| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of the pneumatic roof gate, in which a steel-plate door body fitted to the bottom of a channel to freely rise up and fall down is erected by inflation of a pillow-like air bag provided at its root part on the downstream side and laid down by contraction thereof, that it is necessary to provide an anchor belt for stopping the door body in a predetermined erect attitude between the door body and the foundation concrete, and since the value of the tension applied to the anchor belt is large, it is impossible to make the steel plate of the door body thinner thoroughly, and the improvement in economic efficiency is difficult. SOLUTION: In order to heighten the bending strength of the door body in the diagonal elongating direction, among the longitudinal ribs formed by welding and fitting elongated steel plates having suitable width and thickness in the direction parallel to the stream of water in an attitude right-angled to the steel plate surface on the upstream surface of the door body, the center position of required number of longitudinal ribs is aligned with the center position of a bolt for fixing the anchor belt to the door body pneumatic roof gate, whereby the tension having a large value applied to the anchor belt is diffused over a wide range of the door body by the longitudinal ribs. COPYRIGHT: (C)2006,JPO&NCIPI
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