Hybrid control strategy for seismic protection of a benchmark cable-stayed bridge

This paper presents a hybrid control strategy for seismic protection of a benchmark cable-stayed bridge, which is provided as a testbed structure for the development of strategies for the control of cable-stayed bridges. In this study, a hybrid control system is composed of a passive control system to reduce the earthquake-induced forces in the structure and an active control system to further reduce the bridge responses, especially deck displacements. Conventional base isolation devices such as lead rubber bearings are used for the passive control design. For the active control design, ideal hydraulic actuators are used and an H2/LQG control algorithm is adopted. Numerical simulation results show that the performance of the proposed hybrid control strategy is superior to that of the passive control strategy and slightly better than that of the active control strategy. The hybrid control method is also more reliable than the fully active control method due to the passive control part. Therefore, the proposed control strategy could be effectively used in seismically excited cable-stayed bridges.