Effect of ground motion duration on earthquake-induced structural collapse

Although the influence of ground motion duration on liquefaction and slope stability is widely acknowledged, its influence on structural response is a topic of some debate. This study examines the effect of ground motion duration on the collapse of reinforced concrete structures by conducting incremental dynamic analysis on nonlinear multiple-degree-of-freedom models of concrete frame buildings with different structural properties. Generalized linear modeling regression techniques are used to predict the collapse capacity of a structure, and the duration of the ground motion is found to be a significant predictor of collapse resistance. As a result, the collapse risk of the analyzed buildings is higher on being subjected to longer duration ground motions, as compared to shorter duration ground motions having the same ground motion intensity. Ground motion duration affects the collapse capacity of highly deteriorating (non-ductile) and less deteriorating (ductile) concrete structures. Therefore, it is recommended to consider the duration of the ground motion in addition to its intensity and frequency content in structural design and assessment of seismic risk.