ABSTRACT
This paper reports finite element results predicting the dynamic response of an in situ arch bridge to transient loading. The arch was built in 1992 at Kimbolton, Cambridgeshire. The bridge consists of an 8m clear span of 2m rise and a 0.44m thick arch barrel. A 3-D finite element model was adopted using eight noded solid elements. Natural frequency analysis was carried out to determine the arch’s resonant frequencies and mode shapes. Then a mode superposition procedure was adopted to analyse the response of the arch in both time and frequency domains. The effect of the stiffness of brickwork and backfill materials upon the arch’s dynamic behaviour were studied. Changes in the pavement properties and their effect on the modal characteristics of the arch were also studied. It was found that as the stiffness increased the resonant frequency increased. However the amplitude of vibration of the arch decreased especially when the brickwork stiffness increased. It is hoped that this study will provide a tool for engineers wishing to predict the dynamic characteristics of such structures with the aim of using the method for the integrity assessment of arch bridges.
