综放沿空留巷底鼓影响因素研究及防治

Study on Influencing Factors and Prevention of Floor Heave in Gob-side Entry Retaining

山西某矿2301工作面从切眼回采的过程中,沿空巷道受采动影响发生较大的围岩变形,严重影响了工作面的安全生产。借助简支梁力学模型,通过理论分析得出,影响巷道底鼓量的主要因素是巷道宽度和水平应力,同时采用FLAC3D数值软件模拟2种影响因素下巷道底鼓量的变化。结果表明:留巷宽度对巷道底鼓量的影响最为显著,现场布置沿空巷道时,应尽量避开构造应力集中区。根据模拟结果,并结合2301工作面具体地质条件,合理优化巷道断面尺寸,提高帮部支护强度和底板注浆锚索加固。

The surrounding rock deformation of the goaf roadway was greatly affected by the mining movement,which seriously affected the safety production of the 2301 working face of a mine in Shanxi Prov⁃ince.Based on the mechanics model of simple supported beam,it is found that the main factors affecting roadway floor heave are roadway width and horizontal stress through theoretical analysis.At the same time,FLAC3D numerical software is used to simulate the changes of roadway floor heave under the two influencing factors.The results show that the width of roadway retention has the most significant effect on the floor heave volume of roadway,and the concentrated area of structural stress should be avoided as far as possible when the gob roadway is arranged on site.According to the simulation results and the specific geological condi⁃tions of the 2301 working face,the section size of the roadway is reasonably optimized,the support strength of the wall is improved and the anchor cable of the floor is reinforced by grouting.