In order to reduce the rock fragmentation after open-pit bench blasting and reduce the cost of secondary crushing,a finite element model is established according to the actual geological situation of Yangjialing Mine.The influence of millisecond delay time on the degree of rock damage is studied,and the variation laws of key measurement points with delay time are analyzed.Finally,on-site experiments are conducted and the fragmentation analysis software WipFrag4.0 is used to analyze the rock fragmentation after blasting.The results show that with the increase of the millisecond delay time,the damage degree of rocks first increases and then decreases.When the millisecond delay time between holes and rows is 40 ms and 70 ms,respectively,the damage degree of rock reaches the maximum.Through on-site blasting tests,it is found that when the delay time between holes are 35 ms,40 ms,and the delay time between rows are 65 ms,70 ms,the block size is mainly at 10 cm,and the proportion of blocks larger than 31.6 cm is 21.26% and 23.19%,respectively,which is significantly smaller than other schemes.After analysis,it is found that the distribution law of the block after blasting is in good agreement with the change law of the rock damage degree obtained from the numerical simulation,which verifies the accuracy of the numerical simulation.Through the combination of numerical simulation of rock damage degree with field blasting test,a new idea is provided for the follow-up study of rock damage.
万方数据
维普
