NEHRP Clearinghouse

Title
A Study of Power Spectral Density of Earthquake Accelerograms.
File
PB83101014.pdf
Author(s)
Moayyad, P.; Mohraz, B.
Source
National Science Foundation, Washington, DC., June 1982, 312 p.
Abstract
A statistical study is used to estimate a time-dependent power spectral density of recorded earthquake accelerograms. The study assumes that the strong motion segments of accelerograms form a locally stationary random process whose members exhibit a time-invariant frequency. RMS values are correlated with a variable reflecting the four most commonly used design parameters--peak ground acceleration, earthquake magnitude, epicentral distance, and the duration of strong motion. Such correlations will make it possible to estimate a power spectral density for a specific site and earthquake parameters. The estimated power spectral densities are used to predict the response of a single degree of freedom system at several sites. Results are compared with spectral relative displacement, relative velocity, and absolute acceleration. Findings of the study support the viability of using the random vibration theory in earthquake resistant design of structures.
Keywords
Ground motion; Earthquake engineering; Seismic epicenter; Earthquake resistant structures; Seismic design; Earthquakes; Random processes; Random vibration; Power spectral density; Spectral energy distribution; Accelerometers; Power spectra