宁都硫铁矿浅部开采地表沉降数值模拟与监测研究

The Numerical Simulation and Monitoring Study of Surface Subsidence During Shallow Mining in Ningdu Pyrite Mine

针对宁都硫铁矿在浅部开采中遇到的地表沉降问题,对矿柱稳定性进行分析,采用精密电子水准仪进行现场监测及数值模拟开挖研究,综合分析其地压变化与地表沉降规律。研究结果显示:矿柱的安全系数k值大于1,矿柱稳定,不会发生突发性失稳破坏;在分中段分步开挖后,开挖至最下一中段的位移最大,最大值分别为X方向3.20cm,Y方向1.16cm,Z方向8.20cm,矿区地表不会发生突发性失稳破坏;地表沉降监测结果显示,观测周期内位移最大点为BM5观测点,位移变化值为5.19cm,没有发生明显沉降。经综合分析,可以定性的判定矿区范围内地表不会发生大规模沉降,但为保证今后安全开采,对采空区应引起足够的重视。

According to the problems of surface subsidence during shallow mining in Ningdu Pyrite Mine, the stability of pillars was analyzed, and the high-precision electronic lev- el was used for monitoring and numerical simulation on min- ing, so as to comprehensively analyze the pressure change and the surface subsidence laws. The results showed that, when the safety factor k value was greater than 1, the pillars were stable enough to avoid emergent collapse; during the sublevel and substep excavation, the maximum displacement variation value appeared at the nethermost stage, respective- ly with 3.20cm in the X direction, 1.16 cm in the Y direc- tion, 8.20 cm in the Z direction, and emergent collapse would not occur on the mining surface. Monitoring results showed that during the observation period, the maximum displacement appeared at BM5 observation point, with dis- placement value of 5.19 cm, and there was no obvious sub- sidence. Through comprehensive analysis, the chance of large-scale subsidence was excluded in this mine, but the mined-out areas should be paid more attention for safe min- ing in the future.