The first of two 12.4m diameter Herrenknecht Double Shield Gripper TBMs being used to construct Brisbane’s $1.5bn, 4.6km long Legacy Way Tunnel has broken through – 5 months ahead of schedule. JV Transcity, comprising Brisbane-based BMD Constructions, Italian company Ghella and Spanish company Acciona launched Joyce on the westbound tube in early October 2012 and saw a record 49.7m excavated in one day.
Joyce’s sister machine Annabell, also launched last October, is scheduled to finish boring in June having just reached the 3km mark.
Both machines began work in Toowong, with breakthroughs sited at Kelvin Grove. The TBMs have travelled through a range of geology, most predominantly boring through the rock types Bunya Phyllite and Neranleigh Fernvale, which are common in Brisbane’s western suburbs.
Legacy Way will be lined with a nine-piece ring of precast concrete segments. Approximately 4250 rings are required to line Legacy Way’s twin, two lane tunnels.
Lord Mayor Graham Quirk was reported in local media as saying, “To do 4.6km of tunnelling in six months is a world record, and she also broke the one day record of some 49.7m in one job.”
Federal Infrastructure and Transport Minister Anthony Albanese added, “This is really a tribute to the engineering skills of the companies involved and of the workforce who’ve been able to deliver this.”
Legacy Way is Brisbane City Council’s road tunnel that will connect the Western Freeway at Toowong with the Inner City Bypass (ICB) at Kelvin Grove. It will provide an alternative route to local roads for traffic leaving the Western Freeway and travelling to and from the ICB. Once open in 2015, Legacy Way will reduce, by up to half, the peak hour travel times of journeys from the Centenary Bridge to the ICB.