Alice nears daylight

SCCZEN_A_160514NZHDPWATERVIEW15_620x310It feels like riding some sort of subterranean paddle steamer on a voyage back from the centre of the Earth.

But at a top speed of 8cm a minute, it would have taken us more than 5000 years to get there and back on a giant tunnel-boring machine called Alice.

Luckily, the 88m-long machine – which the Transport Agency imported from China for $55 million to dig twin tunnels to connect Auckland’s Southwestern and Northwestern motorways – has only 300m or so to go before emerging at Waterview early next month.

Although it is thrusting forward at a rate of 20m to 24m a day, engineers are reluctant to commit themselves to an exact date, given the sensitive pressure adjustments needed as the assemblage nears the surface. Despite the roar of 24 engines powered by 22,000 volts of electricity to turn the machine’s giant 14.46m cutting head with its almost 300 tungsten cutting tools at a rate of just under two rotations a minute, an almost total lack of vibration meant it would have been impossible for anyone on the surface to guess its exact position.

Behind us as we visit the 14.46m cutting face of the first tunnel yesterday, about 18m under Great North Rd, stretches a 2.1km cavern of lined concrete curving back to Alan Wood Reserve in Owairaka, from where the giant ground-eater pushed off in November last year.

SCCZEN_080914NZHJOALICE15_620x310Also reaching all the way back is a conveyor belt carrying about 3000cu m a day of soft rock liquidated to a toothpaste-like consistency to be loaded on trucks and dumped at an industrial development site over a disused Wiri quarry.

The air is fresh, courtesy of a massive 2.5m-diameter ceiling intake pipe, and the tunnel is well illuminated by fluorescent lights guiding us to the boring machine.

Not even diesel fumes from a shuttle carrying a 100-tonne payload of 10 concrete sections for the machine to line the tunnel as it goes can foul the air, although there is a dank alkaline smell reminding us to avoid contact with corrosive wash water under our feet.

After being driven most of the way in, we are electronically tagged through a gate to ensure there are no more than 40 people in the tunnel at a time. We are guided on foot the rest of the way on the flat surface of a concrete culvert being laid to carry power and other services before the $1.4 billion motorway link from Maioro St in New Windsor to the Northwestern Motorway at Waterview opens in 2017 with three traffic lanes each way.

Even the culvert – described as a “tunnel within a tunnel” – is a roomy 3.5m wide by 2.5m high. The 40-person limit is to ensure salvage chambers on the machine can provide at least three days of air to their occupants in an emergency.

Once on board the three-decked machine, the roar of 24 motors turning the mining head with its almost 300 tungsten cutting tools at almost two rotations a minute makes conversation difficult. A giant screw rising at 45 degrees from an earth-holding chamber behind the cutting head is dropping grey slurry looking like a bubbling geothermal mud pool on a conveyor belt as the machine’s operator, cocooned in a control room, adjusts balancing pressures to keep the tunnel face stable.

Tunnel construction manager Iain Simmons says the machine has a pushing force of 30,000 tonnes, yet only about 5000 tonnes is typically needed “so he [the operator] has to be really careful”.

19951c7077e4a0efad702a04cf6beb3c3b88afd6_620x310But despite the din and massive power, there is no vibration, which is just as well given that the machine has tunnelled directly below the Mt Albert Pak’n Save supermarket and Oakley Creek at depths of up to 45m.

Mr Simmons says pressure will have to be eased off as the machine edges its way to the surface. He is blase about the prospect soon of breaking through a portal built in a trench next to Waterview Primary School and an embankment which will lift traffic to a three-level interchange for which support structures are already towering 20m above the Northwestern Motorway.

For him, that will simply signal the start of four months of maneuvering the tunnel-boring machine around in a tight trench so it can start digging its way back to Owairaka  to complete the second of a pair of 2.4-kilometre tunnels needed to link the Southwestern and Northwestern motorways, and complete the region’s 47-kilometre western ring route alternative to State Highway One.

Once the machine is fully under way on its return journey, after a two-phase turnaround operation, the Transport Agency’s Well-Connected contracting alliance will begin drilling 16 cross passages between the main tunnels to provide motorists with escape routes in emergencies.

Although the second tunnel is expected to take only until about next September to dig, there is plenty to be done – including building venting towers at both ends – before the full 4.8km Waterview Connection – half of which will be surface motorway – opens in 2017.

Source:

  • Mathew Dearnaley
  • NZ Herald
  • Photos: Jason Oxenham & Dean Purcell

Waterview Project-Time Lapse Video

A time lapse video of the work on the Waterview Project for January 2014

Source: YouTube: Waterview Connection

Waterview Project-Time Lapse Video

A time lapse video of the Waterview Project including the construction of Alice the TBM.

Source: YouTube: Waterview Connection

 

Alice poised for action

Alice, the Waterview Connection’s tunnel boring machine, is lined up at the mouth of her first Mt Roskill wall, ready to dig the country’s biggest roading job.

John Burden, project manager for the Well-Connected Alliance, showed how the shield or cutting face of the world’s 10th-largest tunnel boring machine would soon start eating into the ground to create the first 2.4km southbound tunnel.

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Alice, which can create a 14.4m diameter tunnel up to 17m long a day, not only digs the tunnel with her circular cutter head full of blades and discs but also lines the hole she has dug with concrete segments, completing the process all in one go.

“The tunnel has to be that big to get three lanes of traffic in,” said Burden, aged 51, a civil engineering Auckland University graduate, who heads the project.

Burden was in the successful tendering team, so has been working on the $1.4 billion Waterview job since January 2011 “and we have another 3 years to go”.

Financial incentives and disincentives are built into the contract.

“The commercial organisations in the alliance work to target and get a pain or gain share,” Burden said, describing financial penalties and rewards at various stages.

He cited Alice as an example, saying it had come in “very close to budget, at roughly $55 million”.

“If we didn’t do a good job, all the people in the alliance would be affected and get less money,” Burden said.

Soil or spoil from the tunnels will be removed by a continuous conveyor belt, more than 6km long once it is linked up to the back of Alice.

Source:

  • Anne Gibson
  • NZ Herald
  • Photo: facebook.com/AliceTBM

Alice taking shape after big lift at Waterview

The NZTA’s Waterview Connection team in Auckland is celebrating a key project milestone with the successful lowering into place of the 350-tonne main drive that will power Alice, the project’s giant tunnel boring machine (TBM).

home-cutter-head-installation-img4The main drive, the critical component that will enable the cutting face of the TBM – now known as Alice – to rotate and bore the twin tunnels that will connect the Northwestern and Southwestern motorways, was lowered 40 m into the deep trench where the machine is being reassembled.

The NZTA’s highways manager, Tommy Parker, says the operation demonstrates both the complexity and preparation required for the country’s biggest ever roading project. “This single operation illustrates that this is a project of unprecedented scale in New Zealand,” says Mr Parker. “To have completed it with such little fuss, as if an everyday task, should give all the project’s stakeholders – which in this case is the whole of New Zealand – great confidence in our team’s ability to meet the many challenges that lie ahead in its safe delivery.”

The meticulously planned manoeuvre was carried out using a 600-tonne crane, and required the construction of a deep-piled, reinforced crane platform, capable of supporting a total weight of almost 1200 tonnes above the trench. Despite being only a temporary structure, the platform required deeper and longer piles than any of the permanent structures on the entire project.

Reassembly

Weeks after arriving in her many pieces, Alice is beginning to take shape in the excavated trench of the future tunnels’ southern approach. Reassembly involves the painstaking reattachment of over 300,000 bolts, ranging in weight from a single gram to 4 kg. Around 10,000 of these will be in the main shield alone.
home-the-final-big-lift-img4

The TBM is due to be commissioned and start tunnelling in late October. It will bore two tunnels, both 2.4 km long and wide enough for three lanes of traffic in each direction, to complete Auckland’s Western Ring Route. The 47 km stretch of motorway is identified as one of the government’s national roads of significance to support economic development and improve safety.

The $1.4 billion Waterview Connection – New Zealand’s largest roading project – is one of six projects to complete the Western Ring Route.

The distinctive 14 m wide cutting face – which makes Alice the 10th largest machine of its kind in the world – is scheduled to be lowered into place towards the end of September.

Source:

  • New Zealand Construction News
  • Photo’s: nzta.govt.nz

Mammoth tunnel-borer moved to site

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Roads near Auckland’s $1.4 billion Waterview motorway project had to close to enable delivery of part of a giant tunnelling machine that has arrived from China.

The New Windsor entry point to the Southwestern Motorway and a section of Sandringham Rd Extension were closed for five hours from midnight as the part is trucked from the waterfront, where 97 containers into which the $54 million tunnel-boring machine was packed for its voyage from China are being unloaded.

Transport Agency contractors will spend three months reassembling the 2300-tonne machine with its 14.46m-diameter drilling head in a deep trench at Alan Wood Reserve, before the first of two 2.4km motorway tunnels are drilled.

Sandringham Rd had to close so a culvert can be reinforced to take the extra heavy load.

Source:

  • NZ Herald
  • Mathew Dearnaley

Waterview Tunnel preparation works

At 14 metres in diameter, the twin tunnels of the Waterview Connection will be the biggest in Australasia. Yet the new motorway will burrow quietly beneath the parks and suburbs of the Auckland isthmus, not even emitting a gentle hum to tell those above of its existence.

waterview

Goggles shield Kapeliele Vatuvei’s eyes from the wintry glare and the welding spatter, as the scaffolder works at the southern entrance to New Zealand’s newest and biggest tunnel project.

Deep in the pit, dwarfed by tunnel faces 10 storeys high, workers on the Waterview Connection scurry about looking like tiny orange-coloured ants.

Some drive diggers, scooping out some of the 800,000 cubic metres of dirt that will be removed to create two, three-lane tunnels as part of the $1.4 billion project to link west-bound State Highway 16 and the dead-end SH20.

Others simply whack at the face, handily marked “north bound” in bright blue spray paint, with handheld tools as they prepare the site for when a $54 million tunnel boring machine is switched on in October.

Vatuvei (a distant cousin to Warriors star Manu Vatuvei) is enthralled by the massive job.

“I love starting things off and helping see them through to the end,” he says.

“There’s plenty of action around here and everything’s changing so quickly as we get ready to bore those tunnels.”

Tommy Parker, Auckland and Northland state highways manager for the New Zealand Transport Agency, says 24,000 pre-cast segments are being prepared in an East Tamaki factory for the German-built boring machine, which will install the tunnel walls as it bores.

Its 4.8km return journey will take two years, but the portion of the motorway dipping underground only accounts for half the distance the connection will cover. It will total 5km when finished.

North of the tunnel face, workers are preparing the Waterview side for a cut and cover tunnel entrance and Spaghetti Junction-style interchange with SH16, the Northwestern Motorway.

Watching the workers below, part of a force of 350 that will eventually rise to 750, Parker shares the awe many feel when reflecting on the scale of the project, the biggest transport-related public works project since the Auckland Harbour Bridge was built in the 1950’s.

“It’s a different scale from anything we’ve done in New Zealand. You see this kind of thing in London,” he says. “Everything about this project is big.

The Tunnel Boring Machine (TBM), built in China by German company Herrenknecht, is an Earth Pressure Balance Machine. This means the drill can tunnel under the surface at shallow depths, maintaining the pressure in the ground and preventing subsidence – essential when working under residential and commercial areas.

Source:

  • Cherie Howie
  • Herald on Sunday
  • Photo / Doug Sherring

Tunnelling monster heads to Auckland

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A tunnelling machine dwarfing the world’s largest airliner is bound for Auckland, where it will spend more than two years digging an underground motorway from Owairaka to Waterview.

The $54 million machine – the 10th largest borer of its kind – has been formally accepted from its German manufacturer’s Chinese factory by contractors building the Transport Agency’s 4.8km Waterview motorway connection for $1.4 billion.

With a 2300-tonne circular cutting head 14.5m in diameter, making it as high as a three-storey building, the 97m-long machine could easily swallow the body of an Airbus A380 and most of a rugby field.

The behemoth’s handover this week to the motorway construction alliance at the factory in Guangzhou follows a 14-month design, build and testing programme. It will now have to be dismantled for shipment to Auckland, where it is due to arrive in July.

The alliance has since last winter been digging a huge trench in Alan Wood Reserve, Owairaka, ready to re-assemble the machine in situ, for tunnelling to start in October.

Just lowering it section-by-section into the ground will require a 600-tonne gantry crane straddling the pit, which will be at the western end of 2km of surface motorway from Maioro St in New Windsor.

The machine will spend a year digging the first of two 2.4km tunnels, slotting in pre-cast concrete rings as it works its way through the ground, before being turned at Waterview to dig the second tunnel, burrowing back to where it started.

At a top speed of 8cm a minute, it will chew through up to 10m of ground a day at depths varying from 10m to 47m, beneath a thick layer of basalt rock and Oakley Creek, to complete the final link of the 47km western ring route by 2017.

Source:

  • Mathew Dearnaley
  • NZ Herald
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