11 research outputs found
Dynamic parameters of structures extracted from ambient vibration measurements: an aid for the seismic vulnerability assessment of existing buildings in moderate seismic hazard regions
During the past two decades, the use of ambient vibrations for modal analysis
of structures has increased as compared to the traditional techniques (forced
vibrations). The Frequency Domain Decomposition method is nowadays widely used
in modal analysis because of its accuracy and simplicity. In this paper, we
first present the physical meaning of the FDD method to estimate the modal
parameters. We discuss then the process used for the evaluation of the building
stiffness deduced from the modal shapes. The models considered here are 1D
lumped-mass beams and especially the shear beam. The analytical solution of the
equations of motion makes it possible to simulate the motion due to a weak to
moderate earthquake and then the inter-storey drift knowing only the modal
parameters (modal model). This process is finally applied to a 9-storey
reinforced concrete (RC) dwelling in Grenoble (France). We successfully
compared the building motion for an artificial ground motion deduced from the
model estimated using ambient vibrations and recorded in the building. The
stiffness of each storey and the inter-storey drift were also calculated