Karangahape

Tunnelling works progress at Karangahape station site

Tunnel mining has begun at the site of the future Karangahape Station with a large excavator brought in to create a 15 metre long connection to the caverns of the future station.

Machinery is digging out the short tunnel from the temporary access shaft, 18 metres deep.

Dale Burtenshaw, deputy alliance director for Link Alliance said the connection would be critical.

“This connection is short, but it will become an important and busy ‘construction artery’ for us providing access for people, machines and material,” he said.

Once the 9.5 metre wide and 8m high arch-shaped tunnel is excavated a roadaheader will finish the connection before beginning to dig out the station platform tunnels.

“It’s a clear sign of work ramping up. Our focus is very much on welcoming the Tunnel Boring Machine at Karangahape Station at the end of next year on the first leg of its journey from Mt Eden,” said Burtenshaw.

When complete, Karangahape will be New Zealand’s deepest underground station at up to 35 metres underground. The station will be 217 metres long to accommodate nine-car trains.

Here the tunnel boring machine will arrive after carving out the twin tunnels from Mt Eden Station.

To ensure construction and earth mining noises are limited, a unique acoustically insulated noise enclosure will encase the access shaft.

“The noise enclosure is a bit like a silencer on a car, reducing the impact of construction at street level in a busy part of the city around Karangahape Road,” Burtenshaw said. “The enclosure muffles construction noise and gives us the flexibility to work longer hours to get the job underground done without disturbing neighbours living and working around us.”

Other work such as the installation of reinforced concrete panels are also underway along with utilities relocation. Plunge columns through the centre of Beresford Square are also beginning to be installed to support floor slabs during construction.

roadheaders

Dual roadheaders excavating Cross River Rail tunnels

Two roadheaders are excavating tunnels underneath Brisbane to carve out the route of the future Cross River Rail.

The addition of the second roadheader enables more rock to be excavated each day, with 55 metres of tunnel already excavated at a rate of 1.5 metres each a day.

The over 100 tonnes roadheaders have set out in different directions from the Woolloongabba site. Beginning from the station cavern, one is heading north underneath Vulture Street, and the other is tunnelling south towards the South East Busway.

Blasting is also being conducted at the site to speed up excavation works.

To allow for the excavated rock, including volcanic Brisbane Tuff and conglomerates forming the Neranleigh Fernvale rock that sits under the Brisbane CBD, to be removed from site, a spoil shed built by a local contractor has been constructed at Woolloongabba. By the time excavation is complete, over 132,000 cubic metres of rock and soil will have been excavators. So far, 70,000 cubic metres has been removed.

When complete, the station box shaft will be 32 metres deep, with the future 220 metre-long platform sitting 27-metres below the surface.

Later in 2020, tunnel boring machines (TBMs) will arrive at Woolloongabba. The TBMs are currently being refitted in Brisbane after having completed work on the Sydney Metro project. The TBMs will excavate the twin underground tunnels to the north from January next year. This will speed up tunnelling progress as each can carve out 20-30 metres of tunnel a day.

Roadheaders

Roadheaders meet at future Town Hall station

A significant milestone has been reached on the Melbourne Metro Tunnel project, as three roadheaders meet at what will be the site of the new Town Hall station.

The three roadheaders have been at work creating the cavern and pedestrian connections between the new station and Flinders Street and Flinders Quarter.

“This is a huge milestone for this important project, bringing Melbourne another step closer to a turn up and go rail system, while keeping our construction workers safely on the job,” said Minister for Transport Infrastructure Jacinta Allan.

The new Town Hall station will be one of two interchange stations between the Metro Tunnel and the existing City Loop, with the other being at State Library/Melbourne Central.

When complete, the new station will be 33 metres deep and longer than a city block.

“We’ve made such amazing progress, we now have deep underground a new station entrance at Federation Square, the length of the future station platform and come out at the new entrance at City Square,” said Allan.

The three roadheaders have been working from three different launch sites. The first was launched late last year from City Square and began tunnelling under Swanston Street for the main station cavern. The second roadheader launched under Federation Square and will create the passenger connection between Flinders Street station and Town Hall. The third roadheader excavated the connection between Flinders Quarter and the station.

Each machine weighs up to 118 tonnes and has been working 25 metres below ground level. The cutterheads can cut through rock three times harder than concrete.

Once the roadheaders have finished excavating the stations, the tunnel boring machines will create the twin tunnels between the future Town Hall and State Library stations. All four tunnel boring machines are currently making their way underground towards the CBD.

The project is on track to have trains running through the new tunnels by 2025.

Roadheader gets to work on Cross River Rail

Tunnelling has officially begun on Cross River Rail, with the first roadheader assembled and digging out underneath Roma Street.

Queensland Premier Annastacia Palaszczuk said the occasion marked a major step for the Brisbane rail project.

“Above ground demolition has also been underway for several months at the site of the new station – but today is a huge milestone for this project as we start tunnelling for the first time,” she said.

“This is just the beginning of the underground works, with 5.9 kilometres of twin tunnels and four underground stations to be excavated in total.”

The roadheader was assembled at the site, 18 metres below ground, and is beginning to excavate the 280m long station cavern.

Now underway, the roadheader can excavate up to 50 tonnes of rock and soil an hour, with disruption protected by the acoustic shed at ground level, which stands five storeys high and is 60m long.

Local Queensland company QMW was involved in the manufacture of the roadheader, supplying the cabs. The locally made cabs and remaining five pieces were lowered into the shaft with a gantry crane and then put together underground.

The 22 metre long and 115 tonne roadheader is the first of two machines that will be working at Roma Street.

As work underground progresses, more and more people are working at the various Cross River Rail sites. Already 1,800 people are employed as part of the project, with the total expected to reach 3,000 when the project is at its construction peak in two years.

State Development Minister Kate Jones said that the project is critical to Queensland’s economy.

“Multi-billion-dollar infrastructure projects like Cross River Rail are vital to Queensland’s economic recovery following COVID-19,” she said.

“Coronavirus has had a huge impact on our economy. But we won’t let it derail Queensland’s largest infrastructure project.”

Once complete, Cross River Rail will include 5.9km of tunnels and four underground stations. Roma Street station will be 27 metres below ground and replaces the former Hotel Jen building and Brisbane Transit Centre.

Currently, one floor a week of the Hotel Jen is being demolished.

Metro Tunnel project achieves drilling breakthrough

Victoria’s Metro Tunnel project has reached a significant project milestone by connecting two caverns at the point that will become the new State Library Station in Melbourne. 

Three of the seven roadheader drills being used for underground tunneling works on the project in the city’s central business district met 30 metres underground at the site where the station will be built on Thursday.

Rail Projects Victoria expects excavation of the station area is to be completed by late 2020. The breakthrough, which took eight months to achieve, took place below Swanston Street between Franklin East and A’Beckett Street.

Four roadheaders will be employed for the State Library Station excavation, with the other three to be used for excavation of Town Hall Station.

“In total, more than 500,000 tonnes of material will be excavated – the equivalent of almost 70 Olympic swimming pools – with 1,500 tonnes of rock and soil removed every 24 hours,” the government said in a statement.

The $5 billion Metro Tunnel project will build five stations from North Melbourne to Anzac over a distance of nine kilometres. It is set for completion by 2025.