Project Description

17 Spring Street is a 34-storey tower with 4 basements on the fringe of the CBD. The building is bound by adjacent towers with shallow basements. The building is comprised predominantly of apartment floors with retail podiums offering designer brands within reach of the tower’s occupants. The apartments are designed to provide a high-end city lifestyle by offering beautiful interior design, outstanding finishes and breathtaking views.
As the primary structural engineer, Robert Bird Group was involved heavily from the early stages of the project. RBG has worked closely with the client, architect and other key consultants, to create a design that would maximise the output of the site. Following the novation to the contractor, other key constructability challenges were identified based on the site conditions and adjacent structures, where RBG worked diligently with Hacer to provide solutions that mitigated risk and also increased the buildability of the tower.

Project Challenges

• Top down slab: The design top down slab at 17 Spring Street was not only driven by site constraints, but it also had to be shallow to manage with architectural head-heights below.
• Retention against an adjoining high-rise: The temporary stability of an adjacent high rise was managed whilst constructing the retention system. 900 diameter contiguous piles were provided and monitored daily to ensure that minimal and strict movement controls were adhered to.
• Slender tower with eccentric core: An eccentric core within a slender tower meant that careful considerations of permanent tensile actions within some faces of the core needed to be managed.
• Deep Basement: The construction of the deep basement required a coordinated effort with early works contractors, to produce a staged construction utlising soil anchors, that would safely allow an excavation of almost 20m depth.