桥墩影响下弯槽冰塞形成临界条件和冰厚变化的试验研究

Impacts of bridge pier on ice jam initiation and ice thickness in a curved channel——an experimental study

天然河道中,桥墩的存在改变了局部水流特性,对冰塞形成及演变产生影响。通过模型试验,研究了桥墩存在及桥墩位置不同时对冰塞演变过程的影响,试验结果表明:桥墩的存在改变了桥墩附近的水流结构,使得桥墩附近水流输冰能力相对增大,冰塞厚度减小;相比于将桥墩安置在两弯连接直道段,将桥墩安置于弯道顶点处时,桥墩附近水流输冰能力增大;在两弯连接的直道段和弯道顶点处同时放置桥墩时,弯道平衡冰塞厚度介于单墩放置于两弯连接的直道段与单墩放置于弯道顶点处时的弯道平衡冰塞厚度之间。

The presence of bridge piers in natural rivers would change the local flow field characteristics, and influence initiation and evolution of ice jam. Through model experiment study in which the location of bridge pier constantly changes, the ice jam evolution process under different position of bridge pipers were studied. The experiment results show that the presence of bridge piers changes the local flow field character- istics, relatively enhancing the ability of ice conveyance around and reducing the ice thickness; the ice con- veyance efficiency intends to increase if bridge pier is placed at the apex of a bend, compared to be placed at the midway between two consecutive bends. If bridge piers are synchronously placed at midway between two consecutive bends and the apex of a bend, the balance of ice jam is not smaller than the sin- gle bridge pier placed at two different location of pipers, but between them.