综采面沿空巷道超前动压区煤柱失稳效应与锚注加固技术

Instability effect of coal pillar in advanced dynamic pressure zone of gob-side entry in fully-mechanized mining face and bolt-grouting reinforcement technology

为探究综采面沿空巷道超前动压区煤柱对巷道围岩整体稳定的影响规律,综合采用数值模拟、工程应用等方法,建立沿空巷道超前巷道数值分析模型,研究综采面回采期间不同煤柱宽度下沿空巷道围岩力学和变形响应特征。研究结果表明:护巷煤柱宽度小于5 m时,工作面帮为采动应力主要承载结构,其内部应力及变形均大于煤柱帮,此时工作面帮应作为超前动压区重点加固对象,随着护巷煤柱宽度增加,煤柱承载应力逐渐增加、变形增大,护巷煤柱宽度增加至5 m以上时,煤柱承载应力显著增加,采动应力由沿空巷道两帮围岩共同承载,超前动压区应同时加强两帮支护,基于此开发超前动压区沿空巷道锚注加固技术,并进行工程应用。研究结果可为平顶山矿区类似条件沿空巷道超前控制提供一定参考。

In order to study the influence law of coal pillar on the overall stability of roadway surrounding rock in advanced dynamic pressure area of gob-side entry in the fully-mechanized mining face,a numerical analysis model of advanced roadway in the gob-side entry was established by using the numerical simulation and engineering application methods,and the mechanical and deformation response characteristics of surrounding rock in gob-side entry under different pillar widths during the mining of fully-mechanized mining face were studied.The results show that when the width of roadway protection coal pillar is less than 5 m,the working face wall is the main load-bearing structure of mining dynamic stress,and its internal stress and deformation are greater than those of the coal pillar wall.At this time,the working face wall should be the key reinforcement object in the advanced dynamic pressure zone.With the increase of the width of roadway protection coal pillar,the bearing stress of coal pillar gradually increases,and the deformation increases.When the width of roadway protection coal pillar increases to more than 5 m,the bearing stress of coal pillar increases significantly,and the mining stress is jointly carried by the surrounding rock on the two sides of gob-side entry.The support of the two sides should be strengthened at the same time in the advanced dynamic pressure zone.Based on this,the bolt-grouting reinforcement technology of gob-side entry in the advanced dynamic pressure zone is developed and applied in engineering.The research results can provide some reference for the advanced control of gob-side entry with similar conditions in Pingdingshan mining area.