Breusers , H.N., Nicollet , G ., and Shen , H .W., (1977) ,”Local scour around cylindricd piers “, Jounal of Hydraulic. Res . Delft . the Netherlands , vol. 15, No. 3 , p.p. 221-252.
 Simons , D.B. and Senturk , F . (1970) ” Sediment transport technology ” ; Water Resources Publications , Fort Collins , Colorado , U.S.A.
 Ahmed ,F.,and Rajaratnam,N.(1998),” Flow around bridge piers ” Jounal of Hydraulic Eng. ASCE , Vol. 124, No. 3 . pp. 288-300 .
 Garde , R.J.et.al . (1961) ” Scour around obstructions ” ;Journal of , Irrigation and power , vol 24, p.p 651-660
 Laursen , E.M.(1980) ” Predicting scour at abutments ” ; General Report . No.3 , Dept . of Civil Eng., University of Arizona .
Tikrit Journal of Engineering Sciences (2007) 14(2) 73-85
Effect of Cohesive and Non-Cohesive Soils on Equilibrium Scour Depth
|Saleh Issa Khassaf|
|Civil Eng. Dept., University of Kufa, Iraq|
In this research ,the effect of cohesive soils ( clay ) and non –cohesive soils sand on equilibrium scour depth was studied .Experiments were carried out on two types of clay and two types of sand as a bed material using an obstruction ( pier ) to create a local scour. The effect of flow velocity and Froude number on scour depth and the occurrence time of equilibrium scour depth were studied . The results show that for the same conditions, the rate of scour in the clayey soils is less than in sandy soils. Also the time required for occurrence of the maximum scour depth ( equilibrium depth ) in clayey soils is more than in sandy soils. Two formulas were found to predict the equilibrium scour depth in terms of Froude number ,the first is for clayey soils and the second for sandy soils .
Keywords: Cohesive soil, Non-cohesive soil , Scour depth.