VELOCITY PROFILES AND SCOUR DEPTH MEASUREMENTS AROUND BRIDGE PIERS

Local scour around a model of the Schoharie bridge pier was experimentally investigated in the laboratory. The tests simply focused on the effects of the angle of attack and flow velocity on the maximum depth of scour. Clear-water scour conditions prevailed, that is, the shear stress at the bottom in the upstream flow is always less than the critical value for beginning of sediment motion. The experimental results indicate that the effect of the angle of attack is related to the undisturbed flow Froude number. In particular, the ratio of the measured scour depths for skewed and aligned piers decreases with increasing Froude numbers. Velocity is found to have an important influence on scour depth.