Continuous monitoring of in-service performance of prestressed concrete continuous bridges with two strengthening measures

The strengthening measures without traffic interruption have been widely used for maintenance and renovation of bridges with damage and stiffness degeneration, due to their advantages of convenience and insignificant influence on traffic. However, evaluation of the associated reinforcement effect and service performance is intractable, because on site load capacity tests could not be conducted. In this study, a continuous monitoring method was proposed to evaluate the enhancement effect of the prestressed concrete continuous bridge with two different strengthening measures, by using the measurement data under operation status. First, the Ensemble Empirical Mode Decomposition (EEMD) method was used to distinguish the thermal effect and traffic induced effect. Then, cross-correlation and linear regression analysis was conducted to investigate the relevance of monitored temperature data and extracted thermal effect. Next, the t location-scale distribution was used for probabilistic statistical analysis of the peak values of traffic induced bridge responses. The generalized Pareto distribution (GPD) model and finite element model were used to set the two-level threshold of the bridges. The statistical results of the monitored data with different strengthening measures were compared to evaluate the associated reinforcement efficiency. The results demonstrated that the proposed continuous method performs well in assessment of bridge reinforcement and service performance with no traffic disruption.