淤泥质海岸波致液化及航道骤淤问题初步研究

研究波浪与淤泥海床相互作用导致的海床液化、体积冲刷和高浓度近底悬沙的层移输运问题。采用de Wit提出的液化判别条件及计算方法,结合连云港近岸波浪和淤泥力学特征,计算不同来波条件下淤泥质海床的液化深度;进一步考虑浑水中含沙量对流速的折减影响,计算液化层运移速度分布。计算结果表明,大浪条件下,淤泥质海床可能有较大的液化深度,但层移厚度不大。由于层移含沙量较高,在近底水流驱动下仍能形成较大的输沙率和一定规模的大风天航道骤淤。有关研究成果为海床稳定性分析和输沙计算提供了新的思路和方法。

Preliminary study on problems of wave-induced liquefaction and channel sudden siltation in muddy coasts

This paper studies the muddy seabed liquefaction mass erosion and the transportation of concentrated benthic suspension layer caused by wave and seabed corresponding effect.We apply de Wit liquefaction conditions and calculation method,combine the method with local characteristics of wave effect and sediment transport in the Lianyungang coast,and calculate the liquefied depth of the muddy seabed under different wave condition.We also calculate the velocity of liquefied layers further considering the reduction effect on velocity induced by suspended sediment concentration.The results show that the muddy seabed may have substantial liquefaction depth under wind-wave condition,however the depth of movable liquefaction layer is not obvious.Because of the high suspended sediment concentration,large sediment transport can still be formed in the wave-induced liquefaction layer and the channel sudden siltation with a certain scale in high windy day can occur.The results can provide new ideas for seabed stability analysis and sediment transport calculation.