Mechanism of the rib spalling and the controlling in the very soft coal seam

Studied the mechanism of the rib spalling and controlling in detail,and proposed that main engineering way of controlling the rib spalling was to decrease coal wall pressure and increase the shear strength of the coal wall.The following research results are obtained: the top coal caving technique and increasing the resistance of the support can reduce the pressure on the coal wall.The cohesion and shear strength of the coal wall may be increased by means of the coal wall water infusion.They are effective engineering ways to prevent the rib spalling.The quickly coal wall advance and proper low wall height are also advantageous to the wall stability.