Fillings parameters determine in gob-side entry retaining from fracture position of main roof

Fillings force was influenced by fracture line of main roof in gob-side entry retaining.Based on voussoir beam,three kinds of structure models were established,and through calculating deflection of beam,fillings force changed with depth of mining,width of roadway and fillings were found.Force was minimum with fracture line of main roof in goaf,surrounding rock was easy to be controlled;Force was bigger with fracture line of main roof upper roadway or in coal wall.Force was reduced with fillings was arranged where the fraction of rock A and rock B.Field experiment was done in 1301 work face from Panchun coal with the achievements,gob-side entry retaining was successful.