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...

Abstract Riverbed deformation caused by river-crossing bridge construction can be divided into compression scour and local scour. Compared with scour, fewer studies have been made on the piers. It is noteworthy that, lead to riverbed of whole cross section along a site, which obviously detrimental foundation safety. Based summary existing research findings, prediction model for piers constructe...

Abstract A theoretical framework, based on the phenomenological theory of turbulence applied to scour-related processes due plunging jets cohesionless beds, is considered in this paper. More specifically, its predictive capability assessed herein for large-scale domains, after it was developed small scales elsewhere. The analysis focuses both time-evolution process and equilibrium configuration...

We investigated the impacts of winter litter disturbance on the spread of the nonnative invasive plant Microstegium vimineum (Trin.) A. Camus through experimental removals. We hypothesized that light penetration through the litter layer facilitates the spread of M. vimineum in forested systems. Our objective, therefore, was to quantify M. vimineum spread following litter removal. Linear spread ...

Flip buckets are terminal spillway elements, generating free jets for energy dissipation. Deflectors are an alternative to flip buckets with constructional ease yet of similar hydraulic features. A first experimental study published at the 33 IAHR Congress, Vancouver, investigated deflectorgenerated jets in terms of their air concentration characteristics. For jet impact onto a movable bed, the...

Structures like blunt-nosed chevrons, log deflectors and double-winged frames help in modifying the flow regime channel by concentrating increasing navigability. Moreover, they create scour pools downstream stilling basin, which can be used either as fish refuge or an in-stream storage site for previously dredged material. In this respect, use of wood debris form bundles has gained attention ab...

Scour in a flow field affected by waves, such as river estuaries or shallow waters, is more difficult to predict than scour currents. The main issue predicting the around circular files, undersea bridges, maximum depth and point of occurrence. In case two adjacent piles, location according spacing between piles arrangement method show lot difference compared single pile. this paper, KC number a...