Evaluation of Deep Hole Bench Blasting Effect based on Combination Weighting and Grey Clustering Evaluation

In order to comprehensively evaluate the effect of deep hole bench blasting in Weijiamao Coal Mine, considering the three objectives of blasting quality, safety and economy, eight parameters such as block rate, root rate, back crack distance, loose coefficient, unit consumption, long-meter blasting amount, vibration speed and flying distance were selected as evaluation indexes. Through UAV, high-speed photography, vibration monitoring and other technical means, the field monitoring of four production blasting flat plates in Weijiamao Coal Mine was carried out. In the meantime, the data analysis was carried out by Split-desktop, Motion studio and other software, and the quantitative indexes of the above parameters were obtained. The subjective and objective weights of evaluation indexes are obtained by using analytic hierarchy process and CRITIC method respectively, and then the combined weights of each index are determined based on the principle of maximum sum of squares of deviations. The grey clustering method is optimized by using the center point triangle whitening weight function, and the grey clustering evaluation model of blasting effect is established. The deep hole bench blasting effect of Weijiamao Coal Mine is comprehensively evaluated, and the order of blasting effect of four flat plates is obtained according to the comprehensive clustering coefficient. Finally, the main problems of the flat plate with the worst blasting effect are analyzed by comparing the index data. The results show that the combined weight of explosive unit consumption, bulk rate and base rate is greater than 0.15, which has a great influence on the blasting effect. The order of blasting effect of four flat plates is that 1080 flat plate>1064 flat plate>1096 flat plate > 1112 flat plate. The 1112 flat plate needs to be combined with geological conditions to optimize the bench blasting parameters for the problems of large back crack distance, high unit consumption, small blasting amount per meter and large flying distance.