EVALUATION OF THE STAIRCASES' VISIBILITY IN UMEDA UNDERGROUND STREET BY USING SPACE SYNTAX

When an earthquake occurs, the tsunami caused by the earthquake can threaten people's lives. Especially for low-lying terrain and densely populated areas, it is necessary to evacuate people to a safe place as soon as possible. The predicted water level of the Osaka Umeda Underground Street during the tsunami flood will reach 0.5-1.0 meters. And people inside the underground street need to reach the ground through stairs or evacuate from the exits connected to the surrounding buildings. There are a large number of stairs distributed inside the Umeda Underground Street. This study uses spatial syntax theory and depthmapX software to quantitatively analyze and organize the visibility of the staircases, to evaluate whether the stairs at different locations are easy to be discovered by the crowd during evacuation. And then lay the foundation for further evacuation research. In this paper, the following conclusions can be drawn: The visibility of staircases under different radius restrictions is different. On the whole, the stairs near the integration center and the square nodes have better visibility, and those stairs which require multiple turns and have deeper visual depth are more difficult to find and use.