Evaluation of the response of concrete tunnel linings subjected to fire: a three-dimensional approach

This work is focused on the development of a refined nonlinear constitutive model for the analysis up to failure of concrete elements subjected to fire, able to account the main features governing concrete be-havior, i.e. cracking and crushing. In particular, the model is applied to the structural assessment of unreinforced concrete tunnel linings in order to deal with all the different stages of tunnel life, from its construction to its service conditions, also taking into account the possible development of a fire and its effects on the lining system. The reliability and accuracy of the proposed model are checked against analytical closed-form solutions.