The Effect of strong motion duration on pounding of steel moment frame building

Usually during moderate and strong earthquakes, if the space between the adjacent structures is not enough, structural pounding will occur which is due to the out-of-phase vibration of the structures regarding the differences in dynamic properties of the structures. Different factors contribute in the state of structural pounding, and researchers have already studied several factors including the space between two structures, the type of pounding, force transmission means, reducing the pounding damage and etc. Record is one of the factors which can affect the structural pounding, and one of the most crucial parameters of record is strong ground motion duration which its analysis is very important in the quality of structural response.In this study, effect of strong ground motion duration on the adjacent structural pounding is investigated. To do so, steel moment resisting frames in 5, 8 and 12 floors are designed which are paired together in three forms of 5-8, 5-12, and 8-12 models for nonlinear time history analysis. In this analysis, 15 records that include three intervals for strong ground motion duration are being implemented (0 to 10 seconds, 10 to 30 seconds, 30 seconds and more). Besides, in order to obtain the pounding force between structures, linear elastic elements are used in floor levels.Results show that in structures in which the space equal to 1% of their heights are not considered, with increasing the strong ground motion duration, maximum structural pounding will also increase with a smooth gradient, and for the structures with space equal to 0.5% of their heights, this increase rate is more compared to the structures with no space.