M. Khanzadi, G. Ghodrati Amiri, G. Abdollahzadeh Darzi,
Volume 5, Issue 1 (March 2007)
Abstract
According to performance-based seismic design method by using energy concept, in this
paper it is tried to investigate the duration and damping effects on elastic input energy due to strong
ground motions. Based on reliable Iranian earthquake records in four types of soils, structures were
analyzed and equivalent velocity spectra were computed by using input energy. These spectra were
normalized with respect to PGA and were drawn for different durations, damping ratios and soil
types and then effects of these parameters were investigated on these spectra. Finally it was
concluded that in average for different soil types when the duration of ground motions increases,
the input energy to structure increases too. Also it was observed that input energy to structures in
soft soils is larger than that for stiff soils and with increasing the stiffness of the earthquake record
soil type, the input energy decreases. But damping effect on input energy is not very considerable
and input energy to structure with damping ratio about 5% has the minimum value.