A Nonstationary Stochastic Model for Strong-Motion Earthquakes

Abstract

A brief review of the available tools in the stochastic process theory to accomplish the primary objectives of this study is presented in , Chapter 2. In Chapter 3 the problems associated with processing of accelerograms and their engineering significance are discussed.Also, in this chapter eight strong-motion accelerograms recorded to date at the West Coast of the U.S. are examined for the fundamental assumption of stationarity.In Chapter k, the selection of a nonstationary filtered shot noise process^ for modeling earthquake motions of the type considered in this study is described.Chapter 5 includes some of the results obtained for the pseudo-earthquakes generated from the stochastic model and their comparison with the real earthquake records.Of the many possible choices of filters only one, namely, a second-order-linear filter has been considered.Also, it must be emphasized that records considered here have been registered on firm ground at moderate distances from the epicenter and no attempt has been made to consider effects of soil conditions of the sites.1,2 Brief Review of Related Works The advances in the probabilistic approach to aseismic design of structures and the aspects of this problem that need major attention have (2) been summarized elsewhere.It can be seen from this survey that although earthquakes are distinctly transient in nature, mosjt of the studies made thus far are based on the assumption that earthquake accelerations can be represented by stationary random processes.Several investigators have