Analysis of critical failure depth of surrounding rock of roadway under blasting disturbance

Mathematical expression of critical failure depth of surrounding rock of roadway under blasting disturbance was obtained through elasticity analysis. On the basis, influence rule of roadway excavation radius, blasting vibration speed and cohesion force of surrounding rock on stability of roadway for drilling and blasting excavation were discussed by orthogonal test. Critical blasting vibration velocity which will not destroy surrounding rocks was derived. The analysis results show that as excavation radius of roadway increases by 1 m, the critical failure depth increases by 0.365 m; the critical failure depth increases logarithmically with increase of blasting vibration velocity; the depth of critical failure decreases exponentially as cohesion of surrounding rocks increases; cohesion and blasting vibration velocity are the most significant factors affecting the critical failure depth.