Bridge scour monitoring using Extended Kalman Filter

Abstract

Scouring of bridge foundation is one of the major causes of bridge failure. Scour can be defined as the excavation of foundation or other material from the bed and banks of streams, due to water flow. Scour monitoring is a major requirement to ensure bridge safety. Direct scour measuring instruments such as float-out and radar devices are costly and difficult to maintain. An alternative is vibration-based monitoring techniques that monitor the change in modal properties to identify scour. These methods suffer from low Sensitivity of modal properties to scour depth. This paper proposes a scour monitoring method using Extended Kalman Filter (EKF) that uses time history responses in conjunction with a structural model to identify the scour depth with better accuracy. Foundation stiffness of piers being the most sensitive parameter to scouring, this parameter is estimated using the EKF algorithm that operates with limited response measurements and intact finite element model of piers. The developed method is validated numerically.