Scour Damage Detection of Bridge Piers Using the Vibration-Based Method: Numerical Study on a Steel-Concrete Bridge in France

Abstract

The scour is one of the main reasons for bridge collapse. Soil removal around bridge foundations alters their embedment conditions and affects the stability of the structure. Therefore, scour detection is crucial to ensure the safety of bridges and prevent their failures. This paper presents a vibration-based analysis method for detecting scour in its early stages, using frequency values as a scour indicator. Scour is represented by the degradation of foundation stiffness. A robust expression is developed to calculate the variation of frequency as a function of stiffness variations. Different scour scenarios are numerically simulated on a steel-concrete bridge model, revealing that frequencies related to horizontally displaced modes are sensitive to scour, while the deck bending modes are insensitive. The SVD method used to solve the inverse problem has proven to be robust in estimating stiffness reduction based on frequency changes and identifying the location of scour.