金属矿山嗣后充填采场顶板合理跨度参数研究及建议

根据河北某铁矿现有的开采技术条件，对该铁矿嗣后充填采场的结构参数进行了研究，采用材料力学“简支梁”理论计算及Flac数值模拟相结合的手段分析了采场顶板的安全合理跨度。理论计算合理跨度为18 m左右，数值模拟分析采用3种模拟方案，采用“隔一采一”的开采顺序，由此模拟分析了不同尺寸采场跨度条件下矿岩的应力分布、塑性分布及位移变化情况。结果表明，随着矿房跨度的增加，矿房顶、底板围岩的应力由受压状态逐渐转向受拉状态，尤其是当跨度达到20 m时，矿柱的塑性分布范围增加十分明显，矿柱剪切破坏的程度加大，增加了矿柱失稳的可能，所以采取矿房、矿柱宽度为18 m时是比较合理的，这和理论计算的结果是相符的，同时建议在回采过程中，要加强对矿柱及充填体进行应力应变监测，确保矿体的安全高效回采。

Research and Suggestions on Reasonable Span Parameters of the Stope Roof in Metal Mine with Subsequent Filling

According to the current mining technical conditions of an iron mine in Hebei province，research on structural parameters of this mine with subsequent filling is carried out.With combination of Beam theory in material mechanics and Flac numerical simulation，the safe and reasonable span of stope roof is analyzed.The reasonable span is determined to be about 18 m through theoretical calculation.In numerical simulation，three plans with the mining subsequence of “one and every other ones” are adopted to analyze the stress and plastic distribution and displacements under different stope spans.The result shows that with the span of the stope increasing，the stress of the roof and surrounding rock gradually alters from being pressed to being pulled.Especially when the span reaches 20 m，the plastic distribution range of the pillar increases apparently.The greater shear destruction of the pillar raises its possibility of instability.So，the span of 18 m is reasonable for the width of the chamber and pillar，which conforms to the theoretical calculation.Meanwhile，it is suggested that during the process of stoping，stress-strain monitoring of pillar and backfill should be strengthened to ensure safe and efficient mining of ore body.