感潮河段支流口门枢纽通航水流条件研究

Navigation flow condition of navigation junctionat entrance of tidal river's branch

界牌水利枢纽位于长江下游感潮河段支流口门,受用地条件限制,距江边较近且开敞布置,枢纽外江侧水流受到非对称涨落潮牵制作用明显,涨潮引水情形下,引航道口门区横流超标。物理模型试验结果表明:延长导流堤仅使得横流发生位置提前,并没有减小横流强度;船闸侧岸壁外扩能提前调整水流,为引航道口门区提供遮蔽环境,从而消弱横流,但受口门区用地条件的限制;而导流堤头部透空可较好地分散横流,改善流态,满足通航水流条件,其中透空段的长度取决于横流的分散效果,整个导航墙的长度取决于停泊区的纵向水流控制条件。

Jiepai junction is located at the branch entrance of a tidal river on the lower reach of the Yangtze River, and it is close to the main river and keeps an open layout due to limited land conditions.The branch mouth flow is significantly affected by the asymmetric tidal flow of the main river, and the cross flow at the entrance area of the approach channel exceeds the required value on the flood tide diversion case. The results of the physical model tests show that extension of the channel wall could just move the cross flow＇ s position forward, but can＇ t reduce its value; bank expansion towards the branch center could provide a shelter for the entrance area of the approach channel, and thus weaken the cross flow, but this method is restricted by the land condition; a permeable navigation wall head would disperse the cross flow and improve the flow pattern significantly, length of the permeable section is determined by the cross flow dispersion effect, while length of the whole wall is determined by the longitudinal tidal flow condition at the berthing area.