长江口深水航道回淤二维数值模拟分析

Analysis of 2D numerical simulation of back silting for deepwater navigation channel at Yangtze estuary

长江口深水航道整治工程位于长江口北槽,分三期完成。工程实施后,航道内每年均出现严重回淤现象,航道疏浚维护费用巨大。通过建立长江口深水航道二维数学模型,计算了1997、2001、2005、2009年4个不同时间段典型断面涨落潮流量,分析了长江口深水航道工程实施期间涨落潮流量的变化情况,探讨了航道回淤的原因。一期工程使航道中段落潮流量减小而上段落潮流量增加,二期工程后航道整体落潮流量减小,三期工程的实施减缓了航道落潮流量减小的趋势,而航道内落潮流量的减小可能是出现严重回淤的水动力原因。

The renovation project of deepwater navigation channel at Yangtze estuary is located in the north channel and built in three phases .After construction of the project , the phenomenon of back silting is serious and the cost for dredging and maintaining is huge .With the establishment of 2D numerical model of deepwater navigation channel at Yangtze estuary ,the paper calculated the flux of different sec-tions in 1997 , 2001 , 2005 , 2009 , and analyzed the changes of flux during the construction of the pro-ject,and discussed the reason of back silting .The flow of ebb in the middle of the channel decreases while that in the upper increases after the construction of first phase .Besides, the flow of ebb decreases in the whole channel after the second phase project while the third phase project slows down the decrea -sing tendency .The decrease of ebb flow may be the hydrodynamic reason for back silting .