Experimental vibration analysis of composite bridge superstructure with excessive deformations

Abstract

The paper presents results of experimental vibration tests of dynamic susceptible composite, steel-concrete, multi-girder superstructure of highway bridge with excessive deformations. The whole structural system exhibit disproportionate, low-damped vibrations induced by normal traffic crossing the bridge. The presented series of dynamic tests under real traffic were performed for identification of the bridge dynamic characteristics important for future safety and fatigue analyses. In the paper the tested bridge structure as well as procedure of the performed dynamic tests and applied measuring systems are described together with the numerical model developed during design of the experiment and analysis of the tests results. Measured strains, displacements and accelerations as well as calculated Dynamic Amplification Factors (DAF) are presented for various load scenarios caused by vehicles crossing the bridge. Conclusions regarding effectiveness of applied testing method in identification of the bridge dynamic condition are formulated.