Method for predicting service life of reinforced concrete bridge under conditions of seasonal corrosion and fatigue coupling

Abstract

The invention discloses a method for predicting the service life of a reinforced concrete bridge under the conditions of seasonal corrosion and fatigue coupling. The method comprises the steps: dividing the service life of the reinforced concrete bridge into three stages: corrosion initiation-pure fatigue crack development stage, a rust pit and fatigue crack competing development stage and a structure failure stage; establishing an initial reinforcing steel bar corrosion model and a rust pit growth model based on the Fick second diffusion law and the consideration of the influence of concreterust expansion cracking damage; testing and simulating a reinforcing steel bar crack propagation rule under the influence of a four-season environment, and determining fatigue crack growth characterization parameters; constructing a stress intensity factor model considering the influence of stress concentration, and proposing a steel bar corrosion fatigue crack growth analysis method correspondingto a four-season environment; enabling the structural failure criterion to be clear, combining with the vehicle load observation information, performing the systematic consideration of the competitive coupling relation between rust pit growth and fatigue crack growth, judging a failure mode in real time, and achieving the prediction of the service life of the bridge. The method is novel and reasonable, and can provide technical support for safety assessment of the concrete bridge.

Description

technical field [0001] The invention relates to the field of safety assessment of service bridges, in particular to a method for predicting the life of reinforced concrete bridges under the coupling of seasonal corrosion and fatigue. Background technique [0002] With the rapid growth of traffic volume and the deteriorating environmental conditions, corrosion fatigue has become one of the main reasons affecting the performance degradation of reinforced concrete bridges. Reinforced concrete bridges are constantly subjected to repeated vehicle loads during their service. At the same time, in the coastal environment or in the environment where deicing salt and deicing agent are used in large quantities, the corrosion problem of reinforced concrete bridges is prominent. Corrosion will accelerate the accumulation of fatigue damage to steel bars and significantly reduce the service life of the structure. Local corrosion can also lead to stress concentration. Through the fracture...

AI Technical Summary

Problems solved by technology

In addition, the service environment of bridges changes with the seasons, and there are certain differences in the degree of structural performance degradation in different seasonal environments.

In the existing evaluation methods for the fatigue life of reinforced concrete bridges, no research has considered the effects of seasonal environmental changes and fatigue coupling effects

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