床沙组成对水流阻力的影响

Non-uniformity coefficient effects in alluvial streams

天然情况下,河流泥沙组成多为非均匀沙。河流床沙及其级配组成的非均匀性是影响水流阻力的主要因素之一,研究床沙组成的非均匀性对水流阻力的影响,具有重要的理论和现实意义,本文在大量实验和实测资料的基础上,首次定量探讨床沙级配及其组成的非均匀性对水流阻力的影响,得出非均匀性对水流阻力影响的规律。同时,简要探讨了泥沙颗粒间相互作用关系,为进一步深入研究提供了可靠的依据。

Under natural circumstances, the bed material of an alluvial channel is generally composed of nonuniform sediment, and its nonuniformity coefficient (or geometrical coefficient of standard deviation) is one of the main factors influencing alluvial resistance. The understanding of such an influence has both theoretical and practical importance. Analysis were made on the basis of a great lot of laboratory test data and field measurements from others investigators, this influence was considered quantificational for the first time, and relationships have been established between nonuniformity and flow resistance. At the same time, we discussed the interrelation among the sediment grain briefly and established the credible foundation for further study.