A leak in one of the tunnels being dug for Perth’s Forrestfield-Airport link has caused the temporary cessation of work with the project’s tunnel boring machines.
The small leak occurred on Saturday during works aimed at creating a tunnel cross passage, a throughway to connect the two tunnels and which will be used as an emergency exit once the rail line is operational.
The incident reportedly occurred in tunnel one of the project around a cross passage adjacent to Dundas Road, 200 metres north of Forrestfield Station, which led to the formation of a sinkhole early on Sunday morning and closure of the road.
The tunnel boring machines have now stopped as a precautionary measure and work is continuing to stop ground water from leaking into tunnel one.
While that work is ongoing, a survey of the ground along Dundas Road and tunnel connecting to the cross passage is also underway.
Western Australian transport minister, Rita Saffioti, said that the state government was working with the Salini-Impregilo-NRW joint venture in finding a safe resolution to the situation.
“I have asked the Public Transport Authority to review the timeline of the project, to ensure worker safety is paramount,” Saffioti said.
“In addition, there will be a review into the method used to create future cross passages and surveys are now being undertaken of the ground and the two tunnels in the vicinity of this particular cross passage.”
Due to the leak there has been some movement of approximately 10 tunnel rings near the point of the cross passage. Additional internal bracing is now in place as work continues to stop the leak and resolve the sinkhole damage.
TBM Grace is currently about 3km ahead of this cross passage site and TBM Sandy is located about 2.5km ahead of the site.