Auckland’s City Rail Link (CRL) project continues to chalk up milestones with the completion of mined tunnelling at Maungawhau Station in Mt Eden last week.
The tunnelling crews successfully completed the final 99.5m mined tunnel section, known as the cavern, adjacent to where the tunnel boring machine slid through on its second CRL tunnel drive in 2022.
This marks the end of all tunnelling from Maungawhau Station which has used three types of tunnelling – the TBM Dame Whina Cooper, cut-and-cover tunnelling and mined tunnelling.
Mined tunnelling, which has been taking place at Maungawhau Station since 2020, involves creating a tunnel with machinery such as a jumbo drill, excavators, and a shotcrete machine to stabilise the ground. The area is then waterproofed and concreted with tailormade self-travelling formwork.
During the two and a half years of mined tunnelling, crews excavated about 15,000 cubic metres of spoil, used about 10,000 cubic metres of concrete and shotcrete and installed around 250 tonnes of steel and 4500 square metres of waterproofing membrane in creating mined tunnels extending 296m, about the height of the Empire State Building.
Link Alliance project director Francois Dudouit says the completion of mined tunnelling was a significant achievement.
“These people have been on a long journey, literally and figuratively speaking,” he said.
“The team has faced many technical and environmental challenges and have shown both fortitude and innovation in overcoming those obstacles.
“The completion of this stage of the project is a cause for celebration and a source of great pride.”
The occasion was marked with speeches, awards and flags showcasing the multinational team that has delivered this essential part of the CRL construction.
Work is now beginning on the fit-out of the mined tunnels, including electrical works, signalling, ventilation and installation of the rail tracks upon which the new CRL trains will run.
.png){kind=small}
