Characteristics of Ground Vibrations Induced by Teleseismic Earthquakes and Their Impact on Vibration-Sensitive Facilities

The ground vibrations observed in Taiwan during three teleseismic earthquakes in 2011 by broadband seismometers near major science parks were investigated. Their frequency content was exhibited via spectral analysis, and their effect on structures was examined by response spectra. To assess their possible impact on vibration-sensitive facilities, three vibration criteria in terms of velocity or displacement were utilized. Their predominant frequencies were between 0.04– and 0.16 Hz and somewhat dependent on focal depth and site geology, and they were therefore only influential to very long-period structures. However, the vibration levels exceeded the adopted criteria to some extent, especially at the softer site.