Concrete Tunnel Segments with Combined Traditional and Fiber Reinforcement: Optimization of the Structural Behavior and Design Aspects

Area 08 – Ingegneria civile e Architettura

Precast segments for use in tunnel linings are generally reinforced with conventional rebars that are placed in Reinforced Concrete (RC) elements. In the two last decades, Fiber Reinforced Concrete (FRC) was used in several tunnel linings in combination or not with traditional rebars. In fact, FRC could be a competitive design solution for these tunnel elements as it would allow time reduction in handling and placing the curved reinforcement that has to be used in ordinary RC elements. This research work intends to be a contribution to the knowledge on fiber reinforcement for use in precast tunnel segments.; it is of main interest the combination of conventional and fibrous reinforcement in order to improve the lining structural response. For this purpose, non-linear numerical simulations and non-linear analytical procedures were adopted in order to take into account the post-cracking tensile fiber resistant contribution. The principal mechanisms governing the lining behavior were investigated at SLS and ULS, in order to achieve an optimization of fibrous and traditional reinforcement (rebars).

SINTESI