Laboratory tests were carried out to assess the local scour by three-dimensional wall jets from a square crosssection nozzle. To this end, three different tailwater depths were used and the jet expansion ratio was held greater than ten. Velocity measurements were conducted using a one component laser Doppler anemometer. The jet exit Reynolds number was maintained to 1x10 and this value can be c...

stable pile depth in the Snowy River study (SKM 2005) is outlined. The inputs used in the run of the LLP99 model were: • single soil layer, • very high flexural stiffness of pile (1,000,000 kN/m). • pile width = 0.3 m (i.e. wooden pile), • shear strength in the absence of lateral stress (for unconsolidated sand 150 kN/m was used), • effective unit weight of soil (15 kN/m), • active lateral effe...

application of structures of flow pattern modification is one of the erosion control methods in bends. triangular vanes are among these structures which provide less scour depth compared to the other techniques such as spur dike. since little information on erosion and sedimentation pattern around triangular vanes are available, this study was conducted to study the effect of structure effectiv...

When a jet of gas impinges vertically on a granular bed and forms a crater, the grains may be moved by several different mechanisms: viscous erosion, diffused gas eruption, bearing capacity failure, and/or diffusion-driven shearing. The relative importance of these mechanisms depends upon the flow regime of the gas, the mechanical state of the granular material, and other physical parameters. H...

the efficiency of a collar in reducing the scour depth around circular and rectangular piers is studied at different flow intensities (ratio of upstream shear stress to sediment critical shear stress). rectangular piers aligned with the flow as well as skewed at 5º, 10º, 20º were examined. previous studies had shown that with collar the equilibrium time of scouring increases considerably. to re...

The erosion caused by jets issued from hydraulic structures progressively develops a confined scour-hole on the riverbed. A realistic scour assessment must consider both the influence of the air entrained when the jet plunges into the pool and the flow patterns induced by bottom geometry. This experimental study systematically analyzes the combined influence of jet aeration and pool confinement...

Local scouring in the downstream of hydraulic structures is one of the important issues in river and hydraulic engineering, which involves a lot of costs every year, so the prediction of the rate of scour is important in hydraulic design. Side weirs are the most important of hydraulic structures that are used in passing flow. This study investigate the scouring due to falling jet from side weir...