两坝间水田角深水急滩水流特性及整治措施研究

发布时间：2018-08-20 07:27

【摘要】：两坝间河谷狭窄陡峭，水流湍急，流态紊乱，滩险密布，通航条件十分险恶，其中水田角是长江著名的洪水急流滩，是两坝间最困难的航段之一。为确保长江“黄金水道”的畅通，提高通航能力，对水田角滩段水流特性及航道整治方法进行研究颇为重要。本文采用二维水流数值模拟技术，对两坝间水田角深水急滩的水流特性及其整治措施进行了初步研究，主要工作内容和研究成果有： (1)应用两坝间莲沱段实际水文测验资料对二维水流数学模型进行了细致的验证计算，获取了能较好模拟该河段流场的糙率、网格密度等计算参数。 (2)运用二维水流数学模型对研究河段进行了多级洪水流量的流场计算，，详细分析了滩段的水流条件，指出滩性为以流急碍航为主的基岩洪水急滩，而河谷狭窄、河宽沿程渐缩突扩、流量与过水面积增率不适应、流速横向均匀分布等是成滩主因。 (3)通过常规的扩大泄水断面法等多种开挖方式的研究表明，仅用开挖来扩大泄水面积的方法对陡岸型深水急滩的整治效果并不明显，难以达到整治目标。 (4)基于水深浅流速小的水力特性，提出了一种非常规急滩整治方法—潜坝致浅成缓法，通过对坝体参数多种组合的调试计算，结果表明，仅仅依靠潜坝致浅成缓也难以大幅改善水田角上滩水流条件，其整治效果仅稍优于扩大泄水断面法。 (5)综合扩大泄水断面法和潜坝致浅成缓法，提出了一种“左疏右抬”的综合整治方法，即对岸扩大泄水断面，本岸修筑潜坝减小水深形成缓流航道，可明显改善急滩水流条件，较大幅度提高通航流量，达到整治目标。 (6)最后分析了“左疏右抬”综合整治方法的适用条件，该方法只适用于以流急碍航为主、两岸具有“搭跳”上滩的平面和水流条件、洪枯水位变幅不大的库区深水急滩。
[Abstract]:The river valley between the two dams is narrow and steep, the current is fast, the flow pattern is disordered, the beach is dangerous and the navigable conditions are very dangerous, among which the paddy field corner is the famous flood rapids of the Yangtze River and one of the most difficult sections between the two dams. In order to ensure the smooth running of the "golden channel" of the Yangtze River and improve the navigable capacity, it is very important to study the characteristics of the water flow and the regulation method of the waterway in the section of the Paddy Corner beach. In this paper, the flow characteristics and regulation measures of the deep-water rapids in the corner of the paddy field between the two dams are preliminarily studied by using the two-dimensional flow numerical simulation technique. The main work and research results are as follows: (1) by using the actual hydrological data of the Liantuo section between the two dams, the two-dimensional flow mathematical model is carefully verified and calculated, and the roughness of the flow field can be well simulated. (2) Two-dimensional flow mathematical model is used to calculate the flow field of multi-stage flood flow in the studied reach, and the flow condition of the beach section is analyzed in detail. It is pointed out that the beach character is the bedrock flood beach, which is dominated by the current and hindrance to navigation, while the river valley is narrow, the river width gradually shrinks along the course, and the flow rate is not suitable for the increase rate of the overflowing area. The horizontal uniform distribution of velocity is the main cause of beach formation. (3) through the study of various excavation methods such as the conventional method of expanding the drainage section, it is shown that the regulation effect of the method of expanding the drainage area only by excavation is not obvious for the steep shoreline type deep water rapids. It is difficult to reach the target of regulation. (4) based on the hydraulic characteristics of low velocity of shallow and deep water flow, a method of unconventional shoal regulation, submersible dam shallow-forming method, is proposed. The results show that the method is based on the adjustment and calculation of various combinations of dam body parameters. It is difficult to improve the flow condition of the upper beach of the paddy field by only relying on the shallow formation of submersible dam, and its regulation effect is only slightly better than the method of expanding the drainage section. (5) the comprehensive expansion of the drainage section method and the shallow formation gentle method caused by the submersible dam. In this paper, a comprehensive regulation method of "left, sparse and right lifting" is put forward, that is to say, expanding the drainage section across the bank and reducing the depth of the submersible dam on this bank to form a slow flow channel, which can obviously improve the flow conditions of the rapids and increase the navigable discharge by a large margin. (6) finally, the suitable conditions of the comprehensive regulation method of "left, sparse and right lift" are analyzed. The method is only suitable for the current and hindrance of navigation, and the two sides have the plane and flow conditions of "lap jump" on the beach. Flood and dry water level of the reservoir area with little change in deepwater rapids.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV85

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