Condor Tower ($50m)
Condor Tower, completed in June 2008, was a technically challenging project requiring unique engineering solutions. The client's brief was to vertically extend an existing 9 storey concrete framed building to 29 storey's in height. In conjunction, an 11 storey building was constructed on an abandoned site to the rear of the tower building.
Condor Tower, St Georges Terrace
Major engineering issues involved strengthening of the tower foundations with a partially piled raft and forming the new raft foundation around existing pad footings supporting the 9 storey building. Stiffening of the existing structure to cater for the considerably larger loading conditions of a 29 storey tower also provided challenges.
Constructability played a critical role during design. The physical constraints of working between floor levels meant traditional methods of construction were often not appropriate.
Pritchard Francis completed detailed finite element design models of the structure to assist in design. Close interaction was maintained with the geotechnical consultants to ensure raft and pile designs were appropriate for the varied founding soils below the site. The final structure comprised an insitu concrete stiffened 9 storey concrete frame, precast external concrete panels with insitu concrete permanent form internal walls. Floor slabs utilised precast planks with an insitu topping.
Condor Tower, Hay Street Building
Consisting of 4 split levels of basement carparking and 7 levels of mixed commercial and residential, this building also presented unique challenges in design and construction.
An existing 3 storey deep excavation provided the base for this new development. Existing perimeter diaphragm walls propped at regular centres dictated construction sequencing. Pritchard Francis in close liaison with the geotechnical consultant developed detailed sequencing drawings that allowed for construction to proceed in a practical yet safe manner. Building support varied using the existing diaphragm walls, secant pile walls, raft slab and traditional bored piles.
Insitu concrete columns and slabs formed the basis of construction up to first floor level. Above this, a mix of insitu slabs and precast floor planks with topping was then employed with precast concrete external panels and insitu concrete permanent form internal walls.