By Lynda Myer
Considering that on March 9 a second sinkhole developed on the face of the south-bound tunnel on Sydney’s M6 Stage 1, tunneling process has halted and the workers who were almost 12m beneath the surface, were evacuated and none was injured.
Alongwith geotechnical and engineering assessments, Safework NSW has been notified, and an exclusion zone has been established around a 20m2 area.
According to Transport for NSW: “Initial remediation work, including securing the area, had commenced. As an extra precaution Joint Venture CGU has halted all further tunnelling work in the impacted area while engineers and geotechnical experts assess further.”
Also the placed location of this problem is within a contained construction area not accessible to the public and the site is not located near any residential or commercial properties, which is about 150m away from another area of the tunnel which was evacuated on March 1 when a large sinkhole appeared and caused a partial building collapse in an industrial estate.
Most tenants affected by the earlier subsidence have been able to access their facilities since Friday.
Additionally, in accordance with the Transport for NSW’s report, no other sites on the M6 Stage 1 project had been impacted and any potential changes to construction timelines were not known at present.
January 2022 is the commencing date for construction of the M6 Stage 1 and it is scheduled to inaugurate at the end of 2025. Tunnel excavation is more than 70% complete.
The project includes twin 4km tunnels and tunnel stubs for a future extension of the motorway.
