水科学进展2012，Vol.23Issue(2)：249-255,7.
淤泥质浅滩泥沙临界起动切应力剖面确定
Critical stress profile for incipient sediment motion on muddy shoals
摘要
Abstract
The vertical profile of critical shear stress is determined using both experimental data and in-situ measurements. A tuning fork densimeter is employed to measure the vertical density distributions of mud on the Lianyungang muddy shoals in Jiangsu Province of China. Laboratorial experiments are conducted to study the incipient motion of sediment collected from the sea area where the vertical density of mud is measured. Both annular flume and long straight flume are used in the experiments under gradually increasing flow velocity. The result shows that there is a logarithmic relationship between the mud density and the water depth as revealed by the field survey. Laboratorial experiments indicate that the critical shear stress needed to initiate sediment movement ranges from 0. 1 to 1. 0 Pa for the density of 1 050 ~1 400kg/m3 mud, and the critical shear stress increases exponentially with the densification of the mud layer. As the result, a formula is established to describe the relationship between the critical shear stress and the water depth. The formula could be useful to simulate the incipient motion of sediment particles in a muddy environment.关键词
粘性泥沙/浅滩/泥沙剖面/临界应力/密度分布/水槽试验/定点测量Key words
cohesive sediment/ shoals/ sediment profiles/ critical stress/ density distribution/ flumes/ in-situ tests分类
建筑与水利引用本文复制引用
庞启秀,白玉川,杨华,张瑞波,贾志博..淤泥质浅滩泥沙临界起动切应力剖面确定[J].水科学进展,2012,23(2):249-255,7.基金项目
国家高科技研究发展计划(863)资助项目(2012AA112509) （863）
中央级公益性科研院所基本科研业务费专项资金资助项目(TKS100104) （TKS100104）
