A review of approaches to assessing scour current velocity around existing structures

Abstract

Climate change is credited with increased rainfall frequency and intensity. Rainfall intensity in engineering design or assessment is characterised from statistical analysis of historical records. A deviation from historical patterns introduces risk, particularly to existing structures, as the limits of past design methods are approached or exceeded. Such risk may be amplified and become difficult to predict if climate change combines with physical environmental changes. This paper makes reference to the importance of site observations in designing resilient solutions and highlights the tendency of current guidance/methods to be insufficient due to the lack of available assessment information. It provides guidance on the use of observed information to attain confidence in design parameters and presents equations for establishing current velocities for the design of rock scour protection or assessing observed scour conditions with limited unknown parameters.