Damage Mechanism of Surrounding Rock under Blasting Excavation of the Tunnel.

Based on numerical simulation software LSDYNA and field monitoring data, this paper analyzes the peak particle velocity (PPV) of rock mass at different distances from the blasting face of the roadway. At the same time, the dynamic stress concentration coefficient of surrounding rock under the action of different blasting times and the blasting damage effect of the tunnel are studied. The results show that in the tunnel blasting near the area, the PPV in the vertical direction of the tunnel is maximum in three directions; PPV decreases more slowly in the excavated zone than in the nonexcavated zone. When the explosion source is close to the roadway, the dynamic stress concentration coefficient of the blasting side and the rear side is large, so the vibration standard of surrounding rock should be strictly controlled. [ABSTRACT FROM AUTHOR]