The Greenland Centre is an iconic residential tower in the heart of Sydney’s CBD, which set to become Sydney’s tallest apartment building. The project involves the redevelopment of an existing 27 storey building and construction of an additional 37 storeys on top.
The structural frame of the building will feature the construction of a new reinforced concrete tower on top of the steel frame structure of the existing building. The structural design relied upon existing deep steel girders which span across the short span of the building (approximately 23 m) and these are required by the BCA Deemed-to-Satisfy Provisions to be protected with passive fire protection to achieve fire ratings from 60 minutes up to 180 minutes. Given the existing and in-situ nature of these members, protecting them would be problematic for the project team to achieve.
Holmes Fire was engaged to provide specialist structural fire engineering services to rationalise the passive fire protection requirements of the existing steel girders within the retained portion of the building. Advanced finite element analysis was used to demonstrate that the majority of the steel girders did not require any applied passive protection to maintain structural stability for the duration of a credible fire event (including the cooling phase of the fire). This resulted in major savings on site with regards to project timeframes, labour and material costs, and the improved aesthetic and air quality within the space.
The high degree of structural analysis allowed for the robustness of the structural system to be assessed and quantitatively demonstrated, thereby driving the building design forward and providing a defensible process for gaining development approval.