Numerical simulation on rockburst prevention by cutting stress-relief slots

With the gradual development of rock engineering to the deep, rockburst disaster caused by high geo-stress is getting worse.Cutting stress-relief slots may be one of the effective measures to actively reduce the high geo-stress of surrounding rock and prevent rockburst.In order to explore the prevention effect of slotting on rockburst, this paper conducts different slotting schemes via the discrete element numerical simulation method for comparison and analysis.The results show that the circumferential stress of a roadway will increase after excavation, and the surrounding rock is prone to cause rockburst.Slotting in the surrounding rock can form a triangular low stress area around the slot, and transfer the high stress zone to the slot bottom, so as to achieve the effect of preventing rockburst.However, the effect of stress relief by slotting will be affected by its specific location, and when the geo-stress is high(≥ 50 MPa), cutting stress-relief slots will cause damage to the surrounding rock and destroy its integrity, and induce rockburst.In addition, when the horizontal lateral stress coefficient is small, the elastic strain energy released by slotting at different positions is very similar, but when the horizontal lateral stress coefficient is large, the energy release effect of slotting at the roadway roof is better than that at the roadway side.Therefore, in engineering practice, appropriate slotting method, position and support measures should be comprehensively adopted to prevent rockburst according to the geo-stress conditions(stress level, lateral stress coefficient, etc.) and the stability of surrounding rock of a roadway.