Metronet Project – Thornlie-Cockburn Link

Design

• Various height retaining structures across multiple scenarios (supporting existing structures, services protection, coffer dams to hold water back)

Works

• Installation of permanent galvanised noise wall posts for the new noise walls along the rail line
• Installation and removal of temporary sheet piles across multiple locations along the site
• Installation of permanent galvanised retaining sheet pile walls
• Installation of temporary and permanent circular sleeves for services protection

Challenges

• The project installed noise wall posts amongst critical electrical infrastructure and in some cases required temporary sleeves to be installed prior to the galvanised post being installed. The temporary sleeves were installed as part of the service location and identification works and then built up to allow the Abi Rig access to install the posts in the sleeves. The sleeves were then removed by the rig once the posts were installed.
• Installation of temporary sleeves were used to help install thin walled permanent sleeves for communications towers. The location of the communications towers and the collapsing nature of the soil did not allow conventional piling methods to work. Using a temporary sleeve to install a permanent one also saved costs to the project.
• A new pedestrian bridge at Cameron St adjacent to a waterway required sheet piles to hold water back and allow access to build the structure. The sheet pile removal process was logistically difficult due to access restrictions and our crane mounted hammer was used to remove the sheet piles.