Optimization Method for Pre-splitting Blasting Parameters of Fractured Soft Rock Mass in Cold Regions under Centrifugal Decoupling Conditions
In general,pre-splitting blasting generally adopts a concentric uncoupled charge structure,but due to the gravi-ty of the charge column,the charge column is attached to the hole wall,which may enhance the damage to the reserved rock mass of presplitting blasting.Based on the traditional presplitting blasting technology and theoretical analysis,the calculation formula of the uncoupling coefficient at any point under the condition of centrifugal uncoupling charging is put forward,and the relationship between the formula and the concentric uncoupling coefficient is deduced.Taking Baiyuneboxi Mine as an exam-ple,based on the existing two specifications of pre-cracking charge column,the theoretical analysis shows that,under the prem-ise of not changing the diameter of pre-cracking charge column,when the diameter of pre-cracking charge column is 60 mm,it is necessary to optimize the hole distance and charge structure of pre-cracking charge.Through the field test,the hole distance and the charge structure of the pre-crack hole were optimized,and the optimum hole mesh parameters were obtained.The blas-ting effect before and after the optimization of hole mesh parameters was evaluated by three-dimensional oblique photography technology.After the optimization of hole mesh parameters,the porosity of half wall was increased by 27.09％.The results show that the optimization of pore mesh parameters has a positive effect on protecting the stope slope and maintaining the safety and stability of the slope,and also has reference significance for similar projects.
centrifugal uncouplingfragmented soft rock in cold regionspre-splitting blastingfield test3D oblique pho-tography
万方数据
维普
