Study On Dynamic Effect And Safety Threshold Of Bench Blasting In Reclamation Of Zijinshan Mine

With the deepening of economic and social development,the status of ecological civilization construction is increasingly prominent.The ecological damage in open-pit mining has entered the social field of vision,so mine reclamation has become an important part of enterprise production.As a common form of mine reclamation,bench reclamation often fails due to the slope collapse caused by the blasting of large amount of explosives.Therefore,maintaining the stability of bench becomes one of the important work to ensure the mine reclamation.In this paper,Zijinshan open-pit mining is taken as the research object,and a variety of research methods are synthesized to optimize blasting parameters according to the propagation law of blasting vibration,so as to ensure the stability of adjacent steps.On the one hand,the results provide guidance for the mine production,on the other hand,they also provide reference for similar large-scale mines in the design of blasting schemes.The main contents and achievements of this paper are as follows:(1)Through comprehensive analysis of a large number of blasting vibration,the vibration attenuation laws of the same and different bench blasting applicable to the mine are obtained.According to the error analysis,it is concluded that the influence of elevation on vibration propagation should be considered.(2)Based on the basic principle of dimensional analysis and considering the influence of elevation on blasting vibration propagation,the traditional Sadowski formula is improved,and the monitoring data are comprehensively analyzed according to the improved formula.The vibration attenuation law applicable to the mine is obtained,and the error is controlled within 20%.(3)According to the theory of vibration attenuation,the vibration velocity near the bottom of step slope is 16.14 cm/s,which is used as the safety threshold of blasting vibration.The current blasting scheme is optimized and verified by numerical simulation.(4)According to the optimized blasting scheme,a production bench is selected for industrial test.The results show that the optimized blasting scheme can effectively crush the production bench rock and ensure the stability of the adjacent bench,which creates favorable conditions for subsequent bench reclamation.