Research and Application of Gob-side Entry Retaining Technology by Roof Reducing Subsidence

In order to solve the problems such as serious deformation by gob-side entry retaining, instability of surrounding rock, we carry out gob-side entry retaining technology by roof reducing subsidence combined with geological conditions of 8^＃coal seam in the third fully mechanized working face. This research constructs filling body beside roadway by binder backfill material based on self-developed fly-ash, and constructs roof deep borehole on the side of the gob-side advance the working face to weaken the roof relationship between goaf and filling body. Numerical simulation result shows that the technology makes roof subsidence reduced by 44% and the sides of filling body's deformation reduced by 27%. The effect of application shows that this technique can improve the surrounding's control effect of gob-side entry retaining in Xin'an Coal Mine.