摘要
The stability of ore pillar in mine is essential for the safe and efficient mining.Based on the energy evolvement rule in ore pillar and roadway roof system,the roadway roof and ore pillar are treated as energy release body and energy dissipation body,respectively.Therefore,the double-block mechanical model is established with energy dissipation body and energy release body,and the energy mechanism of ore pillar instability is obtained,based on the fold catastrophe mathematical theory.The research result indicates that the dynamic instability of ore pillar is a physical instability problem caused by the strain softening property of ore mass,and the instability type of ore pillar is determined by the stiffness parameter of double-block mechanical system.When the systematical stiffness parameter is greater than or equal to 1,the equilibrium position of double-block mechanical system passes through shaft K-1 or the origin,from branch 1 of unstable equilibrium state to branch 2 of stable equilibrium state by smooth transition,and the ore pillar shows quasi-static fracture.When the systematical stiffness parameter is less than 1,the equilibrium position of double-block system mutates from branch 1 of unstable equilibrium state to branch 2 of stable equilibrium state by jumping transition,and the ore pillar shows dynamic instability.The research result could provide theoretical guidance for the prevention measures of ore pillar instability.
基金
This work was supported by the National Natural Science Foundation of China(51704095,51774110,51504081)
the Research Fund of the State Key Laboratory of Coal Resources and Safe Mining(13KF02)
the Research Fund of Henan Key Laboratory for Green and Efficient Mining and Comprehensive Utilization of Mineral Resources(S201619)
the Foundation for Higher Education Key Research Project by Henan Province(18A440012,14A440001)
the Ph.D.Programs Foundation of Henan Polytechnic University(B2014-50,B2016-67).
