近距离煤层超前应力演化及动压大巷围岩变形研究

Study on Evolution of Advance Stress in Short Distance Coal Seam and Deformation of Surrounding Rock in Large Roadway under Dynamic Pressure

为了解决近距离煤层采动超前侧动压巷道变形严重问题,以某矿近距离煤层工作面超前动压大巷为研究对象,建立近距离煤层开采数值分析模型,研究超前侧动压巷道围岩受重复采动超前叠加应力影响应力演化规律。结果表明,上位煤层工作面推进到停采线时,巷道围岩应力环境发生改变;下工作面推进至停采线30 m时,超前叠加应力影响到大巷附近;上位煤层工作面推进到停采线,下工作面推进至停采线30 m期间,大巷围岩应力不断增大,而后不断减小,当保护煤柱为60 m,峰值应力达到最小,而后再次增大;动压大巷围岩变形破坏主要原因是工作面超前叠加应力较高、巷道围岩强度较低、支护密度较低、支护能力较差等。研究结果可为类似条件下的动压巷道围岩稳定性控制提供参考依据。

In order to solve the serious deformation problem of mining advance side dynamic pressure roadway in short distance coal seam,a numerical analysis model of mining advance side pressure roadway in short distance coal seam is established to study the stress evolution law of surrounding rock of mining advance side pressure roadway affected by repeated mining advance superimposed stress.The results show that the stress environment of roadway surrounding rock changes when the upper coal seam face advances to the stop-mining line.When the lower working face advances to 30 m of stop-mining line,the superimposed stress will affect the vicinity of the main roadway.During the period from the upper coal face advancing to the stop-mining line to the lower coal face advancing to the stop-mining line 30 m,the surrounding rock stress of the main roadway increases continuously and then decreases continuously.When the protective coal pillar is 60 m,the peak stress reaches the minimum and then increases again.The main causes of the deformation and failure of the surrounding rock in the dynamic pressure roadway are higher advance superposition stress,lower strength of the surrounding rock,lower support density and poor support ability.The research results can provide reference for the stability control of roadway surrounding rock under similar conditions.