Probabilistic seismic analysis of steel moment-resisting frame structure including a damaged column

Abstract

Vehicle collision is occurred in the ground level of buildings accidentally or intentionally. This event is a common scenario of generating structural damages. In some cases, these damages usually have not been retrofitted. Therefore, these initial damages influence on the future behavior of buildings under natural events. In this regard, it is necessary to investigate the performance of buildings with such initial damages during future earthquakes. In this paper, the collapse capacity and endurance duration of steel moment-resisting frame (SMRF) structure with one corner damaged column due to light vehicle impact has been evaluated under seismic excitations. For this aim, an intermediate SMRF with 5-story is modeled in OpenSees software two-dimensionally. Then, the initial damage scenarios are considered with 3 states. The first scenario without considering a damaged column and scenarios 2 and 3 are assumed to have a corner damaged column due to vehicle impact with velocities 60 and 120 km/h, respectively. Moreover, the numerous nonlinear incremental dynamic analyses (IDAs) have been performed under 14 pairs of far-fault earthquake records up to the dynamic instability of the models. Afterwards, fragility curves are utilized in order to specify the collapse capacity and endurance duration of SMRF in three defined scenarios for different performance levels. Finally, the effect of having a corner damaged column is evaluated under selected earthquakes. The obtained results indicated that scenario 3 had a weaker performance compared to other scenarios during seismic records. For instance, in a statistical level of 50%, the values of seismic collapse capacity in scenario 3 is decreased 17% and 41% compared to scenarios 2 and 1, respectively. Also, the new findings showed that endurance duration of scenario 1 was greater than other scenarios. It is increased 28% and 77% versus scenarios 2 and 3, respectively.