| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To realize a new reliable prevention system of urban underground facilities or subways from flood water inflow or submersion, which also enables quick evacuation of refugees, effective prevention of natural disasters such as floods, etc., and improvements on the facilities into safe urban underground spaces contrary to conventional ones, including economical modifying work of their existing entrances and exits within a short construction period. <P>SOLUTION: A top-level staircase part is rotated to stand up nearly vertically to be used as an inflow water preventive door. Usually, at a level where this staircase part is stored, a staircase for refuge is formed by connecting the higher top step of the rotary staircase to the top step of a fixed staircase. In a small gap between a fixed staircase step surface and this movable step, a seal material is applied to completely prevent water inflow or leak through it. Entrance/exit to/from underground facilities is designed as a united structure of which mass production at a factory and transportation by a truck is possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
