BEHAVIOUR OF HOLLOW BRIDGE PIERS FILLED WITH VARIOUS MATERIALS UNDER DYNAMIC LOADS

Abstract

This analytical and experimental investigation is carried out to find the effect of different filling materials in hollow bridge piers on their behaviour under free and forced vibrations. The bridge model tested for this purpose has been tr3ated as the proto-type structure for purposes of theaeetical calculations, In the experimental study, four different fills, which can be commonly made use of, are tried and their effect on damping and natural frequency of the substructure is observed. Free vibration tests are conducted under condition of initial displacement by pulling and releasing the pier itself, Forced vib-ration study is carried out by mounting a mechanical. oscillator on the top of the deck. The theoretical verification of the experi-mental results is done by analysing the bridge pier as a vertical cantilever. The pier is considered either rigidly fixed to the foundation or having some flexib-.ility.at the base. Roth bending and shearing deform-ation or bending deformations only are considered. Some conclusions are drawn as a result of this study which will be useftll in practice and for planning further investigations.