Unearthing Clues to Reduce the Devastating Effects of Earthquakes: The Hilbert-Huang Transform

摘要

In this paper the use of the energy-time-frequency representation, the Hilbert-Huang Transform HHT, for the decomposition and characterization of seismic ground response signals, is discussed. The HHT, integrated by the Empirical Mode Decomposition (EMD) and the Hilbert Transformation (HT), enables engineers to analyze non-stationary oscillation systems and to obtain more detailed intensity descriptions on time-varying frequency diagrams. The advantage of the HHT over other representations is its sharp intensity-localization properties in the time-frequency plane. This paper first provides the fundamentals of the HHT method, and then uses them to analyze recordings of Mexico City soft-soil deposits, indicating that the HHT method is able to extract some motion characteristics useful in studies of seismology and geotechnical engineering, which might not be exposed effectively and efficiently by other conventional data processing techniques.