COLLABORATIVE RESEARCH: Experimental Study of the Effect ofSediment Sorting on Bed Forms, Bed-Surface Texture, and Fractional Transport Rates in Coarse Mixed-Size Sediments

合作研究：沉积物分选对粗粒混合粒度沉积物的床形态、床表面结构和分数输送率影响的实验研究

• 批准号: 9017937
• 负责人: Peter Wilcock
• 金额: $ 2.03万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9017937&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Experimental; Study; Effect; COLLABORATIVE; RESEARCH; Experimental; Study; Effect

When a unidirectional current passes over a bed of coarse mixed-size sediment, a variety of bed forms are generated and there is a segregation of particle sizes among the load, the bed surface layer and the substrate. There is a strong and complex interdependence between the bed forms, the transported sediment and the substrate. Many studies in well sorted sands, both in the laboratory and in the field, have led to fairly good understanding of the behavior of the familiar dune bed forms and the interaction between bed forms and transport. More recently, features variously described as bed-load sheets, gravel waves, and clast jams have been reported in flows over poorly sorted sand-gravel mixtures. The relationships among these seemingly diverse bed features, and their dependence on size segretation in the bed, is unclear. This is an experimental study of the nature of bed features in unidirectional flows as a function of flow strength and sediment sorting involving several sediment mixtures with the same mean size of about 4mm but with widely varying sorting and making series of runs at several mean flow velocities over each sediment mixture. The objective is a unified picture of the fundamental characteristics and interrelationships of the various kinds of bed features produced in these flows. The work will be done in cooperation with Prof. Hiroshi Ikeda, Prof. Shigemi Takayama, and Dr. Fujiko Iseya of the Environmental Research center at the University of Tsukuba. This proposal covers salary and travel for the PI. A companion proposal with identical scientific text is being submitted by Prof. John B. Southard (MIT). The Japanese group already has funds for building the experimental apparatus and conducting the experiments.

当单向电流穿过粗大的混合尺寸沉积物的床上时，会产生各种床形式，并且载荷，床表面层和基板之间存在粒径的隔离。 床形式，运输的沉积物和底物之间存在强大而复杂的相互依赖性。 在实验室和现场中，许多分类沙子的研究都使人们对熟悉的沙丘床形式的行为以及床形式与运输之间的相互作用相当有很好的了解。 最近，据报道，据报道，据描述为床单，碎石波和碎屑果酱的特征是在流量不佳的沙片混合物上的流动中。 这些看似多样化的床特征之间的关系以及它们依赖床上的大小脱糖的关系尚不清楚。 这是对单向流中床特征的性质的实验研究，这是流动强度和沉积物分类的函数，涉及几种平均大小约为4mm的沉积物混合物，但分类且在每个沉积物混合物上的几个均值流速下进行了较大变化的分类。 目标是这些流中产生的各种床特征的基本特征和相互关系的统一图片。 这项工作将与Tsukuba大学环境研究中心的Hiroshi Ikeda教授，Shigemi Takayama教授和藤子Iseya博士合作。 该提案涵盖了PI的薪水和旅行。 约翰·B·索斯德（John B. Southard）教授（麻省理工学院）提交了带有相同科学文本的同伴建议。 日本小组已经有用于建造实验设备并进行实验的资金。