In this work, a simplified numerical model is developed in order to investigate concrete tunnel lining behaviour during fire, taking into account the loss of strength and stiffness of the materials subjected to high temperatures. The appearance of temperature-induced internal stresses and strains in the lining is also considered in the model. With this aim, thermo-mechanical finite element analysis is performed, by linking a heat-transfer analysis with a nonlinear structural simulation, that considers the concrete and steel degradation due to fire and the interaction between tunnel lining and the surrounding ground through the “beam-spring” model. This model is applied to the real case of an existing railway tunnel. The main characteristics of this tunnel, used as input data for the analysis such as the geometrical dimensions and mechanical properties, are investigated through an experimental campaign. The stress state in the tunnel before the fire loading is determined also by an additional analysis considering the excavation of the cross section as well as the installation of the shotcrete support and the final concrete lining. Finally, the time-temperature curve corresponding to the underlying fire-accident scenario is prescribed at the inner surface of the concrete lining. Thermo-mechanical finite element analysis and safety check of the concrete tunnel lining considering also the concrete spalling effect are performed.
Fire safety assessment of concrete lining of a railway tunnel / DE SILVA, Donatella; Di Marino, E.; Viglione, A.; Nigro, E.; Pedicini, M.. - (2017), pp. 711-718. (Intervento presentato al convegno 2nd International Fire Safety Symposium tenutosi a Napoli nel 7-9 June 2017).
Fire safety assessment of concrete lining of a railway tunnel
DE SILVA, DONATELLA
;E. Nigro
;
2017
Abstract
In this work, a simplified numerical model is developed in order to investigate concrete tunnel lining behaviour during fire, taking into account the loss of strength and stiffness of the materials subjected to high temperatures. The appearance of temperature-induced internal stresses and strains in the lining is also considered in the model. With this aim, thermo-mechanical finite element analysis is performed, by linking a heat-transfer analysis with a nonlinear structural simulation, that considers the concrete and steel degradation due to fire and the interaction between tunnel lining and the surrounding ground through the “beam-spring” model. This model is applied to the real case of an existing railway tunnel. The main characteristics of this tunnel, used as input data for the analysis such as the geometrical dimensions and mechanical properties, are investigated through an experimental campaign. The stress state in the tunnel before the fire loading is determined also by an additional analysis considering the excavation of the cross section as well as the installation of the shotcrete support and the final concrete lining. Finally, the time-temperature curve corresponding to the underlying fire-accident scenario is prescribed at the inner surface of the concrete lining. Thermo-mechanical finite element analysis and safety check of the concrete tunnel lining considering also the concrete spalling effect are performed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.