How Far Ambient Noise Measurement May Help to Assess Building Vulnerability?

The use of noise data in seismic diagnosis of buildings is analyzed. From the responses to ambient noise, harmonic excitation and shocks, the dynamic behavior of usual buildings is identified in the range of 10(-5) - 10(-2) g. Taking advantage of the demolition, the influence of the light work elements, full precast facade panels, hearing masonry walls and the presence of neighboring joined buildings is determined. These experiments show that noise measurements efficiently provide reliable data of real interest for understanding the actual building behavior. Then, the integration of these data in a vulnerability diagnosis is presented. It is shown that regular concrete structures are described by suited beam modeling. Thus for a given structure, taking into account the noise data, the adequate beam model, and taking the maximum tensile and compression strains of concrete and steel its damage criteria, two levels of ground acceleration can be determined, namely the Seismic Thresholds of Elasticity and of Yielding. Quantify the levels that onset the structural damages and the plastic hinge may be a useful tool for vulnerability diagnosis.