不同上游来水流量下黄土堰塞坝下切过程试验研究  

EXPERIMENTAL STUDY ON THE DOWNCUTTING PROCESS OF LOESS LANDSLIDE DAM UNDER DIFFERENT UPSTREAM WATER INFLOW FLOWS

作　　者：曹琰波[1,2] 韩宁 马鹏辉 李泽坤[1] 焦其宪 陈立森 薛一凡 王竟晔 冉林 CAO Yanbo;HAN Ning;MA Penghui;LI Zekun;JIAO Qixian;CHEN Lisen;XUE Yifan;WANG Jingye;RAN Lin(Chang'an University,College of Geological Engineering and Geomatics,Xi'an 710054,China;Shaanxi Hydrogeology Engineering Geology and Environment Geology Survey Center,Xi'an 710068,China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]陕西省水工环地质调查中心,西安710068

出　　处：《工程地质学报》2025年第1期279-291,共13页Journal of Engineering Geology

基　　金：国家重点研发计划项目(资助号:2022YFC3003401);国家自然科学基金项目(资助号:42477175).

摘　　要：由于黄土的特殊水敏性,导致黄土堰塞坝极易在水作用下发生溃决破坏,为了解不同上游来水流量下黄土堰塞坝的下切破坏过程,本文共进行了5组不同上游来水流量(0.6 L·s^(-1)、0.8 L·s^(-1)、1.0 L·s^(-1)、1.2 L·s^(-1)和1.5 L·s^(-1))的水槽试验。试验结果表明:(1)黄土堰塞坝的下切过程可划分为3个阶段:冲刷阶段、侵蚀阶段和破坏阶段;(2)不同上游来水流量下黄土堰塞坝展现出相似的下切过程,但最终呈现出不同的破坏模式,即当上游来水流量为1.2 L·s^(-1)和1.5 L·s^(-1)时,发生漫顶溢流破坏,当上游来水流量为0.6 L·s^(-1)、0.8 L·s^(-1)和1.0 L·s^(-1)时,发生管涌破坏;(3)下切过程主要体现在冲刷阶段和侵蚀阶段,流量越大,渗流时间越短,侵蚀率越大,坝体的背水坡坡面更易被侵蚀而破坏;流量越小,渗流时间越长,侵蚀率越小,黄土堰塞坝更易因渗流形成管涌通道。研究结果有望为黄土堰塞坝的机理认知提供一定依据。Due to the strong water sensitivity of loess,loess landslide dams are highly susceptible to breach and damage under the influence of water.To understand the downcutting and damage process of loess landslide dams under different upstream water flow rates,a series of five flume tests with varying flow rates(0.6 L·s^(-1),0.8 L·s^(-1),1.0 L·s^(-1),1.2 L·s^(-1)and 1.5 L·s^(-1))were conducted.The test results show that:(1)The downcutting process of loess landslide dams can be divided into three stages:the scouring stage,erosion stage,and damage stage.(2)Loess landslide dams under different upstream flow rates exhibit similar downcutting processes,but the final damage patterns differ.Overtopping occurs when the upstream flow rates are 1.2 L·s^(-1)and 1.5 L·s^(-1),while piping occurs at flow rates of 0.6 L·s^(-1),0.8 L·s^(-1)and 1.0 L·s^(-1).(3)The downcutting process is most pronounced during the scouring and erosion stages.As the flow rate increases,the seepage time decreases and the erosion rate increases,making the backwater slope of the dam more susceptible to erosion damage.Conversely,at lower flow rates,the seepage time is longer,the erosion rate is smaller,and the loess landslide dam is more prone to the formation of a piping surge channel due to seepage.

关 键 词：黄土堰塞坝 水槽试验 下切过程 漫顶溢流 管涌 

分 类 号：P642[天文地球—工程地质学]