| 摘要: |
| 通过9组室内水槽试验,系统分析了不同周期和波高波浪作用下粉砂质细砂的悬移特性。试验结果表明,在波浪作用下,细颗粒泥沙在水体中悬浮产生明显的三层混浊结构:近底高浓度混浊层、中部混浊层和上部低浓度混浊层。其混浊度的大小与波浪动力条件相关,波浪周期的延长和波高的增加都会使近底层悬沙浓度显著增大,悬沙浓度的波动性在近底层表现得最为突出和复杂;波浪动力条件的改变对上层水体的悬沙浓度基本不产生影响。当波浪作用停止,悬沙开始静水沉降时,近底层水体含沙浓度的变化与波浪要素的比值相关,当波浪要素的比值大于临界值时,底层含沙浓度在一定时间段内反而增加,出现浓度返起现象。 |
| 关键词: 波浪 细颗粒泥沙 悬移特性 三层混浊结构 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(40406025) |
|
| Experimental study on characteristics of suspended fine sediment under wave-loading |
|
|
| Abstract: |
| The transportation mechanism of suspended sediment with wave load is very important for the navigational and coastal engineering in the sea water, especially in the near-bottom layer. The motion characteristics of suspended fine sediment with different wave loads are conducted based on 9-set flume experiments. The results of experiments show that sediment concentration is consistent with wave height and period which appears three-concentration layers: high-concentration near-bottom layer, middle layer with medium-concentration and low-concentration upper layer in the water. Sediment concentration near the bed is obviously higher while wave period is longer, and wave height is larger. The fluctuation behavior of sediment concentration responding with wave property is evident and complicated in a certain water layer near the bed, while the fluctuation behavior are quite weak in the upper layer beyond the bed. The settling pattern of suspended sediment in the still water after wave load is affected by the ratio of wave elements between period and height. When the real ratio is larger than the threshold value of 0.1, sediment concentration in the near-bottom layer would increase rather than decrease within a certain time period. |
| Key words: wave fine sediment suspension characteristics three-concentration layers |
