采空区群稳定性影响因素敏感性分析及其应用

Sensitivity Analysis of Impact Factors of Goaf Group Stability and Its Application

为研究采空区群稳定性各影响因素的主次,以某地下金矿为研究背景,依次推导出矿柱、顶板及采空区群安全系数计算公式,采用正交实验对采空区群稳定性影响因素进行极差分析,获取其敏感性顺序,据此确定采空区群稳定性主控因素,并研究其与安全系数之间的关系及相应的临界值。研究得出采空区群稳定性影响因素敏感性主次顺序为:采空区群顶部—地表距离>矿柱高度>中段数量>顶板厚度>中段矿柱数量>矿柱宽度>顶板纵深>采空区跨度。矿柱宽度是采空区群矿柱失稳的主控因素,矿柱安全系数随矿柱宽度的增加近似呈线性增长,相应的临界宽度为8.4 m;顶板厚度是采空区群顶板失稳的主控因素,顶板安全系数随顶板厚度的增加呈幂函数形式递增且速率逐渐变大,相应的临界厚度为8.7 m;采空区群顶部—地表距离是整个采空区群失稳的主控因素,采空区群安全系数随群顶部—地表距离的增加近似均匀递减,相应的临界距离为124 m。

To study the rank of factors influencing the goaf group stability,the safety factor calculation formula of pillar,roof and goaf goaf were deduced successively based on a underground gold mine.Orthogonal experiment was made to analyze the impact factors of goaf group stability,then the sensitivity rank and main control factors were obtained,then the relationship between the main control factors and the safety factor,the corresponding critical value were also studied.The study showed that the sensitivity rank of goaf group＇s impact factors were as follows in a descending order： goaf group top-surface distance,pillar height,mining level number,roof thickness,pillar number in one mining level,pillar width,roof depth,goaf span.Pillar width is the main control factor of pillar,and its safety factor increased approximately linearly with pillar width with corresponding critical width of 8.4 m; Roof thickness is the main control factor of roof,its safety factor increased with roof thickness in the form of power function,and the rate increased gradually,with corresponding critical thickneess of 8.7 m; top-surface distance was the main control factor of the whole goaf group,and its safety factor declined with the increase of top-surface distance with corresponding critical distance of 124 m.