The Mechanism and Prevention of Rock Burst Induced by Thick and Hard Roof Breakage

Based on the mechanism of static and dynamic load superimposed induced rock burst,taking a thick and hard roof above the coal seam.As the research object,the mechanical model that working face recovery and roadway along the roof breaking induced rock burst was established,deduced the theoretical formula that the increase of average stress and dynamic load caused by roof breakage,and the formula of judgment of roof tensile failure and shear failure.The comparison between the monitoring results of borehole stress meter and the theoretical calculation results showed that the dynamic load and stress increment can be calculated accurately by using this mechanical model,the roof thickness,support width and fracture line is the key factor affecting the dynamic load.Through the discussion of this mechanical model,several effective methods for preventing and controlling impact pressure were pointed out.The construction of the mechanical model provided a new way to identify and prevent the impact of rock burst.