Scour is a phenomenon that occurs as a result of natural erosion by ground water flow and transport of seabed material. In this research, scour around the legs of marine structures is simulated using the FLOW3D.V.9.3™ commercial software. The general scour model consists of two components, namely, the lift and thrust forces. The drag force, that is inserted to the structure, is a combination of...

one of the important issues in hydraulic engineering is inspection of local scour depth around bridge pier. using piles is one of the ways for confronting local scour and erosion. in this study, the experiments were conducted in an 8m long, 0.5m deep and 0.25m wide flume. and the effectof using piles and number of them observed on the amount of scour in three different frude numbers. the shape ...

grade control structures are hydraulic structures used to stabilize a river bed. scour downstream of this structure is the main cause of its failure. studies have developed numerous empirical relations for scour depth prediction that designers must choose between to decide the most effective equation for a specific application. this study tested the condition of submerged jets over beds of sedi...

The effect of a combined system of the bed suction and jet injection as a pier-scour countermeasure on the turbulent flow field is studied in a laboratory flume using an Acoustic Doppler Velocimeter (ADV). The three components of the velocities in the vertical symmetry plane in the equilibrium scour hole in front and rear of the pier under 3-jet injections and bed suction rate Qs/Q0 = 2%located...

in this paper the effectiveness combination of bed sill and collar in reduction of local scour depth at cylindrical piers under clear water flow condition was investigated (v/vc=0.9). in the first of experiments, the bed sill was located in downstream and different distances from the piers. results indicated that minimum distance of the bed sill from the piers in downstream has maximum reductio...

a large number of authors have studied to find out how to control scouring around a pier along direct stream. the objective of this research is then to study a scour pattern around such piers on curves rivers due to the fact that there may be a difference between a flow pattern on a direct line and the meander. thus, this study tries to check whether the use of cable and collar alone and in a c...

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 experimen...

rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. Scour downstream of this structure can lead to failure. Over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

River confluence is a common feature of most irrigation and drainage channels and river systems, where tributary conflicts the main channel. In these section, rapid changes in velocity and discharge, sediment distribution and flow turbulent result in a deep confluence scour, a bar point in the separation zone at downstream of junction corner  and finally vortex flow. Thus, the main goal of this...