Active tendon control of cable-stayed bridges: Theory and implementation

This paper presents a strategy for active damping of cable-stayed bridges, using active tendons. The first part of the paper summarizes the theoretical background: the control law is briefly presented together with the main results of an approximate linear theory, which allows to predict the closed-loop poles with a root locus technique. The second part of the paper reports on experimental results obtained with a 30m long cable-stayed bridge mock-up built on the reaction wall of the ELSA test facility at the JRC Ispra (Italy); this test structure is used to demonstrate the practical implementation of the control strategy with hydraulic actuators. Finally, some potential full-scale applications are identified, concerning temporary active systems for bridges under construction, and permanent systems for suspension bridges.