In situ experiments and beam modelling of existing buildings

This article is devoted to in situ measurements on existing buildings and their practical interest. The response to ambient vibrations, harmonic excitation and shock loading is recorded on an intact building so that the modal characteristics can be evaluated. Measurements gathered after modifications of the building bring quantitative answers on the actual influence of light work elements (like secondary dividing walls). The experimental results show that a Timoshenko beam, simply deduced from the internal structure of the building, describes the dynamic behavior with a good accuracy. The discussion of the results emphasizes the advantages of using the small vibrations measurements for the assessment of existing buildings.