Abstract
We have experienced severe fire accidents in tunnels, such as the accident of Mont Blanc Tunnel or Nihonzaka Tunnel. These accidents triggered many studies for securing safe environment in case of tunnel fire at Europe and Japan. Many researches have been done so far, experimentally or numerically, on the case of tunnel fire, and the behavior of smoke and heat has been discussed. At The spot where a cross-section varies from a shield section to box section, however, the analysis is not sufficient, and it is necessary to be studied. The authors analyzed the behavior of heat and smoke by fire at a tunnel which has plural cross section figurations by means of 3-D numerical analysis. The analysis was done utilizing a freeware, named "FrontFlow/red" developed by a group at Tokyo University. Based on results of analysis, we evaluated escape environment. Thereby, there was no risk of escape environment on the analyzed tunnel.
