Abstract

Aim: The main purpose of this article is to present the results of numerical calculations of evacuation from the road tunnel in the case of fire in three different scenarios. The research is based on the Mont Blanc tunnel catastrophe in 1999. Three tunnel models were generated on this basis: − a model corresponding to the actual conditions in the tunnel during the 1999 fire, − a model reflecting conditions after modifications associated with the tunnel’s redevelopment and its reopening in 2002, − a model referring to the the requirements of Directive 2004/54/EC of the European Parliament and of the Council binding in the EU.

Introduction: In the article, the authors focused on the influence of the distance between shelters or evacuation exits in a road tunnel on the results of self-rescue actions in the event of fire. Tunnels have limited space, so a fire leads to rapid changes in the environment’s parameters and theoccurrence of critical conditions, which can be dangerous for human life. Therefore, the distribution of evacuation exits influences the duration of self-rescue actions.

Methodology: Numerical calculations were conducted for the purpose of defining the Required Safe Escape Time TRSET. The Available Safe Escape Time TASET was determined on the basis of the analysis of the fire in the Mont Blanc tunnel in 1999. The evacuation process is considered safe when the so-called safe escape time criterion is met, i.e. when dependency TASET ≥ TRSET is met.

Conclusions: The results of the numerical calculation confirmed that the modifications after the Mont Blanc fire could ensure safe evacuation in the event of a fire similar to that of 1999. Moreover, in the case of the two remaining fire scenarios (the distance between shelters is 300 m and the distance between evacuation exits to the parallel evacuation tunnel is 500 m), there is no possibility to conduct safe self-rescue actions. Evacuation time largely depends on the movement speed of evacuees, thus the distribution of evacuation exits or shelters should be determined during the design phase taking into consideration the most dangerous scenario, so that each tunnel user would have proper conditions for safe evacuation.

Keywords: evacuation, evacuation exits, fire safety, Mont Blanc tunnel

Type of article: case study