Long-term extreme buffeting response of cable-supported bridges with uncertain turbulence parameters

Although the full long-term method (FLM) is recognized as the appropriate way to identify the design stresses of marine structures subjected to stochastic environmental loading, the FLM has not yet been adopted for the design of wind excited long-span bridges. The results presented in this study show that the current design practice, through short-term extreme response analyses with deterministic turbulence parameters, may significantly underestimate the long-term design stresses of long-span bridges. Both the variability of the turbulence parameters and the uncertainty in the short-term extreme response are found to be important when estimating the design stresses. In addition, the long-term extreme acceleration responses have been compared with the acceleration responses measured in full scale at the Hardanger Bridge, showing considerable improvements to the current design practice.

Automated summary

The study suggests that the current design practice for wind excited long-span bridges, using short-term extreme response analyses with deterministic turbulence parameters, may significantly underestimate the long-term design stresses. Both the variability of the turbulence parameters and the uncertainty in the short-term extreme response are important factors to consider when estimating design stresses. The comparison between long-term extreme acceleration responses and the measured responses at the Hardanger Bridge shows considerable improvements to the current design practice.