Análisis del espectro de fourier de registros sísmicos en función del ángulo de orientación del sensor.

Abstract

The Fourier spectrum is a method to analyze the frequency content of a seismic record and thus, observe the dominant frequencies of a signal. The dominant frequencies of a seismic record may give information about the characteristics of ground, relating these to the fundamental period of vibration of the ground. Generally, this analysis is done, individually, to the two horizontal components of a seismic record. Preliminary studies have shown that, in some cases, the individual analysis of the horizontal components might give inconsistent results, resulting in completely different fundamental periods of each horizontal component. Unless a significant landform locates near the accelerographic station, the fundamental period would be expected to be independent of direction of analysis. This research focuses on the study of the dominant frequencies (or periods) of vibration of horizontal components of seismic records, in such a way that these are independent of the analysis direction to estimate a “unique” dominant period of vibration of the ground for each accelerographic station. In order to further analyze the dominant frequencies of ground motion records, this work proposes to study the Fourier spectrum of seismic records for several rotation angles and compare these with the results using only the horizontal components (East-West and North-South).