Scouring around different shapes of bridge pier

Abstract

Scouring is a complex process dependent on several factors, and local scour is more complex than general scour. This study was an attempt to predict local scour round bridge piers based on general scour in the water stream. Three obstacle shapes were used – circular, round-nosed, and elliptical – as they are predominant in hydraulic structures like bridge piers. For each obstacle shape, scour depth was measured around the periphery for five gradually increasing discharges and in two types of bed material. The local scour results were analyzed to relate them to general scour. Lacey's equation was used to estimate general scour. Models were developed for the three common shapes, by which local scour for any particular shape can be predicted based on general scour in the stream. HIGHLIGHTS Correct estimation of local scour depth.; Incorporation of shape factor for a better scour depth estimation.; Improvement over Lacey's theory.; Relating local scour estimation with general scour.; Better design and safety of hydraulic structures.;

Keywords

• bridge pier
• discharge
• lacey
• local scour
• shape
• silt factor