Study On Stability Mechanism Of Backfill Body In Gob-Side Entry Retaining

By comprehensive using of theoretical analysis,numerical simulation UDEC 6.0 and field test,the different geological conditions on the influence of backfill body stability,including roadway buried depth,thickness of roofs and the fracture position was discussesed;the reinforcement effects of parameters on the bearing capacity of backfill body was revealed.Main results are as follows:(1)Based on theoretical analysis,the factors affecting backfill body deformation including the thickness of main roof and immediate roof thickness,buried depth of roadway;the factors affecting the bearing capacity of the backfill body include packing material mechanical parameters,anchor number,diameter,etc.Numerical simulation showed that the reinforcement stress,high filling area is larger,the higher bearing capacity,can better adapt to the severe deformation of roadway surrounding rocks.(2)Along the solid coal rib,backfill body and gob side waste rock as fulcrums bearing main roof key block of fracture formation and overburden load,coal rib and waste rock bear more load;For main roof,as the load applied to the compression damage of surrounding rocks,and as the carrier of overburden load to tunnel protection.Roadway depth,thickness of roofs and the position of fracture can change the rotation angle and function way of key block,and,in turn,affect the destruction of the backfill body characteristics and deformation of the surrounding rocks of roadway.(3)Numerical simulation prove that adding reinforcement system parameters can change characteristics of filling body and improve its carrying capacity,but the effects of various parameters and influence law is different.(4)Gob-side entry retaining is successful under different geological conditions,by changing the width of backfill body,strengthening the parameters of the support system,at the same time cooperate with advanced reinforcing support,lag support of roadway surrounding rocks,etc.,backfill body can keep intact and stability,which shows that backfill body reinforcement system is reliable,and has good adaptability.