The West Gate Tunnel Project will deliver a vital alternative to the West Gate Bridge, providing a much needed second river crossing, quicker and safer journeys, and remove thousands of trucks from residential streets.

The project will link the West Gate Freeway at Yarraville to the Port of Melbourne and CityLink at the Docklands via twin tunnels beneath Yarraville and an elevated Footscray Road.

The elevated road includes 300 piles of variable height. The piles have been precast in multiple segments, close to the site. Vertical post-tensioning bars assembly together all the segments of each pile.

This construction method of piles is more and more common but requires an impeccable preparation, both in terms of method statement and products definition. Each detail is fundamental for the success of the installation.

Dextra supplied Freyssinet with more than 1,000 tons of Freyssibar+ systems, grade 930/1080 MPa, with nominal diameters of 72mm and 55mm, and 7,500 anchorages for vertical permanent application.

With a close cooperation between DEXTRA, Freyssinet back-office (Technical Department and Freyssinet products company) and the job site staff (Freyssinet Major Project and Freyssinet Australia), the post-tensioning system has been perfectly adapted to the needs of the project.

The bar diameters, steel grade and the design of the anchorages have been validated through qualification tests according to Australian Standards, demonstrating the performance of the system.

This bar system can be used for post tensioning, prestressed ground anchors and any application involving temporary or permanent tie-rods, lifting, suspension, prestressed splices, etc.

Major project construction started in January 2018.

Doha Link is a marine bridge project currently being built West of Kuwait City. It will ultimately be connected to Main Causeway Across Kuwait Bay, another sea link project North of Kuwait City, which connected make together the Jaber Causeway sea link, one of the largest civil engineering project ever built in the Middle East.

The Doha Link stretches West of Kuwait City, It will ultimately solve traffic congestion and offer a direct itinerary thanks to a 7.7km bridge structure built on shallow waters across the Kuwait Bay.

Rebar splicing solution

Dextra has been involved in the early stage of the construction project to provide a technical solution for the splicing of the very large rebar cages making the onshore and offshore foundation piles.

Rolltec® couplers for large diameter rebar (32, 36 and 40mm) were used for the connection of cages and piers. Two grades of rebar are used across the project: ASTM Grade 60 and Grade 80. Rolltec being compatible by design with the higher ASTM Grade 80, same couplers may be used on all applications, simplifying stock keeping.

In addition, smaller diameters couplers for rebar 12mm and 16mm were used for the superstructure and the footing of light poles

One of the main advantages of Rolltec for remote projects its very light machine set up. Rolltec is supported by a single one-man machine, offering a high level of productivity. Because the equipment is relatively small and the rebar preparation efforts were taking place simultaneously on both sides of the sea link construction, Dextra dispatched up to 4 machines on each side of the project to support the piling efforts.

Sonitec tube solution

With large piles of 2.5m diameter and 60m depth in average, it was compulsory for GS E&C to conduct sonic logging tests to examine the integrity of concrete piles, requiring to install 8 tubes in each cage.

To achieve very long tube length and optimize cage preparation output, Dextra Sonitec was the preferred choice of the contractor. Thanks to its light weight and unique Push-Fit® connection feature. Sonitec provides enough flexibility during the cage construction, lifting and assembly of the cage, and remove needs for additional time-consuming welding operations.