连云港徐圩港区航道大风天强淤可能性分析

连云港海域流速不大,徐圩港区规划航道线南北两侧断面,平均流速在0.20～0.40 m/s;波浪作用相对较大,年平均H1/10最大波高为3.58 m;徐圩港区南部紧邻粉沙质区,位于粉沙向淤泥过渡的边缘地带;徐圩港区底质沉积物主要以细颗粒为主,中值粒径一般都在0.01 mm以下,粘土含量在30%以上,属于淤泥质海岸性质;海域年平均含沙量在0.20 kg/m3左右,近岸河口或浅滩表层平均含沙量在0.10～0.20 kg/m3,外海域表层平均含沙量在0.1 kg/m3以下;台风期间海域含沙量骤增,近底层含沙量可达5.0 kg/m3以上。根据国内其他港口大风天回淤问题的研究经验和对骤淤(或强淤)条件的分析以及与连云港港区的对比分析,认为徐圩港区航道开辟后,也会出现大风天强淤情况,但淤积的形式应完全不同于粉沙质海岸。

Analysis of strong silting possibility during strong winds conditions in out channel of Xuwei harbor district of Lianyungang port

The current velocity is not large in the Lianyungang port sea area.The average flow velocity in section is from 0.20 m/s to 0.40 m/s in the Xuwei harbor district of Lianyungang port.The wave action is strong relatively with the highest wave height of 3.58 m.Xuwei harbor district adjacent to silt area in southern area is located at the transitional edge of silt sand to mud.Based on the mass data(e.g.the measured data during normal and windstorm day,satellite images),the results show that in the Xuwei harbor district,(1) the sediment is mainly fine particles,sediment median size is less than 0.01 mm with above 30% clay content generally,and the sea area belongs to the muddy coast;(2) average annual sediment concentration is around 0.20 kg/m3,the surface sediment concentration of the coastal and estuarine shoals in average is from 0.10 kg/m3 to 0.20 kg/m3,the surface sediment concentration of outer sea in average is less than 0.1 kg/m3;(3) during a typhoon,the near bottom sediment concentration could reach 5.0 kg/m3 above.According to the research experience of other domestic ports during winds day,analysis and comparison to sudden siltation(or strong siltation) conditions of Lianyungang harbor district and Xuwei harbor district,the conclusions are that after the channel of Xuwei harbor district opening up,the strong siltation maybe appear during strong winds day,but the type of deposition sedimentation should be totally different from the silt coast.