A Pushover approach for bi-directional excitation, including its evaluation for 3D steel building frames

In this paper, the single run modal pushover analysis based on stories shear and torque proposed for asymmetric-plan buildings (STA), is extended to bi-directional simultaneousexcitation. The efficiency of the current 3D pushover procedures extended to bidirectional excitation through nonlinear time history analysis is investigated in here.Studied current procedures for evaluation are: modal pushover analysis, modified modalpushover analysis, practical modal pushover analysis, and multi-mode pushover analysis. Three low-, medium- and high-rise 3-D steel frame buildings with 10% two-wayeccentricity in plan are studied. The selected buildings are under twenty earthquake ground motion records related to SAC project. Final results obtained from mean values of the twenty earthquakes effects are presented in three edges as the mass center, flexibleedge and stiff edge. It is accomplished that the seismic responses estimated by extended STA approach exhibit great accuracy

Keywords:

Pushover , bi-axial eccentricity , bi-directional excitation , Torque , Shear