上海洋山深水港四期工程水下沉积物分析

为掌握上海洋山深水港四期工程底质泥沙的分布与变化特征,对四期工程近海区开展了柱状取样工作。沉积物柱状取样工作分析结果表明,四期工程水域共有4种沉积类型,即砂质粉砂、砂-粉砂-粘土、粉砂和粘土质粉砂,其中粉砂占全部样品的66%,其次是砂质粉砂占21.74%。工程水域沉积物中值粒径在0.085~0.049 1 mm变化,平均为0.028 mm;柱状样各层粒径比较,表层物质最细,平均中值为0.026 mm,自上而下依次增大;与已建成的港区水域相比,四期工程水域底质表层泥沙略粗于大、小洋山通道水域,分选程度略好于大、小洋山通道水域,物质组成基本相同,仅粉砂含量增高。

Analysis of underwater sediments of the 4th phase project area in Shanghai Yangshan Deepwater Port

In order to master the distribution and change characteristics of the seabed sediment of the 4th phase project area in Shanghai Yangshan Deepwater Port, columnar sampling was carried out. The analysis results of columnar samples demonstrate that： there are four sedimentary types in the 4th phase project area, such as sandy silt, sand-silt-clay, silt and clayey silt. About 66% of all samples is silt, and 21.74% of all samples is sandy silt. The median size of sediment is 0.085~0.049 1 mm, and the average value is 0.028 ram. In comparison of each layer of columnar samples, the surface layer material is the finest. Average value of median size is 0.026 mm, and it increases from upper layer to lower layer gradually. Compared with water area of the completed port district, the surface layer material of the 4th phase project area is coarser than that in channel between Dayangshan and Xiaoyangshan is- lands, and the sorting degree is slightly better. Component of sedimentary type is basically the same, however, the content of silt is higher.