基于正交试验的综放全煤回采巷道稳定性数值分析

Numerical analysis on stability of fully-mechanized top coal mining roadway based on orthogonal test

鹤壁矿区主采厚度为6.0 m左右的厚煤层,综放托顶煤巷道主要采用U型钢支护,需要超前替棚,存在返修率高、投入大和工人劳动强度高等缺点。采用正交数值方法对鹤壁矿区全煤回采巷道的支护参数进行了模拟分析。结果表明:巷道断面收敛系数η受埋深H、支承压力集中系数K、锚索布置N、顶煤厚度h和煤层强度σ的影响依次降低;采用多元回归分析方法,拟合了η与上述因素之间的表达式,预测鹤煤公司九矿3204孤岛工作面K从1.5增加到3.5时,η从11.99%增加到28.42%。结合3204工作面巷道的工程地质条件,提出了高强锚杆+锚索协调支护+被动支架的主被动协调支护方法。现场工业试验表明,采掘期间,巷道围岩变形能够满足回采工作面推采的需要。

The Hebi mining area is mainly mining thick coal seams with a thickness of about 6.0m.U-shaped steel bracket is mainly used for the fully-mechanized caving top coal along the channel,which requires advanced shed replacement,which has the disadvantages of high repair rate,high investment and high labor intensity.The orthogonal numerical method is used to simulate and analyze the support parameters of the full coal mining roadway in Hebi mining area.The results show that the roadway section convergence coefficientηhas the gradually weaken relationship with the following variables,which are buried depth H,supporting pressure concentration coefficient K,anchor cable arrangement N,top coal thickness h and coal seam strengthσ.Using the multiple regression analysis method,the expression betweenηand the above factors is fitted,and it is predicted that when K increases from 1.5 to 3.5 at the 3204 isolated island working face of the 9th Mine of Hemei Coal Company,ηincreases from 11.99%to 28.42%.Combined with the engineering geological conditions of the 3204 working face along the roadway,the active and passive coordinated support method of high-strength bolt+anchor cable coordinated support+passive support is proposed.On-site industrial tests show that during mining,the deformation of the surrounding rock of the roadway can meet the needs of advancing in the working face.