| 摘要 |
PURPOSE:To isolate an inside space from the outside air or introduce the outside air, by providing supporting members in the periphery of a conical space so as to make the same plane height to support a building with stories and detachably providing a covering member in the upper space. CONSTITUTION:A space 30 is formed between the floor plate 20 and the surrounding wall 12 of the uppermost floor structure 16 and an embedded cover plate 32 is arranged on the outer peripheral side of the surrounding wall 12. And further, an actuator 34 moving radially the cover plate 32 is arranged on the outer peripheral side of the cover plate 32. In this case, when an underground structure is used for a nuclear shelter, the cover plate 32 is constituted of lead which can isolate the shetter from radioactive rays. The cover plate 32 is usually radially transferred by the actuator 34 to introduce the outside air into the space 30 of the floor structures 16. When a fire has broken, the cover plate 32 is radially moved by the actuator 34 and the space 30 is completely isolated from the outside air. |
