Abstract:

The underground power house of Zhouning hydropower station has deep cover and is located in intact granite. In order to minimize the impact on the rock crane beam imposed by blasting, related empirical formulas are obtained by means of insitu tests and regression analysis. The controlled charging quantity is back calculated on basis of the empirical formulas so as to ensure the safety of the rock crane beam of the underground power house. Furthermore, efforts are made to make quantitative analysis on the vibration reducing effect of the presplit cracks. The paper can provide reference for the excavation of similar underground power houses in the future.