Cable-Stayed Footbridge: Investigation into Superstructure and Cable Dynamics

Abstract

A 35 year’s old cable-stayed footbridge was investigated into analytically and experimentally to becoming able to rate it’s state of health. The paper presents the dynamic tests performed on this twin-32-m-span prestressed concrete structure and the respective results. Besides the main girder the bridge exhibits an A-shaped pylon as well as eight cables consisting of posttensioned parallel wire tendons. On the one hand, the tests covered experimental modal analyses of the whole structure including main girder, pylon and cables as well as of two of the cables as isolated structures under ambient excitation conditions. In addition, the structure was loaded with a jogger crossing the bridge and the maximum cable response to manual excitation was determined. The latter is not discussed here. The bridge state of health could be rated “satisfying”.