蚀变带内矿体开采中人工假底的应用研究

针对嵩县山金矿业有限公司主矿体位于矿区构造破碎带内，前期采用上向进路充填采矿法对其进行开采时留下了高品位顶底矿柱的开采难题，矿山提出通过在各中段间施工人工假底来对这部分高品位矿柱进行回收。因此，为保证顶底柱回采稳定性和矿石回收率，建立了人工假底薄“板”力学模型，应用弹性力学理论对其失稳机理进行分析；同时在人工假底厚度确定的情况下采用安全系数法分析了进路宽度与高度对进路稳定性的影响，确定安全合理的进路宽度为3.5~4.0 m，高度为3.0~4.0 m；再对人工假底进行配筋设计，并对金属网在人工假底中不同位置时假底位移及应力场变化进行数值模拟分析，得到最安全合理的铺设位置为人工假底中部。将研究结果应用到工程实践中，结果表明人工假底的应用使矿山顶底柱得到安全高效的回采。

Research and Application of Artificial False Bottom in Mining of Orebody in Alteration Zone

The main orebody of the mining area of Songxian Shanjin Mining Co. Ltd. is located in the M1 structural alteration zone and it is strictly controlled by the structural fracture zone.Its occurrence is basically consistent with the M1 structural alteration zone，which is a moderately stable orebody and due to the roof.The rock mass is broken，and the mining area is mainly developed by the upward approach filling method，so the high-grade top and bottom pillars are left behind.In order to ensure the stability of the stope，the top and bottom columns between the middle sections are effectively recovered，and the utilization rate of the orebody is improved.The mine design shall be constructed with artificial false bottoms after the end of the mining in the middle section，and the top and bottom pillars shall be recovered under the artificial false bottom.In order to ensure the recovery stability and ore recovery rate of the bottom and bottom columns under artificial false bottom，a manual false bottom plate mechanical model was established for the artificial false bottom approach，and the instability mechanism was analyzed by the theory of elastic mechanics.When the two sides of the column are filled with the filling body，the artificial false bottom of the roadway is known as the “soft-supported weak plate” structure，and it is easy to cause bending and tensile failure in the middle of the road top plate；and the safety factor is adopted in the case where the artificial false bottom thickness is determined.The method analyzes the influence of the width and height of the approach on the stability of the approach，and determines the safe and reasonable approach width of 3.5~4.0 m and the height of 3.0~4.0 m.According to the strength requirements and the results of the strength test of the mine backfill，the filling is carried out.The calculation of the reinforcement calculation at the bottom of the body is carried out by using a 1∶8 C-material cemented backing body，and the Φ12 mm steel bar with a mesh size of 300 mm×300 mm can increase the tensile strength of the artificial false bottom.The reinforcement design is carried out at the bottom，and the numerical simulation analysis of the false bottom displacement and the stress field change of the metal mesh at different positions in the artificial false bottom is carried out，and the safest and most reasonable laying position is the middle of the artificial false bottom.The findings applied to engineering practice，the results showed that the application of artificial false bottom of the top-pillar mines safe and effective mining.