煤下铝上行开采工艺控制覆岩均匀沉降研究

Study on aluminum mining under coal and uniform settlement control technology of overlying rock

铝土矿空场开采会导致覆岩的不均匀沉降或塌陷,破坏上覆煤层的完整性。为实现煤铝资源的保护性开采,保障煤下铝开采时上覆煤层的完整性,在提出煤下铝开采方法的基础上,分析崩落散体性质对覆岩均匀沉降的影响规律和控制覆岩均匀沉降的基本原理。首先建立了煤下铝开采覆岩移动的非线性弹性地基梁力学模型,分析不同弹性地基系数条件下的力学模型,然后采用数值模拟方法研究崩落散体性质对覆岩移动的影响规律,最后提出煤下铝开采覆岩均匀沉降控制技术方案,并将其应用于工业试验。研究结果表明:较大的崩落散体弹性模量,能有效控制覆岩沉降量,弹性地基系数是控制覆岩均匀沉降的关键,矿块式采场放顶作业是控制覆岩均匀沉降的有效技术手段,密实的胶结充填更有利于控制覆岩的均匀沉降。

Non⁃uniform settlement or collapse of overlying rock is caused by open stoping mining of bauxite,and the integrity of overlying coal seam is destroyed.In order to understand the protective min⁃ing of coal and aluminum resources and ensure the integrity of the overlying coal seam during the mining of aluminum under coal,this paper analyzed the influence of the properties of caving particles on the u⁃niform settlement of overlying rock which adopted the proposed mining method,and the basic principle of the uniform settlement control technology of overlying rock.Firstly,the nonlinear elastic foundation beam mechanical model of overburden movement in aluminum mining under coal was established,and the mechanical model was analyzed under different elastic foundation coefficients.Then the numerical simulation method was employed to study the influence of the properties of caving particles on the over⁃burden movement.Finally,a technical scheme for uniform settlement control of overlying rock in alumi⁃num mining under coal was proposed and applied to industrial test.The research results showed that the large elastic modulus of caving body effectively controlled the settlement amount of overlying rock,and the elastic foundation coefficient was a key factor to control the uniform settlement of overlying rock.The block stope caving operation was an effective technical means to control the uniform settlement of o⁃verlying rock,and the dense consolidated filling was more conducive to controlling the uniform settle⁃ment of overlying rock.