Enrichment of seismic ground motion databases using Karhunen–Loève expansion

Abstract

SUMMARY Best estimate seismic analysis are generally based on time‐domain simulations of structural responses. The seismic load is then modeled by a stochastic process representing ground motion. For this purpose, the analyst can use recorded accelerograms or work with synthetically generated ones. The number of ground motion time‐histories available for a given scenario and site condition is limited and generally not sufficient for carrying out more advanced probabilistic structural response analysis. It is then necessary to have at our disposal methods that allow for generating synthetic accelerograms that realistically characterize earthquake ground motions. However, most of the methods proposed in literature for generating synthetic accelerograms do not accurately reproduce the natural variability of ground motion parameters (such as PGA, cumulative absolute velocity, and Arias intensity) observed for recorded time histories. In this paper, we introduce a new method for generating synthetic ground motion, based on Karhunen‐Loève decomposition and a non‐Gaussian stochastic model. The proposed method enables the structural analyst to simulate ground motion time histories featuring the properties mentioned above. To demonstrate its capability, we study the influence of the simulation method on different ground motion parameters and on soil response spectra. We finally compute fragility curves to illustrate the practical application of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.

A semi-active controller tuning and application to base seismically-isolated structures

“…• even if earthquakes are known to be unpredictable, try to use explicit mathematical models ofẍ g (t), the socalled artificial signals [19], based on some a priori knowledge, e.g., semi-empirical laws related to some local geographical sites, • use available past records of signalsẍ g (t) and compute numerically the solutions of equation 3and use it in (2) to get approximated values. Both situations emphasize the difficulty to construct a general controller based on floor spectrum.…”

New insights in the analysis of the structural response to response-spectrum-compatible accelerograms

“…The number of methodologies proposed up to now in the last three decades to simulate artificial response spectrum compatible accelerograms in addition to the alternative simulation techniques compatible with database of earthquakes (see e.g. [26] and/or site characteristics (see e.g. [19] testifies the interest of the scientific community in this topic.…”

Time-Frequency Energy Distribution of Ground Motion and Its Effect on the Dynamic Response of Nonlinear Structures

“…For the structural seismic response analysis, various studies have been taken to model and simulate the non-stationarity of earthquake ground motion. The studies concentrate on temporal non-stationarity and various temporal non-stationarity models [10][11][12][13][14] have been proposed to describe earthquake ground motion. However, only temporal non-stationarity of earthquake ground motions cannot fully explain the structural response under earthquake ground motion.…”

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