房柱法开采大面积采空区群的稳定性分析

Stability Analysis on Large-area Goaf Group in Room and Pillar Mining Method

为了得到房柱法开采大面积采空区群的稳定性变化规律,利用空区激光探测系统(CMS)对采空区进行精密探测,运用3Dmine与FLAC^(3D)耦合建立数值计算模型,分析了采空区围岩应力、位移、塑性区大小及分布状况。研究结果表明,采场中部部分矿柱中垂直应力最大为106 MPa,明显高于边界矿柱;采场周围矿柱中垂直应力相对较小,顶板跨度越大,下沉量越大,表明大部分矿柱仍具有一定的支撑能力;位于空区群边界的试验采场内矿柱中部垂直应力最大为46MPa,顶底部垂直应力相对较小;采场顶板存在微量下沉,最大下沉量为14.23mm,底板略微鼓起,最大鼓起量为6.5mm,表明顶底板均较为安全。

In order to obtain the stability change law of large-area goaf group in room and pillar mining,the Cavity Monitoring System(CMS)was used to detect the goaf precisely.The numerical calculation model was established by coupling 3D mine and FLAC3D,and factors of surrounding rock in goaf,including the stress,the displacement,as well as the size and distribution of plastic zone,were analyzed.The results are concluded as follows.Firstly,the maximum vertical stress in the central part of the stope is 106 MPa,which is significantly higher than that of the boundary pillar.Secondly,the vertical stress in the pillar around the stope is relatively small,and the larger the roof span,the greater the subsidence,which indicates that most of pillars still have certain supporting capacity.Thirdly,the maximum vertical stress in the middle of the pillars in the test stope at the boundary of goaf group is 46 MPa,and the vertical stress at the top and bottom is relatively small.Finally,there is slight subsidence in the roof of the stope,with the maximum subsidence of 14.23 mm,and the floor is slightly bulging with the maximum bulging amount of 6.5 mm,which indicates that the roof and floor are relatively safe.