Technology of Flexible Supporting for Air Leakage Prevention in Thin Coal Seam Gob- side Entry Retaining with Hard Roof

In order to solve the problem of fresh air in gob- side entry retaining leaked to goaf and caused spontaneous combustion with hard roof, mechanical stru cture model of gob- side entry retaining under hard roof was built, flexible supporting technology with gangue pack and rebar with guniting was proposed, the supportin g effect was verified by test methods, and field test was conducted in No. 2019 roadway of Jiangjiawan Coal Mine. The results showed that flexible supporting technolo gy with gangue pack and rebar with guniting had great compressibilit, which could release part of roof pressure in the early stage of roof movement, and gunite materia | could be better attached to the surface of flexible supporting in the later stage. The roof- to- floor convergence was 230 mm and rib- to- rib convergence was 170 mm and the content of CO in roadway was 0, the risk of spontaneous combustion in goaf was eliminated.