N. A. Obied - Graduate Student, Department of Civil Engineering, University of Basrah, Basrah, Iraq
S. I. Khassaf - Professor, Department of Civil Engineering, University of Basrah, Basrah, Iraq

The most important causes of bridge failure are local scour. In this study, laboratory experiments were conducted to investigate the effectiveness of slot as a protection device in reduction of depth of scour at cylindrical piers under clear water flow conditions. The development time of scour depth at the circular pier with and without a slot as a protection device was conducted. The experiments focused on the effect of using different lengths of slot, calculating efficiency and deriving a suitable equation. It was observed that the scour depth decreases as the size of slot length increases; and also the maximum reduction in scour depth equals to 49%. The technique of dimensional analysis was used, and based on laboratory results an empirical formula was derived by using IBM SPSS statistics v24 software. The coefficient of determination (R²) was determined to be (0.961), There was a good agreement between the predicated and observed data.

Slot, Scour Reduction, Circular pier, Dimensional Analysis