Study And Application On Gob-Side Entry Retaining Technology With Paste Raodside Packing In Thin Coal Seam

Through theoretical analysis, laboratory experiment, numerical simulation and field testing methods, gob-side entry retaining technology with paste cementing material roadside packing is studied in high gas thin coal seam fully-mechanized face.Based on the theory analysis, surrounding rock sporting law of gob-side entry retaining is studied, and "packing body-overlying rock body-coal body" mechanical model is used to calculate the roadway-side supporting resistance. Through field industrial test and laboratory orthogonal experiment, a new type of concrete paste cementing packing material, consisting of cement, sand, coal fly-ash and gangue powder, etc, is developed, the main characteristics of which includes low cost, resistance increasing fast, great strength and good contractibility. Using FLAC3D software, surrounding rock sporting law and stress distribution regularity of gob-side entry retaining are studied, the reasonable width of roadside packing body is gained and the rationality of different-strength gob-side packing support technology is proved. Through theoretical analysis and numerical simulation methods, gob-side entry retaining combined support system including technology of wall-caving strengthening roof ahead the face and different-strength roadside packing support is determined. Aaccording to field engineering conditions, support parameters of gob-side entry retaining and reasonable arrangement of roadside packing system is designed. The industrial test in 1705 east face of Zhaoguan coal mine proved that the research results which brought forward by this article could guide practical production well.