RC

 In countries with a moderate seismic hazard, the classical methods
developed for strong motion prone countries to estimate the seismic
behaviour and subsequent vulnerability of existing buildings are often
inadequate and not financially realistic. The main goals of this paper
are to show how the modal analysis can contribute to the understanding
of the seismic building response and the good relevancy of a modal model
based on ambient vibrations for estimating the structural deformation
under weak earthquakes. We describe the application of an enhanced modal
analysis technique (frequency domain decomposition) to process ambient
vibration recordings taken at the Grenoble City Hall building (France).