长江口北槽深水航道整治工程贮泥坑抛泥过程监测分析*

对北槽航道维护使用的3#贮泥坑抛泥流失率进行现场监测和分析研究。监测内容包括应用多波束地形测量仪测得贮泥坑抛吹泥前后的准确容积变化，采用表层取样法测量贮泥坑抛泥后的表层泥沙密度及采用柱状采样器测量贮泥坑不同深度的泥沙密度，综合容积变化和密度结果可以得到实际入坑泥沙量，结合实际抛泥量计算出贮泥坑的抛泥流失率。监测结果表明该贮泥坑的抛泥流失率达到76%。同步监测的流速结果表明贮泥坑周边动力强、流速快，流速快是造成该贮泥坑抛泥流失率大的主要原因。建议该坑向附近动力弱的坝田掩护区移动以减少该贮泥坑泥沙流失率。

Field measurement for dumped sediment transport at disposal zone of the Yangtze estuary deep navigation regulation project

Dumped sediment transport at the dredge disposal site in the north passage of the Yangtze estuaryis studied by field measurement. The volume of dredge disposal zone is obtained by multi-beam sonar. The densityof surface is measured by sampler-collection and the density of different level is measured by stationary-pistonsampler. The sediment loss ratio from the disposal zone can be calculated by the volume of dredge disposal zone andthe total disposal dredge of the self-propelled trailing suction hopper dredgers. The result shows that the sedimentloss ratio is about 76%. The flow velocity obtained by flow-measure- system is so big that much sediment can becarried out of the disposal zone, which can be used to explain the sediment loss ratio. The location of dredge disposalzone should be moved to the middle section of dams for reducing the sediment loss ration.