Evaluation of local scour calculation equations for bridge piers in sandy riverbed

Abstract

Local scour depth is the key index of foundation design of bridge across river. At present, there are many equations to calculate the scour depth of bridge piers, but the results of different equations vary greatly. It is still a difficult problem for bridge designers how to choose the appropriate equation for calculating local scour depth. Six typical equations for calculating local scour depth were selected to compare and analyze the influences of pier width, velocity, water depth in front of piers and bed sand particle size on the local scour depth. The results showed that bed sand particle size and geometric non-uniformity coefficient had the most significant influence on the scour depth. It was proposed that the prediction equation should be selected according to the size range and uniformity of bed sand.