摘要
三峡工程及长江上游水库群建库运行以来,新水沙形势下荆江河段发生大范围、高强度持续冲刷,导致部分护岸工程段崩岸险情时有发生,对河势稳定、防洪安全及岸线利用等造成较大影响。以2023年下荆江已护险工段“天字一号”段突发崩岸险情及处置为例,通过实测资料分析,揭示了崩岸发生的主要原因为“清水下泄”情势下河床持续冲深、局部河势显著调整变化引起深泓深槽贴岸、河段岸坡地质条件较差以及持续中低水位影响等。基于险情特征,采取水下抛石方式对窝崩险工段及上下游影响段进行应急处置,提出亟需建立体制机制,保障相关建设资金,重视和加强对险工段坡脚变化的动态监测和整治技术研发,完善崩岸监测预警及应急抢护机制等中长期治理建议,为新水沙情势下长江中下游河道崩岸系统防治提供支撑。
[Objectives]Since the operation of the Three Gorges Project and the cascade reservoirs in the upper reaches of the Yangtze River,the new water and sediment regime has caused large-scale and high-intensity continuous erosion in the Jingjiang River section of the middle Yangtze River,resulting in recurrent bank collapse incidents at some revetment sections.To investigate the causes of recent bank collapses at revetment sections and better respond to such dangerous situations,this study examines the sudden bank collapse and its emergency treatment at the“Tianzi-1”revetment section in the lower Jingjiang River in 2023.[Methods]Measured water and sediment data at Jianli station since 1990,annual erosion and deposition data of the lower Jingjiang River since 2003,and measured data on channel topographic changes and geological drilling before and after the bank collapse at the“Tianzi-1”section were used to analyze the causes.[Results]In November 2023,continuous cave-in-type bank collapses occurred at the“Tianzi-1”revetment section in the Hunan segment of the lower Jingjiang River,with collapse lengths of approximately 100 m and 35 m,respectively.The results showed that the bank collapse primarily resulted from continuous riverbed erosion under the clear-water discharge condition,significant changes in local river regime causing deep channel and thalweg migration toward banks,poor geological conditions of the riverbank slope,and the influence of prolonged low-to-medium water levels.Based on the characteristics of the dangerous situation,an underwater stone dumping method was adopted for emergency treatment of the collapsed section and the affected upper and lower reaches.[Conclusions]This recurrent bank collapse at the revetment section highlights that the lower Jingjiang River will continue to face severe threats of bank collapse for the foreseeable future.Without timely reinforcement measures,large-scale damage can occur to existing bank protection structures,seriously threatening flood control safety.Therefore,this study proposes medium-to-long-term governance measures,including establishing institutional frameworks as soon as possible,securing construction funding,strengthening dynamic monitoring of slope toe variations at dangerous sections,enhancing the development of bank failure control technologies,and improving the monitoring,early warning,and emergency response mechanisms for bank collapse.
作者
陈益民
林荡
阳甜甜
郑保
张国华
李凌云
郭超
CHEN Yi-min;LIN Dang;YANG Tian-tian;ZHENG Bao;ZHANG Guo-hua;LI Ling-yun;GUO Chao(Yueyang Dongting Lake Water Conservancy Affairs Center,Yueyang 414000,China;Key Laboratory of River and Lake Regulation and Flood Control in the Middle and Lower Reaches of Yangtze River of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《长江科学院院报》
北大核心
2025年第6期8-13,20,共7页
Journal of Changjiang River Scientific Research Institute
基金
国家重点研发计划项目(2023YFC3209500)
湖南省水利科技项目(XSKJ2023059-58)。
关键词
崩岸
水沙情势
河道演变
险情处置
荆江
bank collapse
water and sediment regime
channel evolution
emergency treatment
lower Jingjiang River
