粘性细泥沙的临界起动公式

The Incipient Motion Formulas for Cohesive Fine Sediments

用上海港杭州湾深水航道试挖航槽的淤泥泥样,进行不同沉积密度条件下的起动试验。论文叙述了试验的条件、情况和主要结果。用实测数据检验张瑞瑾公式窦国仁公式,唐存本公式和沙玉清公式,并加以分析和评述。从粘性细泥沙絮凝的电化学理论出发,导出细泥沙颗粒之间粘着力的表达式,建立包括粗、细泥沙在内的统一的临界起动切应力和临界起动流速公式。该式与已有的公式和实测资料进行比较,符合良好。能较好地描述淤泥不同沉积密度时起动条件的变化,应用建议的起动公式,只需用常规试验测定几项基本参数,便可预报淤泥在不同沉积密度时的临界起动切应力或临界起动流速。

A series of experiments concerning threshold levels under different deposited densities werconducted for the silts dreged from the Hangzhouwan channel of Shanghai Harbor. Paper recounts the test conditions and its main results. Some current threshold functions were examined and discussed. Based on the electron-chemical theory of fine sediment flocculation the cohesive force expression betwen fine grains was obtained. The incipient formulas for shear stress and velocity for coarse and fine sediments were built. The results calculated from these formulas very coicide with the measured data. Suggested formulas can discribe the variations of threshold levels along with deposition densities and are easy to use.