Computational analysis of thermo-chemical and mechanical behaviour of tunnels during fire

In this paper a new procedure for structural assessment of tunnel construction during fire is presented. In particular, it consists of two steps: the first one deals with a realistic evaluation of thermal fluxes, both convective and radiative, for the whole tunnel. In the fires recently occurred in some European tunnels, the duration of the fire was longer than expected and the produced temperature fields were much more severe than those considered in standard codes. Therefore, such a kind of evaluation is of great importance. As the second step, a simulation of the hygro-thermo-mechanical behaviour of concrete structure will be carried out using thermal fluxes previously calculated as thermal input for a fully coupled code, which considers concrete as a multiphase porous material.