Criterion and Its Application for Safety Evacuation During Underground Flooding

Risks of urban flood have been increasing in recent years. Heavy rainfalls that attacked Tokyo, Nagoya and Fukuoka cased the underground inundations. When the underground inundation occurs, people must evacuate to the ground as soon as possible. Therefore, it is necessary to evaluate when and where it becomes difficult for users to evacuate during the inundation. The difficulty of evacuation in stairs has been evaluated with momentum per unit width. However, this criterion can not be applied to a corridor. In this paper, specific force per unit width is introduced as a new criterion to evaluate safety evacuation in both cases. It is difficult to implement safety evacuation when the specific force per unit width is over 0.125m2.