Author(s): Mitsuhiro Terada; Taisuke Ishigaki; Taira Ozaki; Keiichi Toda
Linked Author(s): Taira Ozaki, Keiichi Toda, Taisuke Ishigaki
Keywords: Subway; Underground mall; Pluvial flood; Evacuation; Planning line
Abstract: There are so many subway lines with many stations in Japanese lowland cities such as Tokyo, Nagoya, and Osaka. These subway lines are vulnerable to the pluvial flooding, due to so many heavy rainfalls recently. Inundation of underground mall by pluvial flooding has been studied by many researchers, however, investigations on subway inundation are not so many. In our previous works, spreading of inundation through subway tunnels from one catchment area has been investigated. In this paper, the effect of the newly planned subway line, which is under-passing a big river in Osaka and connects two catchment areas, is investigated by using a drainage model of InfoWorks. In the calculation, two catchment areas on both sides of the river are considered because subway inundation spreads to another side of the river. The used model includes drainage system, underground mall, and fifteen subway lines. Ground level and underground inundations are calculated in the case of extreme rainfall condition in which the maximum one-hour rainfall intensity is 146.5 mm observed in August 2008 near Nagoya. From the result, it is found that inundations of the two catchment areas are influenced each other through subway tunnels under-passing the river and that subway manager and user have to consider early evacuation during heavy rainfall.
Year: 2018