- © 2014 by the Seismological Society of America
Online Material: Table describing reinforced concrete buildings measured in Lima, Peru.
The easiest building parameter to determine is the elastic fundamental resonance period, or its inverse, the fundamental frequency, preferentially used in seismological studies. This period/frequency is directly related to the building stiffness and can be linked to external inputs (acceleration, soil response, etc.), internal history (construction material and quality, structural design, seismic history, etc.), and more complicated factors such as soil–structure interaction. This frequency is generally obtained through building modeling for the most recent structures but is much more complicated or even impossible to determine for old buildings, the blueprints of which are generally not available.
This crucial parameter can be directly assessed in situ using (1) dynamic methods, such as unbinding, harmonic excitation, or percussion (e.g., Trifunac, 1972; Boutin et al., 2001; Crowley and Pinho, 2004) that are expensive, tedious to install, and generally disturbing, (2) traditional earthquake records (e.g., Dunand et al., 2006; Todorovska, 2009), or (3) passive ambient vibration recordings (e.g., Carder, 1936; Trifunac, 1972; Trifunac et al., 2001a,b; Farsi and Bard, 2004; Michel et al., 2008; Farsi et al., 2009; Michel, Guéguen, El Arem, et al., 2010) or other passive method such as coherent Light Detection and Ranging measurement (Guéguen et al., 2010). The most reliable building dynamic parameter estimates are obtained from earthquake records, but this type of data is quite difficult to obtain, very expensive because of the seismic network deployment and maintenance, and heavily dependent on earthquake occurrence, which may be quite a problem in low‐to‐moderate seismic regions.
Ambient vibration recordings performed on building are recognized to provide larger fundamental frequency than those used for earthquake engineering purposes. In spite of this, ambient vibration studies allow to collect numerous data, allowing statistical processing, which …