Optimum Design of a Controlled Cable-Stayed Footbridge Subject to a Running Event Using Semiactive and Passive Mass Dampers

Abstract

Pedestrian-induced actions cause high vibration amplitudes in flexible and lightweight structures such as cable-stayed bridges. The high vibrational response is considered a serious serviceability problem that must be avoided either at the design stage or when retrofitting the structure. The use of control devices, particularly tuned mass dampers (TMDs) and viscous dampers (VDs), can be justified to reduce the structural dynamic response. This paper concerns the optimum design of a cable-stayed steel footbridge and its control devices to withstand a running event while guaranteeing all the serviceability criteria. Four different techniques (no control, VD, and VD with passive or semiactive TMDs) are presented to illustrate the effect of these control strategies in the optimum design geometry, dynamic responses, and cost.