Bridges

Cover of A Comparison of the Effect of Pier Shape on Flood Loading on Bridges
A Comparison of the Effect of Pier Shape on Flood Loading on Bridges
  • Publication no: ABC2017-092-17
  • Published: 21 April 2017

The resistance to flood and debris loading are critical parameters affecting design of bridges under flood loading. For instance, bridges which are under extreme flood could partially or completely immerse in the water, resulting in very notable hydrodynamic loads on the decks and piers. Typical design process would convert the flood loading in to a static force, which cannot reflect the full effect of flood and the debris loading on different shaped piers. Therefore, it is important to investigate the effect of flood loading on piers of different shapes. This work simulates the flooding effect on the piers using a finite volume method in ANSYS Fluent. The pier is modelled as a column with a square cross section or a circular cross section. The pier has been simplified as a nonslip boundary for fluid domain as well as bed and sidewall. It is assumed that the domain size is 5x7x3.5 m3 and the pier is a 0.355 m2 in dimension. A numerical model has been developed to examine the influences of velocity variation in the range of 0.5m/s to 10m/s on the hydrodynamic pressure exerted on the pier. The developed model is employed to explore the behaviour of pressure exerted by food flow on a pier. Comparison between the equivalent hydro-static load suggested by AS 5100 and the numerical analysis has been presented. Outcomes demonstrate that the AS5100 method is appropriate for evaluating the pressure on square piers whereas the method is inadequate for predicting the pressure on circular piers.

* Best Young Author Paper Runner Up: Austroads Bridge Conference 2017