Numerical investigation on damage effect of deep hole pre-cracking roof rock and controlling rockburst
Qi Hao1
Anye Cao1
Changbin Wang2
Zhongyi Tang3
Jiangang Liu4
1.School of Mines,China University of Mining & Technology,Xuzhou 221116,Jiangsu,China2.State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China3.Shandong Energy Group Xibei Mining Co.,Ltd,Xian 710018,Shaanxi,China4.School of Mining and Mechanical Engineering,Liupanshui Normal University,Liupanshui 553004,Guizhou,China
摘要：Deep hole pre-cracking blasting(DHPB)technology is the preferred means of preventing and controlling rockburst induced by hard-thick rock layers in coal mines.When DHPB is applied to hard-thick rock layers,the insufficient knowledge about the crack extension scale under different rock properties and blasting parameters may result in undesirable pressure relief.Therefore,LS-DYNA was adopted to analyse the crack extension characteristics under the combined effect of rock tensile strength,explosive density,blasthole spacing,and decoupled coefficient.The Holmquist-Johnson-Cook model(HJC),veri-fied by the results of blasting experiment and numerical simulation in literature,was used to characterise coal-bearing rocks.Numerical analysis was conducted to study the blasting crack extension and fractal damage for rock tensile strength,explosive densities,blasthole spacing,and decoupled coefficients.The results show that the tensile strength of rock is the key factor for blasting design.The fractal damage caused by blasting increases when the tensile strength of rock decreases.For rocks with lower tensile strength,more blasting energy is consumed by the increasing damage area in the crushed zone.Higher explosive density can promote the development of blasting cracks and increase fractal damage,but the increasing range of the crushed zone also wastes a large amount of energy.As the blasthole spacing increases,the fractal damage decreases,and the crack extension scale in the fractured zone first increases and then decreases,and eventually remains almost unchanged.An optimum interval exists for the decoupled coefficient,and the full utilization of explosive energy within the interval leads to penetrating blast cracks and smaller crushed zones.Based on the simulation results,the optimal blasting parameters for coarse sandstone were validated in the field practice.Monitoring data show that the optimized blasting significantly reduces the risk of rockburst.
机标关键词：damageholedeeproofcontrollingeffectinvestigationnumerical
论文发表日期：2025-08-31
在线出版日期：2026-01-30（本平台首次上网日期，不代表文献的发表时间）
页数：24( 206-229 )
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