大采高工作面沿空掘巷窄煤柱合理尺寸研究

Reasonable Size of Narrow Coal Pillars in Gob-side Entry Driving in Large-mining-height Working Face

以某矿3046工作面留设区段窄煤柱为工程背景,采用极限平衡理论、数值模拟、工程实践三种方法分析沿空掘巷窄煤柱合理尺寸。通过极限平衡理论计算得到沿空掘巷窄煤柱宽度为4.83m^5.64m。通过FLAC3D分析不同煤柱宽度情况下煤柱应力分布和巷道围岩位移分布规律,综合考虑煤柱垂直应力和围岩应力模拟结果得到沿空掘巷窄煤柱宽度为5m^6m。通过现场试验,表明该煤矿柱在锚梁网+锚索联合支护情况下,顶底板移近量为60mm、两帮移近量为65mm,合理煤柱宽度为5m左右。

Taking narrow coal pillars in 3406 working face as engineering background,limit equilibrium theories,numerical simulation,and engineering practice are used to study the reasonable size of the narrow pillars.According to the limit equilibrium theory,the width of the coal pillars ranges from 4.83 mto 5.64 m.Stress distribution of the pillars and displacement distribution of the surrounding rocks are studied by FLAC3 Dat the different width.Considering the simulation results of the vertical stress of the pillars and the stress of the surrounding rocks,the width of the pillars ranges from 5 to 6 m.However,the engineering practice shows that,under the combined support of roof bolting with bar and wire mesh and anchor cables,the reasonable size of coal pillars is around 5 m,with 60 mm roof-floor deformation and 65 mm two-side deformation.