Study On High-level Effect Of Blasting Vibration Of High Side Wall In Deep Underground Cavern

In the large-scale underground power plant underground blasting excavation process,if the blasting vibration is controlled improperly,it will lead to anchorage force of support anchor reduction,concrete cracking,the cohesive force between concrete and rock surface decreases,and the construction of pipeline and electrical equipment fault,loss,damage.However,if the blasting vibration is controlled too conservative,it will directly affect the excavation progress and reduce the efficiency of the project,thereby reducing the efficiency of the project.Therefore,it is necessary to study the propagation and attenuation law of blasting seismic wave along the high side wall of deep underground cavern,which could provide the basis for selecting reasonable construction method and blasting parameters.Therefore,it is necessary to study the propagation and attenuation of the blasting seismic wave along the high side wall of the deep underground cavern,and provide the basis for selecting reasonable construction method and blasting parameters.In this paper,based on the excavation of the right bank of Baihetan hydropower station,it is found that the vibration velocity on the high side wall of the underground cavern has high elevation effect.The ANSYS/LS-DYNA dynamic finite element software is used to explore the variation law and characteristics of the blasting vibration amplification effect of underground caverns under different ground stress conditions.The main contents are as follows:(1)In this paper,the basic theory of rock blasting and the influencing factors of blasting seismic effect are discussed.At the same time,the propagation and attenuation of blasting seismic wave are summarized.Then,the study of blasting vibration effect of rock high slope is proposed to extend to high wall and large span underground cavern.(2)Through the regression analysis of multiple sets of blasting vibration test data in the main transformer,the maximum single peen dose satisfying the blasting requirement is obtained.The frequency characteristics of the measured vibration velocity are analyzed by using the typical particle velocity and time curve.The results show that there is a magnification effect on the vibration velocity of the arch at the arch of the main hole during the blasting excavation.(3)The numerical simulation software is used to analyze the variation law of the surface temperature and the horizontal distance of the underground wall under different stress conditions.The numerical simulation results under different conditions are analyzed,including the characteristics of vibration velocity and the frequency spectrum analysis of vibration velocity.Then,the characteristics of the variation of the vibration height of the high wall underground chamber are obtained under different conditions.According to the distribution law of vibration velocity at different horizontal distance,the distribution characteristics of vibration height enlargement area and the variation rule of vibration velocity amplification zone with increasing horizontal distance are analyzed when the excavation depth of underground cavern is not changed.