Brown Bag: Experimental Study of Local Scour around Three Piers Groups

Pima County Regional Flood Control District Monthly Brown Bag Series

Speakers: Kang Zhou and Jennifer Duan, Department of Civil and Architectural Engineering and Mechanics, UA

Date / Time: Wednesday, May 15, 12– 1 PM

Location: 201 North Stone Ave, 9th Floor

Bridge scour is the leading cause of bridge failure. An accurate estimation of scour depth can not only prevent bridge failure but also improve bridge design. The prediction of bridge scour has been traditionally for a single pier of various sizes, shapes, and alignments with flow. In engineering practice, multiple piers in tandem are preferred because of their advantage to support multi-lane super-structures. For this study, the authors conducted a set of laboratory experiments to investigate local scour around a group of three piers with different sizes, spacing, and attacking angles. Based on the phenomenological theory of turbulence flow, they formulated an analytical equation for predicting the maximum scour depth. The coefficients in the equation were determined by the experimental data from this and other studies. The results showed pier diameter, pier spacing, actual pier width, flow depth, Froude number, and sediment size are important parameters for determining the maximum scour depth.