IMPROVEMENT OF SEDIMENT-CONTROL FUNCTION OF SLIT DAM

狭缝坝防沙功能的提高

• 批准号: 07650603
• 负责人: OKABE Takeshi
• 金额: $ 1.41万
• 依托单位: Faculty of Engineering, The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650603/
• 关键词: SLIT DAM; SEDIMENT CONTROL; VANE-TYPE STRUCTURE; SCOURING; ISOLATED VORTEX; IMPROVEMENT OF EFFICIENCY

The purpose of this reseach is to improve the efficiency of sediment retention dams with vertical slit-openings.First, characteristics of an couple of isolated vortexes, being generated on the both sides of a slit-opening and giving negative effects to the behavior of water and sediment spilling through the slit-opening, were clarified experimentally. The isolated vortexes were found to reduce the efficient area of spilling flow as well as to reversely transport the sediment toward upstream.Some types of additional structure for reducing the negative effects of the isolated vortexes were considered and addition of one or two couples of vane-type structures to the upstream mouth of the slit-opening was selected as a basic idea of improvement.The efficiency of this measure is tested experimntally by changing the number and geometric dimensions of the structures. As the result, it was proved that those stuctures significantluy promote the development of gully streams in medium and minor flood events and thus increase the retention capacity for heavy sediment run-off by big floods.Finally, based on measurements of three dimensional flow velocity, the influence of the vane-type structures to flow and sediment is investigated in order to understand the results of the above-mentioned tests from hydraulic points of view.

本研究的目的是提高垂直开缝拦沙坝的效率。首先，从实验上阐明了垂直开缝两侧产生的孤立涡的特性，它们对垂直开缝的水流和泥沙的溢流行为产生了不利影响。考虑了几种减少孤立涡负面影响的附加结构，并选择在缝口上游口增加一对或两对叶片式结构作为改进的基本思路，通过改变结构的数量和几何尺寸来验证这一措施的有效性。结果表明，这些构筑物对中小洪水条件下沟道水流的发育有显著的促进作用，从而提高了对大水来沙的截留能力。最后，在三维水流速度测量的基础上，研究了叶片式构筑物对水流和泥沙的影响，以期从水力学的角度理解上述试验结果。

项目成果

Okabe, T., Takahashi, K. and Anse, Y.: "Numerical Model for Morphological Process above Debris Dam" Proc. of International Sabo Symposium. Vol.1. 173-180 (1995)

Okabe, T.、Takahashi, K. 和 Anse, Y.：“泥石坝上方形态过程的数值模型”Proc。

T.Okabe, K.Takahashi & Y.Anase: "Numerical model for morphological Process above debris dam" Proc.of International Sabo symposium. Vol.1. 173-180 (1995)

T·冈部、K·高桥