Variation of Maximum Inter-Storey Drift for Steel Moment Resisting Frames Considering the Horizontal and Vertical Seismic Components

Steel Moment Resisting Frames (SMRFs) are widely used to resist seismic loads. Different response parameters such as maximum roof drift, Maximum Inter-storey Drift (MID), and local plastic rotations are used to assess their seismic performance. This study investigates the variability of MID at collapse, evaluates the effect of vertical seismic component and identifies the critical floors. A ten storey SMRF was considered as a case study. Incremental dynamic analysis (IDA) was conducted using five different ground motions considering both the horizontal and vertical components. It was observed that the storey experiencing the MID is not always the severely damaged storey. The vertical seismic component significantly increased the column axial forces and the vertical deformations of the beams, and, thus increased the state of seismic damage in the frame. The effect of the vertical seismic component on the MID was also investigated.