大新锰矿复杂空区群三维数值模型构建方法及胶结充填治理研究

Research on Three-Dimensional Numerical Model Construction Method and Cemented Filling Treatment of Complex Cavities in Daxin Manganese Mine

矿山岩土工程数值分析中研究复杂空区群三维数值模型构建方法对空区治理具有现实意义。为精确分析矿山地下工程围岩移动和应力变化规律,特别是不同采矿方法形成的复杂空区的稳定性和矿柱应力变化,提出了3DMine-Surfer-Rhino-ANSYS-FLAC3D多软件联合建模方法,解决了复杂空区群三维数值模型构建和大数量小尺寸矿房矿柱网格剖分问题。以广西大新锰矿矿体开采为案例,构建了留矿法与房柱法形成的采空区的三维数值模型,模拟分析空区的稳定性和决策胶结充填治理方案。研究结果表明:(1)大新锰矿留矿法开采的空区部分顶柱有垮落风险;(2)房柱法开采的空区部分矿柱变形大,有塑性破坏;(3)对于胶结充填留矿法的空区,隔一充一充填方案治理效果更好,在治理初期地表沉降更小。

In the numerical analysis of mine geotechnical engineering,it is of practical significance to study the construction method of 3D numerical model of complex cavities for the treatment of cavities.The pre-processing ability of geotechnical engineering simulation software is poor,and the current modeling method can’t well build complex geological body numerical model,and cannot fine divide the grid,resulting in the difficulty and work intensity of geotechnical engineering researchers in the early stage of modeling.In order to accurately analyze the law of surrounding rock movement and stress change of underground engineering,especially the stability of complex goaf formed by different mining methods and the stress change of ore pillar,the paper proposed and improved the 3DMine-surfer-rhino-ANSYS-FLAC3D multi-software joint modeling method.The method can solve the problems of 3D numerical model construction of complex goaf group and mesh generation of large number and small size ore pillars.The paper also described the specific modeling steps.The complex cavity group model constructed is closer to the reality,including the undulating form of surface DEM and more refined mesh of cavity and pillar model.At the same time,the total number of model grid elements is reduced,and the grid size of local key research areas can be adjusted according to the needs,so as to improve the accuracy of the calculation of key areas and accurately describe the stress change of ore pillars.This modeling method can be used to flexibly control the sequence excavation of different layers,stages and chambers of the layered ore bodies,and can be used to simulate the production sequence according to the engineering design at the early stage or the actual engineering production sequence at the later stage,so as to find a safe and reasonable mining production plan.A three-dimensional numerical model of goaf formed by shrinkage stoping method and chamber and pillar method was established by taking the mining of manganese ore body in Daxin mine of Guangxi as an example.Research results show that:(1)The Daxin manganese ore of shrinkage stoping method in mining area,empty part of the needle deformation is large,there are risks caving,the surface subsidence deformation is high;(2)The method of room and pillar mining zone,part of the pillar plastic failure,the surface subsidence deformation amount is larger;(3)Method of shrinkage stoping with cemented filling empty area:Fill in the blanks by stage filling area,after filling in the fourth stage,the surface settlement decreased significantly.In the vertical and vertical consolidation filling scheme,after filling one ore chamber with two ore chambers,the surface subsidence is smaller than that before filling,and the area with large subsidence becomes discontinuous.In the scheme of filling one ore chamber with another ore chamber,the surface subsidence deformation is one order of magnitude lower than the former two schemes,and the area of deformation area decreases and the continuity decreases.Among the three filling schemes,the one-filling and onefilling schemes have better governance effect,and the surface is more stable at the initial stage of governance.