The Structural Design of No. 1 O'Connell Street, Sydney

The design and construction of a new high rise office building in the Central Business District of Sydney is described. The building is 38 levels and rises 160 metres above its foundations. The design incorporates an expedited structural system so as to permit work to be carried out on two levels simultaneously. A steel platform was built 22 metres above basement level and temporarily braced. Typical floor construction commenced above the platform while the podium, floors and perimeter walls were being built below. The paper discusses the selection of the structural system.