Design and Construction of High-Performance Long-Span Steel Transfer Twin Trusses Applied in One Hospital Building in Hong Kong

Long-span steel trusses are increasingly used in high-rise buildings to replace reinforced concrete thick transfer plates due to their light weight but high load-bearing capacity. To support multiple stories above the steel transfer trusses, a comprehensive method based on second-order direct analysis has been applied for design optimization of long-span steel transfer trusses in one hospital redevelopment project in Hong Kong. In the project, several 35 m long-span steel transfer trusses are adopted at the 3rd to 5th floors to support the upper 15-story reinforced concrete structure. Innovative technologies such as integrated global and local optimization and integrated design and construction have been explored and made to achieve better uniformity and compatibility in structure. In particular, twin trusses with better structural performance, less fabrication cost and ease of constructability are studied and finally adopted in primary trusses to replace the original scheme of single trusses. The optimal scheme has brought both cost and time saving in fabrication, construction, operation and maintenance stages.