چكيده لاتين :
strong motions database. This database comprises more than 6000 well recorded
three-components data (analog and digital) for which the teleseismic source
parameters were available, or calculated by the records. Here, the one-step
regression method is used in order to develop the attenuation model. The spectral
values of the recorded strong motions in Iran are used to derive the empirical
attenuation laws for different response spectral ordinates at different site
conditions. The empirical relationships are established for the spectral acceleration
as the function of moment magnitude, hypocentral distances, and constant
parameter representing the site conditions. The data set consists of 87 three
component accelerograms, all recorded in 1975-2003. In this paper the attenuation
coefficients are in general accordance with the previous attenuation coefficients
established for Iran. However, the spectral values, obtained here, are greater
in comparison with those gained by the previous studies (1999 and 2006). The
difference might be due to selecting greater motions, recorded in the distances
nearer to the seismic source.
