Self-Centering Structures Against Earthquakes: A Critical Review

With critical lessons drawn from past major earthquakes, the engineering community is appealing for a fundamental shift in the existing design philosophy for structures in seismic zones. One strategy is to endow structures with self-centering (SC) capability. While the concept of SC structures is not new, many novel technologies have been recently emerging that are more efficient, compact, and cost-effective; on the other hand, growing controversy and dispute have also been appearing with deepening investigations. This paper presents a critical review of the evolution of SC technologies and systems for both researchers and practitioners, with an emphasis on post-tension (PT), high-performance spring, and shape memory alloy (SMA) strategies. These SC technologies, together with various energy dissipation options, form the basis of a large part of the newly proposed SC philosophies. This review also includes typical SC structural members such as beam-to-column connections, braces, dampers, shear walls, bridge piers, and isolation bearings, followed by a discussion on the dynamic behavior from a system-level point of view. Available design approaches for SC structures are also touched upon, and practical applications that have emerged over the past decades in several countries including Canada, China, New Zealand, and the US are presented. This paper concludes with an executive summary that covers technological advances, knowledge gaps, and future research directions.