摘要
福姜沙水道是长江南京以下12.5 m深水航道重点治理河段。航道工程实施后,仍需进行疏浚维护保障航道畅通。为了探究航道工程作用下福姜沙水道的滩槽演变特征,并进一步研究其对水沙过程的响应关系,采用基于Hybrid LTS/GMaTS方法的平面二维水—沙—床耦合数学模型进行了数值模拟研究。Hybrid LTS/GMaTS方法在不损失模型计算精度的前提下大幅度提高了计算效率。研究结果表明:1)水动力作用是洲滩变形的主要动力,体现在洲滩整体冲淤和局部形态改变两方面;2)航道工程作用下,福中水道入口处水动力条件明显改善,各特征流量级下均呈现刷深趋势,航道中段呈现“洪冲枯淤”的冲淤特征,主流被归顺在深槽内,且随着流量增长深槽向南摆动;3)边心滩演变和水动力作用共同影响福北水道航道冲淤变化,航道工程作用下靖江边滩、双涧沙沙舌、福北水道的滩槽演变关系和对径流特征响应过程发生根本性变化。对水道整体而言,航槽回淤现象得到显著改善,然而受到洲滩演变和局部水动力减弱的不利影响,福北水道入口处航道条件发生恶化。
Fujiangsha is a key waterway for the 12.5 m deepwater channel of the Yangtze River downstream of Nanjing.After the regulation project,dredging is still necessary to maintain the channel water depth.To explore how the regulation works affect the waterway evolution,a numerical case study was carried out using a shallow water hydro-sediment-morphodynamic model.It is shown that the implementation of the Hybrid LTS/GMaTS method in the model can significantly reduce run times without loss of accuracy.Other numerical results show the following.First,hydrodynamic process is the main driving force of bar evolution,as reflected by the volume and planform change of bars.Second,regulation works lead to hydrodynamic conditions that are favorable for navigation at the entrance of Fuzhong channel,showing on erosion trend under different discharge magnitudes.The middle section of the channel presents the characteristics of“erosion in flood season and deposition in dry season”.The main stream is brought into the deep channel,and the deep channel swings southward with the increase of discharge.Third,the channel condition of Fubei channel is affected by the evolution of bars and hydrodynamic action.After implementation of the regulation project,the evolution relationship between bars,channls and the response process to runoff characteristics has changed.The phenomenon of channel deposition has been significantly improved.However,due to the adverse impact of bars evolution,local channel conditions have worsen.
作者
孙孟喆
胡鹏
李有为
刘奇峰
曹志先
SUN Mengzhe;HU Peng;LI Youwei;LIU Qifeng;CAO Zhixian(Ocean College,Zhejiang University,Zhoushan 316021,China;Ocean Research Center of Zhoushan,Zhejiang University,Zhoushan 316021,China;Changjiang Waterway Planning,Design and Research Institute,Wuhan 430040,China;School of Water Resources and Hydropower Engineering,Wuhan University,Wuhan 430072,China)
出处
《海洋工程》
CSCD
北大核心
2022年第6期62-75,共14页
The Ocean Engineering
基金
国家自然科学基金面上项目(12172331)
长江航道科研实验新基地建设三期工程数学模型软件购置工程项目(2020-KYY-529112-0036)。
关键词
福姜沙水道
深水航道
航道工程
径流特征
滩槽演变
耦合数学模型
局部时间步长
Fujiangsha waterway
deepwater channel
regulation project
runoff characteristics
river bed evolution
coupling mathematical model
local time stepping
