Max headroom

Construction of the diaphragm walls for a tunnelled section of the new Tugun Bypass in Queensland, Australia is about to be completed on time despite tight restrictions on working height.

The new 8.5 km road will relieve congestion where traffic on the Pacific Highway and the Gold Coast Highway converge, close to the cities of Tugun and Cololangatta. But the new route passes close to then end of the Gold Coast Airport runway, which meant that strict height restrictions had to be imposed on the construction work.

Queensland-based Piling Contractors called on help from Bauer Foundation Australia to carry out the challenging foundations work. Due to the location of the tunnel alignment under the flight path into the airport, a height limit as low as 6.2 m was placed on the work.

Bauer used a Liebherr HS852 Grab Low Headroom fitted with a CBC 25 Cutter and specially made tremmie pipes to build the 16500 m² diaphragm wall and 60 barrettes. Work on site started in May this year and is due to be completed at the end of this month. According to the site team, the project has gone well and the only difficulty encountered on site was installing the reinforcement cages in 4 to 6 m sections.