
Due to unexpected tunneling conditions,the tunneling contractor CGU which is building Sydney’s M6 motorway and comprises CPB Contractors, Ghella and UGL, has terminated its work for Transport for NSW. CGU is responsible for the design and delivery of the M6 tunnels and cavern under a A$3.1bn (€740m) design and construct contract.
CGU had downed tools and stated that over the past two years 90%, around 9km, of tunneling had been completed, as a Transport for NSW spokesperson confirmed.
In a statement to T&TI, Transport for NSW said: “We continued to work with the contractor to identify a technical solution to the issues encountered on the project. This is the contractor’s responsibility, but Transport has been proactively seeking to support them in fulfilling their obligations for the past 12 months. The contractor has not demonstrated that it has exhausted the technical options to move forward on their stalled underground works.It is unfortunate CGU now appears to have determined it is in their commercial interest to down tools instead. We’re considering Transport’s position in relation to the contract given the unilateral steps taken by CGU.”
There were two incidents of subsidence on the project in March last year.
The spokesperson said:”Since then Transport for NSW had been working closely with CGU on a new tunnelling design and methodology for the section impacted by subsidence. We are taking time to ensure the new design and mode of construction is safe and viable. The surface work on President Avenue in Kogarah and the nearby active transport links are still expected to open by the end of this year, as scheduled. The M6 Stage 1 tunnel is targeted to open to traffic by the end of 2028.”
January 2022 was the date of commencing construction of the M6 Stage 1.