Architect and Builder April 2020 | Page 48

well as it being positioned above several transfer beams above the deep basement below. Atrium Foof/Façade The atrium roof support structure spans between the two towers with tension rods supporting the hanging 9-storey glass curtain wall as well as the four hanging steel-framed meeting pods. The support girder had specific, carefully considered, camber requirements to ensure deflection into final position as the load from the construction sequence continued to be added. At each stage of sequential loading a survey was conducted on this 48 structural steel structure to compare anticipated movement with the theoretical design values. The design required a 3m deep girder spanning 24.5m with large heavy H sections as members. The resulting weight and the pre-assembled, pre-camber, requirement created challenges in installing this member into place on site. A 180 ton crane was used to lift the 11 ton girder from Oxford Road reaching across the site by 55m to the final installation position. As Rosebank becomes a sought after desti- nation for P grade office developments, 144 Oxford has set the standard for others to follow. 144 on Oxford