波致海床液化引发底边界高浓度悬浮体形成过程的试验研究

Laboratory Study on the Formation Process of High-concentration Suspensions in the Bottom Boundary Due to Wave-induced Seabed Liquefaction

国内外众多现场原位观测的实测资料,其结果表明粉质土海床在波浪作用下,水体底边界会产生高浓度悬浮体。利用在黄河三角洲采集的粉质土制作试验土床开展室内水槽试验,旨在揭示波浪荷载持续作用下海床液化引发底边界产生高浓度悬浮体的过程及机制。根据试验现象及海床土体的孔隙水压力变化、水体悬浮泥沙浓度的时空分布,以及悬浮泥沙的粒度变化等特征,分析认为波浪导致的海床液化能够引发底边界高浓度悬浮体的形成。大量的土体细颗粒从液化土体的振荡边界与渗流通道中的析出,是导致高浓度悬浮体形成的重要原因。对进一步探讨黄河口区异重流现象的产生等科学问题具有一定的指导意义。

The resiults of many domestic and abroad in-sitiu observations show that high-concentrat ion suspen-sions appear at the botom boundary of silty seabed water under wave loading. Fliume to study the formation process and mechanism o f high-concentration suspensions under wave loading at the bottom boundary of silty seabed, which is made using Huanghe River delta silty soil. According to the experiment phenome-na and the resiults of the pore water pressure change, the suspended sediment concentraterns , variation of the particle size, wave-induced seabed liquefaction can cause the formation of high concentration suspension at the bottom boundary. Numerous of fine grains from the oscillatory lquefiable soil entering into the water plays an important role in the formation process of high-concentration suspensions. Theoretical significance in understanding of lots of scientific problems in the Yellow River Estuary is presen-tod, such as the hyperjDycnal flow formation and mechanism and so on.