清水作用下弯道床面变化特性研究  

Research on the Bed Surface Changes of Meandering Channels under the Action of Clear Water

作　　者：陈治舟 郑好 杨克君[1] CHEN Zhi-zhou;ZHENG Hao;YANG Ke-jun(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China)

机构地区：[1]四川大学山区河流保护与治理全国重点实验室,四川成都610065

出　　处：《中国农村水利水电》2024年第12期123-129,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(52379074)。

摘　　要：弯曲河道普遍存在于自然界中,研究清水冲刷作用下的弯曲河道床面变化具有重要意义。主要设计了梯级流量增大试验,探讨清水作用下弯道的床面变化特性。研究表明:同一流量下,在直线过渡段进口处和中部附近,横断面平均流速较大。直线过渡段进口处极易出现淤积和冲刷,程度随流量增大而加剧。流量较小时,直线过渡段泥沙较弯曲段更细。随着流量的增大,直线过渡段泥沙级配与弯曲段趋于相同。在一个完整的弯段内,床面深泓线在弯曲段靠近凸岸,在直线过渡段紧贴边壁。经水流塑造后,床面高程频率分布由正态逐渐变为正偏态。Meandering channels are frequently observed in natural environments,and studying the dynamic behavior and evolution of the bed surface within meandering channels under the influence of clear water erosion has emerged as a crucial area of research.In this article,the primary objective is to devise an innovative experiment,namely a cascade flow increase test,in order to comprehensively investigate the al‐terations occurring in the bed surface of a meandering channel when subjected to the erosive forces of clean water.The research shows:Un‐der the same flow rate,near the entrance and middle of the straight transition section,the average cross-sectional velocity is relatively high.The entrance of the straight transition section is prone to sedimentation and erosion,and the degree increases with the increase of flow rate.When the flow rate is small,the sediment in the straight transition section is finer than that in the curved section.As the flow rate increases,the sediment gradation in the straight transition section tends to be the same as that in the curved section.Within a complete bend section,the talweg is close to the convex bank in the bend section and closely adheres to the edge wall in the straight transition section.After being shaped by flow,the frequency distribution of bed elevation gradually changes from normal to normal skewed.

关 键 词：清水作用 弯道 床面变化 泥沙级配 

分 类 号：TV147[水利工程—水力学及河流动力学]