The incidents occurred on March 1 and 9, about 150m apart. On the first occasion, a sinkhole caused a partial building collapse in an industrial estate. On March 9, workers were about 12m below the surface, excavating the face of the south-bound tunnel, when a hole developed. The workers were evacuated and none was injured.
In a statement to T&TI, a Transport for NSW spokesperson said the cost and timeline of the M6 Stage 1 were now under review.
“Transport for NSW and its delivery partner CGU are currently reviewing the design of the tunnel in areas affected by subsidence and a revised construction programme, both of which will impact the cost of the project. Transport for NSW and the contractor continue to investigate the cause of the subsidence, which affected a 244m section of tunnel,” the spokesperson said.
SafeWork NSW prohibition notices are still in place, and tunnelling can recommence in the areas affected by subsidence only when SafeWork gives approval.
The spokesperson said tunnelling was continuing from the Arncliffe site, with 90% of tunnelling excavation completed across the project.
“Tunnelling fit-out construction is also progressing, including laying road pavements and electrical and mechanical works. Surface road works are also continuing on President Avenue, as well as work on the 5km of active transport connections in and around Bicentennial Park,” the spokesperson said.
“We will keep the community informed once the project’s revised construction timeline is known.”
The M6 Stage 1 is a major road project to provide 4km of twin tunnels connecting the M8 motorway at Arncliffe to President Avenue in Kogarah. It will allow motorists to bypass up to 23 sets of traffic lights on the Princes Highway, and link with Sydney’s wider motorway network.
Construction started in January 2022 and was scheduled to open to traffic at the end of 2025.
