弯槽冰塞水位试验研究

Experimental Study on Ice Jam Stage in a Curved Channel

冰塞的出现造成河道上游水位壅高,常诱发凌洪灾害。天然河道并非理想直线而是蜿蜒曲折的,冰塞的堆积演变过程更为复杂,研究弯道冰塞水位变化规律对于北方河流的防凌工作具有重要意义。通过S形弯槽试验,分析弯槽冰塞水位变化特点及规律,并与直槽和天然河道进行对比。试验结果表明:冰塞水位壅高滞后于冰塞的增厚过程,且平衡冰塞水位增值随冰塞厚度的增加而增加,平衡冰塞水位相对增值随弗劳德数的增大而递减,弯槽平衡冰塞水位相对增值与直槽相比增幅较小。

The formation of river ice jams can cause the stage in upstream to rise,therefore present a severe flood risk to nearby areas. Natural river courses are not always formed in an ideal straight line but in wind,so that the laws of evolution of ice jam may be more complicated.Hence to analyze and research the stage variations of ice jam is important to mitigate the flood disaster in northern regions. By using experimental approach in a S-type curved flume and contrast to the data in straight flume experiment and the field observations,the laws and characteristics of variation in water level were revealed. The experiment results show that the variation of stage is later than the progress of ice jam thickening,and the equilibrium ice jam backwater height increases with the ice jam thickening and decreases with Froude number. In particular,the increase of the equilibrium ice jam backwater height in curved flume is smaller than that in straight flume.