基于二维FDEM的金属矿破碎矿体进路法开挖方式与参数优化研究

Research on Excavation Method and Parameter Optimization of Broken Ore in Metal Mine Based on Two-Dimensional FDEM

采用有限元-离散元耦合方法(FDEM),建立进路尺寸为4.5m×4m的两个模型,对比分析机械开挖和爆破开挖两种条件下,岩体的变形破坏过程与稳定性,以此确定破碎矿体合理的开挖方式。受水平应力与垂直应力影响,进路跨度与高度方向影响不同。分别建立4m×4m、4m×5m、5m×5m、6m×5m、5m×6m进路尺寸的分析模型,模拟机械开挖进路的围岩变形破坏规律与稳定性。根据关键点位移突变判据与围岩破坏范围突变判据,最终得出的结论如下:机械开挖进路尺寸不大于5m×5m时,围岩较稳定;机械开挖进路尺寸大于5m×5m时,机械开挖后围岩稳定性大大降低;机械开挖进路尺寸为5m×6m时,围岩稳定性最低。研究过程与成果可为破碎矿体进路法开采的矿山提供借鉴,指导矿山进行合理高效的生产。

The finite-discrete element method(FDEM)was used to establish two models with a route size of 4.5m×4m.The deformation and failure process and stability of rock mass under mechanical excavation and blasting excavation were compared and analyzed,so as to determine the reasonable excavation method of broken ore body.Due to the influences of horizontal stressand vertical stress,the influences of route span and height direction were different.The analysis models of 4m×4m,4m×5m,5m×5m,6m×5mand 5m×6mroute sizes were established respectively to simulate the deformation and failure lawand stability of surrounding rock of mechanical excavation route.According to the mutation criterion of key point displacementand the mutation criterion of surrounding rock failure range,the following conclusions were finally drawn.Firstly,when thesize of mechanical excavation route is not more than 5m×5m,the surrounding rock is stable.Secondly,when the size ofmechanical excavation route is greater than 5m×5m,the stability of surrounding rock is greatly reduced?*?K$ after mechanicalexcavation.Thirdly,when the size of mechanical excavation route is 5m×6m,the stability of surrounding rock is the lowest.The research process and results can provide a reference for the mines with broken ore body mining by route method.