is liable to form dynamic loading,so powered support needs larger yielding.