阶段嗣后充填采场护壁矿稳定性研究

Study on stability of protection pillar in stope with stage subsequent filling

针对红岭铅锌矿采用阶段空场嗣后充填采矿法中的采空区护壁矿厚度合理取值问题,通过理论计算研究护壁矿应力和挠度变化规律,并利用FLAC^(3D)数值模拟分析方法,对不同工况下护壁矿厚度的稳定性进行研究,最终确定最优护壁矿厚度。研究表明:1)根据压杆变形理论和极限挠度计算,护壁矿最大挠度随着厚度的增大而减小,且护壁矿最优厚度为3 m;2)根据模拟分析可得,护壁矿厚度应当超过3 m,才能更好地保证护壁矿的安全稳定;3)护壁矿z向应力曲线呈倒“U”型分布,最大应力集中在护壁矿两端,与理论应力分布相似。本文研究为相似矿山护壁矿厚度选择提供一定的理论依据和分析方法。

In response to the reasonable value of the thickness of the goaf protection pillar in the stage open stope followed by filling mining method used in the Hongling lead-zinc mine,the stress and deflection changes of the protection pillar are studied through theoretical calculation.Using the FLAC^(3D) numerical simulation analysis method,the stability of the thickness of the protection pillar under different working conditions is studied,and the optimal thickness of the protection pillar is finally determined.Research result shows:1)According to the deformation theory of the pressure bar and the calculation of ultimate deflection,the maximum deflection decreases with the increase of wall thickness.And the optimal thickness of the protection pillar is 3 m.2)According to the simulation analysis,the thickness of the protection pillar should be more than 3 m,to better ensure the safety and stability of the protection pillar.3)The z-direction stress curve of wall thickness is an inverted"U"type distribution,and the maximum stress is concentrated at both ends of the protection pillar,which is similar to the theoretical stress distribution.This study provides a theoretical basis and analytical method for selecting the thickness of protection pillars in similar mines.