Abstract:

Large surrounding rock deformation occurs in support of fault and fracture zone of -650 south tunnel of Yangcheng Coal Mine; and the deformation lasts for a long time. As a result, the surrounding rock geology of -650 south tunnel is tested and studied by indoor experiment, theoretical calculation and support practice; the deformation failure mechanism of the original tunnel support is revealed; the design method for pressurebearing ring support strengthening is put forward; and the composite support method based on concretefilled steel tubular scaffold is designed. The theoretical analysis and experiment show that the counterforce of concretefilled steel tubular scaffold reaches 0.92 MPa and the bearing capacity of composite support based on concretefilled steel tubular scaffold reaches 1.37 MPa, which has exceeded the predicted surrounding rock pressure. The support practice shows that the tunnel deformation can be effectively controlled and the longterm stability of -650 south tunnel can be guaranteed by using composite support based on 194×8 shallow arch concretefilled steel tubular scaffold.

Key words: tunnel support, fault and fracture zone, pressurebearing ring support strengthening method, concretefilled steel tubular scaffold, composite support technology