Alice has now reached halfway on the first leg of her long journey underground at Auckland’s Waterview Connection project.
The giant tunnel boring machine has constructed exactly 1.2km of the first of the 2.4km-long tunnels to connect the city’s Southwestern and Northwestern motorways.
The NZ Transport Agency’s acting Highways Manager, Steve Mutton, says Alice has been almost unstoppable since resuming tunnelling after a planned two week-long maintenance shutdown in May.
“She has reached a snail’s gallop, with 28 metres progress one day last week – her best day yet. That’s not bad when your top speed is only around 80mm per minute.”
Mr Mutton says that since she began her underground travels from Owairaka to Waterview last November, Alice has averaged around 14m per day excavating spoil and installing the tunnel’s concrete lining.
“At those rates, the machine is well on schedule to complete the first tunnel in late September.”
The world’s tenth largest tunnel boring machine is now 32.5m below the surface. On her 1.2km journey so far, Alice has installed 600 tunnel lining rings, each weighing 100 tonnes and comprising 10 pre-cast reinforced concrete segments. She has also removed 197,000 cubic metres of spoil.
“Technologically, burrowing under Auckland is ‘hungry’ work,” Mr Mutton says. “Alice has consumed $90,000 in power charges and $55,000 for water. It’s another example of the complexity and size of this project.”
On her arrival at Waterview in September, Alice will be turned around over the following three months and re-launched on her southbound journey early next year, building the second (northbound) tunnel as she goes.
Construction of the two tunnels will be completed at the end of 2015, when they will be fitted out with the services needed to operate them. These include ventilation fans, communication systems and fire protection. Sixteen cross passages – one every 150m - connecting the twin tunnels will also be built.
The entire project, which includes the motorway connections either end of the tunnels, is due to be opened in early 2017.
The Waterview Connection completes Auckland’s Western Ring Route. The alternative to the SH1 Southern and Northern Motorways will be 47 kilometres long between Albany and Manukau. The Western Ring Route will improve city and regional transport connections, and is identified by the Government as a Road of National Significance because of its importance to New Zealand’s economy.
The Waterview Connection project is being delivered by the Well-Connected Alliance which includes the Transport Agency, Fletcher Construction, McConnell Dowell, Parsons Brinckerhoff, Beca Infrastructure, Tonkin & Taylor and Japanese construction company Obayashi Corporation. Sub-alliance partners are Auckland-based Wilson Tunnelling and Spanish tunnel controls specialists SICE. ENDS