Uncertaintiy effects of structural FE model and turbulent wind loading on bridge buffeting response

摘要

The design of long-span bridges requires accurate finite element (FE) models for reliable predictions of their dynamic characteristics and responses to loads, such as wind or earthquakes. There are inevitably deviations in dynamic characteristics resulted from different FE models with different modeling details. Firstly, the influence of modeling details on structural dynamic characteristics is investigated, including the beam-column joint modeling in tower, the choice of deck models and structural mass simulation. The optimal FE modeling details are proposed for bridges with different structural systems or different girder sections. Then, based on the nature of uncertainties of structural quantities and the characteristic of turbulent wind loading, the sensitivities of buffeting response prediction to structural quantities and wind spectra are both studied through two-dimensional buffeting analysis in frequency domain and three-dimensional buffeting analysis in time domain, respectively.