A two-dimensional active bearing controller of highway bridges

Active control of highway bridge structures subject to earthquake excitation is addressed in this paper. A three degrees of freedom, two-span highway bridge model is used in this study. A state feedback controller to be installed to the bridge model is determined according to a nonlinear optimization design procedure which considers the bounds on the oscillation amplitude and also the constraints on the control force magnitude. The simulation of the controller with the two-span bridge shows that the active controller designed by the nonlinear optimization procedure is very effective. Moreover, robust safety of the active controller is also considered in which the active controller always improves the safety even with some structure changes during an earthquake excitation.