项目名称: 河流粘性岸滩干湿交替特征及侵蚀冲刷机理研究
项目编号: No.51479008
项目类型: 面上项目
立项/批准年度: 2015
项目学科: 水利工程
项目作者: 王军
作者单位: 长江水利委员会长江科学院
项目金额: 83万元
中文摘要: 自然河流受季节变换,水位总在不断变化,导致岸滩始终处于干湿交替状态。对粘性岸滩而言,干湿交替会较大程度改变岸滩土体本身的力学性能,进而影响岸滩土体抗冲性能,与一般的河床冲刷有着较大的不同。本项目以长江荆江河段粘性岸滩为研究对象,引入干湿交替条件,采用理论分析、实测资料分析与室内试验相结合的方法,研究干湿交替粘性岸滩侵蚀与冲刷机理。首先通过天然河道水位变化与演变资料分析岸滩的干湿交替与冲刷特征;再结合现场取样及室内土工试验,分析干湿交替粘性岸滩垂向组成与物理特性,揭示干湿交替对岸滩土体力学性能的影响规律;最后开展水槽冲刷试验,定量分析岸滩土体性能变化对其临界起动条件、冲刷率的影响,建立干湿交替条件下岸滩横向冲刷数值计算模式,利用试验结果与实测资料对计算模式进行验证。这些研究可以丰富河流动力学学科内容、为岸滩冲刷模拟与预测、河道治理提供重要参考。
中文关键词: 河流动力学;泥沙运动;河床演变;水力学
英文摘要: Seasons alternation influents the natural river, makes the water level vary incessant, and the bank is always in alternate wetting and drying condition. According to cohesive bank, alternate wetting and drying condition can changes mechanics properties of soil, and influents the resistance to erosion, which is different from general erosion on river bed. This project is in case of cohesive bank in Jingjiang Reach, Yangtze River, and studies erosion mechanism of alternate wetting and drying bank by the methods of theoretical analysis, field data analysis and Lab experiment. Firstly, the properties of alternate wetting and drying will be analyzed by field data of water level changes and bank erosion; Secondly, ways that flow seepage and dip cohesive destroys bank soil will be researched by field sampling and geotechnical experiment, and the mechanism that alternate wetting and drying condition destroys bank soil will be derived from soil mechanics; At last, based on the flume test of cohesive bank erosion, the influence of bank soil properties variety to its critical initial condition and erosion rate, and calculation model of transverse erosion rate can be obtained. The data of test and field observation can verified the calculation model. This study can enrich hydraulic and river dynamics, and supply reference to simulate and predict bank erosion, and river control work.
英文关键词: river dynamics;sediment movement;riverbed evalution;hydraulics