wt0712

The magazine for the tunnelling professional

www.world-tunnelling.com

Brightwater meets Seattle sewerage demandArrowhead on target in California

Underground support vehicles

How TBMs navigateGuidance

Equipment

North America focus

December 2007 Vol 1 Issue 4


The magazine for the tunnelling professional


CovIWT0712.indd 1 6/12/07 21:54:25

Earth Pressure BalanceSlurry Pressure BalanceHard RockPipe - JackingRolling Stock

BREAKTHROUGHSOLUTIONS

Lovat.indd 1 24/8/07 10:09:04

Going to the fair?TRADE fairs and exhibitions, especially those

concerned with construction, have been having a tough time in the UK these past few years due

to declining attendances. Engineers, consultants and other management-level

personnel frequently cite being too busy to attend which may or may not be understandable.

But it is a pity. Major shows usually have much to offer, not only in terms of innovation and cutting-edge offer, not only in terms of innovation and cutting-edge

products, but also in the products, but also in the conferences that are conferences that are normally associated normally associated with them.

I had the good I had the good fortune recently to visit fortune recently to visit one of Europe’s major one of Europe’s major

civil engineering shows, civil engineering shows, CIVILS 2007, held in CIVILS 2007, held in London on November London on November

20-22 (see review, (see review, pp30-31)pp30-31).

Products on display on display ranged from ranged from

rockbolts and anchors to geotextiles and sprayed concrete; three of the tunnelling industry’s most prominent engineering practices had also taken stands. It’s just a pity there were not more visitors there. It seemed pretty deserted as I strolled down the gangways and alleyways around the 200-odd stands in Earls Court 2.

The organiser has reported a fairly healthy attend ance.

“Over the three days, we had around 5,000 visitors of which we estimate that around 84% were of management calibre. This sort of show is more about quality than quantity.”

Fair enough.Nevertheless, organisers will have their work cut out

if visitor fi gures for shows such as this continue their decline and internet-accessible information continues its inexorable rise both in quantitative and qualitative terms.

George Demetri, Editor

WEB ADDRESS www.world-tunnelling.com

Regulars1 Comment

2-9 Global news and STUVAA round-up of the latest news and technology

30-31 InnovationA review of CIVIL 2007

Atlas Copco Rock Drills www.atlascopco.com 5

Continental Conveyors.co.uk www.continental-conveyor.co.uk 25

Hunter Personnel www.hunterpersonnel.com 4

Lovat www.lovat.com Cov II

Maschinen und Stahlbau Dresden

www.msd-dresden.de 12

Mining Equipment www.miningequipmentltd.com 17

Parsons Brinckerhoff Parsons Brinckerhoff Parsons Brinckerhoffwww.pb.com.au 15

Prime Horizontal www.prime-horizontal.com 14

Propex www.fi bermesh.com 28

Robbins www.TheRobbinsCompany.com Cov III

RocTest www.roctest.com 19

Sandvik www.sandvik.com 3

Steam Engineering www.steamengineering.ca 7

Tunnel Engineering www.tesuk.co.uk 11

VMT www.vmt-gmbh.de 6

Wyo-Ben www.wyoben.com 16

advertisersFRONT COVER

The Brightwater project is a large-scale tunnel and sewer programme that will meet

the demands of North Seattle

1COMMENT

[email protected] (Arch) BA(Hons), DipBldgCons (RICS)

Production [email protected] [email protected]@mining-journal.comAdvertising [email protected]

Advertising [email protected]+44 (0)20 7216 6086Advertising sales [email protected]+44 (0)20 7216 6053

ISSN 0026-5225World Tunnelling is published ten times annually by Mining Communications Ltd, Albert House, 1 Singer Street, London, EC2A 4BQ, UK© Mining Communications Ltd 2007A member of BPA WorldwideA member of the Periodical Publishers Association

CONTENTS

contacts

December 2007

26

10-12 Brightwater projectA large-scale programme will help meet the sewage demands of North Seattle

Brightwater projectA large-scale programme will help meet the sewage demands of North Seattle

Brightwater project

13-19 Arrowhead projectTwo hybrid TBMs are advacning on a drive in southern California

Arrowhead projectTwo hybrid TBMs are advacning on a drive in southern California

Arrowhead project

20-21 TBM guidance systemsHow exactly a TBM navigates in the bowels of the earth

TBM guidance systemsHow exactly a TBM navigates in the bowels of the earth

TBM guidance systems

22 Milwaukee ISS projectTunnels prevent gallons of Milwaukee wastewater polluting Lake Michigan

Milwaukee ISS projectTunnels prevent gallons of Milwaukee wastewater polluting Lake Michigan

Milwaukee ISS project

23-24 Muck-fl ow handlingOutlining muck fl ow control technology in a large-cross-section EPB shield

Muck-fl ow handlingOutlining muck fl ow control technology in a large-cross-section EPB shield

Muck-fl ow handling

26-28 Underground support vehiclesThe range of units designed to perform specifi c post-excavation tasks

Underground support vehiclesThe range of units designed to perform specifi c post-excavation tasks

Underground support vehicles

Features

01WT0712.indd 1 10/12/07 10:04:57

December 2007

�NEWS

Atkins Ramboll wins capital metro project

Copenhagen, Denmark

ATKINS, the largest multi-disciplinary design/engineering practice in Europe, has been appointed with joint-venture partner Ramboll Danmark to provide consultancy on Copenhagen’s Circle metro line.

With a total value of US$2.8 billion, the proposed 15.5 km line is one of Denmark’s largesr-ever railway projects and will include 17 new stations.

Among other things, the Atkins-Ramboll JV remit will include solving the technical problems that the project is likely to face. Its initial scope over the next 18 months will be to take the project from the current concept design through to systems

procurement. But it will also provide consultancy on railtrack, catenary systems (cabling) and the

fully automatic driverless train control system.

Also included in the JV’s remit are rolling stock and a major operation and maintenance centre.

Atkins’ managing director for European operations said: “This is a major project, which will improve Copenhagen’s infrastructure and bring important transport links to a key area of the city.

“It is Atkins’ most significant contract to date in Denmark and we’re confident that it will be an important stepping stone to more high-profile work for

our locally-based business.”Scheduled for completion in

2018, the Metro City Circle Line is expected to be one of the most advanced transport systems in the world.

Atkins has established an international reputation for helping deliver major rail infrastructure projects, including the Dubai metro, the Glasgow Airport Rail Link (GARL) in Scotland and Gautrain in South Africa.

Ramboll Denmark is a leading provider of technical consulting services and knowledge-based total solutions for buildings, traffic and infrastructure, water and environment, energy, industrial processes and telecommunication.

SKANSKA has announced that it recently signed a contract with MTA New York City Transit for the extension of the No 7 Subway Line.

Skanska will receive a 35% share of the US$1.4 billion contract, which involves the extension of the No 7 line between Times Square and West Side of Manhattan, including 3.6 km of new 6.5 m-diameter tunnel constructed at depths of around 40 m.

Also included is the construction of an underground station at 34th Street and the lowering by about 2 m of existing track at the Times Square Station to allow connectivity with the new tunnels. Extensive underpinning of the existing 8th Avenue Subway Line will also be required. The project is scheduled for completion in about 57 months.

Skanska USA Civil signed the contract as part of the S3 tunnel Constructors JV that also features JF Shea Construct-ion (35%) and the Schiavone Construction Company (30%).

The news follows on from the award earlier this year when Skanska won the contract to build the first stage of the Second Avenue Subway line on the east side of Manhattan.

Skanska bags US$400m subway project

New York, US

Copenhagen’s metro will be augmented by nearly 16 km

with the new Circle line

GREECE’S biggest road concession project, the Athens-Tsakona motorway, looks a step nearer to realisation, thanks to the recent signing between the Greek Government and the Apion Kleos Consortium.

Led by Vinci (36%), the consortium also comprises Hochtief of Germany (25%) and Greek companies, Elliniki

Technodromiki-Aktor (18%), J&P-Avax (18%) and Athena (3%).

With work scheduled for a September 2008 start, the concession will involve financing, design, construction and possibly repair of the 365 km toll motorway that will stretch between Athens and Tsakona in the southwest Peloponnese.

The road will be routed via

Corinth and Patras and comprises 163 km of new construction, 82 km of existing motorway and 120 km of repair.

Nine tunnels are envisaged – Xylokastro, Derveni, Mavra Litharia, Akrata, Platanos, Panayiopoula, Ayios Yioryios, Koliri and Elia – ranging in length from 132 to 4,018 m.

Drill and blast will be used for

excavation and trucks used for road haulage.

Estimated tunnel cost breakdowns so far supplied include US$299 million for civil works and US$68 million for E&M equipment, although these figures do not include elements for design and ground investiga-tion. Ratification is expected soon from the Greek Government.

National supermotorway fast becoming a realityAthens, Greece

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�NEWS

DELHI Metro Rail Corporation (DMRC) has awarded the contract for the construction of Airport Metro Express Line-I to a JV comprising Alpine Bau of Austria, Hindustan Construction Company (HCC) and Samsung of Korea.

The US$205 million project will involve the construct-ion of a tunnel and two under-ground stations between New Delhi and Talkatora Garden stations.

Included in the contract is: the design of two TBM-bored 5.6 m-diameter tunnels 2.192 km long, each for a single-track railway, including access and ventilations shafts; and a 1.27 km-long, cut and cover tunnel for twin-track railways with underground stations at New Delhi and Shivaji Stadium.

When the project is completed, currently scheduled for 2010, it will bring the total length of the Delhi metro to 69 km and will go some way to ease the commuter problems of the city, whose population is 15 million.

The JV brings substantial experience to the project. Alpine already has an Indian presence: it is currently constructing the US$116 million, 11.3 km-long penstock tunnel for the Tapovan-Vishnugad hydroelectric power

station in the Himmala-yas.

Siegfried Müller, CEO of Alpine Bau GmbH and responsible for projects in India, said: “We will start on the US$205 million project before the end of this year and aim to complete in less than

three years.” Alpine will be technical

manager on the project. Heading up its Delhi operation will be Robert Sternath, who is supported by a 180-strong core team. A total of 1,800 people will be working on the project.

HCC, a leading Indian construction and infrastructure company, built India’s first metro in Kolkata, as well as several projects in the country’s hydro power and resources sector.

JV trio wins metro orderDelhi, India

Hunter Personnel specialist in worldwide infrastructure recruitment solutions together with Jaypee Group, India’s leading Infrastructure

industrial conglomerate are looking for several Tunnel Project Managers with TBM or Drill and Blast experience. Jaypee Group have been recently

awarded the AMR Project in South India with a contract value of US$ 481.25 Million which is to be completed in 60 months.

The ideal candidates will be Tunnelling Professionals with experience in Contract Management of large tunnelling projects. Ideally with an outstanding track record of achievements, you should possess

inspirational leadership qualities and coordination capabilities, with a � air for quality and penchant for cost & time saving.

You would be responsible for complete technical coordination of the Project, encompassing overall Project Management (Scheduling and

Monitoring of Construction activities), and Quality Management, Contract Management (Billing and Payments) and will report to the Director.

You must have good communication skills and very good command of English Language (Speaking, Reading and Writing).

The posting will be at the Project site, which is 120km from Hyderabad international city and airport. Initially the contract will be for two years, with a view to extend. Salaries will be based on international standards

( negotiable ) and you will be o� ered an excellent package with Furnished accommodation ( single / married status ), Dining facilities available

onsite, Company car, Return � ights ( negotiable ), Basic medicalfacilities will be provided at site and covered fully ( other medical facilities

negotiable ), 30 days paid leave in a year.

Short listed candidates will be asked to attend an interview in London, UK in December ( Date and venue yet to be con� rmed ) .

Tel +44 (0)1202298322Oliver Tse ( [email protected] )

For further details visit www.hunterpersonnel.com

Tunnelling Project Manager ( India )

December 2007

WORK has begun on the first of two tunnels beneath the Allegheny River in Pittsburgh, US, recently as part of the Port Authority’s US$435 million North Shore Connector Project that will augment the T-subway extension by 1.9 km.

Three sections of a 6.7 m-diameter Herrenknecht TBM were lowered into the launch pit around 17 m below ground level. The machine will start excavating twin-bore tunnels linking downtown Pittsburgh with the North Shore.

At 731 m long, the tunnels are due for completion in late 2011 and will serve three new stations, extending the light rail system from downtown Gateway Station to Allegheny Station on the North Shore.

It is hoped that following test borings, the TBM will initially advance around 18 m, after which it will pause for the Christmas break. At the start of 2008, it will

advance a further 50 m for installation of the TBM train and allow excavation to begin properly around mid-January.

The North Shore Connector is a significant regional investment that will support the revitalised Downtown Pittsburgh and North Shore residential areas, business districts, educational institutions, entertainment developments and cultural venues, in addition to enhancing development opportunities. When complete, the T- extension is expected to carry around 14,000 passengers daily.

Work starts on North Shore connector

A FURTHER US$1 billion will be provided by the Port Authority of New York and New Jersey to construct the US$7.5 billion Hudson River rail tunnel project. This is in addition to the US$2 billion pledged by the Authority.

The tunnel aims to almost double the train capacity into Manhattan during rush-hours. Rising petrol prices and increasingly crowded highways are forcing more onto New York’s public transport and it is hoped the tunnel will ease the situation. The project is due for completion by 2017.

The Port Authority of New York and New Jersey is responsible for operating the airports, bridges and tunnels carrying car traffic between New Jersey and New York.

Pittsburgh, US

Route showing the extension to link to the North Shore area

Extra funding for Hudson

New York, US

Airport Metro express project: due for completion in 2010

02,04,06-08WT0712.indd 4 6/12/07 21:09:48

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�NEWS

HAVING flown into a windswept Antwerp on November 13, a select group of invited journalists were treated to the latest offerings from the Portable Air Division of Atlas Copco.

The raft of compressed-air products on display included the TwinAir range of container-ised air compressors – designed for numerous specialised drilling applications in ground engineer-ing. They are hailed as combining the largest volume of air flow at up to 1,058 litres/s and with a small footprint to boot.

Also included in Atlas Copco’s varied product display was the HardHat enclosures, which have now been extended from its

Series 7 range of compressors to cover two ranges of QAX generating sets. Designed for specialised drilling, pipeline and ground engineering contractors, the high impact, crack-resistant tops are designed to eliminate the corrosion problems associated with metal canopies.

On another front, the new range of Series 1 portable air compres-

sors was also unveiled, featuring a much smaller canopy and single-

axle undercarriage, all in a more compact package.

And a new variant of Cosmos was also on display, introduced last year, and designed to offer a remote management monitoring system for compressors and generators, but which has now been improved with the addition of a satellite option: the use of GPS ensures that equipment can be tracked at all times and in any location.

As well as viewing the products on display, journalists were also treated to a 90-minute talk by various AC personnel, including Geert Follens, president of AC Portable Air division.

Belgian compressed-air unveilingAntwerp, Belgium

IF YOU think driving through tunnels can be a boring experi-ence, and let’s face it, which of us doesn’t, then perhaps a drive through the latest Chinese road tunnel might result in an uplifting event.

Located deep inside Hunan Province in central China, the Xuefeng Mountain Express Highway Tunnel has special lighting effects designed to mimic a cloudy blue sky, reports local newspaper Changsha Evening News. Clouds changing against a blue backdrop, it is thought, will go some way to relieve eye strain.

The sequence begins with strong lighting at the tunnel entrance, followed by soft lighting which is finally replaced by the clouded sky, with the whole effect trying to achieve a more gradual visual transition.

As the third-longest highway tunnel in China, the Xuefeng tunnel has taken four years to construct and will cut the journey time needed between Changsha and Huaihua from eight hours to four hours. It opened to traffic on November 8.

Tunnel has a cloudy lining

Hunan Province, China

A PROPOSED A$1.5 billion tunnel in Brisbane, Australia, between Toowong and Kelvin Grove has been given the go-ahead, according to the Brisbane Times.

The 4.5 km Northern Link tunnel will connect the Western

Freeway at Toowong with the Inner City Bypass at Kelvin Grove and could cut motorists’ journey times by nearly half an hour.

Funding of A$500 million for the tunnel was committed by the Federal Opposition in

October, a boost which meant the tunnel project would proceed regardless of who won the up and coming election.

Motorists will have to pay A$3.70 to use the tunnel, which could be ready by 2016.

A blue sky with clouds is designed to help relieve driver eye strain at China’s Xuefeng Mountain Express Highway Tunnel

Tunnel go-ahead ‘down under’Brisbane, Australia

www.vmt-gmbh.de

ttc_magazin_add_rz.indd 11 12.09.2007 12:55:51 Uhr

02,04,06-08WT0712.indd 6 6/12/07 21:10:20

�NEWS

EUROPE’S first commercial high-speed Maglev (magnetic levitation) will be built in Munich, Germany.

An agreement signed on September 25 by signatories that included Bavarian minsters, Deutsche Bahn (DB- German Railways) and GSV (a manufacturing consortium comprising Siemens and ThyssenKrup) finalised the funding of the €1.85 billion Transrapid line to connect Munich city-centre with the airport. Able to travel at speeds of up to 450 km/h, the project will be designed and built by Siemens and ThyssenKrupp.

Great importance is attached to the project by both DB and GSV, which see the project not only as an important step in the future of magnetic levitation technology, but also as a key element in overall

German business competitiveness. The electro-magnetic Maglev system allows trains to hover above the track, providing an ultra-smooth and relatively faster train journey compared to traditional rail technology.

Bavarians, however, seem not to be impressed. A recent poll revealed that 60% of them oppose the scheme, with the city authorities also concerned over the high cost. Peer Steinbrueck, German finance minister, has said that the projected costs will be higher than anticipated as they are based on outdated

calculations.Such reactions are not

good news for the scheme, coming as they do only 15 months after the test run of a Maglev train in northern Germany ended in the deaths of 23 people when it collided with a parked

maintenance vehicle.When Munich’s planned

Transrapid is completed in 2014, it will take only 10 minutes to travel to the airport from the city-centre on the driverless trains, compared to the current 40 minutes. Starting at 17 m below Munich central station, the line will have 8.7 km of tunnel in three sections along its route to the airport.

China operates the world’s only commercial Maglev line – the 30 km link between Shanghai’s commercial centre and its airport at Pudong.

Maglev line in Europe debutMunich, Germany

HYDROGEN cars may be the panacea for reducing CO2 emissions, but recent research highlights their potential danger should they explode in a tunnel.

Unlike a crash with a conventional car, where petrol would collect on the ground and ignite, the scenario with a hydrogen car is more hazardous, according to recent research by Yajue Wu of Sheffield University, England.

Wu’s computer simulation is reported to have shown that in a serious collision, escaping hydrogen would form a giant, high-velocity, 2,000ºC jet flame that would stretch high enough to cause serious damage to the tunnel roof. The findings could cause a rethink on ceiling design if the hydrogen economy starts to take off.

Hydrogen cars driving rethink

Sheffield, UK

Munich will be home to Europe’s first Maglev linePhoto: Transrapid International GmbH & Co KG

Hunan Province, China

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02,04,06-08WT0712.indd 7 6/12/07 21:10:25

December 2007

�NEWS

Sandvik jumbos join giant planCURRENTLY one of the UK’s largest continuing tunnelling projects, the A3 Hindhead Tunnel will be constructed with the help of Sandvik’s tunnelling jumbos.

Main contractor Balfour Beatty recently awarded Sweden’s Sandvik Mining and Construction the supply contract for three DT820-AC twin boom with basket boom drills for use on the 1.8 km twin-bore tunnels. Two of the jumbos will be used for installing self-drilling GRP piles and probe holes, while the third unit will be used for drilling steel canopy support tubes.

The award follows Sandvik’s recent involvement on the Glendoe Hydro scheme in Scotland, where its jumbos and surface drilling machines are being used.

Although construction on the US$740 million A3 Hindhead scheme began in January, tunnelling is due to begin next January. When completed in 2011,

the project will feature 6.7 km of new dual carriageway that will complete the link between London and Portsmouth and alleviate bottlenecks such as that around the A3/A287 signal-controlled crossroads.

The tunnels will have sprayed concrete linings and cast in-situ portals. At Gibbet Hill, the tunnel’s maximum depth of cover is 65 m below ground level. As well as the bored tunnel length, there will also be around 0.1 km of cut and cover.

According to Balfour Beatty, the scheme involves a new style of early design and build contract that brings the contractor into the scheme at a very early stage, to prepare the design and assist with the statutory processes.

CONCESSIONAIRE TT2, the consortium comprising Bouygues Travaux Publics (a subsidiary of Bouygues Construction), HSBC Infrastructure Fund II and Bank of Scotland Corporate, has won the US$738 million Tyne tunnels concession contract. Bouygues TP will carry out the US$517 million construction work.

The project will involve designing and constructing the New Tyne Crossing, comprising a proposed vehicle tunnel beneath the River Tyne in Newcastle, as well as renovating the existing tunnel and the financing and operation of

both tunnels for 30 years.Designed to relieve congestion

on the A19 connecting north and south of the Tyneside region, the project will start in May 2008 and be staged to build the new tunnel and then refurbish the existing, a process due to take four years. About 700 people are expected to be working on the tunnel at peak.

At 1,600 m long, the new tunnel will be the same length as the existing, and will include a 360 m-long section of immersed tube beneath the river, made up of 90 m-long precast concrete elements. When complete, traffic

will be diverted through it to allow renovation and upgrading to begin on the existing tunnel. Traffic will be able to use both tunnels by December 2011.

Funding for the project will come from various sources. Tyne & Wear Passenger Transport Authority will provide a US$236 million subsidy; HSBC Infrastructure Fund II, Bank of Scotland Corporate, and Bouygues Travaux Publics will provide US$80 million in capital, and TT2 has contracted a US$428 million senior debt loan from banks HSBC

Bank plc, Bank of Scotland Corporate and Natixis.

Bouygues Construction chairman and CEO Yves Gabriel said: “This project is our first major civil engineering contract in the UK, and illustrates our ambition to develop all our lines of business in the country.”

LOVAT reports various states of progress of its TBMs globally.

In Seville, Spain, its RME238SE Series 21300 TBM, excavating the second of two tunnels for the city’s Line 1 metro, has recently broken through at the Plaza de Cuba station.

The TBM has encountered geological conditions that mainly comprise gravels, sandy

gravels and blue marls, but also silty sands and clays. The entire alignment is below ground-water table with a maximum 15 m of groundwater height above the tunnel invert. Completion of the 2.2 km-long tunnel is expected in mid-2008.

On another front, an RME129SE Series 23500 EPB TBM was recently delivered to Russian contractor Spetstonnel-

stroy for use on the construction of the Babushkin Substation Cable Tunnel in Moscow. The 3.3 m-diameter TBM will have to bore the length of the 682.5 m-long tunnel in water-saturated soils below groundwater level. Soils will mainly comprise silty sand, fine to course grain sand and gravel, with water height of up to 10 m above the tunnel alignment and depth of cover varying from 5

to 20 m. Lovat also designed and supplied the segmental tunnel lining. Tunnel excavation is set to begin by the end of this year.

In Sydney, Australia, contractor Theiss Pty recently signed a contract with Lovat to deliver a 3.7 m-diameter RMP147SE 22001 TBM, en route to Australia for use in the construction of Sydney’s City West Cable tunnel.

Lovat reports global progress

Hindhead, UK

IRAN and Tajikistan are reported to be speeding up efforts for the construction by Iranian contractors of a tunnel in eastern Tajikistan. Iran’s energy minister recently visited the Tajik capital, Dushanbe, to further foster joint construction works in the Central Asian republic.

Talks were held with the Tajik Transport and Communications minister on the construction of the Charmaghzak tunnel, to be 50 km south of the capital.

If constructed, the US$140 million project would become a key element in the regeneration of the Tajik economy. Following feasibility studies, the Iranians have indicated they would be ready to begin construction.

Iran talks foster tunnel accord

TT2 wins Tyne tunnels concession contract

Seville, Spain; Moscow, Russia; Sydney, Australia

Newcastle, UK

View of the New Tyne Crossing route

Dushanbe, Tajikistan

Sandvik jumbos primed for construction on the Hindhead project in January

02,04,06-08WT0712.indd 8 6/12/07 21:10:39

December 2007

�

COLOGNE, Germany, was the venue for the 21st STUVA biannual event, from November 27-29. Called ‘Connections

by Tunnels’, the conference spanned two days, with technical visits on the third. Attendees have always been well over 1,000. This year, the attendance was one of the highest, with over 1,400 from 29 countries and 130 exhibitors.

CONFERENCEAfter the official opening and welcome speeches, Prof Dr Ing Alfred Haack, managing director of STUVA, gave the keynote lecture on Trend-setting Development in Tunnel Construct-ion and Operation. After a brief summary of the historic development of transport tunnels in Ger-many and the need for new tunnels in Europe and worldwide, Prof Haack stressed the need for technological developments in the building and operation of transport tunnels.

The session on international projects included:Ë�The 3 km-long Grouft twin road tunnels in

Luxembourg.Ë�An update on the development of the Alp

Transit Gotthard twin tunnels.Ë�The construction of the 1.2 km length of the

Gotthard Base Tunnel in squeezing ground.Ë�The progress on the Ceneri Base Tunnel of the

Alp Transit.Ë�The planning and construction of the twin

Carmel Tunnels in Israel.Ë�The special environmental protection

measures required during the construction of the Malmo City Tunnel in Sweden.

Mechanised tunnelling was the subject of the second session. The first paper by Martin Herrenknecht, discussed his company’s 40-plus TBMs made for Chinese metro and road tunnel projects, including the world’s largest two TBMs of 15.43 m in diameter, currently working on the 7.5 km-long tunnels to Chongming Island, Shanghai.

Other presentations in this session included: recent developments in mechanised tunnelling; gasket systems under high water pressure at launch and reception shafts; high shove loads due to TBM steering problems; studies of shield tail deformation during boring; and a paper on

the first use of 19 in (483 mm) wedged-locked, back-loading cutters for the Kárahnjúkar Hydro Project in Iceland.

The last session of the first day was about safety during construction and operation. The first paper discussed ‘Guidelines for Planning and Implementing a Health & Safety Concept to Underground Construction Sites’, prepared by D-A-CH group (Germany, Austria and Switzerland). Although initially a German speaking paper, the guidelines are being discussed with the International Tunnelling Association (ITA), the aim being to gain international acceptance. Other papers covered: measuring stresses in tunnel linings; new techniques to improve safety with fuel cells; wireless signal transmission, and other control technology; and criteria for assessing different types of busy road junctions in tunnels.

Day 2: R&D anD fiRe pRotectionTwo papers on research and development began the second day, with one on the future role of the International Tunnelling Association in underground construction; and, STUVA and its involvement in European construction research.

The second session on fire protection was a key one involving six papers. The first, from STUVA, covered structural fire protection in underground stations, various smoke removal systems, protection to stairways and improved

features for rolling stock. Other papers covered the use of lifts for the evacuation of physically impaired people during fires; testing and safety equipment in the Gotthard Base Tunnel; fire tests of water mist systems in road tunnels; sprinkler systems; and telecommunications, person detection and co-ordination of emergency services in tunnel construction.

Tunnelling in difficult ground conditions was the subject of the third session. Papers covered the increasing use of freezing methods in the construction of tunnels; experience and problems in the use of ground freezing in Berlin; geotechnical challenges in the construction of the Schmücke Tunnel in Thuringia, Germany; and, yielding systems for tunnels in heavily swelling rock.

During the afternoon, papers on legal, contractual and insurance issues were presented. These covered new contractual provisions in road tunnels in Germany; risks of incidents during construction; coping with contractual requirements; legal arguments in the construction, shortcomings and damages related to underground works; ground-related risks in connection with alternative proposals; and, the new international insurance “The Code of Practice for Risk Management of Tunnel Works”.

The last session, as always, covered underground construction works in Cologne, and was an introduction to the site visits the next day. Five papers covered the many working sites in Cologne. The urban development and transport systems, the challenges in the construction of the North – South Light Rail Line, including the special measures used, minimising risk when underpinning the foundations of structures, and special aspects of the construction of the southern section.

Seven site visits on the third day completed an excellent and informative conference. In 2009, the conference will be in Hamburg.

StUVa sets new recordFormerly a mostly German affair, the STUVA-TATUNG ’07 conference on developments in underground construction is becoming a more international event. Rodney Craig visited for World Tunnelling

eXHiBitionS & confeRenceS: Germany

The STUVA Prize for a special innovation in underground construction was first awarded in 1997. The 2007 recipient was the Dutch Betuwe Route project, the second time awarded to a project, not an individual.

The project has provided a goods-train link between the Port of Rotterdam in the Netherlands and the Ruhr District in Germany. It was officially opened by Queen Beatrix in June. The 104 km of new alignment in the Nether-lands includes five tunnels totalling 18 km in length. Three main tunnels were built with one EPB and two slurry TBMs; for the first time, one of the slurry TBMs combined excavation and erection cycles concur-rently.

STUVA prize The Betuweroute: the Netherlands’ link to the Trans European Network’s Trans European Freight Rail Network

09WT0712.indd 9 6/12/07 21:12:21

December 2007

10FOCUS: North America

CURRENTLY under construction, the Brightwater System will add crucial plants and conveyance systems to meet

the rapidly-growing North Seattle area. Fortu-nately for the area’s residents, foresight in the 1950s and continued analysis of sewer systems has culminated in this large-scale major tunnel and treatment programme to meet current and future needs.

Turning influent into clean useful effluent that can safely be deposited environmentally in the area’s bays and sounds, the project will be covered as three separate jobs, each having its own unique conditions.

On October 20, 2005, the first contract on the long-awaited Brightwater Conveyance System was bid, with the low bid of US$131 million presented by the JV comprising Kenny Construction (Sponsor), JF Shea Company and Traylor Bros. After a lengthy protest by the second bidder Jay-Dee/Coluccio JV, the project was awarded on December 29, 2005 and the notice to proceed issued on January 30, 2006.

GeOlOGiCal SettinGThe Brightwater Conveyance System lies within the Puget Trough, a structural basin between the Olympia Mountains and the Cascade Mountains, formed by the Juan de Fuca oceanic plate being thrust beneath the North American Continental plate. A north-south compressional regional stress component caused by the northward movement of the Sierra Nevada tectonic block has created a series of smaller blocks and basins within the volcanic bedrock. Depth to bedrock in the project area (122-457 m) will not be encountered during construction. The bedrock is overlain by glacial and non-glacial sediments, through which the Brightwater Conveyance System will be built.

Puget Trough’s geological history is dominated by a succession of at least six continental glaciations. As glaciers advanced, large lakes were formed where silt and clay were deposited. As the ice sheets advanced further to the south, the supply of sediment to the lake coarsened and sand and gravel filled the lowland. When the ice reached about the latitude of the project, sub-glacial melt water

and ice reworked the sediment and rock, carrying further south. As the climate warmed, the ice stagnated and began to melt as the ice front receded, depositing its entrained sediment over the uncovered landscape. Each successive glaciation partially eroded the pre-existing ground surface, and then deposited a fresh sequence of sediment over the land.

GrOUndwaterA sequence of aquifers and aquitards varying in thickness and lateral continuity have been formed by this depositional environment. Aquifers comprise granular water-bearing sediments and the aquitards contain finer-grained sediments reducing water flow. In the project area, six deposits were identified as aquifers or aquitards. Groundwater flow through the area is initiated by recharge infiltrating the ground in uplands and moving down until reaching the uppermost regional aquifer.

Movement of groundwater between the upper aquifer and the underlying aquifers will be slow, reflecting the layered nature of the glacial and non-glacial deposits, and the presence of thick lower-permeability confining deposits. The presence of vertical gradients between aquifers means changes in groundwater head will be experienced as the tunnel heading transits from one hydro-geologic regime to another. Groundwater head at the tunnel invert

intrados will be up to 3.2 bar pressure at locations along the East Combined Tunnel.

COnStrUCtiOnIn January 2006, the contractor mobilised on site, installing utilities and screen/sound wall, followed by placing the guide walls for the (IS) shaft, 39.6 m deep, and the (IPS) Shaft, 48.76 m-deep.

Bencor, the slurry wall subcontractor, started actual slurry-wall excavation in June 2006 on the (IS) shaft but finished in early fall after a six-week delay due to an operators’ strike against the ready-mix concrete suppliers in King County. This was followed by the 27 m deep IS shaft excavation in the wet and the pouring of the 4.1 m steel reinforced tremie plug. After dewatering, a cast-in-place final lining of the shaft was achieved in two three-pour lifts, including portals for launching the Brightwater-East tunnel, the receiving portal of the

A major large-scale tunnel and treatment programme will go a long way to meet the sewerage demands of North Seattle. Jack Burke reports

Brightwater on track for north Seattle

Ë

Ë�4,282 m of 5.74 m-diameter, EPB TBM mined tunnel using 5.1 m inside diameter bolted, gasketed pre-cast concrete segments for a primary liner.

Ë Installing and grouting 4,328 m each of 122 cm, 168 cm, 68.58 cm and 213 cm-diameter pipes inside the tunnel with three runs of fibre-optic cable.

Ë 741m of 183 cm-diameter microtunnel including three shafts with structures, one Influent Structure (IS) for mining 22.5 m deep and 24.3 m diameter, with 39.6 m-deep slurry diaphragm walls, tremie slab and final concrete wall lining.

Ë One Influent Pump Station shell (IPS) 25.3 m deep, twin 25.6 m (inside diameter) cells, with 48.8 m-deep slurry diaphragm walls, tremie slab, and final lining.

Ë Two short 3.66 m-diameter connector tunnels.Ë One extraction shaft 12 m deep x 12 m wide and 42.6 m long for connection to treatment

plant piping.

East Contract: project details

Aerial view of the Brightwater site, May 2007

10,12WT0712.indd 10 6/12/07 21:01:10

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Brightwater-Central tunnel and three more portals for a microtunnel and two connecting ones between the IS and IPS structures.

Hayward Baker placed jet grout blocks for all the break-outs and break-ins to the IS shaft – 5.9 m for the Brightwater-East Combined Tunnel, 4.9 m for the Brightwater – Central Bothell Combined Tunnel, the 1.8 m North Creek Connector Microtunnel, and a large block for the length of the two 3.7 m by 10.6 m-long interconnecting tunnels.

Before the Brightwater-East tunnel could start, the 1.8 m-diameter micro tunnel had to be finished from the (IS) Shaft to Pit No 1, a caisson 6 m in diameter and 23 m deep with a tremie poured plug in the wet before dewatering. After finishing the first 275 m run, the microtunnel was extracted and prepared for two more runs (365 m and 100 m), using two further 6 and 8.5 m-diameter caissons, both 23 m deep with tremie poured plugs. All the caissons and the IS and IPS slurry walls used fibre-glass reinforcing steel in the concrete for the respective portals.

After completion of the IS slurry walls, Bencor started the slurry wall panels for the Binocular twin 25.6 m-diameter shafts and centre wall using 48.7 m deep, 1.22 m-thick panels. The slurry walls were finished in January 2007.

After completing the concrete lining in the (IS) shaft and finishing the microtunnel, a concrete

launch pad was placed across the IS shaft in line with the tunnel and affixed with launching rails to assemble the 5.9 m Lovat EPB TBM. A critical delay in manufacturing the Lovat EPB TBM was due to the late delivery of the cutterhead drive bearing made by Rotek, Ohio, which was due to increased government priority orders for the Iraq war. A request for a time extension is under review by owner King County.

On July 17 and 18, TBM tests took place in Toronto, with non-production bearing and disassembly starting the same week. Delivery of the TBM started in early August and the production bearing installed in the motor plate at Lovat and delivered to site on August 31. TBM assembly took place on the launch block, but suffered problems associated with the front and rear articulation seals. These have been replaced

after reworking the seats, but they could not be tested until the EPB TBM and shaft seals are pressure-tested after installing the first three tunnel precast segment rings.

The TBM has mined through the slurry wall into the jet-grouted block and the first intervention (free air) was completed on October 19. Final phase II TBM assembly was finished during the week of October 21, followed by mining 4.6 m and sealing the portal before breaching the portal block. The TBM and portal seals were tested by pressurising the tunnel face while in the block.

With the completion of the slurry walls at the Influent Pump Station (IPS) and the excavation in the wet of the twin 25.6 m-diameter, 30 m-deep shafts, preparations were made for the massive 4 m-thick, steel-reinforced tremie pours. The preparations (underwater with divers) included the underwater cleaning of the tremie contact area around the perimeter of the shaft, the removal of the formed keys in the slurry walls, insertion of shear dowels, placement of concrete pedestals to support the placement of the 91 t (100 tons) of reinforcing steel, not including structural support frames, for each plug.

After final preparations were made for the first tremie pour (west lobe), on October 27, with eight fixed tremie pipes 30.5 cm in diameter and one floating tremie pipe attached to a floating work platform, the pour was initiated using 7.6 m3 transit mix trucks supplied by Glacier Concrete – which arrived at an hourly rate of up to 40 – to give the 2,052 m3 (2,700 yd3) total. The west lobe pour started at 4am and was done by 3am the next day, utilising two dedicated Glacier concrete plants and two Brundage-Bone Schwing 47 m boom concrete pumps. The size of the pours meant it was necessary to pour the tremies separately and to have a

weekend in between due to concrete supply requirements for other Glacier customers and overtime restrictions for transit mix drivers.

Preparations then began on the same process for the tremie pour in the remaining east lobe. On November 10, the east lobe was poured without a hitch.

December 2007

Ë

Boring pipe 96 in the micro tunnel, view west. Above right: TBM for Brightwater-East

“Before the Brightwater-East

tunnel could start, the 1.8 m-diameter micro tunnel had to be

finished”

10,12WT0712.indd 12 6/12/07 21:01:31

December 2007


THE Arrowhead Tunnels Project repre-sents the fi nal portion of a 70 km water conveyance facility that will

bring up to 28 m3/s of water into Southern California. The 13 km tunnelling project is well underway and consists of two, 5.8 m-diameter TBM bores through extremely vari-able geological conditions.

The tunnels lie near the base of the San Bernardino Mountains and several signifi cant faults, including the San Andreas, run within 1 km of the tunnel alignment. Other signifi cant faults cross the tunnel alignment and water pressures in the tunnel have been recorded as high as 20 bar (300 psi).

Conditions have ranged from hard rock with no water infl ows to full-face granular material under 10-bar pressure and of over 32 litres/s (500 gal/min) infl ows. Due to the range and severity of ground and water conditions encountered, the owner-contractor-designer team eventually found that adjusting the means and methods for greater responsiveness – virtually on a day-by-day basis – was needed to suit the conditions.

PROJECT HISTORYFollowing the award of the fi rst contract to Shank/Balfour Beatty in January 1997 for US$88.4 million, the project was mobilised and work started at the city portal. The plan was to drive westwards to daylight at Strawberry Creek Canyon Portal in Waterman Canyon.

Shank/Balfour Beatty opted for support by

concrete segments expanded against the rock, with screw jacks in the open crown, for temporary support. The fi nal lining would be Reinforced Concrete Cylinder Pipe (RCCP). TBM design was by the contractor, and included hydraulic segment erector and associated probe and grout drilling packages. The contractor designed and fabricated the segments on site.

An extensive pre-excavation grouting programme and a cycled grouting project were established. Excavation took place on a single

shift, with maintenance on swing shift and grouting operations conducted from 9pm to 7am. As the tunnel advanced, heavy, high-pressure water infl ows and squeezing ground halted the TBM’s progress and made it obvious that the ground conditions were different from those indicated in the documents.

Forward progress came to a halt and resumed slowly. In 2000, after mining about 2,400 lin m, all work was permanently suspended when large ingresses of water at pressures up to 17 bar were encountered. The water ingress rate was critical as the agreement with the US Forest Service and other water users mandated maximum water infl ow not to exceed 37 litres/s in the East tunnel. Negotiations resulted in contract cancellation, TBM removal, construction of a bulkhead at the tunnel face, and the excavated tunnel lined with 3.65 m-diameter RCCP and fully encapsu-lated with cellular grout in late-2000.

ARROWHEAD EAST & WEST IIThe Arrowhead East and West Tunnels have a fi nished inside diameter of 3.65 m and cross the mountainous terrain north of the City of San Bernardino. The work includes completing the East Tunnel, constructing the West Tunnel, fi nishing the links between the tunnels with pipe-lines and restorating the site. The remaining 6,840 m of the East Tunnel excavation must proceed in a down-grade drive from the Strawberry Creek Portal. Building the 6,062 m West Tunnel is being completed from the Waterman Canyon Portal.

Both tunnels have been excavated through variable ground conditions ranging from highly fractured to massive, moderately jointed igneous and metamorphic rocks. Numerous faults and shear zones containing clay gouge, crushed rock, brecciated and highly fractured rock have been encountered. At or near the existing ground surface, the rock mass can be completely to moderately weathered but at tunnel depth ranges from highly altered to fresh. The East Tunnel is being excavated beneath ground cover of 15-630 m, while the West Tunnel has ground

Arrowhead on target in the ‘Sunshine State’Jack Burke outlines the problems, challenges and solutions implemented on the Arrowhead Project in Southern California, where two hybrid TBMs are advancing on a diffi cult project

Ë

File photo showing an aerial view of the Strawberry Creek

TBM assembly

The San Bernadino Mountains

13,15-19WT0712.indd 13 10/12/07 10:46:11

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cover in the 15-335 m range. High 15-335 m range. High ground water infl ows with high hydrostatic pressures were anticipated pressures were anticipated through the highly fractured through the highly fractured rock mass along both tunnel rock mass along both tunnel alignments. Much of the high-alignments. Much of the high-volume, high-pressure groundwater volume, high-pressure groundwater infl ows have been controlled using an infl ows have been controlled using an effective pre-excavation grouting programme. The limitations of such a programme in a variable and highly fractured rock mass were constantly reviewed and modifi ed.

GEOLOGY / GROUND CONDITIONSBoth tunnel alignments lie beneath mountainous terrain that is part of the San Bernardino National Forest. The area’s geology is highly complex and ranges from intact to highly-weathered and altered gneiss, marble/calc-silica gneiss and granitic rocks. These challenging conditions necessitated the design of two, one-of-a-kind, hard-rock TBMs, subsequently modifi ed to suit the prevailing ground and water infl ow conditions.

ADVANCE RATESThe more water encountered at the face, the slower the overall mining advance rates. This was due to the need to perform more pre-excavation drilling, grouting and water handling, as well as the presence of excess quantities of fi ne material often found with the muck. Fault, gouge and shear zones have also contributed to slower advance rates, as well as to highly altered rock.

PRE-EXCAVATION DRILLING AND GROUTING OPERATIONSProbing and grouting ahead of the TBM (probe-hole drilling and pre-excavation grouting) was required for both tunnels. It was necessary to:Ë Minimise and control the effects of tunnel

excavation on the groundwater resources in the project area to satisfy the requirements of the USFS Special Use Permit.

Ë Reduce ground-Reduce ground-water infl ows into water infl ows into the tunnel to the tunnel to facilitate excavation facilitate excavation and installation of and installation of the primary support the primary support system that would system that would ultimately benefi t ultimately benefi t installing the fi nal installing the fi nal tunnel liner.tunnel liner.

Ë Improve the ground conditions and, therefore, tunnelling advance rates.

The US Forest Service Special Use Permit limited groundwater infl ows into the tunnel heading to no more than 37 l/s (580 gal/min) for the West Tunnels and 33 l/s for the East Tunnel. This was achieved by combining the following:Ë Pre-excavation water

control and ground improvement grouting in multiple stages as needed.

Ë Filling of discontinuities in the rock mass as encountered to avoid running or ravelling ground conditions at the face, around the shield and the primary segmental tunnel liner.

Ë Fitting watertight prim-ary support, providing full ground support with backfi ll grouting.

Ë Fitting infl atable segment collars, in combination with backfi ll grouting.

Ë Installation of drain holes through the precast tunnel lining in specifi c locations as needed to relieve excess groundwater press-ure and improve ground conditions for mining.

Pre-excavation grouting was initially performed, as directed by the owner, to reduce groundwater infl ows to typically 16 litres/s in the 30 m interval from the tunnel face back to the portal. However, the extent and potential for improvement in ground stability could not be quantifi ed directly by more grouting. Furthermore, it was always uncertain whether probe drilling would be

successful in detecting groundwater infl ows and geological features that would impact the mining operations.

Pre-excavation grouting was initially planned along any length of tunnel depending on measured probe hole infl ows from two verifi cation holes. The owner established an initial value in which a probe hole infl ow that exceeded 0.06 l/s/m (0.3 gal/min/ft) (or a concentrated fl ow of 114 l/min) at any point in the probe hole) represented the threshold at which pre-excavation grouting was initiated.

Drilling and grouting equipment and methods were designed for stage grouting since some drill-holes would not stay open due to unstable ground conditions, such as highly fractured

Controlling water infl ows was key

Ë

ËInside the tunnel

13,15-19WT0712.indd 15 10/12/07 10:46:18

16

rock, gouge, weathered and altered rock. Experience found that due to the uncertainty of groundwater infl ows through a fractured rock mass, probe holes would not necessarily detect all potential groundwater infl ows, as well as areas where mining would be diffi cult.

Probe-hole drilling took place ahead of the tunnel face through 15 drill ports at 1.5° in the TBM face and 19 locations at 4°, also through the face. Two probe holes were normally drilled about 180º apart along the longitudinal axis of the tunnel. A minimal overlap of 6.1 m at the face between successive set-ups of probe/grout holes was enough to maintain a grouted plug. Probe holes were limited to 61 m in length and grout holes to a maximum 45 m due to the uncertainty in hole location for longer holes and the reduced effectiveness of grouting long holes away from the face.

To date, a great deal of time spent driving the tunnels has been taken up with pre-excavation drilling and grouting before the TBM was able to advance. Notwithstanding, this operation was crucial to successfully and safely mine the tunnels through highly variable strata and in sometimes unknown and uncertain geological and water-bearing features that needed grouting for water control and/or ground improvement.

Other grouting projects were also required to control water infl ows (see Tables 1 and 2).

SEGMENT LINING, EDPM GASKETSA bolted and gasketed, precast concrete segmental lining was specifi ed as the primary support system for the entire length of both tunnels. Previous reports and publications substantially addressed the design and manufacture of precast segments.

GROUND BEHAVIOUR The contract documents described the subsurface conditions and behaviour anticipated during construction of the East and West

Tunnels. These documents and, in particular, the Geotechnical Baseline Report (GBR), presented the owner’s best judgment based on data from surface geologic mapping, exploratory boreholes placed along and in the general area of the tunnel alignments, and assumptions about the contractor’s means and methods for tunnel excavation and support. The minimum requirements for tunnelling equipment specifi ed by the owner were co-ordinated with the anticipated ground conditions and behaviour.

Item Description Pre-excavation grouting Annular grouting Water Ground Voids Stage I Stage II A CEMENTITIOUS PRODUCTS 1 Portland cement – Type II ● ● ● ● ●

2 Portland cement – Type III ● ● ●

3 Rapidset cement ● ● ●

4 Micro-fi ne cement ● ● ❍

5 Fly ash ● ●

B CHEMICAL PRODUCTS 1 Polyurethane grout ● ● ❍

2 Sodium silicate ❏ ❏

3 Colloidal silica ● ❍ ❍

4 Minova Celbex 802 ❏

● = Primary grouting material; ❍ = Secondary grouting material; ❏ = Trial & test grouting material

Table 1: Grouting and corresponding operationsË

FOCUS: North America

13,15-19WT0712.indd 16 10/12/07 10:46:19

17

GROUND BEHAVIOUR TO DATEWhile the anticipated ground conditions were “variable”, as generally described in the GBR, a wide spectrum of ground types and behaviours was actually encountered. The rate of change from one type to another was often frequent and even dramatic, to the extent that extremely hard material could be encountered on the same day as soft and raveling material. Also, the face could exhibit very competent hard material (with and without water infl ows) at the same time as loose ground in another portion of the face.

Periodically, acute geological features would release signifi cant fl ush infl ows and even fl owing ground resulting in the formation of a cavity that required an immediate halt to mining

Ë Stage I backfi ll grouting: Injected as the TBM advanced to fi ll the annular void surrounding the segmental tunnel lining with a sand-cement (Type II) grout. Various anti-dispersion agents and grout accelerators were also used on an experimental basis.

Ë Stage II contact grouting: Injected periodically as the TBM advanced and completed the fi lling of the annular void surrounding the tunnel liner with neat cement (Type II) grout.

Ë Drainage holes: Installed at 20° through the segmental tunnel lining to relieve excess hydrostatic pressure and infl ows into the cutterhead plenum and to assist with ground stabilisation and pre-excavation grouting procedures.

Several grouting materials have been used to control infl ows and ground improvement. Some are still in use depending on mining conditions at the heading (See Table 1). Other materials are under test and may be used later for water and ground control needs.Ë Micro-fi ne cement: Used for most rock and rock-like conditions to curtail water infl ows and

improve structural properties of the rock mass for mining. Various mix designs and pressures were routinely used.

Ë Types II and III cement: Used for most rock conditions to curtail water infl ows and improve properties of the rock mass for mining, following the completion of grout injection with micro-fi ne cement.

Ë Colloidal silica grout: Used in strata that while producing water infl ows, resisted penetration from micro-fi ne cement grouts – even in diluted concentrations. This material was successful in reducing water infl ows.

Ë Polyurethane grout: Used in the tunnels with limited success to control groundwater infl ows and fi lling voids. Based on experience, this material did not work well under high water pressures when injected in to bore holes.

Ë Chemical grout: Sodium silicate grout was used in the tunnels and portals to consolidate loose and brecciated rock and to control groundwater. This material had limited success in tight rock formations and where clay was present.

Table 2: Grouting materials

Ë

Checking water

ingress


13,15-19WT0712.indd 17 10/12/07 10:46:27

December 2007

18

operations and then backfi lling. On occasions to date, decomposed rock acting like sand and silt, blocky ground with large pieces dislodged from the face, both white and grey marble, as well as very competent granitic material have been encountered.

High in-situ water pressures and fl ows have, from time to time, been very adverse and have daunted the pre-excavation grouting programme to the extent that this programme was often adjusted before each mining cycle and constantly assessed during actual grouting to be responsive to the actual conditions encountered.Sometimes, unusual ground conditions have been encountered that have resulted in various situations and delays to the work (see Table 3).

The contractor’s tunnelling crews, together with the owner’s geological and grouting experts, developed a toolbox of fl exible and innovative means and methods to cope with a wide range of ground and water conditions. The aim was to achieve effective pre-excavation grouting and to optimize the TBM advance safely while constantly controlling water and ground conditions.

TBM CHANGES & TRAILING GEARBased on experience and performance in the variable ground and water conditions, several modifi cations were made to the TBMs in 2005 to cope with the conditions (see Table 4).

SLURRY HANDLING & SEPARATION Slurry handling and separation systems did not originally form part of the Herrenknecht TBMs. The TBMs did, however, have a powerful dewater-ing system in accordance with specifi cations and were designed to pump high volumes of water from the heading out of the tunnel. As truly hybrid rock-cutting machines, the TBMs were designed to operate with a screw auger for muck handling but not with a pressurised plenum chamber, unless fi nes build-up in the auger could be established – based on muck characteristics.

They were not designed to handle high volumes of fi nes (sand-sized particles) that, in

practice, could sometimes be way in excess of 50% of the material excavated from the tunnel face. Additionally, and to compound the problem, excess water conditions periodically developed in the heading that overwhelmed the muck-handling system and, therefore, affected the mining production to the point where an alternate or supplemental means of handling the muck was needed (see Table 5).

This innovative system was integrated into the existing TBM and trailing operating systems and equipment wherever possible, so as to become a

seamless function and controlled with the overall mining operations.

CONCLUSIONS & SUGGESTIONSThe Arrowhead Tunnels Project is probably one of the most challenging tunnel projects in the US, having taken longer to excavate than planned.

The ground and groundwater conditions are extremely variable and could not be adequately predicted due largely to the extent of ground cover as well as the degree, frequency and severity of the alterations in the rock mass,

Squeezing and packing ground around the TBM:Ë Squeezing ground Extremely high thrust pressures needed to advanceË Packing ground Extremely high thrust pressures needed to advanceË TBM seized in ground Thrust force up to 114 MN applied to the shieldË Unstable ground/squeezing Hand-mining around the shield to free the TBM

Ravelling ground conditions at the face:Ë Tunnel face ravels Delay to the tunnel advance rate due to loss of faceË Tunnel face loose & fall-out Delay to allow for backfi lling the face with sand-cement groutË Tunnel face partial collapse Breasting and special grouting operations to stabilize

Weak rock drilling conditions at the face:Ë Weak rock at face Slow penetration rates due to hole collapseË Ravelling drill holes Hole collapse and loss of steel needing casings to advanceË Seating grout packers Ineffective and time consuming due to loss of groundË Seating grout packers Multi-stage drilling and grouting needed to be effective

Hard rock conditions at the face:Ë Very hard rock Slow advance rates, heat build-up in TBM, cutter wearË Very hard massive rock More cutter wear, machine repairs, more time to advance

Water infl ows and pressures:Ë Excess water pressure Delay to drain and secure the heading from excess waterË Excess water infl ows Additional grouting to seal and secure vital equipmentË Excess fi nes in muck Mucking and slurry separation systems overwhelmed

Tunnel plug unstable, weak or leaking grout:Ë Unstable plug at face Delay to drilling & grouting until grout sets in multiple stagesË Weak plug at face Grout leakage and pressure loss limiting effectiveness

Table 3: Ground conditions, behaviour and impacts on mining operations

Description Original TBM design Modifi ed TBM designCutterhead operational torque (kNm) 2,000 3,520 Cutterhead exceptional torque (kNm) 2,323 4,400Cutterhead speed (max rev/min) 9.75 7.5Cutterhead rear annular gap (mm) 100 75 Shield thrust (kN) 29,270 58,540 Probe drilling holes 26 each (1.5° & 8° lookout) 45 each (1.5°, 4° & 8° look-out)Probe drills 4 each; 1 front, 1 erector, 2 rear 5 each: 2 front,1 erector, 2 rearScrew auger 13.35 m single-piece unit 4-piece (3.35 m each piece)EPBM capabilities None Sensors, mixing arms, foam mixerSlurry handling/separation system None 54 litres/s (850 gal/min) max

Table 4: changes and improvements to the TBMs

Grouting and face conditioning


Ë

13,15-19WT0712.indd 18 10/12/07 10:46:30

19

December 2007

including the infl uence from nearby faults. The pre-excavation grouting programme was intended to address and arrest groundwater infl ows into the tunnel as a measure to comply with the US Forest Service Special Use Permit. Ultimately, this essential drilling and grouting programme was adjusted to be more fl exible and used to accomplish the following:Ë Install probe holes to measure water infl ows and

to assess the rock mass character, relative hardness and stability.

Ë Inject cement grouts and/or colloidal silica grout to curtail water infl ows and to improve the quality of the rock mass for mining. Alternate grout materials have been tested and used periodically.

Ë Improve the effectiveness of Stage I and II backfi ll grouts at enveloping the seg-mental tunnel liner without the adverse infl uence of excess water infl ows surrounding the tunnel and the TBM.

Ë Help minimise the stress relaxation of the rock mass as a result of the modest over-excavated volume needed to advance the TBMs in all ground conditions.

The TBMs, as originally designed, modifi ed and adjusted throughout the tunnel drives, should be considered a signifi cant achievement toward improving tunnelling technology and mechanical excavation capability in very adverse ground conditions, and an example of the combined use of innovative systems.

The stout design and high-quality manufacture of the precast segmental tunnel liner was also a

hidden benefi t. This is especially true when it was tested in situ with as much as 114 MN thrust, or four times the original TBM thrust load, in order to move the TBMs forward in very diffi cult squeezing and packing ground conditions.

An effective pre-excavation drilling and grout-ing programme was absolutely essential to successfully mine the tunnel in the presence of high groundwater pressures and fl ows. Optimisation of the programme was a continuous task and just as the ground conditions were variable, the pre-excavation drilling and grouting project was equally fl exible and adjusted to suit. A prescriptive and

infl exible programme would have proven to be unworkable and not been responsive to the ground conditions and behaviour encountered.

The owner, designer and contractor constantly worked together to discuss and evaluate various means to drill and grout in order to control water (fi rst), then to improve the ground (second), so as to be able to mine the tunnel faster and reduce risks. Groundwater pressures and fl ows and their effects on the ground behaviour became the “enemy” and were eventually treated in a manner that not only provided control of infl ows but also improved the safety and production of the overall mining operation.

Description System or capacity Primary equipmentPeak fl ow rate 54 litres/s Habermann slurry pumpNominal fl ow rate 41 litres/s Habermann slurry pumpSolids separation Screens, clarifi er and centrifuge Brandt Equipment at the portalFines suspension <6% nominal to a 15% maximum

(by volume) and dependent on fl ow character

Slurry medium Water in a closed re-circulation circuit with additives injected at the plant

Table 5: Slurry separation system design and operating characteristics – original design

“An effective pre-excavation

drilling and grouting

programme was absolutely

essential”

Variable groundwater conditions encountered

Probe fl owsmeasure water infl ows


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Piezometers • Extensometers • Load cells •Total pressure cells • Temperature sensors •Strain gauges • Data acquisition systems

Onsite technical assistance also available

Complete Range of Instruments for Tunnel Monitoring

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13,15-19WT0712.indd 19 10/12/07 10:46:40

December 2007

20

GUIDANCE systems are being continually enhanced, thanks to the rapidly expand-ing use of tunnelling machines for the

mechanical excavation and removal of spoil during the tunnelling process. This ensures that the desired alignment is maintained even at the rates of advance achieved by the current genera-tion of tunnelling machines.

Other tunnelling methods, such as the sprayed concrete lining method with partial face extraction machines, have also extended the range of guidance and profi le monitoring systems that have been developed over recent years.

As the machine operator can seldom see where he is going when steering a tunnelling machine, he must be supplied with information regarding the machine’s position and orientation in relation to the required alignment.

Since the fi rst use of mechanical tunnelling machines, this has generally been successfully undertaken by conventional surveying methods, however, the results supplied were only a periodic snapshot and it soon became evident that a continuous and real-time indication of the machine’s location was required.

Following its development in the early 1960s, a HeNe (Helium Neon) tunnel laser, working to passive targets, has been used to supply this positional information. This has now been replaced in almost all cases by a laser reference projected from a Motorised Total Station (MTS) onto an Active Laser Target Unit, or by the use of the EDM (electronic distance measurement) feature working to one or

more retro-refl ective prisms. The addition of servomotors to the electronic

laser theodolites makes it possible to:1. Create interactive control between the projector of the laser beam and the point of impact on the active laser target unit, thus ensuring that the laser beam is kept middle of target at all times, thereby giving continuous measurements. Software control of this type of instrument by the guidance system also permits the laser beam to be switched off during its coordination routine as a safety measure to protect the work force from any unexpected exposure.2. “Seek” retro-refl ective prisms, if their effective position has moved since the last coordinated measurement, by using the inbuilt automatic target recognition (ATR) feature. This allows the theodolite to seek and measure the position of one or more retro-refl ective prisms. When two or more prisms are mounted on a tunnelling machine, they can be measured on a regular basis, and by measuring their position, the guidance system is able to determine the position and orientation of the machine. If more prisms are used or are used in conjunction with inclinometers, the precision of the system is increased due to crosschecking capabilities. This, however, also has the effect of increasing the time needed for each measurement cycle.

The time taken to locate and measure to each prism means that the system is carrying out frequent, although not continuous, measure-ments and calculations of the machine’s position; these are therefore based on historical (albeit suffi ciently recent) not real time measurements.

To achieve the necessary accuracy, the spacing between the prisms should be, according to some manufacturers, at least 2 m longitudinally and at least 300 mm laterally, although the use of a top of the range (i.e. ±1.5” (37mm) ±0.5mgon) theodolite would be needed to achieve the necessary accuracy. Alterna-tively, increasing the

spacing between prisms, if space on the machine and backup gear allows, would permit the use of a standard (±3.0”±1.0mgon) theodolite.

Recent advancements in these primary components have tended to be in the reliability and ruggedness of the components for 24/7 use in the tunnelling environment. The sensitivity of the latest generation of active targets has been improved by the use of the latest components. This enables them to perform in the often hostile environment of the typical tunnel working area.

In the case of systems that work to a retro-refl ective prism, it is necessary to produce a method of recognising the correct prism in a work area that may also contain numerous refl ective surfaces that would give erroneous results. The standard survey prism has now been modifi ed to give a controllable shutter that opens

Recent guidance systems evolution for tunnelling machinesHow exactly does a TBM navigate in the bowels of the earth? Nod Clarke-Hackston, International Sales Manager at VMT GmbH, explains

Latest generation of the Active Laser Target Unit

Above: Hostile working environment for an ALTU and below: Shuttered prism

Main operator display

TECHNOLOGY: TBM guidance systems

20-21WT0712.indd 20 6/12/07 20:49:47

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21

Recent guidance systems evolution for tunnelling machinesin synchronisation with the programmed Motorized Total Station.

Presenting the results to the machine operator should be via a clear comprehensive graphical display showing the position and orientation of the machine with respect to the desired alignment. The proposed future alignment of the tunnel ahead of the machine should also be depicted to the machine operator to enable him to anticipate the necessary steering adjustments.

Any guidance system, whether manual or state of the art high technology, must continually detect and compensate for any movement of its primary reference. Movement beyond a pre-set, allowable amount must generate a warning or error message to the user. Optical effects such as refraction, which will have an effect on all types of optical measure-ment, can also interfere with the results. Careful selection of target and reference locations can minimise, but not completely eliminate, these influences.

Some guidance technologies, such as north-seeking gyro-based systems that measure the direction of its fixed axis against ‘north’, achieve position indications that are based on a sequence of accurate dead reckoning values.

However, there is no intrinsic tie-in to the survey in the tunnel and as one of the fundamental properties of all gyroscopes is drift, it is necessary to survey the machine and update the systems’ values at least during each shift and sometimes more frequently at the advance rates that are frequently experienced.

The level of the machine is normally determined using a sophisticated water level system that automatically compensates for atmospheric pressure variations and density changes in the fluid in the system. The advantage of this type of system is the ability to negotiate very tight curves.

However, irrespective of the type of guidance system to be used on a tunnelling machine, a

suitable survey window must be available to enable periodic precise measurement of the machines’ position to take place. This sight path runs from the survey station, through part or all of the backup equipment to a reference target on the forward section of the tunnelling machine. Obviously, this path must be unobstructed for the measurements to take place. Since this path must run reasonably parallel with the machine axis and its backup gear the size of the survey window tends to be limited and its position is not always in the most useable location for measurement purposes.

Partial face extraction machines such as roadheaders and excavators are mainly used over short distances for the excavation of firm rock or of geometrically different forms of profile. Until recently, the face area to be excavated was indicated by the last erected supports or by manually

marking it with spray paint.

The accuracy of excavation was mainly dependant on the experience of the machine operator and the operational

safety was considerably affected by having the surveyor work in an unsupported area of the face when marking up the profile. Additional adverse circumstances such as dust, vibration and a high noise level complicated the control of the cutter arm for a precise excavation, so visual steering was very time consuming and inaccurate.

In order to minimize the material costs for the excavation and support methods and at the same time accelerate the production process

despite unfavourable factors, companies such as VMT GmbH and others have developed

guidance systems for partial face cutting machines to accurately monitor the cutting of the required profile. These systems are based on the Motorized Total Station System measuring to one or more prisms installed on the body of the roadheader or excavator.

The movement of the boom or cutter arm is monitored by sensors or encoders to determine the cutterhead position in relation to the desired profile which is displayed to the machine operator on the machine’s monitor in near real-time, thus allowing the operator to accurately position the cutting tool.

The flexibility of these partial face extraction machines also presented a major problem in providing a suitable communication link between the Motorized Total Station fixed on the tunnel wall and the rest of the equipment installed on the tunnelling

machine. This has now been successfully overcome by the use of WLAN connections.

Developments of existing equipment will continue. New concepts to give the operators of tunnelling machines the necessary information will evolve, driven by the requirement to construct tunnels at a faster and more cost effective rate.

Guidance system configuration on TBM

Profile monitoring software linked to the Roadheader Guidance System

TECHNOLOGY: TBM guidance systems

“Irrespective of the type of

guidance system to be used on a tunnelling machine, a

suitable survey window must be available to enable

periodic precise measurement of the machines’

position to take place”

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December 2007


EXTENDING Milwaukee’s Inline Storage System (ISS), which comprises 31.2 km (19.4 miles) of hard-rock tunnels on

average around 90 m below ground level, will ensure the area can cope with increased waste-water volumes. This will reduce the risk of base-ment back-ups and sewer overflows.

This latest scheme, awarded in May, will add a further two miles of deep tunnel to the system, allowing it to hold 33% more water than the original 1.7 billion-litre-capacity scheme completed in 1993.

Milwaukee Metropolitan Sewer District (MMSD) operates an extensive sewer system that collects, conveys and stores wastewater from local sewerage systems. Under the scheme, wastewater flows to local systems, is collected by the district’s intercepting system then conveyed to two wastewater treatment plants.

MMSD is a regional government agency serving 1.1 million people in a 420 square mile service area and provides wastewater treatment and flood management to 28 communities.

Shortly after the award went to Affholder, Insituform, the parent company of which Affholder formed the tunnelling division, requested to be relieved of the bid by the Milwaukee Metropolitan Sewerage District (MMSD) as it was closing the Affholder Tunnel division.

After serious consideration, the owner entered into a legal condition known as ‘novation’ that would allow the assuming of the contract to the second bidder at no increase in cost to the MMSD. This took place on May 15 with the award to Shea/Kenny J/V.

HamptOn ROad aCCeSS SHaFtThis consists of a 91.4 m-deep, 9 m-diameter shaft with about 23 m of overburden. Before freezing and excavation, the shaft will be grouted from the surface with two concentric rows cased through the overburden into the top of the rock and extending below the shaft invert. The shaft will be supported in the overburden by freezing the area, the final shaft lining will be

advanced concurrently with the excavation of the shaft in rock and be completed to within 6 m of the excavated shaft invert before blasting the next round.

mill ROad aCCeSS and VentilatiOn SHaFtThis shaft will be excavated to a diminished diameter of 7 m, to 90 m deep and with 21 m of overburden to be frozen; the shaft pre-excavation will be grouted also with two concentric rows of holes from top of rock to a depth extending below shaft invert.

The shaft will also be initially supported as required with wire mesh, mine straps and rock dowels. Final shaft lining will be advanced concurrently with the excavation of the shaft in rock and completed to within 6 m of the blasted invert. There is a possibility that the pre-excavation grout holes may miss or not effectively grout some high water inflow features. If this happens and the inflow is greater than 454 litres/min at the shaft heading, the contractor at the direction of the resident engineer, shall grout appropriately from within the shaft to reduce the inflow down to a manageable rate.

tBm tUnnelConnecting the two shafts is a TBM-bored, 3,276 m-long rock tunnel, 7 m in diameter, with a finished diameter of 6.4 m. The Hampton Shaft site will have an extension of the tunnel 45 m south from the shaft and a 3 m diameter, 2.4 m finished diameter hand-mined tunnel to connect the new storage tunnel with an existing ISS. The entire tunnel and connection will be lined with 305 mm of cast in-place concrete.

With the contract award, the joint venture erected extra trailers for the crew and office personnel on the office complex they had furnished for the Siphons Project but with some of the Affholder employees continuing their positions.

To refurbish the Robbins main beam hard-rock TBM, the main frame from the previous Milwaukee Project recently completed was used and a new rebuilt cutterhead previously used on the Buckskin Mountain job in Arizona added. Shop facilities near the project to rebuild the TBM and trailing gear were also from the recent Milwaukee Project.

The components are arriving at the shop and the contractor personnel under the direction of Norm Hutchins will turn out the TBM in as near-new condition. The unit should be ready to go down the shaft as soon as the access shaft excavation and lining is completed.

GEoloGyThe tunnel will be bored through bed rock consisting of dolomite clays. The major formations are the Racine and Waukesha Formations, (Niagaran Group, Upper Silurian), with overburden mainly comprising glacial tills.

iSS extension enhances milwaukee water storageDeep tunnels prevent billions of gallons of Milwaukee area wastewater from polluting Lake Michigan. This latest US$81 million tunnel will extend the storage capacity by 33%. Jack Burke reports

The following personnel are on site for the ISS Project: Danny Martz, project manager; Len Postregna, project Engineer; Norm Hutchins, TBM superin-tendent; Keith Walters, master mechanic; Bonnie Senkowski, office manager; Randy Britton, safety; Dutch Vliegenthart, vice-president

At the core of the project are two shafts connected by a TBM excavated tunnel, with a hand-mined connection to the existing ISS.

The project

View down the Hampton Rd access shaft

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23

IN CONVENTIONAL EPB shield tunnelling, plastic flow of excavated soil within the cutter chamber, which is indispensable for

stable excavation, has never been analysed, and the method is little used to excavate tunnels of 10 m in diameter. This project aimed to develop a system for visualising the flow of soil inside the chamber.

INTRODUCTIONMetropolitan Expressway Company Ltd is constructing the 47 km-long Central Circular Route of the Metropolitan Expressway outside the Inner Circular Route in Tokyo. At about 8 km in radius from the city centre, the aim is to alleviate traffic congestion in the centre. Sections of 26 km, about 60%, of the Central Circular Route, have been completed and are in service. The other 20 km sections comprise the Shinjuku Route on the west side and the Shinagawa Route on the south.

Shield tunnelling is being used to construct the 11 km-long Shinjuku Route beneath heavily-congested roads to minimise the adverse effects of construction on local residents. Large-cross-section shields of more than 10 m in diameter are used on all eight sections where shield tunnelling takes place.

Large-cross-section slurry shields over 10 m diameter have often been used because they help stabilise the face. In this project for a highway tunnel (work sections SJ51 to SJ53 (clockwise), a 12.02 m (outer diameter) EPB shield, which, at the time of order, was the largest in the world, was adopted because the construction base was narrow and no space could be secured for installing the equipment needed for a slurry shield. Engineers were also concerned at the effects of slurry seeping into the ground or surrounding structures where there was shallow depth of overburden.

In EPB mode, establishing plastic flow of excavated material in the cutting chamber is crucial for stabilising the face and for smooth removal of excavated material through the screw conveyor. In a large-diameter EPB shield, it is unknown whether appropriate agitation is possible to ensure the plastic flow of slurry, and this has prevented the use of EPB shields on large-cross-section tunnels. The problem has yet to be solved because no method has been established for quantitatively grasping the establishment of plastic flow.

In this project, muck-flow control technology used in the cutting chamber of an EPB shield was developed and applied to maintain face stability and ensure safe excavation, thereby solving problems involved when using large-cross-section EPB shields. The technology enabled the contractor to quantitatively assess the plastic flow of excavated material in the cutting chamber and to carry out the following:Ë�Quantitative excavation control by evaluating

the plastic flow of the muck in the chamber.Ë�Appropriate system design for agitation and

muck removal in the chamber.

OUTLINE OF MUCK-FLOW CONTROL TECHNOLOGY“Plastic flow” is essential for stabilising the face and for the smooth removal of excavated material through the screw conveyor. Where plastic flow exists, excavated material starts flowing at a deformation rate (shear strain occurs) when the shear stress in the material exceeds a certain yield value. Where the plastic flow of the excavated material in the cutting chamber is efficient, the rotating cutter face causes the excavated material to flow and facilitates its mixing with additives for excavation and agitation. As a result, the excavated material flows at a deformation rate. When the chamber is clogged, the velocity of the material is high and the deformation rate is low (see Fig 4). Where the excavated material is blowing from the screw conveyor, velocity is low and deformation rate is high.

To analyse muck flow, calculate velocity and deformation rates in the chamber and evaluate plastic flow, we developed a 3-D model of the cutting chamber interior. To reflect the actual chamber conditions for analysis purposes, a flapper was developed and four were installed on the bulkhead in the chamber. Flaps were rotated with electric motors during excavation to measure the variations of torque due to muck flow. The flapper was also modelled for analysis.

Where results were in agreement with measurements, it was determined that the calculated velocity and deformation rate were those existing in the chamber. Muck flow control technology enables visual display of velocity and deformation rates in the chamber based on analysis results. Then, quantitative control of injection of additives for excavation becomes possible.

Controlling muck flow in a TBM cutting chamberIn this abridged paper, H Dobashi & M Matsuda, Metropolitan Expressway Company, and K Matsubara & A Kitayama of Obayashi Corporation outline muck-flow control technology in a large-cross-section EPB shield

Velo

city

of m

uck

flow

(m/s

ec)

Appropriate flow

Blowing

Clogging

Condition of agitated muckSolid

Muc

k flo

w c

ause

d in

the

cham

ber

by th

e ro

tatio

n of

the

cutt

er

LiquidSemisolid

Cutter support area

Cutter peripheral area

Agitator area

Z=0.45mZ=0.9mZ=1.7m

0.75 1.3

Cutter face BulkheadChamber

Fig 4: Muckflow velocity and deformation rate

TECHNOLOGY: Muck-flow handling

Fig 6: Points of evaluation Ë

23-24WT0712.indd 23 6/12/07 21:50:47

December 2007

24

For example, additives are injected exclusively at the points where there seems to be no appropriate plastic flow. The condition in the chamber can also be grasped in real time by controlling the variation in the torque of the flapper during excavation. Thus, actions can be taken promptly in response to changes in the properties of the muck in the chamber. The technology also enables quantitative design of an agitation system beneficial to the establishment of plastic flow based on the results of analysis using an arbitrary model of the agitation system in the chamber.

CHaMBER CONdITIONs dURING sMOOTH ExCavaTIONDuring the project, the screw conveyor removed the muck smoothly without any blowing occurring along the tunnel alignment. It was therefore assumed there was plastic flow of muck in the chamber and the face remained stable.

Results analysed show that velocity and deformation distribution rates are not uniform transversely but are different at the cutter’s peripheral area, cutter support area and agitator area. In the longitudinal direction, velocity and deformation distribution rates are different at the three cross sections between the cutter face and the bulkhead.

Fig 7 shows logarithms of velocity (m/s) on the y-axis and logarithms of deformation rate (litres/s) on the z-axis in the areas shown in Fig 6. The plotted points move toward the centre of the graph in the agitator and cutter peripheral areas as the cross section moves from the cutter face to the bulkhead. Plastic flow of muck is therefore assumed in these areas. In the cutter support area on the other hand, the movement toward the centre of the graph is not so outstanding.

Velocity is available due to the rotation of cutter supports, but no mixing and agitation takes place. Plastic flow is therefore unlikely to be established. In the project, excavation could be carried out while maintaining face stability. As a result of analysis, however, plastic flow in certain areas was found to be unlikely, at which point additives for excavation were also injected.

CHaMBER CONdITIONs dURING MUCK BLOWINGWhen blowing occurs, excavated material pressurized in the chamber moves through the screw conveyor in the form of a liquid; its pressure is not reduced to air pressure at the outlet, and the volume of muck can no longer be controlled by adjusting the speed of rotation of the screw conveyor. When pressurised muck is being removed smoothly, its pressure in the chamber is reduced to that of air pressure owing to resistance in the screw conveyor as the muck reaches the outlet; the volume of muck can be controlled by adjusting the rotation speed of the screw conveyor.

Muck-flow control technology was used to calculate the pressure in the chamber through the outlet of the screw conveyor being analysed. The pressure acting on the muck in the chamber was reduced in the screw conveyor and no longer acted at the outlet of the screw conveyor during smooth excavation. When muck blowing occurred, pressure was not reduced at the outlet.

ExCavaTION CONTROL BasEd ON FLappER TORqUE vaRIaTIONTo establish the plastic flow of excavated material in the chamber, the properties of the muck removed through the screw conveyor have been conventionally evaluated by visual inspection or by slump tests. Adjustments to additive quantity injected for excavation should be determined on the basis of evaluation results. In this project, additive injection was controlled using muck flow control technology.

Based on the velocity and deformation distribution rates identified in analysis, excavation additives were injected not only at

the front face of the cutter but also at points where plastic flow was found to be unlikely. Additive quantity was adjusted according to flapper torque variations.

During excavation, flapper torque increased rapidly, so more additives were injected. Once it stabilised, the volume of additives was reduced. Flapper torque changes sooner than the change in property of the excavated material removed through the screw conveyor. Controlling the volume of additives according to flapper torque can control the change in plastic flow in the chamber. Thus, safe excavation can be carried out.

The tunnel was excavated over a length of 2,020 m with the geology varying from cohesive soil to gravel layers. Muck flow control technology helped complete the excavation smoothly without adverse effects on the ground surface or on adjacent structures, which included railway tracks and bridge foundations.

In this study, agitation and mixing systems were designed in four cases for analysis. It was found that velocities were more or less the same in all cases. Deformation rate in the chamber was highest in case 4. This was considered the optimal agitation system capable of establishing the plastic flow of muck.

It was confirmed that, for the first time, muck-flow control technology facilitated the evaluation of the effects of agitation and mixing systems quantitatively. Thus, the technology enables the smooth mixing of muck and additives in the chamber, as well as the design of an agitation system that is effective for establishing plastic flow.

CONCLUsIONThe “technology for muck flow control in the cutting chamber of an earth pressure balance shield enables tunnel excavation based on the results of evaluation of the plastic flow of the muck in the chamber.

Thus, greater face stability can be ensured.The technology for controlling muck flow in

the cutting chamber of an earth-pressure-balanced (EPB) shield of large cross-section will help increase the cross-section of an EPB shield and allow EPB shields to be used in more and more projects.Fig 7: Velocity and deformation rate in each cross-section

z=1.7

0

0.05

0.1

0.15

0.2

0.25

0.3

0.010.1110Deformation rate(1/sec)

Velo

city

(m/s

ec)

Agitator areaCutter support areaCutter peripheral area

z=0.9

0

0.05

0.1

0.15

0.2

0.25

0.3

011.010.0 1Deformation rate(1/sec)

Velo

city

(m/s

ec)


z=0.45

0

0.05

0.1

0.15

0.2

0.25

0.3

0.010.1110Deformation rate(1/sec)

Velo

city

(m/s

ec)


Table 1 shows analysis of plastic flow results in the chamber. It also shows the distributions of velocities and deformation rates in the chamber at three cross sections. The directions and lengths of arrows indicate the directions and levels of velocities

Near the cutter face At the middle of the chamber Near the bulkhead

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0

(m/sec)

Velocity(m/sec)

Deformationrate(1/sec)

Legend

TECHNOLOGY: Muck-flow handling

Ë

23-24WT0712.indd 24 6/12/07 21:51:06

A World Leader in Conveyors and Conveyor Technology

Continental Conveyor LimitedWest Quay Road, Sunderland Enterprise Park, Sunderland, SR5 2TD. UK

Tel: +44 (0)191 516 5353 Fax: +44 (0)191 516 5399 E-mail: [email protected]

A CONTINENTAL GLOBAL GROUP COMPANY

EQUIPMENT: Underground support vehicles

WHEN it comes to transporting materials during tunnel construction, or performing a host of other tunnel-

related tasks, the variety of vehicle you might see in a tunnel under construction is vast. When it comes to materials haulage, the main choice is between a conveyor or vehicular means. Conveyors have been covered in past articles. Here, we will look at the more conventional vehicular systems that are available, whether rail-bound or rubber-tyred systems.

Rail systems are used on tunnel construction throughout the world and offer numerous advan-tages compared to rubber-tyred solutions. They offer improved productivity but can be a little infl exible when compared to rubber-tyred vehicles.

Rail-bound systems work effectively on gradients below 3%, although they may have diffi culty over this limit as often encountered on the construction of metro and road tunnels beneath rivers. Traction on rail systems may be exacerbated when overspilling water and mud result in a loss of adhesion between wheels and rails, at which point the adhesion factor is not normally better than µ = 0.12-0.15.

Germany-based Schoma (www.schoema-locos.de) makes a range of standard and narrow-gauge locomotives for tunnelling of 5-60 t. Its smaller-capacity locos are especially suited to small tunnel profi les, especially those for small water or cable applications. The larger locomotives have been used on projects such as metros in Madrid, Barcelona, Seville and Toronto. The company has a long tradition of making locomotives and now has a global reach, manufacturing vehicles up to a maximum of 80 t. Equipped with diesel engines complying to exhaust emissions regulations, locos are designed to be compatible with all common track gauges. They can be fully customised with an array of functions and special equipment that includes multi-traction operation, wheel slide detection and air-conditioned cabins.

In 1992, Schöma was involved in the construction of the Athens Metro, where it encountered a relatively steep gradient of 4%. It was at this time that the idea of using the payload to increase adhesion between wheels and rail was considered. The solution devised comprised a locomotive-driven platform car which also carried a muck container, mortar container and other parts of the payload.

But driving a platform car could only be achieved by electric power or hydraulic pressure. Since diesel-electric or battery powered locos are not very common for heavy trains and steep gradients, such a system could only work with a hydrostatic drive.

The driven platform car (sometimes called a tandem) is equipped with hydraulic motors, fi tted to each axle in a two-axled version or to each bogie in a four-axled version. The same types of motors are fi tted to the locomotive and these are fed by hydraulic pumps driven from the diesel engine. Locomotive and tandem are connected via high-pressure hoses for the supply and return fl ows of oil.

Such systems are relatively sophisticated and a microchip-controlled PLC system is necessary to control the hydraulics. Pumps and motors are designed for variable oil fl ow to make the necessary adjustments to achieve maximum traction or maximum speed.

As a further safety device, Schöma introduced an electro-magnetic retarder brake, which increases the braking force on the downgrade.

Hydrostatic systems are operated under continuous pressure, which means that braking torque can be generated when the train is going downhill.

In 1996, Schöma started to develop its own PLC systems for this type of train. These not only control hydrostatic components, but also the diesel engine and pneumatic brakes, so as to make driving as easy and as effi cient as possible.

To keep speeds constant on downgrades, the braking power of the diesel engine (engine brake), the hydrostatic transmission and retarder brake are not subject to any wear and are applied so as to avoid or reduce the use of mechanical friction brakes which are subject to wear.

Together, the diesel engine, hydrostatic transmission and the retarder provide strong braking to keep the speed constant when going

downhill. Schöma’s PLC system optimises the application of these brake systems in order to avoid or reduce using the mechanical friction brakes.

The company’s locomotives and tandems are available in two-axled versions (max weight around 40 t) and four-axled versions (max weight 60 t). One or two tandems can be coupled to each locomotive. Using a loco with tandem requires a lower capital outlay than two locomotives working in double traction.

BENEFITSThe investment required for one locomotive with tandem is much lower than for two locomotives operating in double traction. Forming a supply train with one locomotive and one or two tandems will generally incur lower capital costs than using larger locos operating in double traction. When a conventional system is installed, larger locos will be needed for steeper gradients. More engine power is required to achieve the same speeds because the locos weight is just ‘dead’ weight. Clearly, the higher the

The underground understudiesA huge range of

underground support vehicles exist for tunnelling, all designed to perform a specifi c post-excavation task. Here are some options

26

December 2007

26-28WT0712.indd 26 10/12/07 09:40:50

EQUIPMENT: Underground support vehicles

engine power, the greater the fuel consump-tion and of course, the higher the exhaust emissions. A wear-free braking system reduces the consumption of brake pads and lowers maintenance costs.

One solution has been to design a platform car – driven by the locomotive – that can carry a muck container, mortar container and other parts of the payload.

CLAYTONOriginally a general engineering company that subsequently supplied narrow-gauge locomo-tives to the coal-mining industry, UK-based Clayton (www.claytonequipment.co.uk) looked for other markets when coal faced a sharp decline by the 1990s. As a result, it turned to non-coal and export markets. This included tunnelling, to which the company today supplies a range of products that include battery locomotives from between 1.75 and 40 t.

In 2006, the company supplied four small battery locomotives to the London Underground designed to haul materials and equipment in narrow tunnels with steep gradients and tight curves. Trolley locomotives (3-40 t) are also made by the company, as are diesel (5-40 t) and fl ame-proof variants.

GIA INDUSTRI ABGIA (www.gia.se) states its ambition is to become a complete supplier of mining and tunnelling equipment worldwide. Based in Grangeberg, Sweden,

the company makes a range of locomotives and utility service trucks. Locomotives can be diesel- or electrically-powered, and are for high-speed and traction force, being designed for easy operation and serviceability. Utility and service trucks are available in a choice of rigid or artic-ulated 4-WD chassis and can also be used as a base for a small dump truck or personnel carrier.

IRWIN CAR When it comes to the transportation of underground personnel, Irwin Car (www.irwincar.com) makes various rubber-tyred,

battery-powered ‘mantrip’ and supervisory vehicles. Cars can be specialised to suit individual tunnel requirements. Typical features include 4-WD, heavy-duty parallel shaft, mine duty pneumatic tyres, and a modular design for ease of maintenance and service, with optional extras that include foam-fi lled tyres, choice of battery capacities,

wide-profi le terrain tyres and additional lights. The company says that combining these options results in over 40 different models.

SCHARF With an international presence, Scharf (www.smtscharf.com) is well-known for its rail-bound transportation systems in under-ground construction. This includes the design, manufacture, delivery, installation and maintenance for the transport of personnel, equipment and material, including for tunnel applications with small cross-section or steep

27

December 2007

Clayton trolley locomotive

Scharf rail-bound transportation

Atlas Copco’s truck-mounted Unigrout automated

grouting plant

26-28WT0712.indd 27 10/12/07 09:41:00

28EQUIPMENT: Underground support vehicles

gradients. In particular, the company can tailor products for the tunnelling industry, including tunnel monorails and loading equipment.

Earlier this year, Scharf supplied a monorail for the recently-completed 6.3 km-long cable tunnel that is designed to replace overhead electricity pylons on London’s Olympic 2012 site at Stratford. Included in the contract were all the rails for the tunnel and its three shafts, as well as two trains. The monorail is equipped with cameras and can be operated by remote control from the surface. It can transport up to fi ve people and works independently in both directions with remote operation.

Since the 1940s, Michigan-based Construction Equipment Company (www.constructionequipmentcompany.com ) has been supplying the tunnelling and mining industry with equipment and other services. Its huge range of equipment supplied includes tunnel cars and muck cars, rail equipment, ventilation equipment, tunnel-boring machines.

A wide range of vehicles can be seen during the construction phase of a tunnel, including locomotives, dumper trucks, mini excavators and personnel carriers. But from Atlas Copco (www.atlascopco.com), you might also see the following – the world’s largest mobile grouting rig combining mixing, pumping and recording of

grout treatment. It can be used where leakage and infl ux of water are problematic or where groundwater levels are needed to stay constant.

The truck-mounted Unigrout is an automated mobile grouting plant offering a grouting capacity of 10 m3/h and allowing the on-site mix of a range of grouts to suit the ground conditions encountered at each section of the excavation. As the rock conditions change, the mix can also be changed at the touch of a button, which claims the manufacturer, can save time. Only two operators are needed over the entire range of mixing, pumping, recording and supplying

the grout into holes.The unit was recently supplied to Veidekke

for use on the Norra Länken tunnel under construction in Stockholm, Sweden.

USED EQUIPMENTIf it is used equipment you are after, a look at Mining Equipment’s website will reveal a host of used equipment for tunnelling and mining. This ranges from compressors and conveyor belts to hoists, locomotives, service trucks and scoops. And you never know, you might fi nd a bargain (www.miningequipment.com) .

The Terex Schaef (www.terex-schaeff.com) TC48E tunnel excavator is a little underground excavator that comes with an electric power drive.

Its safety features, in particular those of the electrical system, have been designed to fulfi ll the high standards required for tunnel excavation. Based on the Terex mini excavator TC48, the unit is characterised by having good manoeuvrability and is aimed at compressed air-driving in tunnel excavation; its low-noise 22 kW electric drive is useful where tunnel ventilation conditions require zero emissions. As well as the attachable bucket, other types of attachments and hydraulic transverse cutting units can be used.

Mini excavators

The TC48E tunnel excavator

26-28WT0712.indd 28 10/12/07 09:41:02

The UK’s biggest and best drilling, piling and trenchless construction show, GeoDrilling 2008 will provide a superb opportunity for manufacturers, contractors, buyers and specifiers of trenchless construction and drilling services to gather in one place, to assess the current developments in the market, and to develop leads and contacts for new business and future projects.

GeoDrilling 2008 will exceed all your expectations by providing an exhibition containing the top names in the industry, international delegates with the credentials to make all the right buying decisions, and a seminar programme packed with the best speakers covering the issues which matter to you.

GeoDrilling 2008 will attract more than 150 exhibitors and some 2,000 visitors and we very much hope you will be one of them.

If you are in the construction and piling industry, then GeoDrilling 2008 must not be missed.

If you would like further information about GeoDrilling 2008, contact Eileen Smith on +44 (0) 20 7216 6077 or at [email protected]

Supported by:

GDIshow2008ad.indd 1 10/12/07 11:33:22

December 2007

30

Web creates sales deckCONSTRUCTION tends to be a fragmented process that results in limited communication between competing contractors and jobsites. Leftover materials and plant could be sold on, while excess materials sent to landfi ll could be sold to other projects.

Furthermore, products left over from temporary works are discarded or sold as scrap. And recycled aggregates that could be sold directly to other projects for a fair price are instead sold for less than that to middlemen. So to improve on this sort of resource ineffi ciency, the website www.constructionresale.co.uk has been set up in the UK and launched at Civils 2007-11-23.

Designed as a resource forum, it is essentially a sales platform that will aim to link up contractors and their jobsites, regardless of size or parent company. And because the equipment/materials for sale are not branded, it is not possible to see who is selling, which should encourage contractors who otherwise would not communicate with each other to do so.

Designed in a familiar online sales style, the website has clear categories and the option to sell at auction or to set a fi xed price. Contractors can register online at www.constructionresale.com to achieve improved resource effi ciency, reduced waste related overheads, reduced material costs, less reliance on middlemen, access to available industry materials and access an industry-wide audience of buyers and sellers. Construction resale recently won the NCE 2007 innovations award.

Sat mapping detects ground movementWHETHER a tunnel is feasible or not is established at concept stage and a good precursor to a full geological survey might be to use a satellite map that can reveal movements in urban and rural areas. UK-based NPA Satellite Mapping provides such a service.

The company specialises in Satellite Radar Interferometry (InSAR) which it says has the ability to measure minute relative elevational changes of the Earth’s surface and structures down to millimetric levels. So, for potentially lower cost and covering a wider area, it can provide a degree of precision in the vertical domain that is far greater than normally possible with GPS.

For over a decade, satellite radar images have been recorded over much of the Earth’s surface on a near-monthly basis to produce an archive that can provide an important historical record of gradual and subtle surface or structural movement in urban areas. Such knowledge can be useful for tunnelling and mining projects. Also, vulnerable ground or infrastructure can be identifi ed for ongoing monitoring.

The technique is able to map historical ground motion events, assess hazard-prone urban areas, detect pre-event strain and stress, and map post-event deformation and ground changes. For example, in areas of seismic, volcanic and landslide risk, the imaging can indicate areas of high, medium and low displacement intensity which could have a bearing on a proposed tunnel and so could be a useful fi rst step.

Ground motion associated with the following activities has been detected: Ground settlement associated with the construction of the Jubilee Line tunnel extension (centre-left); Telecommu-nication tunnel settlement (bottom-left); Uplift associated with groundwater recharge (top-right).

The company provides a free feasibility assessment to establish whether its technology is appropriate for users’ engineering projects.

www.npagroup.com

White geomembrane is a refl ectorGSE Lining Technology manufactures a complete range of geosynthetic products for tunnel waterproofi ng, as well as providing technical support and installation services.

TECHNOLOGY: Innovation

At the recent CIVILS 2007 show in London, George Demetri caught up with some of the more innovative products on display

The image left shows ground and structure motion across central London, UK, dating from 1992 to 2005. Points have been colour-coded according to their average annual motion rate; red represents subsidence of more than 5 mm/y; green represents stability; blue represents uplift of more than 5 mm/y.

Showcasing the best of CIVILS 2007

GSE lining technology

30-31WT0712.indd 30 6/12/07 21:23:54

December 2007

31

GSE TunnelLiner is a highly flexible polyethylene geomembrane specially designed for high-performance tunnel lining applications. It consists of a black core layer and two white outer layers which greatly facilitate visual inspection, and is available in two fire resistance grades (B1 and B2).

The white surface ensures that any score marks or punctures are more easily visible than with conventional geomembranes. The surface also acts as a light enhancer, reflecting all natural light in the tunnel.

Expansion and contraction of the geomem-brane is reduced by the white surface, allowing reinforcing steel and concrete to be placed without interference from wrinkles.

www.gseworld.com

Reverse osmosis does the trickHYDROTECH’S MPS System has been designed to provide guaranteed protection against water ingress and keep dry new and existing structures. The system is guaranteed for the lifespan of the structure. The active reverse electro-osmotic system is designed to dry out

and keep dry structures of concrete, brick and masonry. Tunnels that suffer from chronic water ingress problems are also suitable for application.

The technique is based on charging the water with electricity to reverse the natural process of osmosis. This, say the makers, also reverses the saturation problem, so that water that has already accumulated is evacuated to allow the complete drying and restoration of the structure to its original condition in four to six weeks. Another claimed benefit is that the corrosion of reinforcement is slowed down.

Hydrotech’s MPS System was

recently applied to the construction of a northwest London underpass, comprising a cut-and-cover concrete box that is completely below the water table. According to Hydrotech, previously applied traditional methods, such as matting and concrete additives, had failed to solve the problem. Hydrotech’s MPS system has proved to be very successful.

www.hydro-usl.com

Natural lining material keeps water outSODIUM bentonite is the key component in Cetco’s geosynthetic clay liners (GCLs) that are used, among other things, to provide a waterproof lining to tunnels. They usually comprise a layer of low-permeability sodium bentonite sandwiched between needle-punched, geosynthetic carrier components all in a layer that is less than 10 mm thick. Supplied to site in 5m-long rolls, typical widths for tunnelling applications are around 1,100 mm wide.

In application, the sheet material is overlapped and fastened to the tunnel walls with a nail gun. If the walls are too rough, they will normally be shotcreted to which the liner can be attached using a nail gun with washers.

Puncturing the liner is not a problem as the bentonite will swell to form a self-healed ‘repair’. This action is due to the composition of the bentonite, comprising mainly of mont-morillonite – a layered clay mineral whose broad, thin platelets act as a hydraulic barrier.

www.cetcoeurope.com

DSI displays tunnelling arm’s fresh focus GLASS-FIBRE rockbolts, anchors and mini-piles formed the focus of the Dywidag-Systems International (DSI) stand. But there is more to

the company than these core products. From an organisational point of view, DSI divides its activities into Construction and Underground.

Falling clearly into the latter category, the recently established tunnelling division combines all the tunnelling activities of the newly-acquired companies of Alwag in Austria, DSI-Soprofint in Chile and American Commer-cial in the US.

One of the company’s ongoing projects is a 2.6 m diameter, 615 m-long water, power and communication tunnel that will run beneath the runways at Indianapolis airport. Because the airport needs to be in continuous operation, it is vital that no settlement occurs beneath the runways. Due to the geology and its location beneath the groundwater table, an EPB TBM is being used to drive the tunnel which, in place of concrete segments, is being lined with sealed, heavy steel liner plates due to engineering requirements. It is the longest-ever EPB-driven tunnel to make use of steel liner plates.

www.dywidag-international.com

TECHNOLOGY: Innovation

Showcasing the best of CIVILS 2007TRADE associations have traditionally played a valuable role in promoting the activities of their respective fields. Here are two that were present at Civils 2007.

SCA ENjOYS STEAdY GrOwTHORIGINALLY formed in 1976 by a small group of Gunite contractors, the Sprayed Concrete Association (SCA) has grown considerably over the years. In addition to promoting sprayed concrete generally, the SCA produces and maintains specifications and codes of practice; is involved in education and training, and promotes discussion and technical exchange.

www.sca.org.uk

COrrOSION prEVENTION ASSOCIATION SpUrS r&dCONTRACTORS, consultants and manufacturers working in the field of corrosion prevention for concrete and masonry encased steel are all represented by the Corrosion Prevention Association (CPA). An authority on cathodic protection and other corrosion techniques, the CPA encourages research in a wide range of concrete-corrosion related fields, in addition to a range of publications.

www.corrosionprevention.org.uk

Two trade groups take a stand

30-31WT0712.indd 31 6/12/07 21:24:01

SUPPLIES AND SERVICES

December 2007

32SUPPLIES & SERVICES

DIRECTIONAL DRILLING

Dealers Supplying:-

Directional Drilling Rigs, Auger Boring Systems

Mud Cleaning Systems, Mud Mixing Systems

Tracking Systems, Drilling Fluids

Down Hole Tooling, Drill Rods

Tel: 0044 (0) 1424 854112

Fax: 0044 (0) 1424 854231

E-Mail: [email protected]

www.tadrilling.co.uk

An Authorised Distributor of American Directional Drill An Authorised Distributor of American Directional Drill ®

Applied Felts Limited Castle Bank MillsPortobello Road

Wakefield WF1 5PS

Tel: +44 (0) 1924 200535 Fax: +44 (0) 1924 366951 email: [email protected]

Specialist Manufacturers of Cured-In-Place Materials for the Rehabilitation of Pipes

and Conduits www.appliedfelts.com

Tunnelling EquipmentHire & Supply

Specialist Plant Associates

Tel: +44 (0) 1234 781882 Fax: +44 (0) 1234 781992

E:[email protected]

Agents

DRILLING & GROUTINGEQUIPMENT

Mini piling/Piling casing (up to 32")Casing advancing systemsReverse circulationRotary percussiveWater well casingDrill rods: Friction welded up to 51/2" Capacity up to 14" diameter Length up to 10 metresGrouting and bentonite equipmentManufacturer of spares and accessories

The only API spec 7 approved drilling equipment

manufacturer in the UK!

COLCRETE EURODRILL

DRILL PIPES RODS TUBULARS

CIVIL ENGINEERING PIPE EQUIPMENT

SEWER RENOVATION

FOR SALEJeLaDo Drilling Services

LTD & Co. KGGraf-Edzard-Str. 7,

Tel: +49 4943 990662 Fax: +49 4943 990664www.hddrigs.de · [email protected]

1: American Augers DD-140, 700m rods, 1200 liter pump, reamer etc.

2: Vermeer D80x100, approx. 2000h, year 2000, 750l aplex pump, 620m rods

3: Vermeer D50x100, approx. 4000h, year 2000, 500l kerr pump, 500m rods

4: Huette HBR 206D, approx. 2200h, year 1998, 470m rods

“We have TCI Three cone bits for all Ditch Witch terrar machines for 760 €”

Specialists in Tunnelling, Civils and Construction Recruitment.

Tel: +44 (0)1202 298322E-mail: [email protected]

www.hunterpersonnel.com

RECRUITMENT

• Shaft sinking • Tunnelling / Timber Headings • Deep Drainage • Specialist Plant

Hire Materials for the Rehabilitation of Pipes

Timber Headings

32 Brunshaw Avenue, Burnley,32 Brunshaw Avenue, Burnley,Lancashire, BB10 4LTLancashire, BB10 4LT

Tel/Fax: 01282 452666 Mobile: 07917 625802

E-mail: [email protected]

HEAD OFFICE Contact: Gareth Hector, Director of SalesMining Communications Ltd, Albert House, 1 Singer Street, London EC2A 4BQ, England.Tel: +44 (0)20 7216 6060 Fax: +44 (0)207 216 6050 E-mail: [email protected]

ASIA, CANADA, SCANDINAVIA, SOUTH AFRICA, US, REST OF WORLD Contact: Richard Dolan Tel: +44 (0)20 7216 6086 Fax: +44 (0)20 7216 6050 E-mail: [email protected]

AUSTRALIA Contact: Wendy Hora PO Box 7045, Leura, NSW 2780, Australia.Tel: +61 2 4784 2209 Fax: +61 2 4784 2311 E-mail: [email protected]

ITALY & SWITZERLAND Contact: Fabio Potesta/Daniela ChiusaMedia Point and Communications SRL, Corte Lambruschini – Corso Buenos Aires, 8 5° piano – Interno 7-16129 Genova, Italy. Tel: +39 (010) 570 4948 Fax: +39 (010) 553 0088 E-mail: [email protected]

GERMANY & AUSTRIA Contact: Gunter Schneider GSM International, Postfach 20 21 06, D-41552 Kaast, Germany. Tel: +49 2131 511801 E-mail: [email protected]

JAPAN Contact: Kazumi Yamazaki Accot Corporation, Yamazaki Bldg, 7-19-4 Nishiogu, Arakawa-ku. Tokyo 116-0011, Japan. Tel: +81 3 3800 3229 Fax: +81 3 3800 3844 E-mail: [email protected]

ADVERTISEMENT OFFICES

32WT0712.indd 32 10/12/07 11:07:10

One breakthrough after another. Innovation.

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Robbins Innovations.indd 1 28/8/07 12:12:44

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