长江口外高桥六期码头港池泥沙回淤分析

Sediment siltation at Waigaoqiao Phase VI harbor basin of the Yangtze Estuary

概述长江口外高桥六期码头工程河段的河势及水流泥沙条件,并对临近的外高桥一、二期港池泥沙回淤现状进行调查分析。通过吴淞口至横沙水道的平面二维潮流数学模型,分析工程实施对水流的影响。最后通过半经验公式结合数模结果对本期工程码头港池、调头区及引起的周边泥沙回淤进行预测估算,结果显示:工程实施对码头上下游一定范围内水流有影响,其中码头桩基附近平均流速最大减少30%左右。外六期码头港池的年平均泥沙回淤强度为1.85～3.30 m/a,年回淤量约27.6万m3,调头区的年平均泥沙回淤强度为0.65～1.15 m/a,年回淤量约11万m3。

The river regime and current ＆ sediment conditions of the river reach where the Yangtze Estuary Waigaoqiao Phase Ⅵ wharf locates is described, and the status of sediment siltation at the neighboring harbor basins of Waigaoqiao Phases Ⅰ ＆ Ⅱ is investigated and analyzed. Based on the 2-D current mathematical model for the channel between Wusongkou and Hengsha, we analyzed the effect of the engineering＇ s implementation on the current. Using the semi-empirical formula combined with the result of mathematical model experiment, we predicted and estimated the sediment siltation at the harbor basin, turning area and the surroundings. The results reveal that the engineering＇s implementation exerts an influence on the current within a certain scope of river area at upstream-downstream, esp., the average flow rate near the wharf＇s pile foundation has a maximum reduction of 30%. The annual average strength of sediment siltation at the Phase VI harbor basin is 1.85-3.30 m/a, and the annual back-silting quantity is about 0.276 million m3; The annual average strength of sediment siltation at the turning area is 0.65-1.15 m/a, and the annual back-silting quantity is about 0.11 million m3.