长江上游透水丁坝水面线分布试验研究

丁坝是长江上游航道整治中最常用的整治建筑物，工程实践中多采用抛石透水丁坝，此类丁坝具有一定透水性, 在现有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效果。通过水槽概化模型试验，研究了3种空隙尺寸和5种空隙率工况下透水丁坝周围水面线分布情况，对比分析了不同空隙率和不同空隙尺寸等因素对透水丁坝周围水面线的影响规律。结果表明:相比实体丁坝，在一定的空隙率和空隙尺寸条件下，透水丁坝对其上游的壅水效果更佳，同时还可增加其下游水深，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、延长其使用年限以及改善生态环境等方面也具有更积极的作用。

Experimental studies on flow profile of permeable spur dikes in upper reaches of Yangtze River

The spur dike is one of the most frequently-sed hydraulic structures in the waterway regulation works of the upper reaches of the Yangtze River. And in the engineering practice, the riprap permeable spur dikes are often used in the waterway regulation projects because they have certain permeability. In the studies of water-ediment characteristics of the spur dikes, the influences of permeability on the existing spur dikes located in the Yangtze River are seldom considered. Different porosities and void sizes have different effects on improving the water level field and velocity field near the permeable spur dikes. Based on the flume generalization model tests, studies of the flow profile distribution around the permeable spur dikes under the conditions of three void sizes and five porosities are carried out in this research. And the influence law of different void sizes and different porosities on the flow profile around the permeable spur dikes is understood through comparative analysis. The analysis results show that the backwater effect of the permeable spur dikes is better than that of the solid spur dikes under certain void ratios and void sizes. The permeable spur dikes can also increase the downstream water depth and reduce the vertical and horizontal water surface gradients, which has a more positive effect on improving the flow patterns of the narrow section of the right bundle of the permeable spur dikes, thus reducing the damage of the permeable spur dikes, prolonging the service life and improving the ecological environment. The research results have certain reference value for the design of waterway regulation structures and the improvement of waterway regulation effect in the middle and upper reaches of the Yangtze River.