عنوان مقاله [English]
One of the main characteristics of the near-fault ground motions is low time interval between horizontal and vertical ground motion peaks, which can be coincidental when the source distance is less than 5 km. Generally, vertical peak ground motion occurs earlier than the horizontal one, thus has a significant effect on the response of the structures. In this paper, the effect of time interval between peak response in the horizontal & vertical components of ground motion is evaluated on the seismic behavior of RC Buildings. In this regard, regular RC buildings (in plan and elevation) with 4, 7, 10, 13, 16, and 20 stories and moment-resisting frame system in the ground type II are analyzed by OpenSees code. Then, the nonlinear static and dynamic analyses were done
under the seven near-fault records, accordingly. These records were selected from the various parts with different magnitudes and frequency contents. The effect of vertical component of ground motion as well as time interval between horizontal and vertical ground motion peaks has been explored on the seismic behavior of RC buildings including column axial forces, lateral displacement, base and story shear force, horizontal period as well as order and pattern of plastic hinge occurrence. Results showed that time interval between horizontal and vertical ground motion peaks has considerable effect on the columns axial force; this effect is higher on the internal columns rather than perimeter columns. It can be explained that the effect of time interval between
horizontal and vertical ground motion peaks on low-rise buildings is higher than those of medium- and high-rise buildings. The effect of vertical component of ground motion on the column axial force variation tends to decrease with the increase of time interval, which, nevertheless, has small effects on the lateral displacement and story shear.