Seismic Collapse Risk Assessment of Frames with Post-Tensioned Connections and Viscous Dampers

Steel self-centering moment-resisting frames (SC-MRFs) are a class of resilient structural systems that avoid damage in beams and eliminate residual drifts under the design basis earthquake. These systems have been combined with viscous dampers to improve their seismic performance by reducing storey drifts. However, the collapse capacity of SC- MRFs has not been evaluated, since their performance has been only examined for seismic intensities up to the maximum considered earthquake. In this paper, seismic collapse capacity of SC-MRFs with viscous dampers located in the near-fault region is evaluated. The collapse risk of these type of structural systems is assessed through incremental dynamic analysis along with a model that takes into account the near-fault directivity effect in the framework of probabilistic seismic hazard analysis. Results confirm the superior collapse performance of SC-MRFs, compared to that of conventional moment-resisting frames.