Damage detection and rehabilitation on a curvilinear steel box girder bridge by multistage model updating

This paper presents an efficient model-updating method suitable for complex finite element model with shell and solid elements utilising static inspection data. Based on the standard parameter estimation procedure, a simplified parameterisation procedure based on engineering experience and static inspection was used. Moreover, the parameter estimation was conducted by stages according to the sensitivity level of parameters. To verify the effectiveness of the algorithm, a curvilinear steel box girder bridge is taken as a research case study. General damage detection and corresponding rehabilitation are conducted. It indicates that the parameterisation procedure can meet the practical engineering demands. The multistage model-updating method is more effective and efficient than direct model updating, especially when low sensitivity level parameters are removed from the parameter groups. The updated model can contribute to reveal the behaviour of the structure and can be used for related safety assessment and rehabilitation according to the case study. It is proved that the method shown in this paper works well for existing complex structures. It is sufficient for practical engineering demand and can provide useful reference for similar projects.