عنوان مقاله [English]
In this study, the role of input motion characteristics on the amount of residual settlement of shallow foundations relied on liquefiable soil is investigated. First, two-dimensional numerical model is created using finite difference software FLAC-2D, and the UBCSAND constitutive model. After verification of the numerical model with the results of a centrifuge test, behavior of foundation is investigated under different earthquake loadings. To evaluate the effect of the input motion characteristics on foundation settlement, three records from Irpinia 1980, Northridge 1994, and Landers 1992 earthquakes are used. The frequency contents of these records are considerably different. These records are scaled to five levels of PGA (including 0.05g, 0.1g, 0.2g, 0.3g, 0.45g) to be used in the analyses. The results of the analyses demonstrate that the amounts of foundation settlement for the same PGA in three records are considerably different. Therefore, the use of PGA alone might be insufficient to predict the amount of foundation settlements. This fact is shown in Figure (1a). Figure (1b) illustrates the amounts of foundation settlement against the mean period of records at different PGA levels. It is observed that the mean period of records which indicates their frequency content, has a significant influence on the values of foundation settlements.