Optimization Of Millisecond Time Based On Electronic Detonator To Control Vibration Velocity Of Deep-hole Blasting

Deep-hole blasting under complicated surrounding conditions has strict requirements for blasting vibration control.The development of electronic detonators has created conditions for precise blasting.However,empirical,semi-empirical and semi-theoretical methods were often used in practical projects to calculate millisecond time.Non-uniform calculation methods and large calculation errors may suppress the advantages of electronic detonators.This thesis takes the deep-hole blasting project in China Resources University in Xiao Jing Bay as the research object,by means of the combination of theoretical analysis,numerical simulation and engineering verification to analyze the influence of the millisecond time of deep-hole blasting on vibration velocity,and by optimizing millisecond time to realize the goal of controlling blasting vibration velocity under complex conditions.(1)This thesis studies how to determine the calculation method of the millisecond time,through the study of the basic theoretical calculation method of the millisecond time,it finally chooses the formation of a new free surface theory to calculate the inter-hole millisecond time,a flat-throw model based on the push-wall hypothesis to calculate the inter-row millisecond time.(2)Numerical simulation of millisecond time.According to the theoretical calculation results of millisecond time,inter-row differential time is fixed and inter-hole millisecond time varied.ANSYS/IS-DYNA is used to carry out dynamic finite element simulation and to analyze the effect of the precision of millisecond time on the blasting vibration velocity.Numerical simulations of 9 ms,10 ms,11 ms,12 ms,13 ms,14 ms,15 ms,16 ms and 17 ms were carried out respectively.The simulation results show that the blasting vibration velocity is the lowest in 15 ms,which meets the engineering requirements;and the influence of blasting vibration velocity of 1ms,2ms and 3ms precision difference has on this project is 0.9%~8.1%,2%~13%,2.5%~9.5% respectively.(3)Engineering verification of millisecond time.The engineering blasting tests of 9ms,11 ms,12ms,13 ms and 15 ms millisecond time are carried out respectively.The experimental results show that the blasting vibration velocity of 15 ms is the smallest,and the numerical simulation of blasting vibration velocity of 15 ms millisecond time is 18% different from the measured results.This thesis shows that it is reasonable to use the new free surface theory and the flat-throw model based on the push-wall hypothesis to calculate the millisecond time in a project similar to the deep-hole blasting in China Resources University in Xiao Jing Bay.The precision difference of 1ms millisecond time has a great influence on blasting vibration velocity and the optimization of differential time has great engineering significance for controlling blasting vibration velocity and realizing precise blasting.