粗化床面发展过程中非均匀沙起动试验研究  

Experimental study on incipient motion of non-uniform sediment during bed armoring process

作　　者：刘春晶[1,2] 陈月 张凌峰 张宇 LIU Chun-jing;CHEN Yue;ZHANG Ling-feng;ZHANG Yu(State Key Laboratory of Watershed Water Cycle Simulation and Regulation,China Institute of Water Resources and Hydropower Research,Beijing 100048,China;Key Laboratory of Sediment Science and Northern River Training,Ministry of Water Resources,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100048 [2]中国水利水电科学研究院水利部泥沙科学与北方河流治理重点实验室,北京100048

出　　处：《泥沙研究》2023年第4期1-8,共8页Journal of Sediment Research

基　　金：国家自然科学基金项目(12072373,51679260);中国水科院“十四五”创新团队支持项目(SE0145B022021)。

摘　　要：非均匀沙在水流作用下会形成表层粒径大于底层的床面粗化现象,同时表层粗颗粒还会形成聚集结构体。已有非均匀沙起动研究仅考虑粒径差异,对多颗粒组成的粗化结构体及其影响问题考虑不足。在水槽中开展了非均匀沙床面粗化发展过程试验,分析了粗化床面条件下的起动条件及起动判别标准。结果表明,粗化床面发展可分为中粗颗粒出露、中颗粒结构体形成、粗颗粒结构体形成等3个阶段,粗化结构体对泥沙颗粒的起动和输移造成较大影响。粗化床面条件下非均匀沙起动临界希尔兹参数为0.015 5~0.023 5,小于均匀沙床面。USACE输沙率标准不适用于非均匀沙粗化床面,而Parker标准与韩其为标准均可在一定程度上反映非均匀沙粗化对泥沙起动的影响,其中韩其为标准与实测值更接近。Under the action of flow,there exists a river bed armoring phenomenon of coarse sediment particles with aggregated structure on surface layer and fine particles on the lower layer.Most of the existing studies on the incipient motion of non-uniform sediment only consider the difference in particle size,it is insufficient to study the armoring structures and their effects formed by multiple particle compositions.A flume experiment on the development process of non-uniform bed surface armoring has been conducted,and the initiation conditions for criteria of non-uniform sediment on armoring bed are analyzed.The results show that the development of bed armoring can be divided into three stages:exposure of medium to coarse particles,formation of mediumsized structures,and formation of coarse particle structures.The armored structures have a significant impact on the initiation and transport of sediment.The critical Shields parameter for the initiation of non-uniform sediment under armored bed surface conditions is between 0.0155 and 0.0235,which is lower than the results obtained for uniform sediment.The sediment transport rate criteria of USACE are not applicable to nonuniform bed surfaces,while both Parker criteria and the Han Qiwei criterion can reflect to some extent the he interaction of particles with different sizes on sediment initiation motion.Among them,the Han Qiwei criterion is closer to the measured values.

关 键 词：非均匀沙 推移质输沙率 起动标准 水槽试验 粗化床面 

分 类 号：TV142.1[水利工程—水力学及河流动力学]