Mechanism of Collapse of Tall Steel Moment Frame Buildings Under Earthquake Excitation

We expound on the nature of collapse of one class of tall buildings (steel moment frame buildings) under earthquake excitation. Using a parametric analysis of a couple of index buildings subjected to idealized ground motion histories, we establish the ground motion features that cause collapse in these structures. Systematically mapping damage localization patterns, we track the evolution of the collapse mechanism. We demonstrate the existence of a select few preferred mechanisms of collapse in these buildings and describe the associated physics using wave propagation through a shear beam. A simple theory based on work-energy principles can identify these mechanisms