Author(s): G. Yu; S. K. Tan; S. Y. Lim; M. C. Ong
Linked Author(s): Soon-Keat Tan, Guoliang Yu, Siow-Yong Lim
Keywords: Bridge pier; Local scour; Lightweight bed material
Abstract: This paper presents the results of 137 sets of experiments conducted in a large concrete open channel, 29 m long, 6 m wide and 0.6 m deep to investigate the scour formation for different pier shapes and flow conditions. The bed material used was lightweight cylindrical plastics with a specific gravity of 1.05, a uniform size of 2.8 mm in diameter and 3.3 mm in height. The equivalent spherical diameter is 3.1 mm. The pier shapes tested include 5 circular piers of different diameters, sharp-nosed piers and rectangular piers with 4 different aspect ratios of pier width to length. Four representative existing methods of the scour depth of piers have been assessed using the experimental data and it was found that none of the methods are applicable for lightweight bed material. The main reason is that the effect of density of bed material is not sufficiently considered in these formulae.
Year: 2003