Extension of STA pushover procedure to bi-directional excitation, considering constant load pattern

The single run modal pushover analysis based on stories shear and torque proposed for asymmetric-plan buildings (STA), is extended to bi-axial asymmetric buildings under bidirectionalsimultaneous excitation. The basic steps of the extended procedure is as same as the original STA other than the load pattern assumed to be constant, and the pushoveranalysis is run in two orthogonal direction separately. Accuracy of the extended STA and modal pushover analysis (MP A) are evaluated through the nonlinear time history analysis (NTHA) of three low-, medium- and high-rise 3-D steel frame buildings. Results indicate precise prediction of seismic responses by extended STA.