Incorporating uncertainty into bridge pier scour estimations

“Pier scour” is the erosion of a streambed in the vicinity of bridge pier foundations and may eventually cause the bridge to become unstable. Fuzzy regression is used to develop a pier scour regression equation based on crisp laboratory data in which the regression coefficients are fuzzy parameters, thus producing fuzzy output. Field data is used to test the equations. The model provides a range of scour estimates for any given set of input data, each with an associated degree of belief. A number of drawbacks to this method are also presented