宽级配非均匀沙运动特性研究  

Study on motion characteristics of wide graded non-uniform sediments

作　　者：王思莹[1] 段文刚[1] 李利[1] 

机构地区：[1]长江科学院水力学研究所,湖北武汉430010

出　　处：《人民长江》2011年第13期72-75,105,共5页Yangtze River

基　　金："十一五"国家科技支撑计划课题(2008DAB29B02;2009BAK56B03)

摘　　要：为了探索泥沙在水力作用下的运动规律,通过水槽试验,对均匀沙、连续和不连续宽级配非均匀沙的沙床发生起动和冲刷的运动特性进行了观察和对比分析。将均匀沙的沙莫夫公式加以推广,表征了非均匀沙各级运动对应的临界流速与水深及各材料参数的关系,拟合得到了不同种类的沙床发生各级运动对应的临界流速系数。计算结果与试验现象的对比分析表明,与均匀沙相比,连续宽级配非均匀沙一旦发生起动,其颗粒运动更容易加剧形成冲刷;而缺粒径段的不连续宽级配非均匀沙,由于大颗粒的荫蔽阻挡作用,冲刷较难形成。In order to explore the sediment transport laws under hydraulic action,the incipient motion and scouring action of uniform sediments,consecutive and inconsecutive wide graded non-uniform sediments were observed and compared in a flume experiment.The relationship between the critical velocity of non-uniform sediments at different grades and the water depth and the material parameters was described based on extension of Sharmov formula of uniform sediment.And the critical velocity coefficients of the movement of different sand beds were fitted accordingly.The comparative analysis of experimental and calculated results revealed that,compared to the uniform sediment,once the incipient motion occurs,it is easier for consecutive wide graded non-uniform sediments to develop into sourcing action;however,it was more difficult for the inconsecutive ones that lack of some diameter ranges to develop into sourcing action because of the shadowing effect of larger particles.

关 键 词：泥沙运动 非均匀 宽级配 临界流速 

分 类 号：TV142[水利工程—水力学及河流动力学]