瓮福磷矿矿柱安全留设尺寸确定与现场监测

Safety pillar thickness determination and local monitoring in Wengfu phosphate

留设安全矿柱是房柱式开采体系中保护井巷、地表及建筑物的安全一种常用方法,矿柱的合理尺寸选择及其稳定性对采场安全极其重要.结合瓮福磷矿磨坊矿5#井开采的实际情况,提出应用FLAC3D数值模拟逐步逼近法来确定该矿安全矿柱留设尺寸,并采用平板梁理论对其进行分析计算.结果表明,逐步逼近法得到的安全矿柱厚度和平板梁理论的计算结果较为吻合.通过2种方法的研究结果对比分析,确定该矿点柱式房柱的基本参数为:矿房跨度在14m左右,矿柱厚度在5.5～6.0m之间.通过对磨坊矿5#井采空区上覆岩层移动规律的监测,发现岩层移动相对稳定,地表沉降量控制在160mm以内.

The appropriate size and stability of safety pillar, which is a way of protecting the Shaft and Tunnel and the buildings of surface, are very important for the safety of the stope. According to the field engineering condition of the Mofang member NO. 5 mine in Wengfu phosphate, the appropriate size of safety pillar is calculated by using methods of FLAC3D numerical simulation successive approximation method and the plate beam theory. The numerical result shows that the pillar safety thickness calculated by successive approximation method is in good agreement with that by the plate beam theory through comparison. The pillar thicknesses are determined to be from 5.5 to 6.0 m, responding to the pillar span of 14 m. By monitoring the goals overlaying strata of Mofang member NO. 5 mine, it is found that the strata movement is relatively stable, and the values of ground surface settlement are controlled to be within 160 mm.