隔离矿柱回采稳定性影响因素的正交试验分析

通过分析隔离矿柱在回采过程中的影响因素，结合工程实际，选取了隔离矿柱矿房侧壁的回采高度（A）、侧壁厚度（B）、采场长度（C）、采场宽度（D）、是否采一充一（E）和第二步骤充填是否采用全尾砂胶结充填（F）6个影响因素，每个影响因素取2个水平，选用L₈（2⁷）正交表，确定了8个模拟试验方案。建立了隔离矿柱回采模型，对隔离矿柱开挖之前的应力分布进行反演分析，运用FLAC^3D数值模拟软件对正交试验方案进行开挖模拟运算，分析了各个方案隔离矿柱回采之后的应力分布情况及其位移变化，得出模拟结果。分析结果显示：A、B、C、D、E、F 6个影响因素产生的Y方向位移极差分别为4.8、0.698、1.404、1.305、1.623、0.164 mm，即隔离矿柱矿房侧壁的回采高度（A）对其稳定性影响最为显著，而第二步骤是否采用全尾胶充填（F）影响最小。

Orthogonal Tests Analysis on the Influencing Factors for the Stoping Stability of Isolated Pillars

By analyzing the influencing factors for isolated pillars in recovery process，and combining with practical engineering，six influencing factors for the isolated pillar and room including stope sidewall height(A)，sidewall thickness(B)，stope length (C), stope width (D), whether alternating backfill after mining(E), whether the full tailings cementing backfill at second step(F).Two levels are selected for each factor.8 simulation experimental programs were identified by analyzing the selected orthogonal table L₈（2⁷）.The isolated pillar model was established，and the stress distribution of the isolated pillar before excavation was analyzed by refutation.The excavation with orthogonal scheme was simulated based on FLAC3D numerical simulation software.The simulation of stress distribution and displacement after the isolated pillar was mined. The analysis results show: the displacement ranges of 6 influence factors A,B,C,D,E,and F in Y direction are respectively 4.8,0.698,1.404,1.305,1.623 and 0.164 mm.That is to say,the stope sidewall height (A) of isolated pillar has the most significant impact on its stability，and whether adopting the full tailings cementing backfill at second step (F) has a minimal impact.