Numerical Research And Its Application On Bench Blasting Hole Network In Shuang Li Mine

The main index to evaluate the blasting effect in step blasting in open pit mines is the bulk rate,which is related to the pore network parameters,charge stru cture,explosive consumption and other factors.In the southern section of Shuangli mine,the increase of bulk rate is a serious problem,which leads to the secon dary crushing of ore,and the secondary crushing directly leads to the increase of the total cost of the mine and the decline of production efficiency.Therefore,the level of bulk rate directly affects the economic benefits of the mine and has an important impact on the mine.It is of great significance in theory and practice to study the method of reducing bulk rate.By studying the actual situation of Shuangli mine,on the premise of reducin g the blasting cost as much as possible and referring to the principle of wide hole spacing blasting technology,it is found that adjusting the parameters of hole pattern is the most economical and reasonable method to solve the problem of bulk yield.In this paper,by using the combined method of theoretical deduction and com puter simulation,in the south for rock physical properties,on the basis of the experimental data is collected through a cylindrical rock failure mechanism under the effect of blasting load and rock failure criteria are the basis of single span burden area,puckering burden area as a fixed value,intensive coefficient m for variables,using the principle of dichotomy designed m = 2,3,4,5,6,5 groups control experiment numerical model,using the finite element dynamic analysis software ls-dyna for both could hole blasting process in numerical simulation,Through the ls-prepost post-processing software to get the top part of the interval and the peak stress of the table and the effective stress time history diagram,the best range of intensive coefficient between 2 ~ 3,continue to three groups was de signed using the principle of dichotomy,to simulate the model in comparison m = 2.25,m = 2.5,m = 2.75 three sets of model,increase the loading position monitoring unit data after further comparison,determine the intensive coefficient m = 2.5 as the best value.Then the hole spacing and row spacing are determined,and finally the engineering blasting test is carried out in the mine to verify the numerical simulation results.After adopting the new scheme of M =2.5,the bulk yield is reduced from 6%of the original scheme to 0.22%.Meanwhile,the shape of the blasting reactor is complete and the cutting surface is neat.The results show that M =2.5 is the best density coefficient.Based on rock lithology,the single hole burden area is determin ed by the range of fracturing,and then the density coefficient and hole spacing are determined.The solution of shuangli ore problem is of reference significance to th e popularization and application of wide hole spacing blasting technology in open pit mines.