Construction Simulation and Stress Characteristics of Large Span Tunnel Crossing Fault Fracture Zone

Abstract

Combined with the engineering of a large span tunnel passing through the fault fracture zone, the settlement of the crown in the fault zone is studied. The stress situation of the secondary lining in the fault is analyzed. The influence zone of fault fracture zone is put forward based on the first principal stress of structure. The results show that: (1) The fault fracture zone has great influence on the settlement of the crown when the step method is used, and the settlement value is 2.14 times that of the fault free zone. (2) The fracture convergence zone will obviously postpone the convergence time of crown settlement. In this case, 2nd construction steps are delayed. (3) The fracture pressure zone will obviously increase the lateral pressure of the secondary lining structure, which is 1.3 times of that in the fault free zone. The tensile stress concentration of the secondary lining walls at the fault is 1.17 times of that without faults. (4) Based on the first principal stress of the secondary lining wall, the width of the fault is 16m, and its influence area is about 3.5 times of its own width.