NONLINEAR SOIL BEHAVIOR IN THE NEAR-FIELD; A CASE STUDY ON THE RECENT IRANIAN ACCELEROMETRIC DATA

The nonlinearity of soil behavior in the near-field during the strong ground motion is of great interest among the strong motion researchers in the recent years. In this paper, the relationships between the predominant periods and the natural periods are developed in order to obtain the limit of the nonlinearity and the near-field area. Finally, it is suggested that the limit of ۰.۳۳g for the beginning of nonlinearity it: the Manll earthquake.