沉积型铝土矿采空区矿柱-顶板支撑系统滑移突变失稳分析

Analysis on Catastrophic Sliding of Pillar-Roof Supporting System in a Sedimentary Bauxite Goaf Mine

基于沉积型铝土矿采空区失稳多为沿结构弱面滑移剪切破坏的特征,借助能量耗散理论和突变理论,构建矿柱-顶板支撑系统滑移突变失稳模型,研究受结构弱面影响的系统失稳机制,分析各内控因素对采空区稳定性的影响.结果表明:采空区突发滑移失稳是由支撑系统的内控因素和外控因素协同作用的结果.外控因素既定条件下,各内控因素敏感度由大到小依次为:采空区跨度b,矿柱宽度a,软弱带厚度B,结构弱面倾角θ,矿柱屈服区宽度c.软弱带厚度B和结构弱面倾角θ的敏感度略小于采空区跨度和矿柱宽度的敏感度,在实际工程中,应密切关注结构弱面因素的影响.晨光铝土矿工程实例验证了计算结果的可靠性.研究成果可为此类矿山采场参数设计提供依据.

Based on the instability characteristic of a sedimentary bauxite goaf mine,which showing a shear failure along weak structural planes,a catastrophic sliding model of a pillar-roof supporting system was established by using the energy dissipation theory and the catastrophe theory.The instability mechanism related to the weakness structural plane was studied,and the influence of various internal control factors on the stability of the goaf was analyzed.The results indicate that the sudden sliding instability of the goaf is caused by the combined action of the internal and external control factors of the supporting system.When the external control factors are fixed,the sensitivity of each internal control factor can be listed from large to small as:goaf span b,pillar width a,thickness of weak zone B,structural weakness plane angleθ,pillar yield zone width c.The sensitivity of the thickness B of the weak zone and the inclination angleθof the weak structural plane are just slightly smaller than that of the goaf span and the pillar width,which means that the influence of the weak structural plane should be paid more attention in actual projects.The reliability of the calculation results was verified in the Chenguang bauxite project.The research results can provide basis for stope parameter design of such mines.