抛石沉降附加历时及其对漂距的影响分析  

Analysis of additional duration of riprap settlement and its effect on drift distance

作　　者：许光祥[1,2] 楼金仙 蒋孜伟 童思陈[1,2] XU Cuang-xiang;LOU Jin-xian;JIANG Zi-wei;TONG Si-chen(National Engineering Technology Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China;Key Laboratory of Hydraulic and Waterway Engineering of Ministry of Education,Chongqing Jiaotong University,Chongqing 400074,China;Changjiang Chongqing Waterway Bureau,Chongqing 400010,China)

机构地区：[1]重庆交通大学国家内河航道整治工程技术研究中心,重庆400074 [2]重庆交通大学水利水运工程教育部重点实验室,重庆400074 [3]长江重庆航道局,重庆400010

出　　处：《泥沙研究》2023年第6期74-80,共7页Journal of Sediment Research

基　　金：国家重点研发计划项目(2018YFB1600400);重庆市基础研究与前沿探索项目(cstc2018jcyjAX0534)。

摘　　要：沉降附加历时是指抛石按实际变速沉降与以稳定沉速匀速沉降之间存在的历时差,目前还没有深入研究。基于抛石沉速和行程的理论方程式,引入沉降形阻系数、单径稳降历时和粒径水深比等参数,简化了抛石沉速和行程的理论公式结构,给出了沉降总历时和附加历时的精确解及等同的近似解,建立了沉降附加历时无量纲关系式和平均沉速理论计算式。实例分析表明,沉降附加历时比随着粒径水深比呈线性增加。基于流速垂线均匀分布的漂移速度和漂距方程,建立了相对漂距与佛汝德数和粒径水深比的无量纲表达式。分析结果表明,当粒径水深比为0.01~0.05时,忽略附加历时可使漂距偏差达到5%~50%,当粒径水深比为0.1时,偏差甚至超过100%。The additional duration of riprap settlement refers to the duration difference between the riprap settling at the actual variable velocity and at the uniform velocity in the steady state,which has not been thoroughly studied yet.The theoretical equations of the settling velocity and stroke of riprap are deduced and simplified by introducing some parameters,such as the settling shape resistance coefficient,steady settlement duration of single particle and ratio of particle size to water depth.The exact solutions and the equivalent approximate solutions of the total duration and the additional duration of riprap settlement are given out,the dimensionless relation formula of additional duration and the theoretical calculation formula of average settling velocity are established.The example analysis results show that the additional duration ratio of settlement increases linearly with the ratio of particle size to water depth.By assuming linear distribution of the vertical flow velocity and the drift distance equations,the dimensionless expressions of the relative drift distance with Froude number and ratio of particle size to water depth are also established.The results show that the drift distance deviations induced by ignoring the additional duration can reach 5%~50% and even exceed 100%as the ratio of particle size to water depth get to 0.01~0.05 and 0.1,respectively.

关 键 词：抛石 沉速 沉降附加历时 稳前历时 漂距 

分 类 号：U617[交通运输工程—船舶及航道工程]