Study on the wing crack propagation behaviour of defective medium under delay blasting

This study investigates the wing crack propagation behaviour under delay blasting via experiments and numerical simulations. The results show that when boreholes are detonated simultaneously, the stress waves from the remote borehole enhance the propagation of wing cracks. When the explosion stress waves are superimposed, the peak crack propagation velocities increase by 10.50%. When the stress waves interact with the running cracks, the peak propagation velocities increase by 37.64%, and the enhancing effect is most obvious. In the case of a long delay time, the dynamic mechanical parameters in the second phase are lower than those in the first phase.