Study on elevation effect of blast wave propagation in high side wall of deep underground powerhouse

Abstract

In the excavation for underground powerhouse, the blasting vibration leads to dynamic disturbance for construction safety and stability, which means such vibration should be monitored and mitigated. In this paper, the Baihetan Hydropower Station is involved, and the blasting vibration is monitored along either the vertical or the horizontal direction. The monitoring results of the distribution of blasting vibration on the high sidewall shows the vibration velocity at some positions far away from the detonation source is greater than that near the source. Such abnormal elevation amplification phenomenon is different from the distribution of blasting vibration on the slope of open-pit mine. To address this phenomenon, the dynamic finite element simulation is conducted. The comparison between the simulation results and monitoring data validates the proposed solution. Furthermore, the propagation law of blasting vibration velocity of high side wall is proposed, and the local elevation amplification effect of blasting vibration velocity is clarified. Finally, the modified Sadovskii formula is presented, and the reliability and accuracy of the modified formula for the vibration velocity of particles in the direction of elevation are verified and improved through data comparison.