摘要
粘性细颗粒泥沙在盐淡水混合区域遇电解质海水发生絮凝,从而改变了泥沙原有的沉降特性。选用长江口南槽悬沙,在双向环形水槽中进行盐度、含沙量、流速等不同条件下组合实验。结果表明:不淤流速与泥沙粒径密切相关,而含沙量、盐度等条件可以忽略,多种组合条件下均表现为50～60 cm/s;沉降速度随着断面平均流速的增大而逐渐减小;平衡含沙量与流速呈对数关系,低流速条件下盐度影响较大;泥沙的淤积百分比与流速表现为二次曲线关系,淤积量与盐度并非成严格正相关关系,而是与流速、含沙量等因素关系较密切,且在低流速情况下与初始含沙量关系不大。
The cohesive fine sediment will flocculate when they meet electrolyte seawater in brine and fresh water mixing area,and the original sedimentation characteristics will change.The suspended sediment in the south passage at the Yangtze river estuary was used to conduct ex- periment in the two-way annular flume about sediment concentration,salinity velocity and flow velocity.The results show that the non-silting flow velocity has close relation with sediment grain size,while the role of salinity and sediment concentration in sedimentation can be ignored.During the whole experiment,the non-silting flow velocity is 50～60 cm/s,the settling velocity of sediment is reduced gradually along 'with the increase of aver- age flow velocity.The balance sediment concentration is logarithmic function of velocity,and salinity can do much influence on it under lower veloci- ty.The deposition percentage is conic relation with flow velocity.Deposition quantity is not strictly positive correlation with salinity,and it is always affected by velocity and salinity together.Meanwhile,it has not close relation with original sediment concentration in lower velocity.
出处
《人民长江》
北大核心
2008年第16期48-51,共4页
Yangtze River
关键词
含沙量
流速
盐度
絮凝
双向环形水槽
南槽
sediment concentration
flow velocity
salinity
flocculation
two-way annular flume
south passage
