The project includes one of the longest drives carried out in WA. This project involves the construction of a 1.9 km wastewater pipeline with a diameter of 2.2 metres (m) through a combination of micro tunnelling and open trench construction.
The northern corridor of the metropolitan area will benefit from the addition of this pipeline to the wastewater distribution system.
The project has kicked off with the clearing of affected areas and the construction of access tracks. Rob Carr has considered protecting the habitat of endangered species and protecting fauna. To meet the prerequisites as per the Conservation Act 1950, a regular fauna handler/relocator was appointed.
Over 10,000 bees were rescued from an area to be cleared at one of the locations close to a launch shaft.
In March 2022, the company’s new AVN1800 tunnel bore machine arrived in Western Australia. A naming competition was held for the TBM, where several members of the community participated, and BAKTON was placed first with 63 per cent of the votes. The name was suggested by local resident Peter Sexton, to honour his father, Maurice Sexton, and grandfather, Bruce Baker. Both have been regarded as pioneers of artisian drilling in Western Australia, and the name serves as a tribute to their work.
Bakton has been operational since May 2022. The AVN is on its route to its first receival shaft, which is at a depth of 13 metres.
The first launch shaft was completed by mid-April 2022 and is located in the existing carpark of the North Metropolitan TAFE, Clarkson. To accommodate the TAFE’s students and personnel over the duration of the project, a new parking lot was built adjacent.
The last shaft is located at Hall Road, on the other side of the Mitchell Freeway. This shaft is currently 50 per cent complete and will be 27 m deep when fully constructed. This is the deepest of the five shafts to be constructed.
The shafts will be constructed using a combination of in situ concrete caisson, precast segments installed by underpinning and shotcrete depending on the geotechnical conditions encountered. The geotechnical conditions are expected to be a combination of sand and pinnacle limestone varying from hard to soft.
The open trench section of sewer has reached 75 per cent of completion and is projected to be completed by mid-June.
The job includes four drives ranging from 188 m to 637 m. The longest drive is curved with a radius of 600 m and will pass under the Mitchell Freeway and the Joondalup Railway Line. The AVN1800 was selected for the project due to its ability to work in mixed ground conditions of both sand and hard limestone.
The whole project is due to for completion in early 2023.
For more information visit Rob Carr.
This article featured in the June edition of Trenchless Australasia.