| 摘要 |
In order that bridges located in exposed sites do not increase the risk of flooding at high-water, they are raised on at least one side in the form of bascule bridges in order to allow the water to run freely in its bed. The reaching of the high-water level and the high-water itself determine the moment when the bascule bridge should be raised. When the high-water level is reached, water can flow through lateral openings (1) in the bank into tanks (2) and fill the latter. The weight of the filled tanks (2) is sufficient to raise the bascule bridge on one or both sides out of its operating position into the high-water position. The raised bridge allows the high-water to run freely in its entire bed. When the high-water has receded, the water is let out of the tanks (2) and the bridge is lowered into its operating position once more. |
