Project: SYDNEY HARBOUR BRIDGE - STRUCTURAL INVESTIGATION

CLIENT: RTA (now RMS)

COMPLETION: 2004

As requested by RTA (now RMS), a non destructive structural investigation of the Sydney Harbour Bridge Facades at No. 3 Cumberland Street was carried out in April 2004. The areas investigated were the front elevation adjacent to Bridge Climb Facility and the rear elevation of the bay on the west side. Each façade is approximately 30m long and 18 m high and encompasses the arch fascias, the underside face of the arch, the infill walls above the arch, the two piers and the parapets.

A radar gram profile of the subsurface was plotted from the impulse radar commissioned for continuous scans along the traverse across the surface. The high frequency radar was set to scan to a depth of up to 400mm.

The investigation has recovered internal information from a number of different levels. The information includes the cover to the reinforcement for protection purposes, delamination of the render from the internal structure, anomalous responses related to variations in the either internal masonry or mass concrete condition in terms of voiding, honeycombing or deterioration in structural integrity of the internal materials.

Following the radar profiling, an extensive tap test was carried out on both facades to locate areas of druminess that are indicative of delamination and this was used to schedule removal of debonded concrete considered at risk of falling from the structure.