Coal Rejects Backfill Support Technology of Gob-side Entry Retaining in High Gassy Mine

According to the high deformation features of the surrounding rock in the coal rejects backfill gob-side entry retaining,taking the gob-side entry retaining of No.2013N coal mining in Xinyang Mine as the study object,a theoretical analysis method was applied to analyse the causes of the high deformation value of the gob- side entry retaining,long sustained deformation time,the serious periodical roof falling influence of the goaf. With the numerical simulation means,the paper analyzed th e stress and displacement variation law of the gateway roof,two sidewall and gob-side entry retaining during the construction process of the gob-side entry retaining. Th e site observation method was applied to reveal the support mechanism of the gob-side entry retaining. The results showed that the surrounding rock deformation of the gob-side entry retaining could be divided into three stages. The three stages were a mining influence unobvious stage,mining influence serious stage and mining defor mation stable stage. The application of the bolt,steel mesh and anchor combined support mode could effectively reinforce the coal and rock mass,prevent large bed sep aration occurred in the roof, improve coal mass strength of the two sidewalls and prevent large deformation occurred in the gob-side entry retaining.