an attempt was made to develop a method for sizing stable riprap around bridge piers based on a huge amount of experimental data, which is available in the literature. all available experimental data for circular as well as round-nose-and-tail rectangular piers were collected. the data for rectangular piers, with different aspect ratios, aligned with the flow or skewed at different angles to th...

The local scour around bridge piers is one of the main causes failures. In this study, hole dimensions circular were investigated under clear water conditions for various steady flow rates. experiments performed with four different pier diameters and seven rates by using uniform sediment a median diameter 1.63 mm geometric standard deviation 1.3. After each bathymetry was determined. New empiri...

A reliable prognostics framework is essential to prevent catastrophic failure of bridges due to scour. In the U.S., scour accounts for almost 60% of bridge failures. Currently available techniques in the literature for predicting scour are mostly based on empirical equations and deterministic regression models, like Neural Networks and Support Vector Machines, and do not predict the evolution o...

A theoretical investigation of local scour downstream of grade-control structures based on two-dimensional jet diffusion and particle stability is experimentally verified. Turbulent jet diffusion reduces fluid velocity near the bed particles and equilibrium scour is obtained when noncohesive bed particles cannot be removed from the scour hole. Equilibrium scour depth is written as a function of...

Improved understanding of scour and sedimentation processes near and at highway bridges is dependant on collecting reliable field data. Field data collection programs, however, have been hindered by inadequacies in instrumentation and measurement technologies. Through a coordinated program of research, the Federal Highway Administration (FHWA), State Highway Agencies (SHAs), National Cooperativ...