Prestressed active post-tensioned tendons control for bridges under moving loads

Abstract

This paper proposes a new innovative mechanism for active bridge vibration control due to moving load using active prestressed post-tensioned tendons. King Abdullah's Hospital Bridge at the Jordan University of Science and Technology is employed in this study. This bridge consists of eight spans each is 25 m resulting in a total length of 200 m. The bridge system is treated as an elastic continuum coupled with a single degree of freedom moving oscillator representing the moving vehicle. A linear time-varying model used to simulate the bridge-vehicle system. The dynamic behaviour of the prestressed concrete bridge studied for the uncontrolled case, and the effect of the prestressing force on the response of bridge-oscillator system is illustrated. Two linear quadratic gaussian (LQG) controllers with time-varying gains and constant gains designed to mitigate the bridge vibration due to the moving oscillator for different velocities. The control strategy regulates the post-tensioned tendons' force so that the system vibration diminished. The results indicate that the proposed control mechanism is efficient for reducing the vertical displacements of both the oscillator and the bridge by up to 83% and the vertical accelerations by up to 83 and 42%, respectively. Additionally, the robustness of the controllers are investigated and illustrated. The results show that the proposed mechanism is robust and stable. Copyright © 2006 John Wiley & Sons, Ltd.