Structural behavior of SFRC tunnel segments

The paper addresses precast tunnel segments for the Line T02 of Saronno-Malpensa railway (Italy). After the experimental determination of the material properties, the structural behavior of the lining is simulated with FE analyses based on Non Linear Fracture Mechanics (NLFM). The numerical analyses presented herein will be mainly focused on the force exerted by hydraulic jacks on the ring during the excavation process. The numerical analyses were carried out considering different loading configurations and atypical boundary conditions in order to investigate the advantages coming from the use of Steel Fiber Reinforced Concrete (SFRC) in terms of crack control and of bearing capacity. An optimized reinforcement, based on the combination of rebars and steel fibers, is proposed.