Deer Isle Bridge: Efficacy of Stiffening Systems

For the last several years the Deer Isle suspension bridge in Maine has been the subject of a field survey by the U.S. Federal Highway Administration. At this writing, on‐site wind and vibration measurements are continuing. The present paper examines the effectiveness of the post‐construction modifications for avoiding excessive aeroelastic response. The paper describes a finite element analysis of this rather complicated bridge and the inferences drawn therefrom. The study is a part of ongoing research into methods for both sharpening and corroborating the prediction of the wind response of flexible bridges. The present study confirms the efficacy of cable bracing added to the original bridge by its designer with the aim of defending it against wind‐induced oscillation.