Authors: Burghard, Stefan and Fischer, Oliver
In numerical analyses and the design of load-bearing structures under fire loads, the incorporation of material damage behavior is of utmost importance for a realistic prediction of the load-bearing and failure mechanisms. This particularly applies to restraint structures subjected to high temperatures such as permanent concrete tunnel linings, i.e. secondary linings (conventional tunnelling) and precast segments in TBM-driven tunnels, respectively.. Furthermore the simulation of so-called "natural fire scenarios" and the derivation of the corresponding tunnel specific thermal loads provides the potential to reduce the actions to be considered, based on the individual boundary conditions and requirements. In particular, for re-analysis and the assessment of existing tunnels, this method (tunnel-specific temperature fields) yields a contribution to sustainability and resource consumption because in many cases retrofit and strengthening works may be avoided.
Keywords: fire; accident; tunnel; FEM; CFD; concrete; numerical simulation; concrete damage model