Bolting-support- grouting cooperating support technology of fractured surrounding rock roadway in large loose circle

In order to solve the vicious circle of support-destruction-repair-redestruction in Dafosi locomotive repair cavern,the paper analyzed the mechanism of insta bility and destruction based on the determination of the surrounding rock mechanical properties and the loose circle test,and adopted the internal and external bearing mod el to study on its cooperative control principle: the internal bearing structure provides confining pressure to impel formation and stability of external bearing structure,and th e external bearing structure bears most of the strata stress to protect internal bearing structure. Increasing support and surrounding rock residual strength of internal beari ng structure can make boundary location of external bearing structure close to roadway and reduce the deformation and radius of fractured zone. Then the internal bearing structure is anchored in stabilizing surrounding rock of external bearing structure by using high prestress cable. Finally,it formes the internal and external cooperative beari ng structure to control the deformation of surrounding rock effectively. Used the principle,this paper designed the strengthen supporting and repairing technology,and miner al pressure observation showed the maximal two sides and roof to floor convergence was 61、87 mm. The large deformation was controlled effectly and supporting effect was obvious.