长江中游周天河段演变分析与整治措施研究

发布时间：2018-11-05 15:05

【摘要】：长江是我国第一大河,贯通东西部地区最重要的水运主通道,货运量突破20亿吨,已连续12年位居全球内河首位。长江中游上起宜昌,下至鄱阳湖湖口,长达900km,是连接上下游航道的重要纽带。保持长江航道的畅通,对促进长江黄金水道尽早发挥社会效益具有积极的作用。然而,位于长江中游的周天河段,滩槽格局变化频繁,航道条件较差,历来是长江中游上治理的重点和难点。周天河段上连郝穴水道,下接藕池口水道,全长约28km,以胡汾沟为界自上而下分为周公堤水道和天星洲水道。河段内不仅洲滩冲淤多变、主流摆动不定,而且上下水道相互作用、关系密切,使周天河段即具有上荆江河段洲滩变化频繁的特征,又有下荆江河段上下关联性强的显著特点,演变规律十分复杂;近期,三峡水库蓄水运用后,来水来沙条件发生改变对坝下游河床的演变造成剧烈影响,周天河段作为较早受三峡水库蓄水运用影响的河段,“清水”持续冲刷使该河段航道条件趋于恶化,碍航问题频发,严重制约了长江中游航道的畅通,亟需开展浅滩演变规律和航道整治措施的研究工作,以改善本河段的航运条件。本文以长江中游周天河段航道整治工程作为依托,以水文泥沙和实测地形资料为基础,运用统计学方法分析了来水来沙特点及变化特征;从周公堤与天星洲两水道相互关联的属性出发,系统分析并总结了周天河段的演变规律,预估了变化趋势;借助二维水沙数学模型对该河段进行了数值模拟研究,验证了河演分析的结果;在河演分析的基础上,提出了该河段的航道整治工程方案;利用三维紊流数学模型验证并优化了工程方案。本文主要结论如下:1、周天河段内的两水道上下关联性强,不仅主流之间相互作用,而且洲滩之间冲淤消长;2、周公堤水道内的蛟子渊边滩是影响其它滩形变化的最重要滩体,在周天河段中起到承上启下的作用;3、三峡水库蓄水后,周天河段河势格局整体较为稳定,但局部地方仍存在一些不利的变化;4、周天河段目前存在的航道问题:周公堤水道过渡段浅区水深不足,以及天星洲洲体冲刷后退,使得航道边界不稳定;5、周天河段的治理思路:控制周公堤水道放宽段的主流摆动,同时避免对颜家台春灌站取水口造成影响;稳定天星洲水道过渡段的洲滩格局;6、根据整治方案数学模型的研究认识,潜丁坝坝体适量透水不会削弱坝体的挑流作用,还能在一定程度上减缓坝体上游泥沙的淤积,建议在颜家台区域布置1道透水面积比例处于10%~20%范围的潜丁坝。本文的研究工作对于探索周天河段的浅滩演变规律;分析新水沙条件下河床的发展趋势;研究长直过渡段浅滩的治理措施等具有一定的参考价值和实际意义。
[Abstract]:The Yangtze River is the largest river in China, which runs through the most important waterway in the eastern and western regions. The cargo volume exceeds 2 billion tons, which has been the first inland river in the world for 12 years in a row. The middle reaches of the Yangtze River up Yichang and down to Poyang Lake, 900 km long, is an important link between upstream and downstream waterways. Maintaining the smooth passage of the Yangtze River plays a positive role in promoting the Yangtze River Golden Waterway to bring social benefits into full play as soon as possible. However, in the Zhoutian reach in the middle reaches of the Yangtze River, the beach pattern changes frequently and the channel conditions are poor, which has always been the focus and difficulty in the regulation of the middle reaches of the Yangtze River. The total length of the reach is about 28km, which is divided into Zhougong dike waterway and Tianxingzhou waterway from the top to the bottom. In the reach, not only the beach scour and siltation is changeable, the mainstream swinging is uncertain, but also the interaction between upper sewers and sewers is close, which makes the Zhoutian reach have the characteristics of frequent beach changes in the reach of the upper Jingjiang River and strong correlation between the upper and lower reaches of the Jingjiang River. The law of evolution is very complex; Recently, after the storage and operation of the three Gorges Reservoir, the changes in the conditions of incoming water and sediment have had a severe impact on the evolution of the riverbed downstream of the dam. The Zhoutian reach is an earlier section affected by the water storage and utilization of the three Gorges Reservoir. The continuous scour of "clear water" makes the waterway condition of the reach worse and hinders navigation frequently, which seriously restricts the smooth flow of the channel in the middle reaches of the Yangtze River. It is urgent to carry out the study on the rules of shoal evolution and the regulation measures of the channel in the middle reaches of the Yangtze River. In order to improve the shipping conditions of this reach. Based on the waterway regulation project in the middle reaches of the Yangtze River, based on hydrological sediment and measured topographic data, the characteristics and variation characteristics of incoming water and sediment are analyzed by statistical method in this paper. Based on the interrelated properties of Zhougong dike and Tianxingzhou two waterways, the evolution law of Zhoutian reach is analyzed and summarized systematically, and the trend of change is forecasted. The numerical simulation of the reach is carried out with the aid of two-dimensional water and sediment mathematical model, and the results of the river simulation analysis are verified, and based on the analysis of the river model, the waterway regulation project of the reach is put forward. The three-dimensional turbulent mathematical model is used to verify and optimize the engineering scheme. The main conclusions of this paper are as follows: 1. The relationship between the two waterways in the Zhoutian reach is strong, not only the interaction between the mainstream, but also the erosion and siltation between the banks; 2, the Jiaoziyuan edge beach in the Zhougong dike waterway is the most important beach body which affects the change of other beach shape, and plays a connecting role in the Zhoutian reach; 3. After the three Gorges Reservoir impounded, the river regime pattern of the Zhoutian reach is relatively stable, but there are still some unfavorable changes in the local areas. (4) the current waterway problems in the Zhoutian reach: insufficient water depth in the shallow area of the transitional section of the Zhougongdi waterway, and the erosion and retrogression of the Tianxing Island, which make the waterway boundary unstable; 5. The control thought of the Zhoutian reach: controlling the mainstream swing of the relaxed section of Zhougongdi waterway, avoiding the influence on the intake of the spring irrigation station in Yanjiatai, stabilizing the beach pattern of the transitional section of Tianxing Zhou waterway; 6. According to the study of mathematical model of regulation scheme, the proper water permeability of submersible dike body will not weaken the dredging effect of dam body, but also can reduce the silt deposition in the upper reaches of dam body to a certain extent. It is suggested that 1 submersible dike with a ratio of 10% to 20% should be arranged in the Yanjiatai area. The research work in this paper has certain reference value and practical significance for exploring the shoal evolution law of Zhoutian reach, analyzing the developing trend of river bed under the condition of new water and sediment, and studying the control measures of the shoal in the long straight transition section.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV147

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