Local Scour at Skewed Bridge Piers

Presented herein are experimental data showing the influence of pier skewness, also referred to as angle of attack, on depth of local scour at rectangular and oblong bridge piers. The data are compared with the well known Laursen and Toch (1956) curves for the skewness factor K α , the latter being shown to lead to underpredictions in some cases. Equations for K α , which envelop all the data from the study, are given. For design, it is recommended the local scour depth at skewed bridge piers be estimated from an equation which is based on the projected width of pier, the equation thereby inherently accounting for the effect of pier skewness.