摘要: |
丁坝是长江上游航道整治中最常用的整治建筑物,工程实践中多采用的是抛石透水丁坝,此类丁坝具有一定的透水性,现有长江上游丁坝水沙特性研究中极少考虑透水性对此类丁坝的影响,不同的空隙率和空隙尺寸对改善透水丁坝附近水位场及流速场具有不同的效果。本文通过水槽概化模型试验,研究了4个空隙尺寸和5个空隙率工况下透水丁坝周围的水面线分布情况,通过对比分析得到不同空隙率、不同空隙尺寸等因素对透水丁坝周围水面线的影响规律。最终得出:相比实体丁坝,透水丁坝在一定的空隙率和空隙尺寸条件下,对丁坝上游的壅水效果更佳,同时还可以增加丁坝下游水深条件,降低纵横向水面比降,对改善丁坝右侧束窄段水流形态、减轻丁坝水毁、延长丁坝使用年限、改善生态环境等方面也具有更积极的影响。研究结果对长江中上游的航道整治建筑物设计和改善航道整治效果具有一定的参考价值。 |
关键词: 透水丁坝 空隙率 水面线 空隙尺寸 |
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Experimental Research on Water Surface Characteristics of Permeable Spur Dams in the Upper Reaches of the Yangtze River |
XU BAIQIANG, YUTAO
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Chongqing Jiaotong University
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Abstract: |
Spur dike is one of the most frequently-used structures in the waterway regulation engineering of the upper Yangtze river. Besides, the riprap groin with a certain permeability is usually used in the engineering. The results of improving the flow field are different because of the different rates and scales of the pore, however that is rarely considered in existent studies. In this study, we design some experiments to study the water surface profile around the permeable groin in the cases of different rates and scales of the pore. Furthermore, we seek out the correlation law between the water surface profile and the porosity or the scale of the pore. In the results, the permeable groin with appropriate porosity has better ability of water damming compared with the solid dam. Moreover, the permeable groin has positive effects on increasing the depth of water, reducing the water surface slope, contracting water on the right side of the groin, mitigating the groin damaged by flood and improving the environment. The study of this paper can give some proposals to the designers to design the regulation structures and improve the regulation effect. |
Key words: permeable spur dike void ratio water surface line void size |