This paper is going to present a combined approach with the conventional fatigue analysis and the fracture mechanics based concept with Waibaidu Bridge as an example. With this method the remaining fatigue life and safety of old riveted truss bridge are also calculated. Firstly, a 3-dimensional finite element model which can reflect the actual mechanic behavior is established on the basis of the existing bridge archives (the original design documents, maintenance records, etc.) and through the calibration with the in-situ measured values (deformations, strains and eigenfrequencies). Secondly, the traffic situation of the bridge is investigated. With the traffic data obtained the statistic parameters describing the traffic flow are determined. The stress histogram and stress spectrum are computed by means of the Monte-Carlo Method and the stress influence surface. Compared to the one-day in-situ measured stress spectrum the traffic load spectrum is derived. Thirdly, the fatigue life and damage of all the tension members is calculated with the conventional fatigue analysis based on the S-N curve. With the service factor calculated an inspection priority is determined. Fourthly, the fracture mechanics is applied. The intial crack size is assumed through the visual inspection and ultrasonic detection method. The vital members of this bridge are identified by the simulation of failure scenario. With two simplified fracture mechanics models -CCT and DECT, the critical crack size and failure mode are analyzed. The remaining fatigue life is calculated through the simulation of crack growth. According to the calculation results the inspection interval and maintenance management are determined.
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