Role of conditioning intensity measure in the influence of ground motion duration on the structural response

Although several research studies have examined some effects of ground motion (GM) duration on the structural responses, many questions in this field remain unexplored and unaddressed. One area that remains a topic of debate in this field is that no outcomes can be found with regard to the effect of GM duration on structural responses when considering different choices of conditioning intensity measures (IMs). This study examines the role of the conditioning IM in the degree that GM duration influences the structural responses. To this end, the seismic demand in three different structural systems from low- to high-rise buildings are estimated using multiple stripe analyses subjected to different sets of GMs from shallow crustal seismic zone. It is found that duration of GMs from shallow events affects the structural response but not as much as that reported for GMs from subductions events. The results also reveal that the importance of GM duration mainly depends on the considered conditioning IM. Specifically, GM duration does not substantially affect the structural responses in terms of probability of collapse if peak ground acceleration, peak ground velocity, spectrum intensity, spectral acceleration at higher modes are implemented as the conditioning IMs. On the other hand, in the case of cumulative absolute velocity and spectral acceleration at the fundamental and lengthened periods, the structural responses are considerably affected by GM duration.