隔板對泥砂導流及局部沖刷之試驗研究

本試驗主要目的，在了解導水型隔板對泥砂導流特性及本身所產生局部沖刷坑之探討。試驗結果顯示，在於相同方向之水流攻角下，表層導流式隔板不論其入水深度，甚至深入底床，其泥砂導流方向都是一樣。而底部導流式隔板約於突出河床高度為0.5倍水深時，其對泥砂導流方向互異，形成一分界點，亦即造成冲淤現象正好相反。中間導流式隔板，當其隔板下部緊貼底床時，與底部導流式隔板相同，隔板高度約在0.5倍水深時，泥砂導流仍有互異的情形發生。在於相同方向之水流攻角下，底部導流式隔板突出河床高度大於0.5倍水深時，其造成之沖淤現象和表層式隔板一樣。表層導流式隔板下部允許水流通過，其向下水流通過隔板下部，並於其後方下游處造成局部沖刷坑；而底部導流式隔板則沖刷坑產生於近隔板之上游處。

關鍵字

隔板；泥砂導流；局部沖刷

並列摘要

The aim of this study is undertaken to know the directions of sand motion and the positions of local scouring due to the effect of different flow-training panels. It is known by experiments that the sand motion is caused by helix in a clockwise direction of the angle of attack is smaller than π/2, no matter how large the opening of the surface panel. The bottom panels have a critical height about 0.5 times local water depth at design stage. In other words, the panel's height is above or under the critical depth of bottom panels, while the sand-training is quite different. The middle panels, not close to the surface and the bottom, only in the case the panel's bottom is close to the river bed have the nearby phenomenon of depositing and scouring with the bottom panels. In the same angle of attack with flow, the bottom panels with the height greater than half local water depth at design stage have the same phenomenon of depositing and scouring with the surface panels. The open space under the surface panel allows the flow passing, then the local scour will take place at downstream, but the bottom panel has the local scour at upstream nearby.

並列關鍵字

Panel ； Sand controlled ； Local scouring

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