长江下游侧滑型窝崩成因及其力学机制  

Analysis on the cause and mechanism of the pit-collapse of lateral-silde type in the lower Yangtze River

作　　者：张幸农[1] 应强[1] 假冬冬[1] 陈长英[1] ZHANG Xingnong;YING Qiang;JIA Dongdong;CHEN Zhangying(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院、水文水资源与水利工程科学国家重点实验室,江苏南京210029

出　　处：《水利水运工程学报》2023年第2期9-15,共7页Hydro-Science and Engineering

基　　金：国家自然科学基金资助项目(U2040215,52079080)。

摘　　要：为全面认识长江下游各类窝崩的形成原因和力学机制,以和畅洲头窝崩为例进行全面分析,进而借鉴土力学方面成果,提出相应的失稳模式和估算方法。结果表明:和畅洲头窝崩属于侧滑型窝崩,其成因主要是岸滩土体中存在易液化的粉砂层,当外界出现一定的振动扰动因素,粉砂层液化条件成熟时则成为滑动层,液化层和上覆土层分多次发生大幅度侧向滑移,土体滑出窝塘口门进入河道深槽,随后被河道主流迅速分散搬运至下游。采用数理统计方法,得到土体滑移距离与液化层厚度和滑移层倾角之间幂函数形式的经验公式。研究结果可为长江下游此类窝崩的预警和治理提供参考。For comprehensive understanding about the formation causes and mechanical mechanisms of various types of pit-collapses in the lower reaches of the Yangtze River,taking the pit-collapse in the Hechangzhou head as an example,deep analysis was done,and then the soil mass instability model and displacement estimation method were proposed based on the results of soil mechanics.The results show that the pit-collapse in the Hechangzhou head belongs to lateral-slide type.Its formation cause is a there is a silt layer easy to liquefy in the beach soil.When there is a certain external vibration disturbance factor,once the liquefaction condition is mature,the silt layer becomes a sliding layer,the liquefaction layer and the overlying soil layer would turn into large lateral slides.The slide soil mass would skid out of the collapse pond mouth into the deep channel groove,and then is quickly dispersed and transported to the downstream by the main river current.The empirical formula of power function between the distance of sliding soil mass and the thickness of liquefied layer and dip angle of sliding layer can be obtained by using mathematical statistics method.These results can provide a reference for the early warning and managing of such collapse in the lower reaches of the Yangtze River.

关 键 词：长江下游 窝崩 成因 力学机理 土体侧向滑移 

分 类 号：TV861[水利工程—水利水电工程]