CPB Contractors has made significant progress on the Sydney Metro – Western Sydney Airport Surface, Civil and Alignment Works (SCAW) project with the recent completion of construction on one of the most complex sections of the new 23-kilometre alignment. Delivery of this metro section involved building an elevated viaduct over the Warragamba pipelines, which transport 80% of Sydney's water from Warragamba Dam to filtration plants for treatment each day.
Working in coordination with WaterNSW to ensure minimal impact on water supply, the CPB Contractors and United Infrastructure teams methodically constructed a two-span section of elevated viaducts in one month.
CPB Contractors Project Manager Vishal Khosla explains the efficiency and safety-focused process the project team used to deliver this complex portion of works.
"We scheduled this highly technical task during Sydney's cooler months as water demand is lower... This allowed the WaterNSW crews to safely depressurise and deactivate one pipeline at a time, enabling the installation of 26 precast segments up to 15.3 meters above the pipelines," adds Vishal.
The preparation for constructing the viaducts involved strengthening the ground around the pipelines and conducting thorough vibration and settlement monitoring throughout construction. Central to the strategy for protecting the integrity of the pipelines was the project team's innovative use of Underslung Temporary Beams (UTBs). These purpose-built UTBs were used to support the segments while our crews lifted and positioned the precast segments, eliminating risks to the pipelines below.
In a joint venture with United Infrastructure, a consortium of Western Sydney-based companies including Burton Contractors, JK Williams and Mulgoa Quarries, CPB Contractors’ delivery of Sydney Metro’s SCAW project includes:
- 3.5 kilometres of elevated viaduct at Orchard Hills and Luddenham
- 6.7 kilometres of earthworks for track formation
- A 190 metre long rail bridge over the new M12 motorway
- A 20 metre long rail bridge within the airport
- Temporary and permanent access roads
- Bulk earthworks for the stabling and maintenance facility site