不平衡输沙悬移质粒径级配的垂线分布规律  

Vertical distribution of grain size gradation for the non-equilibrium sediment transport conditions

作　　者：马子普[1,2,3,4] 郭庆超 关见朝 乐茂华[3,4] MA Zi-pu;GUO Qing-chao;GUAN Jian-zhao;LE Mao-hua(Yellow River Institute of Hydraulic Research,YRCC,Zhengzhou 450003,China;Research Center of Levee Safety and Disaster Prerention,MWR,Zhengzhou 4503,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing 100038,China;China Institute of Water Resources and Hydropower Research,Bejing 100038,China)

机构地区：[1]黄河水利委员会黄河水利科学研究院,河南郑州450003 [2]水利部堤防安全与病害防治工程技术研究中心,河南郑州45003 [3]流域水循环模拟与调控国家重点实验室,北京100038 [4]中国水利水电科学研究院,北京100038

出　　处：《泥沙研究》2022年第4期1-7,共7页Journal of Sediment Research

基　　金：国家自然科学基金青年项目(52009145,42041004);中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2019-11);水利部堤防安全与病害防治工程技术研究中心开放课题基金资助项目(LSDP202107)。

摘　　要：基于不平衡输沙含沙量垂线分布公式,推导得到不平衡输沙条件下的悬移质粒径级配垂线分布公式,分析了悬移质泥沙粒径级配及中值粒径的沿程变化规律。结果表明:“上细下粗”的粒径级配垂线分布规律同样适用于不平衡输沙条件,冲刷时该规律最为明显,平衡时次之,淤积时最不明显。不平衡输沙过程中不同水深处的悬移质级配差异较大。底部含沙量及级配相同时,同一高度水层处冲刷时的泥沙级配较淤积时细。单向冲刷过程中,各水层悬移质中值粒径沿程逐渐变粗;单向淤积过程中,各水层悬移质中值粒径沿程逐渐变细。悬移质级配调整的速度,下部水层明显快于上部水层。相同水力条件与床沙组成及河床边界条件下,达到饱和时的悬移质级配及中值粒径相同。Based on the non-equilibrium profile formula of suspended sediment concentration,the grain-size profile formula of suspended sediment and gradation suiTable for non-equilibrium sediment transport conditions are derived respectively.The vertical distribution law of grain-size and gradation,together with the variation of median size along the way are analyzed.The results show that the vertical distribution law of grain-size being"upper fine and lower coarse"is also applicable to the non-equilibrium sediment transport conditions,and which is most obvious in the scour state.The gradation of suspended sediment varies in different flow layers.With the same bottom sediment concentration and gradation,the gradation at the same height is finer for the scour state than the deposition state.During the unidirectional erosion process,the median particle size of suspended sediment at each layer becomes coarser gradually.During the unidirectional deposition process,the median particle size at each layer decreases gradually.The gradation tends to be sTable when the non-saturation parameter approaches 1,the particle size gradation and median particle size are same at sTable conditions for the determined hydraulic,bed sand composition and riverbed boundary conditions.Under the same hydraulic,bed sediment composition and riverbed boundary conditions,the suspended sediment gradation and median particle size tend to same when reaching the saturation state.

关 键 词：不平衡输沙 悬移质 粒径级配 非饱和度参数 中值粒径 

分 类 号：TV142.1[水利工程—水力学及河流动力学]