Influence of design parameters of prestressed yieldable bolts on stability of deep mine roadway

The new prestressed yield bolt (PYB), a kind of extensional bolt, has excellent adaptability to the adjacent rock deformation. The PYB has been applied in the practices of supporting deep coal mine roadways. Considering the interface relationship between rocks, contact relationship between adjacent rocks and bolts, boundary conditions and prestress loading methods, a finite element model for the PYB supporting system is established. A real deep mine roadway supported by the PYB is selected to analyze the effects of performance parameters (yield load and the maximum yield distance) and design parameters (space length, length and diameter of bolt, prestress) of the PYB. The results and conclusions may provide some references to the engineering design of the PYB supporting system.