Shear‐controlling rocking‐isolation podium system for enhanced resilience of high‐rise buildings

Abstract

AbstractRapid urban growth has been paired with a rapid increase in the demand for high‐rise buildings, and has accelerated the need for developing more resilient high‐rise buildings in earthquake‐prone regions. Current best practices for the seismic design of high‐rise buildings follow a performance‐based design approach that allows the designer to use innovative structural systems, select performance objectives, and verify seismic performances targeted at multiple levels of seismic intensity. As shortcomings in conventional code‐designed high‐rise buildings continue to be revealed by strong earthquakes, the importance of more resilient high‐rise systems is increasingly evident. Several high‐performance systems have been proposed to limit the excessive seismic demands attributed to higher‐mode effects in high‐rise buildings. However, these systems still face design challenges associated with distributed damage and residual deformations. This paper proposes a novel self‐centering base mechanism for high‐rise buildings that independently limits both shear forces and overturning moments at the base to mitigate higher‐mode effects, while eliminating residual deformations and controlling concentrated stresses within the structure that otherwise would need to be designed for. The schematic overview of the proposed system is first introduced, followed by the detailed design of a physical embodiment developed based on a reference 42‐story RC core wall building. Results of a numerical case‐study comparison confirm that an enhanced seismic performance is achieved through the proposed system with minimum damage and negligible residual deformations even following major seismic loading. The proposed system, with further investigations, also has the potential to be applied to a wider range of structural systems.