Abstract
The soil classification method based on the natural period of the ground is used to estimate the design earthquake at surface. Although the natural period could express a predominant period of earthquake motion if the ground behavior is in region, it cannot take the nonlinear behavior into consideration. So, in this study, the soil classification method for a large-scale earthquake motion was proposed. The proposed method classifies the ground by using both a natural period and the strength of the whole ground. Thereby, the soil classification considering the nonlinear behavior of the ground is possible. The proposed method was applied to the various ground models. It was verified that the coefficient of variance of the structural response decreases significantly by using the propose method compared with the method using only natural period. This method makes it possible to estimate the ground and structural responses more precisely without any supplemental surveys. Furthermore, the proposed method is applicable also to the various earthquake levels. The proposed method is effective as the soil classification method in order to carrying out a rational seismic design and seismic reinforcement.
