基于等效粒径概念的非均匀沙起动条件研究

摘要：分析表明运用等效粒径概念进行非均匀沙起动临界条件计算是很简便的。基于Parker提出的非均匀沙起动两种极限状况，提出了一个简单的等效粒径表达式。通过取不同的荫蔽参数，该等效粒径表达式可近似表达八家有代表性的非均匀沙起动公式的荫蔽暴露作用，这表明由于床沙特性和粗化程度的不同，荫蔽参数本应是不同的。用韩其为整理的长江寸滩站卵石起动资料，回归得到寸滩站卵石起动计算公式。该公式形式简单,运用于王兴奎整理的范围更宽的寸滩站资料时，表现良好。为长江寸滩站合理选用卵石起动条件提供了依据。

Study on the incipient condition for non-uniform sediment based on the concept of equivalent grain size

Abstract: It is convenient to use the concept of equivalent grain size to study the incipient motion condition of non-uniform sediment. A simple formula for computing equivalent grain size is put forward based on the concept of two limiting case, which was introduced by Parker. This formula considered the variation of hiding parameter can nearly simulate the hiding effect of eight typical incipient condition formulas, this indicates that the hiding parameter should be variational along with the chang of bed materials and bed armoring degree. Analyzing the experimental data of cuntan station at Yangtze River obtained by Han qiwei, a simple incipient velocity formula is studied out, this formula performs consistently well in the test of the widened range experimental data of cuntan station at Yangtze River obtained by Wang xingkui. It is useful to select appropriate incipient equation in Cun tan station, Yangtze River.