Abstract
The earthquake intensity to structure should be evaluated in consideration of the frequency characteristics of earthquake motions, the effect of plastic deformation of structure and so on. So a scale which is determined uniquely for the earthquake ground motions should not be used for the evaluation of earthquake intensity to all structures, but simple scale may be useful from the point of view of structural engineering if the scale is used in the reasonable application range. In this paper, maximum acceleration, maximum velocity and maximum displacement of earthquake ground motions, which are determined by filtering the long period components of earthquake ground motions because of their little effect to structure, are used as a scale of earthquake intensity, and their reasonable application range are shown based on the correlation coefficient between the non-linear response of one mass system due to earthquake motions and the maximum amplitude of them. As a conclusion, the characteristics of structure should be considered largely with respect to its stiffness when maximum amplitude of earthquake ground motions are used as a scale of earthquake intensity to structure. That is, maximum acceleration may be used as a scale for the evaluation of earthquake intensity to the structure of shorter period than 0.3 seconds, maximum velocity is for the structure of the period from 0.3 seconds to 1 second and maximum displacement is for longer period than 1 second.
