Assessment of Safety on Evacuating Route During Underground Flooding

Abstract

Heavy rainfalls over 50 mm/hr have been observed frequently in the last decade in Japan. If a sewage system in urban area could not drain such rains, flood water would be flooding and flowing into underground spaces such as subway or basement of building. As the area of underground space is limited, flood water fills up the area in a short time. It is very dangerous situation and people should evacuate from there as soon as possible in order to save their life. To draw up an evacuation plan, it is important to assess the safety of evacuating route. In this paper, the method of safety assessment on the evacuating route is discussed on the basis of experimental results and flood simulation data in an underground space. In order to assess the safety on an evacuating route, the value of the specific force per unit width, M=0.125m², is used in this study, of which value has been obtained in the previous work. Using the relation between M values and evacuating speed, the assessment of safety on evacuating routes during underground flooding has been carried out well and the data for preparing an evacuation plan have been shown. The data are very useful for the people to evacuate from when and through which route.