ENGINEERING FAILURE ANALYSIS, cilt.18, sa.2, ss.572-581, 2011 (SCI-Expanded)
The base floors of the existing buildings are generally arranged as garages or offices. No walls are built in at these floors due to its prescribed usage and comfort problems. But upper floors do have walls separating rooms from each other for the residential usage. In these arrangements, the upper floors of most buildings are more rigid than their base floors. As a result, the seismic behaviors of the base and the upper floors are significantly different from each other. This phenomenon is called as the weak-storey irregularity. Weak stories are subjected to larger lateral loads during earthquakes and under lateral loads their lateral deformations are greater than those of other floors so the design of structural members of weak stories is critical and it should be different from the upper floors.