Simplified prediction of wind-induced response and stability limit of slender long-span suspension bridges, based on modified quasi-steady theory A case study

The Hardanger Bridge is currently under construction in Norway It will have a main span of 1310 m and a girder that is only 183 m wide which implies that wind-induced vibration is a major concern in the design Buffeting response and flutter analysis of the Hardanger Bridge are treated in this paper The self-excited forces are modelled using aerodynamic derivatives obtained from free vibration tests, quasi-steady theory and a suggested modified quasi-steady theory The stability limit predicted using aerodynamic derivatives corresponded well with the wind tunnel results while the quasi-steady theory severely underestimated the critical mean wind velocity for the section model used in the wind tunnel tests A new set of modified quasi-steady coefficients are suggested where the experimental results of the aerodynamic derivatives are used to obtain frequency-independent model coefficients The critical velocities predicted by the modified quasi-steady coefficients differ only by 4-5% from estimates based on the aerodynamic derivatives The response predicted by the suggested simplified aerodynamic model is also presented and the results indicate that adequate estimates are achieved (C) 2010 Elsevier Ltd All rights reserved