Design Of An Active Controller For Quincy Bayview Bridge, Illinois, U.s.a., Against Seismic Excitation-part I: Model Updating

摘要

This paper deals with the updating of a 3-D finite element model of an existing cable-stayed bridge. The objective of the updating is to arrive at a model that captures experimentally observed modes to the closest extent. Simultaneously, it has been attempted to keep the model as compact as possible as well as numerically stable such that the model may be used for the implementation of active control strategy against seismic excitation. The updating has been attempted primarily by using catenary element for modeling of cables in place of equivalent truss element, constraint equations in place of bearing elements in the deck-pylon interface as well as for rigid links connecting the spine with cables. Further, due to the existence of large axial force, the P-△ effect for deck and pylon members has also been considered. The configuration of the updated model for linear dynamic analysis has been adopted from the dead-load-deformed shape, which has been arrived at by carrying out nonlinear static analysis. The modal characteristics of the updated model have been validated with experimentally observed values. Moreover, the performance of the updated model has also been compared with alternative models formed by a combination of truss and catenary element in modeling of stay cables, with or without P-△ effect on deck and pylon.