Behavior of Irregular RC Structures Subjected to Horizontal and Vertical Seismic Excitations

Abstract

The past earthquakes show that the structures are not designed well to prevent the effect of earthquakes. Irregular structures have become very popular, and they carry a risk of failure during strong ground motions. The aim of this study is to evaluate the behavior of vertical irregular structures when subjected to both components (horizontal and vertical) of seismic excitations. Stiffness and mass irregularities are considered throughout the study. In this study, Four 2D models with 6-storey each were chosen to represent this problem. All the models were analyzed insides SAP2000 V21 software and designed according to ASCE 7-16 seismic code. Analyses were performed using nonlinear time history analysis using Newmark's average method. However, five different ground motions for both components in the near field region were obtained from the PEER website and scaled inside the seismomatch 2020 program. All the frame models are analyzed under two different loading cases: 1) Horizontal Only and 2) Horizontal plus Vertical. The structure's response in the form of maximum inter-story drifts, the axial force of column, joint acceleration, and mass participation ratio are compared under two loading conditions.