Some Remarks on the Mitigation of Long-Span Bridges Structural Vibrations Induced by Wind and Earthquake

Herein, two models of long-span bridges, namely a suspension and a cable-stayed one, are developed at the numerical level in the ANSYS FE code, starting from original data, and they are used to simulate the structural response under wind excitation and seismic excitation. The main goal of this study consists in the evaluation of a control strategy, designed and proven effective for the wind action, considering the suspension bridge, or for the seismic action, for the cable-stayed one, when the bridge structure is subjected to the seismic and the wind action respectively. This paper is intended to collect the recent advances in the mitigation of unwanted vibrations on different long-span bridges typologies for underlining general observations and strategies useful for their protection. The attention has been initially given to seismic and wind excitation, characterized to high intensities and low probability of occurrence. However external actions described by low intensity and high probability of occurrence has been also addressed by evaluating the effectiveness of the proposed control strategies in the mitigation of unwanted indirect effects, as the fatigue damage in steel frame deck.