Instability effect of coal pillar in advanced dynamic pressure zone of gob-side entry in fully-mechanized mining face and bolt-grouting reinforcement technology
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 mechan-ical 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 de-formation are greater than those of the coal pillar wall.At this time,the working face wall should be the key reinforcement ob-ject 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 surround-ing rock on the two sides of gob-side entry.The support of the two sides should be strengthened at the same time in the ad-vanced dynamic pressure zone.Based on this,the bolt-grouting reinforcement technology of gob-side entry in the advanced dy-namic pressure zone is developed and applied in engineering.The research results can provide some reference for the ad-vanced control of gob-side entry with similar conditions in Pingdingshan mining area.
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