硬岩矿深部开采过渡区厚度优选与数值分析

针对某铁矿进入深部开采过程中采场出现的地压问题,优化并选取了合理的采场参数.考虑到矿体中存在软弱夹层,会对过渡区的稳定性造成影响,通过极限平衡法,决定采用8.5,10及12 m厚度的过渡区以备选用,运用大型数值分析软件FLAC 3D进行三维数值模拟,对其稳定性进行对比分析.结果表明,随着厚度的增加,过渡区中应力集中现象越来越小,在开挖过程中,顶板位移也随着厚度的增加而减小,仅12 m厚过渡区的塑性区没有贯通.所以留设12 m过渡区可保证采场的稳定,满足过渡期间安全生产的要求,为矿山的安全平稳过渡生产提供依据.

Optimization of Transition Zone Thickness and Numerical Analysis for Deep Hard-Rock Mining

Aiming at the ground control problem during underground stoping at deep iron mine， some reasonable stope parameters were chosen and optimized. In consideration of weak intercalated layer would influence the stability of transition zone， 3 kinds of alternative thickness of the transition zone which were 8.5， 10 and 12m were selected by using limit equilibrium method. Besides， three-dimensional numerical model was established with the large-scale numerical analysis software FLAC 3D， which was used to make a comparative analysis of its stability. Numerical results showed that the stress concentration during the process of mining becomes less obvious and the displacement of roof decreases with the increasing thickness of transition zone， and the plastic zone at only 12m thickness of transition zone has not been connected. It follows that 12m transition zone can guarantee stope stability， and satisfy safety production requirements during the transition period， which provides basis for the safe production of mine transition.