Author(s): Y. M. Chiew; R. Ettema
Linked Author(s): Yee Meng Chiew
Keywords: Bridge pier; Froude number; Model study; Reynolds number; Sediment transport; Similitude
Abstract: This paper examines overlooked scale effects that have led to shortcomings in predictive equations for local scour at bridge piers. It uses dimensional analysis to obtain a complete set of dimensionless parameters without preconceived assumptions as to which parameters can be neglected. The resulting functional relationship is compared with those in the literature, and two outstanding parameters, ▲ and gD ▲ are identified. The two parameters, which have substantial impact of pier-scour development, respectively express similitude in the frequency and strength of eddies shed from a pier. Using published experimental data, the study shows how ▲ indeed has a profound influence on scour hole development, with the dimensionless depth of scour associated with a small circular pier (D = 16 mm) being 1.8 times that of its larger counterpart (D = 766 mm) when effects of all other dimensionless parameters are absent.
Year: 2003