近距离煤层“上采下掘”巷道破坏分析及防治措施研究

Analysis and prevention measures of tunnel damage in close distance coal seam“upper mining and lower excavation”

“上采下掘”巷道主要受多次动压影响,矿压显现剧烈、支护难度大,上部煤层回采使得下部巷道准备困难,围岩变形加剧。本文以3201回风顺槽为工程研究背景,采用FLAC^(3D)软件,通过分析不同宽度煤柱垂直应力分布特征、下部巷道布置方式对其稳定性影响、相向“上采下掘”应力分布、时空关系等,为巷道布置、掘进提供设计依据。本研究方法可在类似条件的矿井提供参考。实践表明:“上采下掘”期间,巷道采用内错布置,上下进入扰动期后,停止上部回采,错峰施工,同时对下部巷道采取补强支护,可有效控制巷道的围岩变形。

The“upper mining and lower excavation”roadway is mainly affected by multiple dynamic pressures,resulting in strong underground pressure behavior and difficult support.The upper coal seam extraction makes it difficult to drive the lower roadway,and the deformation of the surrounding rock intensifies.This article takes the 3201 return air roadway as the engineering research background,and uses FLAC^(3D) software to analyze the vertical stress distribution characteristics of coal pillars with different widths,the impact of lower roadway layout on its stability,the stress distribution of opposite“upward mining and downward mining”,and the spatiotemporal relationship,providing design basis for roadway layout and excavation.This research method can provide reference for mines under similar conditions.Practice has shown that during the upper and lower mining periods,if the roadway adopts an internal staggered layout,after entering the disturbance period,the upper mining should be stopped and staggered construction be carried out,and reinforcement support is adopted for the lower roadway,the deformation of the surrounding rock of the roadway can be effectively controlled.