矿柱形态对地下矿山采空区稳定性影响规律

Analysis of Influence of Shape Effect of Pillar on Stope Stability

地下矿山采用房柱法开采时采场点柱一般不进行回收,矿柱约占储量的20%~30%.为减少矿柱矿量,同时保证矿柱及采场的稳定性,利用三维建模软件Midas-GTS-NX及有限差分法软件FLAC3D联合模拟计算,对矿柱形状进行模拟分析及对比研究,分析了相同围岩条件下不同形状的矿柱自身及采场顶板的稳定性.研究表明:方形和圆柱形矿柱稳定性较好,但圆柱形矿柱较方形矿柱回采率高,其余形状的矿柱在相同围岩条件下容易产生应力集中现象,稳定性较差.在实际生产中可考虑留设圆柱形点柱,既能保证采场稳定又可提高回采率.该研究为房柱法开采中的矿柱和采空区稳定性判定提供了参考依据.

When the underground mine is mined by the room-and-pillar method, the stop-point pillar is generally not recycled, and the pillar accounts for about 20% to 30% of the reserves. In order to reduce the mineral amount of the pillar, and to ensure the stability of the pillar and stope, the three-dimensional modeling software Midas-GTS-NX and the finite difference method software FLAC3 D were combined to simulate the calculation, and the stability of different shapes pillars and the roof of the stope were analyzed under the same surrounding rock conditions. The research shows that the stability of square-section pillar and the circular-section pillar are good, but the circular-section pillars have a higher recovery rate than square-section pillars, the remaining shape of the pillar is prone to stress concentration under the same surrounding rock conditions, and the stability is relatively poor. In the actual production, it is considered to leave cylindrical point pillar, which can ensure the stability of the stope and increase the recovery rate. The study provides a reference basis for the stability judgment of pillars and goafs in room-pillar mining.