Study On Multi-stage Model Modification And Life Prediction Of Bridge

In recent years, health monitoring of bridge is one of the hotspots of engineering 。 Build a finite element model which consistent with the actual bridge is the key of health monitoring of bridge. In order to solve the shortcomings of lack of precision and large computation in traditional finite element model, Multi-stage model updating method is proposed. In this paper, In order to do some works of assessment and ongoing maintenance, the remaining life of bridge methods is studied in-deep. And then, those theories studied above are applied to ShiHe bridge project. The specific content of this paper is divided into the following three aspects.Firstly, use the selected to be updated parameters to do parameter sensitivity analysis in the model updating of the bridge. After that, parameters are grouped according to the sensitivity values. And then, do model updating for each group of parameters in turn according to response surface method, which is called Multi-stage model updating method of bridge. Compared with the traditional single model updating method, It’s not only reduces the amount of calculation, but also improve the accuracy.Secondly, for the two cases that the steel is protected by the concrete and exposed in the air. Discuss the durability of steel and concrete materials in both cases. And then, get a corresponding reliability of bridge according to the model of reliability. Use the reliability index and Criteria for judging failure under the two circumstances. Calculate a mathematical model of the remaining life of the bridge. Using the model calculated remaining life method has the advantages of simple and intuitive.Thirdly, the Multi-stage bridge finite element model updating and residual life prediction methods are used into ShiHe bridge project. The error rate is decreased from 3.938% of single update method to 1.379% after update, and reducing the amount of calculation. The effect is quite good. Do some life predictions for the bridge, using the modified bridges model and monitoring data. Calculate the function of remaining life of the current bridge.Multi-stage bridge model updating method proposed in this paper can doing updating bridge model efficiently. The Multi-stage bridge model updating and residual life prediction methods are used into ShiHe bridge project, and show that the accuracy is meet the requirements of its engineering. The result of life prediction can provide a scientific basis for bridge maintenance and repair.