Blasting Vibration Safety Criterion of Surrounding Rock of a Circular Tunnel

Abstract

In blasting excavation, the safety of existing structures is always affected. In the past, the vibration velocity of the incident wave is always used to determine the blasting vibration safety criterion, which is not easy to monitor. In this paper, blasting waves are simplified as plane P-waves. Based on the wave function expansion method and the Mohr–Coulomb strength criterion, the responded vibration velocity is used to establish the blasting vibration safety criterion of surrounding rock of a circular tunnel. Combined with a specific engineering case, the influence of the frequency and the radius of tunnel is analyzed. Results show that the maximum radial vibration velocity is greater than the maximum tangential vibration velocity and it is used to determine the safety criterion. The blasting vibration safety criterion increases with the increasing frequency when the frequency is low and it fluctuates slightly when the frequency is high. The influence of the radius of tunnel is complex and the influences are opposite when the frequencies are low and high.