张庄铁矿-390 m中段采场间柱尺寸优化

张庄铁矿首采中段即将结束，由于-390 m新中段矿体水平厚度变大，且采矿阶段高度由60 m变为85 m，为确保高阶段采场分步骤安全回采，并能保证矿山生产能力，研究将矿体厚度按推荐的采场安全长度140 m分为2种采场布置方式，并采用间断和连续2种不同形式的隔离矿柱，通过3D σ有限元法模拟计算分析2种形式共6组尺寸方案的隔离矿柱应力变化趋势，最终确定在矿体厚度为100～140 m时，采用10～12 m宽的间断隔离矿柱；矿体厚度大于140 m时，采用18～20 m宽的连续隔离矿柱。结果为采场安全高效回采提供了理论依据。

Optimization of the Size of Stope Ore Pillars in -390 m Middle Section of Zhangzhuang Iron Mine

The first middle section of Zhangzhuang Iron Mine is about to end.The horizontal thickness of ore body of -390 m new middle section increases,and the height of the mining stage changes from 60 m to 85 m.In order to ensure the safe stope mining step by step in the high stage stope and ensure the production capacity of the mine,the orebody thickness is divided into two kinds of stope layout according to the recommended safe stope length of 140 m,and the isolated ore pillar is divided into two forms: discontinuous and uninterrupted.The stress variation trend of isolated ore pillar in two forms and six groups of size schemes is analyzed by using the finite element method of 3D σsimulation calculation.The results show that when the orebody thickness is 100~140 m,10~12 m wide intermittent isolation pillar can be adopted;When the thickness of ore body is more than 140 m,continuous isolated pillar with width of 18~20 m is adopted.The above results provide a theoretical basis for safe and efficient stope mining.