Legacy Way Tunnel, Brisbane
Creating efficiencies in smoke duct corbel anchorage through new technologies
Legacy Way in Brisbane is a 4.6 kilometre tunnel that connects the Western Freeway at Toowong with the Inner City Bypass (ICB) at Kelvin Grove.
The tunnel, constructed by Transcity JV, incorporates a smoke duct above the roadway for extraction in the event of a fire. This duct is formed from pre-cast panels, supported by a continuous corbel.
Construction of the smoke duct and corbel was the most extensive use of anchors in the tunnel's fit-out. The anchors consisted of 103,200 N20 reinforcing bars bonded 270 millimetres into the segment lining. Reinforcement was tied to these anchors before the corbel was cast.
Meetings between Hilti and Transcity JV design and construction teams, along with subsequent evaluations and assessments, identified the Hilti HIT-HY 200-R SafeSet system with the TE-YD hollow drill as fulfilling the stringent performance requirements. This system is also significantly more productive than traditional drilling and anchoring methods.
The faster drilling speed and elimination of anchor hole cleaning resulted in time savings of up to 90 seconds per hole, as well as a dust-free working environment. There was also an assurance that the anchor holes were always clean and ready for injection of the HIT-HY 200-R resin. Hilti combihammer drills and vacuums were secured to Herrenknecht automated rigs attached to rails on self-propelled gantries.
The success of this critical application is an example of how good design practice and successful integration of new technologies can make short work of even the most complex construction tasks.
Herrenknecht rig and Hilti hammer drills and vacuums on the Legacy Way Tunnel in Brisbane
Smoke duct corbel on the Legacy Way Tunnel