长洲枢纽变动回水区汇流河段羊栏滩航道整治研究*

羊栏滩位于郁江与黔江汇合处,又处于长洲枢纽的变动回水区内,滩段水流急、流态乱、横流大,航行条件恶劣,航道尺度由Ⅳ级提高到Ⅱ级的难度很大,主要通过物理模型进行研究。针对本滩的水力特性,对比航槽拓宽、黔江汇流口改善工程、大沙左汊开挖分流以及大沙中槽开挖分流等4种整治思路,提出了开挖非航槽分流方案,实测整治效果分析表明:模型试验预报的大流速区数值、位置与原体基本一致,工程实施后航道条件得到明显改善。

Channel regulation of Yanglantan beach in the confluence reach of Changzhou hub fluctuating backwater area

Locating in the confluence of Qian river and Yu river,and in the fluctuating backwater area of Changzhou hydro-junction as well,Yanglantan beach is characterized by trong currents,chaotic flow,large cross-flow and poor navigation conditions.It is very difficult to increase the channel dimensions from class Ⅳ to classⅡ,which would be studied mainly by the physical model.Based on the hydraulic characteristics,four improvement ideas are compared such as channel widening,improvement engineering at the junction in Qian river,excavating at the left branch or in the middle channel of Dasha for diversion.The scheme of excavating out of channel for diversion is advanced.The analysis of measured regulation effect shows that the value and location of large flow field which is predicted by the model test are consistent with the original,and the the channel conditions have been improved significantly by the engineering.