水科学进展2016，Vol.27Issue(6)：858-866,9.DOI:10.14042/j.cnki.32.1309.2016.06.008
河床采沙挖槽的溯源冲刷影响规律
Retrogressive erosion induced by sand excavation on a riverbed
摘要
Abstract
For understanding the issue of retrogressive erosion induced by excessive sand excavation on riverbed, in-cluding the influential factors, migration and prediction method, this paper provides a numerical model which is based on a set of equations consisted of the one dimensional Saint-Venant equation, the bed load transport equation, and the Exner equation under clear-water conditions. The MUSCL-Hancock method, a type of TVD ( Total Variation Diminish-ing) scheme, was used to distinguish the governing equations with space-time second-order accuracy. The finite vol-ume and finite difference methods were used separately to determine the water-flow and Exner equations to speed up computation. The model was validated by laboratory experiments which were also used to investigate the erosion process. Results show that erosion rates appear high in the early scour stage, and the retrogressive length at the early 30% time reaches to 80% of the equilibrium retrogressive length. The erosion rate increases significantly as inflow in-tensity, headcut height and hydraulic drop increase. The linear increasing ratio of equilibrium retrogressive length to flow discharge is 0. 8 which is higher than that to height of hydraulic drop. The maximum erosion depth is approximate-ly half of the height of headcut. Once retrogressive erosion occurs, it develops rapidly and depends on inflow intensity and height of the hydraulic drop. When considering reasonable water-sediment interactions the present model can ac-curately and quickly predict the erosion process.关键词
采沙河床/数值模拟/溯源冲刷/跌水/平衡输沙Key words
sand excavation/numerical simulation/retrogressive erosion/hydraulic drop/equilibrium sediment transport分类
建筑与水利引用本文复制引用
齐梅兰,刘茜,李金钊..河床采沙挖槽的溯源冲刷影响规律[J].水科学进展,2016,27(6):858-866,9.基金项目
国家自然科学基金资助项目（51578062）；中国铁路总公司科技研究开发计划资助项目 （）
