Learn about Keller's design and construction approach for a support of a heritage seawall to enable ex-situ remediation of former gasworks contamination.

Photo of HMAS Platypus site

The project

The former HMAS Platypus site, a submarine docking and maintenance facility, was located on land originally reclaimed to service a gasworks that operated through the early part of the 20th Century. As part of the restoration of the foreshore, the site was remediated and it is now accessible to the public.

The challenge

Design and construction of Jet Grout columns to reinforce the historic sea wall, and to form a gravity retaining structure that permitted excavation to about 7m depth, as much as 5m below sea level. In addition, Jet Grouting around an historic structure to underpin its foundations, as well as internal jet grouting to stabilize the sub-floor materials.

The solution

Keller utilised a number of drill rigs set up for Jet Grouting, including a limited access rig that proved essential inside existing buildings. The grout mixing equipment was set up on the old wharf, and cement shipments and most deliveries arrived by barge, so inconvenience to neighbours was mitigated as far as possible.

Project facts


Thiess Pty Ltd

Keller business unit(s)

Keller Australia

Main contractor(s)

Sydney Foreshore Authority