Inference Of Blasting Vibration To Open-pit Slope And Vibration Prediction

Topography and geology condition is the key factor to influence the propagation of blasting seismic wave, and due to the particularity of blasting seismic wave which is reduced from the special topography condition of deep open-pit mine, the peak particle velocity of blasting vibration around mines has not been predicted by traditional Sadov's empirical formula. Therefore, it is much needed to find a suitable propagation law of blasting vibration in deep open-pit mine.In this paper, based on the prediction of peak particle velocity of blasting vibration, it is analyzed that the variation law of peak particle velocity of different measured points on reserved boundary bench at the situation of same blasting center distance and different initiation point. The result is that the horizontal distances at different space positions between initiation point to step's bottom and between measuring points to step's vertex significantly influence the prediction of blasting vibration.By using theoretical analysis, physical mechanism that blasting vibration wave propagate and decay in the rock can be obtained; analyze the law of wave propagate in the special topography open-pit mine, including using the theory wave reflection and transmission propagate in the medium to demonstrate elevation amplification firstly, and combination previous study experience secondly, finally, concluding that elevation amplification which is not in finitely amplified has its peak value.Through the theorys of wave propagating in the homogeneous medium and multilayer media, attenuation law of elastic wave propagate in the rock can be gotten, which provides important theoretical basis for studying the attenuation law of blasting vibration.Using LS-DYNA to study the three-dimensional numerical simulation of open pit bench blasting, combined with energy analysis, study the attenuation law of blasting vibration total energy and peak particle velocity with the variation of blast center distance. The results show that the attenuation law of peak particle velocity is coincident with the attenuation law of blasting vibration total energy, all happened in the near area of blasting center.Simulate the explosive process by introduced the blasting injury factor, and using the damage constitutive model JHC of LS-DYNA, and get the radius of fragmentation zone and crack area.Base on the blasting injury theory and wave theory, conclude that buffer blasting can reduce the blasting vibration up to50%. The range of injury is smaller obviously than having not using buffer blasting hole.Combined with energy analysis and dimensional analysis, the main influence factors of blasting vibration is put forward and determine the basic variable of dimensional analysis, after which the blasting vibration forecasting formula is derived base on dimensional analysis, then get the very formula which reflect the flat distance between the explosion source and step bottom, and the flat distance between measuring point and step vertex. Besides, do the error analysis for the derived formula, using Matlab program composition combined with the numerical simulation.The field test results show that the derivation formula predict the peak particle velocity of blasting vibration in deep open-pit mine correctly and effectively, which has a great guiding significance to the safety of open-pit mine.