Abstract: As the influence of mining from up to down of No.15 coal seam in No.9101south fully mechanized face of Gaizhou Coal.Breaking of main roof ahead of workface has resulted in hysteresis breaking of goaf main roof,the increased weighting interval and hanging area,delayed caving of immediate roof.That has caused decreasing of power stroke of support column and support crushing.In order to reduce the occurrence of support crushing,This paper introduces general situation of No.9101south fully mechanized face,process of support crushing,reason of support crushing,measures of support crushing,experiences of support crushing,which has reference value under similar coal mines.

Key words: Mediumthick seam, Fully mechanized face, Support crushing, Experience