Research On Energy Utilization Ratio Of Rock Fragmentation By Blasting

On the basis of summarizing the mechanism of explosive detonation,the energy distribution of explosive rock breaking process and the mechanism of smooth blasting,the energy distribution of explosive rock breaking is further divided in detail.The existing charging structure,including the eccentric charging structure which may appear in engineering practice,and its theoretical influence on the utilization rate of rock breaking energy and smooth blasting effect are analyzed.It provides guidance for the research scheme of improving the energy utilization ratio of explosive rock breaking.The main research contents and conclusions are as follows:Firstly,the experiment of critical diameter of emulsion explosive is designed and implemented.The results show that the confinement material can reduce the energy loss of lateral rarefaction wave in the process of detonation propagation,and then increase the critical detonation diameter and detonation velocity.The critical diameter and detonation velocity of the explosive increase with the increase of the impedance of the confined material.Near the critical diameter,the detonation velocity is positively correlated with the charge diameter,and the detonation velocity increases with the increase of the thickness of the confinement material.Secondly,the super large concrete model experiment is designed and implemented.The experimental results show that the decoupling coefficient has a significant effect on the energy utilization rate and blasting effect of explosive.With the increase of uncoupling coefficient,the energy utilization rate of rock breaking by explosive increases first and then decreases,and there is an optimal uncoupling coefficient.Under this condition,the optimal uncoupling coefficient is k=2.7,and the rock fragmentation degree is the highest under this uncoupling coefficient.Eccentric uncoupled charge structure can effectively improve the rock breaking energy utilization rate and smooth blasting effect of explosive,improve the local action ability of explosive,greatly improve the rock breaking effect,reduce the rock damage at the reserved side to the maximum extent,and improve the rock breaking energy utilization rate of explosive.Finally,using ANSYS/LS＿DYNA software is used to simulate smooth blasting.The simulation results show that the eccentric charge structure can effectively adjust the energy distribution of explosive rock breaking.It can significantly increase the peak stress of blast wave acting on the eccentric side blast hole wall,and adjust the distribution range of rock crushing area and fracture area.Reduce the decay rate of total energy of rock mass in the near area of blast hole,and reduce the proportion of energy consumption in the fracture area.More energy is used for far rock fracture,which increases the proportion of explosive energy used for rock fracture,and then improves the effective utilization rate of explosive energy.The results of this paper provide a theoretical basis for parameter optimization of smooth blasting engineering.An eccentric uncoupled charge structure is designed,which provides a solution for the application of eccentric uncoupled charge in practical engineering.