Comprehensive evaluation of roadway cut blasting based on an entropy-weighted optimized matter-element cloud model

Abstract

The comprehensive evaluation of cut blasting constitutes a multi-objective decision-making problem in underground rock engineering. When the differences among alternative blast design schemes are marginal, it is essential to account for the boundary fuzziness and mutual interactions of the various evaluation indicators to support the comparative selection of blasting schemes. This study developed an entropy-weighted optimized matter-element cloud (EW-OMEC) model based on an adaptive cloud-parameter calculation method. Three main criteria and twelve key evaluation indicators were selected to construct the blasting effect evaluation system. Damage volume derived from numerical simulations was introduced as an evaluation indicator and analyzed jointly with field-measured data. The proposed model was applied to the roadway blasting evaluation in the Liyan Coal Mine. The results show that the EW-OMEC model can effectively characterize boundary fuzziness among adjacent evaluation grades. Blasthole utilization ratio and block size distribution are the two largest indicator weights of the six schemes, corresponding to six field blasting trials. The entropy weights of blasting quality, economic benefits and adverse effects of blasting are 44.72%, 24.84% and 30.44%, respectively. According to the principle of maximum correlation degree, scheme P 6 with subdrilling depths of 0.35 m for both the cut holes and the empty holes obtained the highest comprehensive evaluation among the six schemes. Further field applications under independent engineering conditions are required to assess the broader applicability of the proposed method.