Influence of Ground Motion Variability on Design Spectra in Areas of Low to Moderate Seismicity

This paper examines the sensitivity of uniform hazard response spectra to the variability of the ground motion attenuation in areas of low to moderate seismicity. The variabilities of a number of published attenuation relationships are examined. Many of these relationships show that the standard deviation tends to increase as the natural period increases and some show a tendency for the standard deviation to reduce as the earthquake magnitude increases. These published works tend to be derived from earthquake data for areas of high seismicity and therefore the paper includes a critical review of what values of standard deviation are appropriate for regions of low to moderate seismicity