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1.
1 . INTRODUCTIONThebedloadtransporthasbeenextensivelystudiedinthepastfewdecadesandmanyformulasforpredictingbedloadtransportratehavebeenpresented(Einstein 1950 ;Meyer Peter 194 8;Bagnold 1973;Engelund 1976;Yalin 1972 ;Samaga 1986;andKarim 1998) .Whenappliedtostreamswithpartial…  相似文献   

2.
CONCENTRATION DISTRIBUTION OF SEDIMENT IN BED LOAD LAYER   总被引:2,自引:1,他引:1  
In this paper the concentration profile in bed load layer is derived based on kinetic theory. According to observations, particles moving in near wall region behave differently during ejection and sweeping of turbulence burst, as indicates that they are subject to different influences from turbulence, and therefore, the forces acting on particles are not the same. Consequently, particles moving in bed load layer are classified into two groups, one lifted upward by ejections, the other carried back to bed by sweepings, and the forces corresponding to upward and downward motions are proposed. By solving the basic transport equation of kinetic theory, the velocity distribution functions, upward and downward fluxes of particles in bed load layer are derived. Upon assumption of equilibrium sediment transport, concentration profile in bed load layer is obtained. Verification is also presented in this paper, which shows that the concentration profile produced by the relation proposed in this paper agrees with observations well.  相似文献   

3.
1 . INTRODUCTIONTheconditionofincipientmotionofsedimentisoneofthemostbasicproblemsinsedimentmovementmechanics .Thisproblemhadbeens  相似文献   

4.
SIZEDISTRIBUTIONSOFCOARSESANDBEDLOADINTURBULENTFLOWFIELD¥ZhangHong-wu;WangShan(InstituteofHydraulicResearchYellowRiverConserv...  相似文献   

5.
灰色理论在电力系统负荷预测中的应用   总被引:2,自引:0,他引:2  
结合一个实例,提出了用灰色理论模型来预测电力系统负荷的方法。  相似文献   

6.
本文阐述了高应变动测技术中波速确定的主要方法 ,总结分析了它们在高应变动测技术中的缺点 ,并提出了一种利用高应变动测结果来确定桩波速的新方法  相似文献   

7.
给出了对流换热边界条件下的地下球型洞室温度分布规律,采用弹性理论多层厚壁球壳接触问题模型,建立了温度荷载与均匀内水压力联合作用下的地下球型洞室应力计算方法,导出了砼衬砌弹性温度自生应力σr^h、σθ^h和弹性约束应力σr^h、σθ^h的精确解计算公式,用算例介绍了具体计算步骤。  相似文献   

8.
介绍深航基地停机坪工程的软基处理.该工程采用了堆载预压为主的软基处理方案,在处理过程进行了总沉降以及水平位移的观测,观测值均满足设计要求.  相似文献   

9.
提出水平液面式孔内电视系统测量孔斜的误差因素。并对液体的毛细作用、误差精度、钻孔顶角、容器直径引起的误差进行分析。  相似文献   

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