This paper quantifies the impact of using different ground motion selection methods to evaluate the seismic performance of steel special moment frames. Two methods are investigated: a traditional approach, herein referred to as the PEER method, and a newer approach know as the CMS method. Amongst other differences, the PEER method uses the risk-based maximum considered earthquake (MCER) as the target spectrum, while the CMS method uses the conditional mean spectrum. Two special moment frames (4- and 8-story) designed in accordance with ASCE/SEI 7-10, are used to represent archetype steel frame buildings on the west coast of the United States. The seismic performance of these frames are assessed with the nonlinear dynamic procedure prescribed in ASCE/SEI 41-13, using ground motions selected and scaled in accordance with both methods. The performance of the buildings is evaluated at the Collapse Prevention (CP) performance level for a far-field site located in Los Angeles. The analysis results show that the two ground motion selection methods lead to different structural response predictions, where the ground motions selected and scaled using CMS predicts a better structural performance. These results provide motivation for building standards, such as ASCE/SEI 41, to advocate implementing the CMS method as an alternative ground motions selection approach. The results also shed light on the influence of the ground motion selection method in the design of new buildings using the performance-based seismic design methodology.
Proceedings Title: 16th World Conference on Earthquake Engineering
Conference Dates: January 9-13, 2017
Conference Location: Santiago, -1
Pub Type: Conferences
Ground motion selection, conditional mean spectra, steel moment frame, seismic assessment