HS2 Chiltern tunnel launchpad ready for giant TBMs

Grant Prior 2 years ago
Share

Preparation for the arrival of HS2’s first giant tunnelling machines is now complete with construction of the 17m high headwall and ground reinforcement at what will become the south portal of the 10-mile long Chiltern tunnel.

Main works contractor Align JV – a joint venture formed of Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick – has spent seven months excavating more than 160,000 m3 of material in order to create a level surface from which the two enormous machines will launch early next year.

Weighing in at 2,000 tonne and stretching for 170m – the two tunnel boring machines (TBMs) are being built by German tunnelling specialists Herrenknecht – and due to arrive at the site, near to the M25, later in the year.

Alongside the excavation, a specialist team of subcontractors including Roadbridge and KV JV – formed from Keller Group plc and VSL International – also constructed a 17m high headwall through which the TBMs will break to begin their three-year long tunnel drive.

In order to reinforce the ground behind the headwall, more than 636 soil nails – some up to 20m long – were driven into the wall and connected to the concrete lining.

The nails, consisting of steel or glass fibre reinforced polymer tendons, were inserted using a specialised drilling rig in a delicate operation which can take up two hours.

This reinforcement is required to hold the ground and the surface of the wall in place as the TBMs begin to break through.

Welcoming the milestone, Mark Clapp, HS2 Ltd’s C1 Senior Project Manager said: “The completion of the headwall and ground reinforcement is a major step towards the start of tunnelling.

“Safety is of course our top priority. The new covid-19 processes and procedures put in place by Align ensured that we were able to keep to schedule while keeping everyone safe – and I’d like to thank the whole team for pulling together during what has been a difficult few months for the whole construction industry.”

Daniel Altier, the Align Project Director added: “The completion of the soil nailing is a very visual example of how we are preparing our South Portal site for the arrival of the TBMs later this year. It is now clear for all to see where the TBMs will start their journey.

“This has been a great team effort by all concerned, considering the challenges caused by Covid-19, including HS2, Align and our colleagues at Roadbridge and the KVJV.”

Align is delivering the C1 portion of HS2 phase 1 which includes the 10 mile long twin bore Chiltern tunnel and the 3.4km Colne Valley Viaduct. The work is being led by an integrated project team based at the site just inside the M25.

Work on site was paused for four days at the start of the coronavirus lockdown in order to deep clean the work site and put in place new hygiene and social distancing procedures in line with government advice and industry best practice.

Once work is complete, the whole construction site will be landscaped with material excavated from the tunnels and trees planted in order to blend it in with the surrounding countryside.

Latest news

Eric Wright wins tricky £52m Liverpool transformation

Contractor working with engineers at Ridge and Partners on "challenging" Stanley Lock Flight site
19 hours ago

Investment giant buys Bristol M&E contractor

RDCP Infrastructure acquires Avon Combined Electrical Services
24 hours ago

Demolition start for £50m Farnworth town centre rebuild

Caddick Construction is tipped for main works due to start in the spring
1 day ago

L&G Modular strikes deal to build 1,000 affordable homes

Modular homes business teams up with Hampshire's Vivid housing association
1 day ago

Former Erith operations director joins John F Hunt

Scott Exell named new operations director at demolition specialist John F Hunt
1 day ago

Green light for £135m Leeds twin tower resi scheme

Construction to start in New Year on 500 build-to-rent apartments
2 days ago

Mace hits 1m tonnes carbon saving target for clients

Present work pipeline betters 2026 carbon emission saving target
1 day ago

Plans in for £40m surf park at former Kent colliery

Seahive surf lagoon and health resort will be built near Deal
2 days ago

Crushed demolition worker vows to return to industry

Shannon Brasier hoping to return to construction following horror accident
2 days ago

Mount Anvil to start 900-home North London estate rebuild

Planning approval paves way for Barnsbury Estate rebuild in Islington
2 days ago

Green light for major laboratory campus in Cambridge

Developer BioMed to tender first building on 600,000 sq ft lab complex in the New Year
2 days ago

Belfast firm signs the biggest work deal yet under Project Gigabit

Fibrus to hook-up rural Cumbria to lightning-fast broadband under £108m deal
2 days ago

McLaren wins Leeds logistics park contract

Work to start imminently on warehouse complex for Firethorn Trust
3 days ago

Work restarts on £683m waste power plant after site death

Construction suspended for a week of investigations following fatality
3 days ago

Demolition starts on £135m Wigan Galleries scheme

Contractor BCEGI starts work on project to redevelop Wigan town centre
3 days ago

Amey CEO to step down following private equity buyout

Amanda Fisher to leave once business is transferred to new owners
3 days ago

New body set up to vet plant operator card schemes

Contractor trades bodies unite to tackle competency concerns over plant operator skills cards
3 days ago

Kier leads switch to hybrid battery generators

Battery units work alongside smaller generators cutting run times by nearly 60%
3 days ago

Plans in for first Leeds co-living scheme

Watkin Jones submits plan to convert old Direct Line HQ into 230 studio flats
3 days ago

Demolition worker crushed by excavator

Court hears 20-year-old woman was left with "life changing injuries"
4 days ago

Government pays £700m for 50% stake in Sizewell C

New body, Great British Nuclear, will be set up to develop pipeline of nuclear projects
4 days ago

Costain wins Heathrow Airport asset renewal deal

Firm takes early contractor involvement role in Terminal 2 baggage handling upgrade
4 days ago

Worker killed on £683m waste power plant site

Fatal collision involving heavy goods vehicle on giant north London site
4 days ago

HS2 JV shifts four Wembley Stadiums of earth in record time

EKFB team digs and hauls 15 million cu m of muck in 20 months
4 days ago

Milestone wins £300m Wiltshire highways upkeep

Ringway will hand over to Milestone in March next year
4 days ago

Low-risk business model helps Renew post record results

Renew reveals latest acquisition with £15.6m purchase of water specialist Enisca
4 days ago

London Albert Embankment hotel towers approved

Two separate hotels rising to 26 and 29 storeys approved
4 days ago

Keltbray names new director of strategic engineering

Tim Lohmann takes up newly-formed role to drive innovative engineering solutions
4 days ago

Go-ahead for £200m lithium refinery on Teesside

Work to start next year on Europe's first lithium hydroxide processing plant
5 days ago

HS2 agency workers paid the wrong wages

Payroll software problems leave workers out of pocket
5 days ago

Contractor services