渗流对潮沟沟壁崩塌影响的三维物理模型试验研究  

The influence of seepage on bank collapse of muddy tidal channel:three-dimensional physical model

作　　者：龚政[1] 唐帅 赵堃[1] 张凯丽 GONG Zheng;TANG Shuai;ZHAO Kun;ZHANG Kaili(Jiangsu Key Laboratory of Coast Ocean Resources Development and Environment Security,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学江苏省海岸海洋资源开发与环境安全重点实验室,江苏南京210098

出　　处：《水科学进展》2023年第2期290-298,共9页Advances in Water Science

基　　金：国家重点研发计划资助项目(2022YFC3106204);国家自然科学基金资助项目(51925905)。

摘　　要：潮沟在海岸动力作用下因沟壁崩塌而频繁地迁移摆动,显著影响潮滩-潮沟系统的稳定性。现有研究多关注涨潮时期潮沟内部的水流冲刷,落潮期间的渗流侵蚀过程却少有涉及,亟需研究渗流对潮沟沟壁稳定性的影响机制。本研究通过物理模型试验探究渗流对潮沟沟壁崩塌的影响,从沟壁崩塌类型、沟壁线变化过程和沟壁后退速率3个方面开展分析。研究结果表明:沟壁破坏类型与渗流水头相关,渗流水头的增加导致破坏类型由悬臂破坏转变为张拉破坏;沟壁后退速率与渗流水头之间存在正相关关系。本研究揭示了渗流作用下潮沟沟壁崩塌的力学机理,阐明了落潮不同阶段沟壁的崩塌过程,对研究潮沟演变有重要意义。Tidal channels migrate frequently under the combined actions of coastal dynamics and bank collapse,significantly affecting the stability of tidal network systems.However,existing studies mainly focus on in-channel flow erosion during flood tides,while less efforts are devoted to bank retreat driven by seepage erosion during the ebb tides.It is thus urgent to understand the underlying mechanism of bank collapse that driven by seepage.This study investigates the impact of seepage head height on bank collapse through physical experiments,including bank collapse modes,bank line variations and bank retreat rate.Results show that the process of bank collapse is related to seepage head height.We observe a transition of bank collapse mode from cantilever failure to tension failure,with increased seepage head height.A positive correlation between bank retreat rate and seepage head height is found.Overall,this research reveals the mechanism of bank collapse driven by seepage,and explains the distinct failure process of bank collapse over ebb tides,which is of great significance to the study of tidal channel evolution.

关 键 词：沟壁崩塌 渗流 物理模型 潮沟 潮滩 

分 类 号：TV139.1[水利工程—水力学及河流动力学]