Local scour around a cylindrical pier in a channel with an erodible bed or natural bed is a common problems in bridge or pile supported structure. The highly unsteady complex flow field around a circular pier produces scour hole mainly for the presence of vortices. The main mechanism that drives the formation and evolution of the scour hole around bridge pier is horse shoe vortex motion. In the...

The scour phenomenon around bridge piers causes great quantities of damages annually all over the world. Collars are considered as one of the substantial methods for reducing the depth and volume of scour around bridge piers. In this study, the experimental and numerical methods are used to investigate two different shapes of collars, i.e, rectangular and circular, in terms of reducing scour ar...

Scouring around a bridge pier is a complex phenomenon. More laboratory experiments are required to understand the scour mechanism. This paper focused on time development of local scour around piers and piles in semi integral bridges. Laboratory data collected at Hydraulics Laboratory, University of Malaya was analyzed for this purpose. Tests were performed with two different uniform sediment si...

The evolution of bridge pier scour is very important for bridge safety warning and assessment. During typhoon seasons in Taiwan, the torrential river flow often causes scour monitoring instruments to fail in their attempt to measure the temporal variations of pier scour depths. To better understand the scouring phenomenon during a large flood event, this study proposes a fast and reliable metho...

Prediction of bridge pier scour depth is essential for safe and economical bridge design. Keeping in mind the complex nature of bridge scour phenomenon, there is a need to properly address the methods and techniques used to predict bridge pier scour. Up to the present, extensive research has been carried out for pier scour depth prediction. Different modeling techniques have been applied to ach...

Prediction of maximum local scour is necessary for the safety and economical design of the bridges. A number of equations have been developed over the years to predict local scour depth using laboratory data and a few pier equations have also been proposed using field data. Most of these equations are empirical in nature as indicated by the past publications. In this paper attempts have been ma...

This paper presents the use of genetic programming (GP) as a tool to predict pier scour depths based on clear-water conditions of laboratory measurements by past researchers. Four main dimensionless parameterspier width, approaching flow depth, threshold flow velocity, and channel open-ratio are considered for predicting the scour depth. The performance of the GP equation is verified by compa...

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...

Local bridge scour is caused by the interference of bridge piers with the flow of water and is characterized by the formation of scour holes. Local scour occurs at a bridge pier when the local flow field is strong enough to remove bed materials. Several variables affect the scour depth including the flow intensity, the relative flow depth, the pier-width, and the properties of the river bed mat...

Scour is by far the primary cause of bridge failures in the United States. Scour and other hydraulic effects are particularly threatening because the deterioration is often invisible , hidden beneath turbid water. Many scour monitoring methods attempt to measure the development of scour pockets themselves. However, this is difficult due to debris — both floating and submerged — and shifting str...