感潮河段分汊型河道航道整治初步研究.pdf

南京水利科学研究院硕士学位论文摘要摘要感潮河段多为临近沿海的经济发达地区,航道畅通是这些地区经济发展的重要保证。目前,随着我图国民经济的迅速发展,感潮河段的航道条件不能适应沿江经济建设的高速发展,航道条件急需提高。对感潮河段的舷道治理虽进行过一些研究,多数借用无潮河流的分析方法和设计思路,并取得了一些有益的成果。其实感潮河段有其自身麓永沙特点和演变规律,感潮河段壶于受双向水流的影响,演变规律较单向河流更为复杂,而处在感潮河段的分汉型河道的水流特点就更难以把握。其航道整治方法有待于进~步改进。本文首先在以往研究基础上,通过分析感潮河段的水力特性,针对感潮河段分汊型河道的水沙运动及碍航特性,总结感潮分汊河段航道整治的措施,通过河床演变分析、河工物理模型试验的方法,进行了落成渊汉道航道整治的初步探讨。研究的内容和主要结论有: (1)进行了研究河段的河床演变分析和碍航成因分析,根据落成测汉道的航道整治原则,结合感潮河段的水力特性,通过实施丁坝群方案或潜坝方案整治工程措施,达到增强航道内水流强度,提高退水期的输沙能力的目的。(2)通过丁坝群方案和潜坝方案的定床模型试验研究结果综合分析可见, 丁坝群方案以坝高lm方案较优,潜坝方案以坝高Om方案较优,而丁坝群方案与潜坝方案相比,又以丁坝群方案相对较优。需要指出的是,本方案仅仅从水流角度和节省工程投资的角度进行了比选,其工程效果如何?尚需进行动床模型试验的迸一步论证。(3)在熬治水位的选取时,通过壅水、航槽流速的变幅、落成洲左汊分流魄的变化以及主流线变化等因素的影响来综合比较,最终确定较优的整治工程方案和相应的整治工程高程,并以此作为本河段的憋治水位。(4)运用无因次分析的方法,构建了落成洲汊道左汊分流比与整治工程相对高程之间的关系。(5)通过因次分析的方法,建立了航槽流速与丁坝群高程的关系式。关键词:感潮河段;落成洲汊道;航道整治;整治建筑物高程南京水利科学研究院硕士学位论文 abStract Abstract Tidal reaches usually flow through thecoastal economic developed areas,and theunblocking ofchannel guarantees economic continual development ofthisareas. atpresent,、Ⅳith the rapid development of our national channel condition intidalreaches cannot meet the needs ofeconomic development inthe areasalong theriver,SOthey must beimproved are some studies on channel regulation intidalreaches,most ofwhich use theanalysis method and design ideainnon—tideriver,and some beneficial plishment have been obtained. In fact,tidal reaches have their own hydrological sediment characteristicsand evolution tidalreaches are affected bytwo—way flow,the evolution law plex than unidirectional ismore difficult tograsp the flow characteristics ofbranched channel in tidal methods of channel regulation need tobefurtherimproved. Based on theprevious researches,by analyzing thehydraulic characteristics in tidal reach,according to flow and sediment transport and the characteristics of obstructing navigation of the branched channel intidalreach,summarizing the measurments ofchannel regulation ofbranched channel i