Soletanche Bachy has announced that its March Construction division, working in joint venture with its microtunnelling specialist Bessac, have been awarded a key contract on New Zealand’s City Rail Link (CRL) project.
CRL is the largest infrastructure project ever undertaken in New Zealand and includes a 3.45km twin bore rail link at up to 42m below ground level.
CRL will connect with the existing network at Mount Eden, where the newly awarded contract will see a new storm water tunnel built between the residential streets of Water Street and Nikau Street to replace an existing storm-water pipe that was in the path of the CRL tunnels.
According to CRL chief executive Chris Meale, the NZ$16.5M (£8.7M) contract is a milestone for the project. “The focus to date has been in the city centre with the Britomart and Albert St works,” he said. “This year we will start some early works at Mount Eden in anticipation of the tunnel and stations main contract award in 2019.”
CRL has said that the “March Bessac Joint Venture contractors have extensive pipejacking and underground work experience in New Zealand and internationally and were chosen for a combination of their expertise, the innovation they brought to the tender and for their commercial offer”.
According to Soletanche, the chosen solution was to install the pipe in a single run with a micro-tunnel boring machine, instead of two envisaged under the client’s initial solution. To respond to all the project’s constraints, the route involves two very tight bends, with a minimum radius of 150m. The pipes used must be equipped with special joints of the right dimensions to fit this curve. This innovative procedure has already been employed by Bessac’s teams on a site in the Paris region.
This alternative meant a shorter timetable and a reduced volume of work, thanks to the elimination of one shaft resulting in an overall saving time’ work.
“As a result of the contractors’ smart thinking, the works will be less disruptive and will take less time than first anticipated. That’s a win for the project and for the neighbours,” said Meale.
Preliminary work on the Albert Street site is due to start in early 2018, between Wellesley Street and Victoria Street. Soletanche Bachy, through the Major Projects division and its local subsidiary March Construction, as part of a consortium with Downer NZ, is already working on the CRL site in the heart of Auckland, where the teams are participating in the construction of two rail tunnels under the city’s first post office, a historic building that is now home to the Britomart Transport Centre.