BULIMBA SEWER TRUNK MAIN
Investing to upgrade Brisbane’s sewerage network, the Bulimba Creek Trunk Stage 2 Sewer Upgrade involves installing a 4.25km gravity trunk sewer between Wecker Road, Mansfield and Settlers Street, Carindale, with 3.6km being installed using trenchless technology. The Stage 2 project is a continuation of duplicating the existing sewer network and increasing capacity in the network. Stage 1 and 1A upgrades were completed in 2004-2006 and 2011-2013 in Mansfield, Wishart, Eight Mile Plains and MacGregor.
In this Australian-Japanese joint venture, Abergeldie and Obayashi are engaged to design and construct the pipe-jacked and open cut sections, as well as nine maintenance holes for the Stage 2 works.
An Abergeldie owned AVN slurry shield tunnel boring machine (TBM) is being used on the pipe-jacked sections of the sewer. The boring machine is guided by a VTM navigation system and is coring out a 1800mm tunnel, pushed forward by a jacking machine with sections of the sewer pipe following behind the TBM. This micro-tunnelling method is highly effective as it minimises impacts and disruption to the shaft locations avoiding the need to have extensive open trench construction along the whole 4.25km alignment, thus reducing the overall impact to the community and environment of these large infrastructure projects.
The works have been divided into 5 x 700-850m jacked pipe sections requiring construction of six temporary shafts to launch and retrieve the TBM, the deepest of which is 45m. Currently, 4 of the 5 tunnel drives have been completed.
Over the course of construction, the team has overcome challenges such as flooding in the tunnel at Bulimba Creek, varying geological ground conditions, high water ground water pressures requiring hyperbaric interventions, undertaking 24 hour tunnelling in close proximity to residential properties and working in environmental sensitive locations.
Queensland Urban Utilities