A laboratory investigation of bed-load transport of gravel sediments under dam break flow |
| |
| Authors: | Khabat Khosravi Amir Hooshang Nezamivand Chegini James Cooper Luca Mao Mahmood Habibnejad Kaka Shahedi Andrew Binns |
| |
| Institution: | 1. Department of Civil Engineering, University of Guilan, Rasht, Iran;2. Department of Watershed Management Engineering, Sari Agricultural Science and Natural Resources University, Sari, Iran;3. School of the Built Environment, Heriot-Watt University, Edinburgh Campus, Edinburgh, UK;4. Department of Geography and Planning, School of Environmental Sciences, University of Liverpool, Liverpool, UK;5. School of Geography, University of Lincoln, Lincoln, UK;6. School of Engineering, University of Guelph, Guelph, Canada |
| |
| Abstract: | Dam break flows and resulting river bed erosion can have disastrous impacts on human safety, infrastructure, and environmental quality. However, there is a lack of research on the mobility of non-uniform sediment mixtures resulting from dam break flows and how these differ from uniform sized sediment. In this paper, laboratory flume experiments revealed that coarse and fine fractions in non-uniform sediment had a higher and a lower bed-load parameter, respectively, than uniform sediments of the same size. Thus, the finer fractions were more stable and the coarser fractions were more erodible in a nonuniform bed compared to a uniform-grained bed. These differences can be explained by the hiding and protrusion of these fractions, respectively. By investigating changes in mobility of the mixed-size fractions with reservoir water levels, the results revealed that at low water levels, when the coarser fractions were only just mobile, the bed-load parameter of the finer fractions was higher than the coarser fractions. The opposite was observed at a higher water level, when a significant proportion of the coarsest fractions was mobilized. The higher protrusion of these grains had an important effect on their mobility relative to the finer grains. The transported sediment on these mixed-sized beds was coarser than the initial bed sediment, and became coarser with an increase in reservoir water level. |
| |
| Keywords: | Dam break Bed-load transport Gravel Laboratory flume |
| 本文献已被 CNKI 维普 万方数据 ScienceDirect 等数据库收录！ |
|
