无黏性泥沙休止角与表层沙摩擦角试验  

Experiment on Angle of Repose and Angle of Surface Friction of Cohesionless Sediment

作　　者：孟震[1] 王浩[1] 杨文俊[2] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [2]长江科学院水利部江湖治理与防洪重点实验室,武汉430010

出　　处：《天津大学学报（自然科学与工程技术版）》2015年第11期1014-1022,共9页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51279012);国家科技支撑计划资助项目(2012BAB04B01)

摘　　要：鉴于对泥沙颗粒水上和水下休止角孰大孰小的认识还不统一、分选系数η对非均匀沙休止角影响的认识还存在分歧以及对泥沙休止角与表层沙摩擦角差异性的研究还不够全面,进行了无黏性重质均匀和非均匀沙的休止角和表层沙摩擦角试验.休止角试验采用依水槽内一侧的自然堆积法,表层沙摩擦角试验采用槽道底板粘沙、表面铺沙的倾斜法.结果表明,泥沙颗粒水上休止角大于水下休止角;中值粒径D50相等条件下,非均匀沙休止角并不严格随分选系数η的增大而增大,而是随偏度系数S的减小而增大;表层沙摩擦角与休止角所反映的物理图景不同,二者在数值上存在较大的区别,建议河流动力学和风沙物理学等教科书编纂时需慎重对待二者的差异性.To date,there is no consensus as to whether the sediment angle of overwater repose is bigger than that in submarine condition,whether the angle of repose increases with the increase of sorting coefficient η of non-uniform sediment,and whether the angle of repose equals to that of surface friction of sediment.Experiments were carried out with cohesionless heavy sediment on angle of repose with the natural accumulation method and angle of surface friction with the tilting method.The results show that the angle of overwater repose is bigger than that in submarine condition,and the angle of repose does not increase with the increasing of sorting coefficient monotonously but with the decreasing of asymmetry coefficient S of non-uniform sediment within the same median diameter D50.It is also shown that the physical pictures of the angle of repose and the angle of the surface friction are quite different and the difference value is noticeable,which is ignored by most textbooks related to river dynamics and aeolian physics.

关 键 词：无黏性沙 休止角 表层沙摩擦角 分选系数 偏度系数 

分 类 号：TV141[水利工程—水力学及河流动力学]