Author(s)

J. S. Antunes do Carmo

Abstract

Scour in the vicinity of structures may be caused by the combined effects of local, contraction and natural scour, and may also be aggravated by the effects of navigation. It may occur as a result of natural changes of flow in the channel, as part of longer-term morphological changes to the river, or through man’s activities, such as building structures in the channel or dredging material from the bed. This paper presents a study on the scour process in a fluvial environment, in order to prevent a construction from failing. The experiments related to this research on scour in rivers and bridge failures were conducted in the Hydraulics Laboratory of the Civil Engineering Department of the University of Coimbra. We hope these results may be useful for testing and calibrating design methods for estimating equilibrium depths of local scour around bridge piers. Keywords: local scour, piers in rivers, scour protection, experimental study. 1 Introduction Structures built in rivers and estuaries are prone to scour around their foundations. If the depth of scour becomes significant, the foundations’ stability may be endangered, with a consequent risk of the structure suffering damage or failure. CIRIA [1] refers to several cases of bridge failure due to scour, some causing loss of life and most resulting in significant transport disruption and economic loss. Richardson and Davies [2] cite several studies of bridge failures in the USA. In a report for the Transport and Road Research Laboratory, Wallingford et al. [3] listed some notable bridge failures due to scour. Melville and Coleman [4] cite 31 case studies of bridge failures and damage in New

Keywords

local scour, piers in rivers, scour protection, experimental study.