Author(s): Yee-Meng Chiew; Yan Lu
Linked Author(s): Yee Meng Chiew
Keywords: Keywords: Riprap protection; Bridge pier scour; Suction; Sediment transport; Turbulence intensity; Dunes
Abstract: The study investigates the performance of riprap protection around a bridge pier under the influence of bed suction. Published studies have identified five main failure mechanisms associated with riprap failure around bridge piers without suction. They are shear failure, winnowing failure, edge failure, bedform-induced failure and bed-degradation induced failure. The experimental data revealed that suction can reduce the threat of winnowing failure by decreasing the level of turbulence around the pier. However, in the case of high flows accompanied by dunes in which bedform-induced failure is the dominant failure mode of pier-riprap, suction can affect the stability of pier-riprap in two ways: (1) it increases the height of dunes thus enhancing the threat of bedform-induced failure; and (2) it decreases the turbulence intensity around the pier. The overall effect is dependent on the relative magnitude of these two opposing effects.
Year: 2005