APPLICATION OF STRUT-AND-TIE METHOD ON OUTRIGGER BRACED CORE WALL BUILDINGS

摘要

Outrigger braced core wall structure often forms the major lateral load-resisting system to provide the required moment resistance and lateral stiffness for high-rise buildings and skyscrapers. Due to practical considerations, outrigger braces are usually made of structural steel and cast into the reinforced concrete core walls for the buildings in Hong Kong. The correct structural analysis and design of the connections are vitally important to enable it to carry huge amount of internal forces. This paper aims to enhance practicing engineers to understand the general structural behaviour of outrigger braced core wall system. Strut-and-tie method is applied to analyze the whole lateral structural system. The complete load transfer mechanism between the outrigger brace and the core wall is displayed. Many practical concerns in design including the structural behaviours of different configurations of outriggers, the effect of openings through the core wall adjacent to the outrigger brace, the arrangement of shear studs on outrigger brace and the shear link arrangement in core wall are briefly discussed. Some common deficiencies in numerical modelling of this system are pointed out and a set of recommendations related to finite element modelling is given for reference.