Shaking table test of a supertall building with hinged connections connecting a gravity load resisting system to a lateral force resisting system

Abstract

Considering a common practical engineering structure, namely, a concrete-filled steel tube (CFST)-steel frame-core tube structure, the rigid connections between the steel beams and the columns/core are modified into hinged connections. In this manner, a 1:40 reduced scale specimen representing a real supertall building that consists of 68 storeys and four underground storeys is constructed for a shaking table test to study the seismic performance of the structure. Numerical simulations are performed to analyse the time history responses of a CFST-steel frame-core tube structural system with three different connection configurations: hinged joints, rigid joints and strengthened layers (which are defined as storeys equipped with outrigger and belt trusses to limit inter-storey drift). The results indicate that the earthquake damage to the structure mainly occurs in the lower storeys at the connections and the corners of the core tube. The seismic response of the structure under the long-period ground motion is significant. The largest inter-storey drift ratio of the core tube reaches 1/26, which exceeds the threshold of the frame-core tube structure system in the Chinese Code by a factor of 3.8. Both the rigid joints and the strengthened layers can reduce the inter-storey drift ratio of the structure.

Keywords

• cfst-steel frame-core tube structure
• hinged connection
• shaking table test
• seismic performance
• numerical simulation