Probabilistic fatigue life updating for bridges based on comprehensive structural monitoring data

Abstract

Fatigue failure is one of the main mechanisms of bridge failure. When a bridge is constructed, it should be designed such that it can survive a target period. However, the bridge strength degrades over its service life. For decision-making with respect to the effective maintenance of bridges, it is thus essential to predict their remaining fatigue life. However, it is a very challenging task because the fatigue life of a bridge should be predicted based on its current condition, and various sources of uncertainty exist. This paper presents a new approach for predicting the probabilistic fatigue life of bridges based on comprehensive structural monitoring data. The proposed method (1) predicts the probabilistic fatigue life by employing a finite element (FE) model that is updated at the global level using the ambient vibration under general passing vehicles and (2) updates the fatigue life based on crack detection data at the local level. The proposed method is applied to a numerical bridge example, and the impact of structural degradation on the fatigue life of a bridge is discussed.