<p>Every year many bridges worldwide destroy by the floods due to non-structural reasons, but mostly hydraulic design parameters. In this study, velocity and shear stress contour changes around the bridge piers of oval and circular shapes have been discussed and compared. 3-D modeling was done using Open FOAM software. Flow turbulence was considered using k-&epsilon; RNG turbulence model and governing equations were Navier-Stokes equations. The results showed that the bridge pier shape has a significant effect on the flow pattern and riverbed shear stress that is effective in prediction of the scour pattern. The results also showed that shear stress around the oval pier was lower than the circular one, and hence, less scour occurs around this type of pier.</p>