Key Parameters of Roof Cutting of Gob-Side Entry Retaining in a Deep Inclined Thick Coal Seam with Hard Roof

Energies

Yajun Wang¹  Manchao He¹  Jiong Wang²  Xingyu Zhang²  Zimin Ma³  Jinzhu Hu³ 

[1] Deep Underground Engineering, China University of Mining &Technology, Beijing 100083, China;;State Key Laboratory for Geomechanics &

关键词: gob-side entry retaining by roof cutting (GERRC);    deep inclined;    thick coal seam;    hard roof;    surrounding deformation;   

DOI  :  10.3390/en12050934

来源: DOAJ

【 摘 要 】

Gob-side entry retaining by roof cutting (GERRC) employed in a deep inclined thick coal seam (DITCS) can not only increase economic benefits and coal recovery, but also optimize surrounding rock structure. In accordance with the principles of GERRC, the technology of GERRC in DITCS is introduced and a roof-cutting mechanical model of GERRC is proposed to determine the key parameters of the depth and angle of RC. The results show that the greater the RC angle, the easier the caving of the goaf roof, but the length of cantilever beam increases. The depth of RC should account for the dip angle of the coal seam when the angle is above 20°. Increasing the coal seam dip angle could reduce the volume of rock falling of the goaf roof, but increase the filling height of the upper gangue to slide down. According to numerical model analysis of the stress and displacement of surrounding rock at different depths and angles of RC, when the depth of RC increased from 9 m to 13 m, the distance between the stress concentration zone and the coal side is increased. When the angle of RC increased from 0° to 20°, the value of roof separation is decreased. GERRC was applied in a DITCS with 11 m depth and 20° RC angle, and the field-measured data verified the conclusions of the numerical model.

【 授权许可】

Unknown