北江清远至河口段推移质选沙研究

Study on Bedload Selection of the Reach from Qingyuan to Hekou of Beijiang River

采用理论分析、变坡水槽试验与实体模型试验相结合的研究方法,针对北江清远至河口河段推移质泥沙特性及运动特性,作了泥沙起动及输移的水槽试验。根据起动试验结果,得出了反映颗粒的隐蔽和暴露作用的隐暴系数表达式;根据输移试验,并通过与其它公式进行比较,得到适应于该河段的推移质输沙率公式。同时,实体模型试验采取选沙方案后,试验成果与实际相符合。

Based on the theoretical analysis together with experiment in laboratory flume and physical model,an experiment about incipient motion and transport rate of the bedload was conducted in laboratory flume according to the bedload characteristics and its motion characteristics of the reach from Qingyuan to Hekou of Beijiang River.The pattern of sediment incipient motion and transport was analyzed.Nonuniform bed materials and their mutual influences were accounted by a hidingprotruding coefficient.Nowadays,the results of many formulas of nonuniform sediment transport rate are too different to get the same value.The feature of the bedload transport rate of nonuniform sediment was studied and its calculating formula was established.The result of the movable bed model experiment is in accordance with the naturally measured result.