E. Safak, DETECTION AND IDENTIFICATION OF SOIL-STRUCTURE INTERACTION IN BUILDINGS FROM VIBRATION RECORDINGS, Journal of structural engineering, 121(5), 1995, pp. 899-906
Citations number
11
Categorie Soggetti
Engineering, Civil","Construcion & Building Technology
Soil-structure interaction (SSI) can significantly alter the character
istics of recorded motions in buildings. The dominant frequency record
ed in a building subjected to SSI is always smaller than the dominant
frequencies of the fixed-base building, and of the foundation when no
building is present. A building with SSI is a noncausal system because
of the coupling between the motions of the foundation and the superst
ructure. The presence of SSI can be detected by investigating the caus
ality of the building's impulse response. For causal systems, the ampl
itudes of the impulse response function at negative times are zero, wh
ereas for noncausal systems they are comparable to those at positive t
imes. The identification of SSI refers to extracting natural frequenci
es of the fixed-base building and the foundation from the recordings o
f the foundation and upper stories. The ratio of the Fourier amplitude
spectrum of the top-story accelerations to that of the foundation acc
elerations permits the identification of the natural frequency of the
fixed-base building. Two examples confirm the validity of the suggeste
d methods. The first example involves a 10-story simulated building an
d its calculated response, whereas the second example involves a 30-st
ory real-life building and its recorded response during a large earthq
uake.