Advances in Structural Engineering Research
339654 - The Influence of Non-Spectral Intensity Measures on the Structural Responses
Friday, April 20
3:30 PM - 5:00 PM
Although it is well acknowledged that the severity of earthquake ground motions (GMs) can be categorized considering different features of GMs, non-spectral features of GMs (e.g., GM duration) are not explicitly considered in seismic design requirements. This study examines the impact of neglecting non-spectral parameters of GMs on the intensity- and risk-based structural responses. The structural responses of three steel moment resisting buildings in terms of maximum inter-story drift ratio and maximum floor acceleration are compared when subjected to different ensembles of GMs, which are selected based on the generalized conditional intensity measure (IM). It is found that neglecting non-spectral IMs could induce a bias up to 50% in the structural responses depending on the considered building and damage metric. Furthermore, the findings confirm that GM duration in terms of significant duration even in case of shallow events is an important parameter to be incorporated in GM selection. The induced error in the risk-based structural responses due to neglecting GM duration could vary up to about 41% depending on the applied conditioning IM. When it comes to the intensity-based assessments, 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 collapse capacity is considerably affected by GM duration. Finally, this paper will provide several suggestions to be used to modify the computed structural responses resulted from a set of GMs that it is selected based on ignoring non-spectral parameters of GMs.