Rehabilitation of steel concentrically braced frames with rocking cores for improved performance under near-fault ground motions. Issue 6 (June 2017)

• Record Type: Journal Article
• Authors: Qu, Bing; Sanchez-Zamora, Francisco; Pollino, Michael; Hou, Hetao
• Is Part Of: Advances in structural engineering. Volume 20:Issue 6(2017)
• Page Start: 940
• Page End: 952
• Publication Date: 2017-06
• Subjects: concentrically braced frame -- near-fault -- rehabilitation -- retrofit -- rocking -- seismic performance; Structural engineering -- Periodicals; Construction, Technique de la; Structural engineering; Periodicals; 624.1
• DOI: 10.1177/1369433216668101
• Languages: English
• ISSNs: 1369-4332

Abstract

This article focuses on evaluating the adequacy of a seismic rehabilitation technology which adds rocking cores to deficient steel concentrically braced frames in near-fault regions. Two demonstration buildings were rehabilitated with the technology. Seismic performance of the rehabilitated buildings was evaluated through numerical simulations. Analysis results suggest that the code-compliant concentrically braced frames may be vulnerable to collapse under the fault-normal components of the near-fault ground motions, approximately having a probability of exceedance of 10% in 50 years. It is found that the Rocking Core technology is effective in reducing the inter-story drift responses of the demonstration buildings under near-fault earthquakes. The rehabilitated systems can further benefit from the use of hysteretic energy dissipating links between the rocking cores and existing concentrically braced frames. This article also addresses the influence of the rocking cores on modal properties of the rehabilitated buildings. It is found that the rocking core with moderate stiffness does not significantly alter the modal properties of a rehabilitated concentrically braced frame.