鄱阳湖黏性底质淤泥固结起动规律试验

Experimental study on initiation law of consolidated cohesive sediment in Poyang Lake

为研究鄱阳湖黏性底质淤泥固结起动规律,采用玻璃水槽测量了不同淤积历时及水深条件下黏性底质淤泥起动流速,根据试验数据拟合得到鄱阳湖底质淤泥起动与淤积历时和水深的经验公式,并将结果与相关文献泥沙起动经验公式计算结果进行对比。结果表明,鄱阳湖黏性底质淤泥固结程度随着淤积历时的增加经历了新落淤、固结初期、加速固结、固结稳定4个阶段,起动流速与水深呈正相关关系;淤积1 d起动流速与相关文献泥沙起动经验公式计算结果较接近,淤积历时越长,试验结果与经验公式计算结果相差越大。

In order to study the initiation law of consolidated cohesive sediments in Poyang Lake,the incipient velocity of cohesive fine sediment under different deposition duration and water depth was measured in a glass flume.Through a series of experiments on incipient motions after the deposition and consolidation,the variation laws of incipient velocity affected by the deposition duration and the water depth were found.According to the test data,the empirical formulas for the incipient motion,deposition duration and water depth of Poyang Lake sediment were obtained by fitting process,and the test results were compared with the calculation results of empirical formulas for the sediment incipient motion in the relevant literature.The results show that the consolidation degree of cohesive sediments in Poyang Lake went through four stages as the duration of sedimentation increases:the new sedimentation,the initial consolidation,the accelerated consolidation,and the stable consolidation.There was a positive correlation between the incipient velocity and the water depth.Meanwhile,the incipient velocity of sediment deposited for one-day was close to the result calculated by the empirical formula,the longer the deposition duration,the greater the difference between test results and empirical formula calculation results.