A Compact Probabilistic Representation of the Chi-Chi Earthquake Ground Motion - Reinforced Soil Engineering: Advances in Research and Practice - page 468

2 A Compact Probabilistic
Representation of the Chi-Chi
Earthquake Ground Motion
A. W. Smyth
Columbia University, New York, New York, U.S.A.
S. F. Masri
University of Southern California, Los Angeles, California, U.S.A.
C. H. Loh
National Center for Research on Earthquake Engineering, Taipei, Taiwan
ABSTRACT
A previously developed procedure to condense nonstationary random excitation
data to perform analytical random vibration response studies is used to
investigate the 1999 Chi-Chi (Taiwan) earthquake, recorded ground motions.
An ensemble of free-field ground motion records from the main earthquake
event collected from locations near the Chelungpu fault were used to create the
second, order statistics of the earthquake excitation. Using the compaction
procedure, the covariance matrix of the excitation process was spectrally
decomposed by the Karhunen-Loeve expansion. The dominant eigenvectors,
that is, those with the largest eigenvalues, represent the dominant energy time
histories in the random process and can be used to characterize the dominant
features of the earthquake process. Second-order descriptions of the
transient dynamic response of discrete systems to the compact form of the
earthquake process are obtained. This type of result can be used to facilitate