Dynamic Characteristics of Five Buildings During Strong and Low-Amplitude Motions.
Dynamic Characteristics of Five Buildings During Strong
and Low-Amplitude Motions.
Celebi, M.; Phan, L. T.; Marshall, R. D.
International Journal of the Structural Design of Tall
Buildings, Vol. 2, 1-15, 1993.
buildings; damping; earthquakes; frequency; period;
strong-motion; testing; vibration; dynamic
The objectives of this paper are to present  a
comparison of dynamic characteristics of five buildings
determined from recorded strong-motion response data and
from low-amplitude (ambient vibration) tests, and  a
description of the low-amplitude ambient testing and
PC-based data-acquisition approach that is integrated
with the permanent strong-motion instrumentation in the
five buildings. All five buildings are within the San
Francisco Bay area and the strong-motion dynamic
characteristics are extracted from the October 17, 1989
Loma Prieta earthquake response records. Ambient
vibration tests on the same five buildings were
conducted in September 1990. Analyses of strong-motion
response and low-amplitude test data have been performed
by many investigators. The present study differs from
numerous previous investigations because  in this
study, accelerometers in the five
permanently-instrumented buildings were used during the
low-amplitude testing, and  rapid screening of the
strong-motion response data was achieved with a
concerted use of a system identification software. The
results show for all cases that the fundamental periods
are appreciably lower than those determined from
strong-motion response records. The data set collected
during this study is a useful contribution to the data
base of dynamic characteristics of engineered structures
and reconfirms the differences between the dynamic
characteristics identified from storng-motion records
and from low-amplitude tests.