Parametric study on tunnel linings in fiber reinforced concrete combined with traditional reinforcement

In the present paper, the structural behavior of tunnel segments has been investigated by means of a 2½ D model which enables to take into account the influence of longitudinal and ring joints on lining internal forces (M,V). The research aims to study the grouting phase (during construction) as well as the embedded ground load condition (final state) in order to evidence the most critical resistant mechanism.
The results refer to a broad parametric study developed in order to get a better understanding on the actions occurring in segmental lining during the final state and the grouting process (construction stage). Two different lining geometries were considered: the first one corresponds to the Brescia metro line, which is a single deck metro with an internal diameter (Dint) of 8,15 m; the second one represents a highway tunnel having a larger diameter (14,90 m). Several tunnel depth projections and ground conditions were considered.