Structural control solutions can offer a decisive contribution to reducing the consequences of strong events in earthquake-affected areas, enhancing structural resilience. Furthermore, the inherent feature of some control systems, which can adapt themselves to different loading levels, can be exploited when structural conditions change due to local failures. This occurs by changing the working parameters of the control system in real time or, even if very short, over the period between two seismic events. This work deals with resilience of seismic control solutions for cable-stayed bridges through a case study represented by a standard bridge control benchmark from the literature. A strategy for recovering the optimal configuration of the controlled bridge after a damaging event is presented. Emphasis is given to the time interval between the damage occurrence and the restoration, which represent the essential aspect of the resilient behavior. Finally, the formulation of a robustness index and general procedures that suggest how to quantify resilience for the control system of cable-stayed bridges in the context of multiple hazards are explored.

An updated version of the ASCE benchmark on controlled cable-stayed bridges has been recently developed in the ANSYS framework. It includes new aspects in the relative transversal motion of the main girder with respect to the towers in the simulation of the stay cable dynamics with respect to the coupled motion of the main girder in the soil-structure interaction and the numerical formulation by assuming full geometric nonlinearities. Analyses are carried out in a multiple support framework in a time domain by using the earthquake records as collected from the benchmark original statement. The original benchmark configuration considered earthquake restrainers in the transverse direction. The proposed updated bridge model first reproduces this kinematic arrangement, and a new configuration with transversal releases is subsequently implemented. The control strategies consist of passive and decentralized semiactive systems working in the horizontal plane and are also those studied in a previous investigation for the original statement. When the devices are implemented in the transversal direction, the proposed schemes distinctively mitigate the transversal structural response of the bridge with reasonable efficiency.