弯曲分汊河道典型险段成因分析及治理思路  

Analysis of causes of typical dangerous levees in curved braided channels and treatment ideas

作　　者：练伟航[1,2,3] 李海彬 宫鹏杰[1,2,3] 张广传 丘佳永[1,2,3] LIAN Weihang;LI Haibin;GONG Pengjie;ZHANG Guangchuan;QIU Jiayong(Guangdong Research Institute of Water Resources and Hydropower,Guangzhou 510635,China;Guangdong Key Laboratory of Hydrodynamic Research,Guangzhou 510635,China;National and Local Joint Engineering Laboratory of Estuarine Water Technology,Guangzhou 510635,China)

机构地区：[1]广东省水利水电科学研究院,广东广州510635 [2]广东省水动力学应用研究重点实验室,广东广州510635 [3]河口水利技术国家地方联合工程实验室,广东广州510635

出　　处：《人民长江》2023年第12期1-7,共7页Yangtze River

基　　金：广东省水利科技创新项目(2023-06)。

摘　　要：西江下游沙口河段近年来出现多次较大岸坡塌方险情,在实施塌岸修复工程后,险段出险隐患仍未得到有效缓解。结合沙口河段1999~2016年水下地形数据开展了河床演变分析,并通过建立一、二维水动力数学模型开展典型频率洪水工况下险段河道水流特性分析。研究结果表明:沙口河段2010年后河床已趋于稳定,但在较大洪水条件下仍可能发生0.3~0.5 m幅度的冲刷;险段所在的左汊河道为主要泄洪通道,险段近岸流速较大;险段成因及发展主要受河势及堤基地质条件的影响,土体自重和坡内渗流是出险的主要因素,水流冲刷则有助推效应。结合实地调研成果,提出了河势调整和岸坡防护相结合的治理思路,可为后续险段综合整治工作的开展提供参考。In recent years,there have been many large bank slope collapses in the Shakou dangerous levees of the lower reaches of the Xijiang River,Guangdong Province.After the implementation of the bank collapse reinforcement project,the hidden danger of the dangerous levels has not been effectively alleviated.Based on the underwater topographic data of the Shakou section from 1999 to 2016,the riverbed evolution analysis was carried out,and the flow characteristics of the dangerous levees under typical frequency flood conditions were analyzed by establishing one-dimensional and two-dimensional hydrodynamic mathematical models.The results show that the riverbed of Shakou reach is stable after 2010,but the erosion with the intensity of 0.3~0.5 m depth may occur under the condition of a large flood.The left branch is the main flood discharge channel where the dangerous levees are located,and the nearshore velocity of the dangerous levees is large.The causes and development of the dangerous levees are mainly driven by the river regime and the geological conditions of the embankment base.The self-weight of the soil and the seepage in the slope are the main factors causing typical dangerous levees,and the water flow erosion has a boosting effect.Combined with the results of the field investigation,the idea of combining river regime adjustment with bank slope protection was put forward,which can provide a reference for the follow-up comprehensive improvement of dangerous levees.

关 键 词：分汊河道 河床演变 水流特性 险段治理 西江 

分 类 号：TV143.3[水利工程—水力学及河流动力学]