Roof Breakage and Disaster Principle and Control of Shallow Mining in Steeply-inclined Coal-seam

In order to obtain the roof breakage rule of mining shallow steeply-inclined coal-seam with horizontal slicing mining and ensure safety,applying physical analogue experiment to researching roof caving rule,roof caving condition was analyzed by mechanics model. Numerical simulation was used to simulate the effect of blasting roof with 3DEC. Result showed that roof was difficult to cave in shallow mining steeply-inclined coal-seam and roof hanging was easy to occur. large area of roof caving could result into rock-burst. By forced caving in mining the first and second slice,roof potential energy could be effectively reduced,and caved gangue could aslo ensure safety of mining lower slices.