Em. Rathje et al., SIMPLIFIED FREQUENCY CONTENT ESTIMATES OF EARTHQUAKE GROUND MOTIONS, Journal geotechnical and geoenvironmental engineering, 124(2), 1998, pp. 150-159
It is often useful in earthquake engineering practice to characterize
the frequency content of an earthquake ground motion with a single par
ameter. Three simplified frequency content parameters are examined: me
an period (T-m), predominant period (T-p), and the smoothed spectral p
redominant period (T-o). These frequency content parameters are calcul
ated for 306 strong motion recordings from 20 earthquakes in active pl
ate-margin regions. These data are used to develop a model that descri
bes the magnitude, distance, and site dependence of these frequency co
ntent parameters, Nonlinear regression analyses are performed to evalu
ate model coefficients and standard error terms. The results indicate
that the traditional T-p parameter has the largest uncertainty in its
prediction, and that previous relationships proposed to predict T-p ar
e inconsistent with the current data set. Moreover, T-m is judged to b
e the best simplified frequency content characterization parameter, an
d it can be reliably estimated.