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Evaluation and optimization of blasting approaches to reducing oversize boulders and toes in open-pit mine

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International Journal of Mining Science and Technology 2020年第3期30卷 373-380页

作者： Zhendong Leng Yong Fan Qidong Gao Yingguo Hu College of Hydraulic and Environmental Engineering China Three Gorges UniversityYichang 443002China China Gezhouba Group Explosive Co. Ltd.Chongqing 401121China School of Highway Chang’an UniversityXi’an 710064China Yangtze River Scientific Research Institute Wuhan 430010China

A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.

关键词： Rock blasting Blasthole diameter Oversize boulders Rock toes damage distribution

Numerical Simulations of Tungsten Alloy Rods Penetration into Alumina Ceramic/Armor Steel Composite Target

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Journal of Beijing Institute of Technology 2008年第3期17卷 253-258页

作者：李金柱黄风雷张连生 State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

The Johnson-Holmquist constitutive ceramic model is re-implemented into the LS_ DYNA3D program to simulate the penetration of long rod projectile into ceramic/armor steel composite targets. The damage evolution, fracture propagation, and spall damage in the ceramic/armor targets is represented during the simulation procedure and the accuracy of the penetration depth comparing between the simulating and experimental results is reliable with an error less than 8 %. The relationship between the mass efficiency factor, differential factor and ceramic tiles thickness is given out for the penetration results with/without a cover plate.

关键词： alumina ceramic mass efficiency factor JHC model damage distribution

Early warning of rock mass instability based on multi-field coupling analysis and microseismic monitoring

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Transactions of Nonferrous Metals Society of China 2019年第6期29卷 1285-1293页

作者： Zhou-quan LUO Wei WANG Ya-guang QIN Jun XIANG School of Resources and Safety Engineering Central South University Changsha 410083 China Fankou Lead?Zinc Mine Shaoguan 512325 China

In order to overcome the limitation that rock mass instability warnings are caused by a lack of deep consideration of the inherent mechanism of disaster formation, early warning signs of rock mass instability were detected and multi-field coupling was analyzed. A multi-field coupling model of a damaged rock mass was established. The relationship between microseismic activity parameters and rock mass stability was analyzed, and a multi-parameter early warning index system was established and its solution program was compiled. Based on the D-S data fusion theory,an early warning model of rock mass instability combining multi-field coupling analysis and microseismic monitoring was constructed. Taking an underground mine stope as an object, the multi-field coupling model and its solution program were used to analyze mining response characteristics. The seismic field data were used to verify the accuracy of the multi-field coupling analysis. The early warning model was used to predict the instability of stope rock mass,and the early warning result is consistent with a real-world scenario.

关键词： rock mass instability microseismic characteristic parameters D-S evidence fusion multi-parameter early warning damage distribution