WT0803

The magazine for the tunnelling professional

www.world-tunnelling.com

Brightwater West; Site entitlement clauses

San Vicente pipeline production techniques

Support and haulage vehiclesSupport and haulage vehiclesEquipmentSan Vicente pipeline production techniquesSan Vicente pipeline production techniquesTunnelling segments

North America focus

March 2008 Issue 6


The magazine for the tunnelling professional


CovIWT0803.indd 1 25/2/08 11:12:31

Lovat.indd 1 25/2/08 09:33:09

Visionaries open up new areas

T wo news items this month will perhaps attract more attention than others. The first (p9) con-cerns the recent unveiling of Strukton Groups visionary plans for Amsterdam, involving a significant amount of infrastructure being relocated underground.

Designed in conjunction with Amsterdam-based architects Zwarts & Jansma, the visionary scheme aims

to improve Amsterdams chronic traffic

problems and improve the city economically.

The other news item, perhaps more

mundane but equally significant for urban

development, concerns the construction of a

Tesco supermarket over a new con-

crete arch, spanning a railway cutting

in Gerrards Cross, England (p6). The scheme shows how a simple, concrete arch tunnel can yield land for development. Rolled out on a larger scale that could mean many extra hectares created out of nothing.

Both schemes exemplify tunnelling as a cost-effective, environmentally-friendly way of increasing urban space, opening up cities, making them more accessible and creating new places that did not exist before.

But, it should be remembered that such schemes are necessarily based upon an initial concept of tunnelling as a means of improving the urban environment, allied with the tunnelling sectors ability to advance that concept expertly.

In the words of my predecessor Lawrie Williams, tunnellers all need to learn to put forward their viewpoint in as erudite a manner as possible, to give them a chance to win their day for a more environmentally-friendly solution to many urban transportation problems.

George Demetri, Editor

WEB ADDRESS www.world-tunnelling.com

Regulars1 Comment

3-9 Global newsA round-up of the latest news and technology

22-23 InnovationThe latest equipment releases and upgrades

Atlas Copco www.atlascopco.com 7

Boart Longyear www.boartlongyear.com 10

Chemgrout www.chemgrout.com 21

Erkat www.erkat.de 22Geokon www.geokon.com 8

Gomaco www.gomaco.com 9

Grindex www.grindex.com 15

Hny www.haeny.com 14

Herrenknecht www.herenknecht.com 2

Lovat www.lovat.com Cov II

Maschinen und Stahlbau Dresden www.msd-dresden.de 21NDCO www.ndcogroup.com 17

Robbins www.TheRobbinsCompany.com Cov III

RocTest www.roctest.com 11

RST Instruments www.rstinstruments.com 6

Sandvik www.sandvik.com 5

VMT www.vmt-gmbh.de 4Wyo-Ben www.wyoben.com 16

advertisersFRONT COVER

Robbins conveyors on the Epping to Chatswood (aka Parramatta) Rail Link in Sydney, Australia, which featured two horizontal, two vertical and one stacker conveyor. The horizontal conveyors

were crown-mounted and ran 6km in length with more than 80% in curves

1COMMENT

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

Production [email protected] editor [email protected] [email protected] [email protected]

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

World Tunnelling (ISSN 1756-4107) USPS No: 023-551 is published monthly (except January and July) by Mining Communications Ltd, Albert House, 1 Singer Street London EC2A 4BQ England.

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CONTENTS

contacts

March 2008

18

11 North America: BrightwaterThe 6.4km-long Brightwater project combines TBM and micro-tunnelling

12-13 North America: Contractual procedureDr Peter J. Tarkoy looks at site clauses that cover unforeseen conditions

14-15 Technology: ConveyorsDesiree Willis of Robbins Co looks at the improvements to todays systems

16-17 Interview: Alfred HaackRodney Craig discusses his old friend, Alfred Haack, who recently retired

18-19 Technology: Tunnelling segmentsSequentially lining the San Vicente Second Aqueduct Pipeline Project in the US

20-21 Equipment: Support/haulage vehiclesGeorge Demetri gets to grips with a sector that is as huge as it is varied

Features

01WT0803.indd 1 26/2/08 14:30:56

Scotland: Breakthrough for neSSiS hydropower.

h e r r e n k n e c h t a g | u t i l i t y t u n n e l l i n g | t r a f f i c t u n n e l l i n g B r i ta i n

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Herrenknecht AG D-77963 SchwanauPhone + 49 7824 302-0Fax + 49 7824 [email protected]

www.herrenknecht.com

Britains most efficient hydropower plant is being built at the world-famous Loch Ness in the Scottish Highlands. With 100 megawatts, it will produce sufficient power to provide 250,000 people with environmentally-friendly electricity. The power plant is located in a cavern below the south eastern lake shore and is supplied with water from a reservoir through a tunnel that is almost 8 kilometers long.

In September 2006, the Herrenknecht S-351, a Gripper TBM with a diameter of 5.03 meters and the name Eliza Jane took up tunnelling with a gradient of up to 12 percent. The TBM cut through the hard rock with best weekly performances of up to 270 meters negotiating altitude differences of 600 meters. A top tunnelling performance which helped to bring the project rapidly to completion: On January 7, 2008 the ma chine reached its target ahead of schedule.

05

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e

PROJECT DATA

S-3511x Gripper TBMDiameter: 5,030mmDriving power: 2,200kWTunnel length: 7,750mGeology: hard rock

CONTRACTOR

Hochtief Construction AG

g l e n d o e | B r i t a i n

108_eAz_Glendoe_WorldTun_200x275_04bp.indd 1 20.02.2008 16:16:19 Uhr

Vinci/Eiffage win Marseilles dual-deck tunnel contract

France

Super tunnel to end traffic woes in Auckland?

New Zealand

Cross-section through the proposed double-deck Prado tunnel in Marseilles

March 2008

NEWS

Intertunnel 08 readyWhat is hailed as the largest rail and tunnelling industry exhibition returns to Lingotto, near Turin. InterTunnel 2008 and Expo Ferroviaria will be held in parallel from May 20-22 in Turin. This InterTunnel promises to be a lively event, featuring leading suppliers of equipment, products and services. Visitors are expected from government, infrastructure management, public service companies, contractors, consultants, other tunnel specialists and health & safety people.

More details: www.intertunnel.com

Melbourne eventMelbourne will host the 13th Australian Tunnelling Conference from May 4-7 at the Hilton on the Park hotel. The theme will be Engineering in a changing environment to reflect the environmental, technical, legal and social frameworks associated with tunnelling projects. It will be opened by Ken Mathers, CEO of South Eastern Integrated Transport Authority. Other speakers include Dr Martin Herrenknecht and John Gardiner, CEO of ConnectEast on the EastLink project.

www.atstunnellingconference2008.com

ConeXPo on CourSeSome 125,000 industry professionals are due to descend on Las Vegas, US, for Conexpo, the triennial construction exhibition and conference highlighting equipment, products, technology and services. The exhibition (March 11-15), at the Las Vegas Convention Center, should attract 2,300 exhibitors spread over 195,000m2 of indoor and outdoor space. During the five-day exposition, the organisers look set to host over 120 education sessions. It is supported by 85 industry organisations from around the world.

More details: www.conexpoconagg.com

IN BRIEF

A CONSORTIUM led by French infrastructure company Vinci (58.5%) in partnership with construction and concession company Eiffage (41.5%) has won the contract for the Prado Sud tunnel concession in Marseilles, France. The JV was recently selected by the Marseille Provence Metropolis Urban Community.

At 1.5km long, the US$281million contract will comprise constructing an extension to the existing Prado Carenage tunnel and will link the A50 motorway to the local road network at the Avenue du Prado 2 and Boulevard Michelet. Included in the contract are the financing, design, construction, maintenance and operation of the tunnel in a concession that will last 46 years.

Like the East tunnel currently under construction on Paris A86 orbital motorway on which both Vinci and Eiffage are involved, the Prado Sud tunnel will also have dual decks that will superimpose two levels of traffic, both having two lanes.

Width and height restrictions of 3.2m will be needed in a design that complies with current safety regulations and is equipped with a permanent surveillance system.

Financing the tunnel will be through road tolls that will be paid to the concession holder, the Prado Sud company.

Work is scheduled to take five years to complete and is expected to last until spring 2013, when the tunnel will begin operating.

AUCKLAND, New Zealands largest city, could get a 5km-long, six-lane motorway tunnel to ease its traffic congestion. Currently considering its construction, the government may soon be seeking partners for the design, construc-tion and operation of the project.

Part of a by-pass designed to allow traffic to get from the citys west to the south, the US$1.6 bil-lion Waterview Connection will run from Mt Roskill to the Northwestern Motorway and will have a beneficial effect on the citys economy.

Although other options are being considered, a tunnel is thought to be the favoured option, which the government has said it

would like completed by 2015. If a public-private partnership is

used to build the tunnel, much of the money would come from the private sector, in which case the tunnel is likely to be a toll tunnel. A steering group is assembled to ascertain whether the private sector should be involved.

Located at around 50m below ground level, a deep tunnel would not be that much more expensive than a cut and cover, according to finance minister Michael Cullen, once the cost of acquiring property is taken into account. Tunnelling investigations are ongoing, before the acquisition of any land.

KNOWN as the biggest little city in the world, Reno in Nevada, US, will be the venue for the 12th US/North American Mine Ventilation Symposium, to be held on June 9-11. The event will include a session on tunnel ventilation.

To be hosted by the University of Nevada, Reno, Mackay School of Earth Sciences and Engineering, it is the first time a university has partnered with a private firm to host the event. Aimed at giving mine ventilation experts, professionals and students the opportunity to network and exchange ideas, the event will allow visitors to register for workshops, technical field trips and sightseeing trips. Attendance at workshops and field trips, the organisers say, may quality for professional development hours for PE and other certifications.

More details and registration: www.unr.edu/ventsymp2008

US

Biggest little city to host symposium

03-04,06,08-09WT0803.indd 3 25/2/08 11:06:28

NEWS

Excavation begins on Hindhead Tunnel project

UK

TUNNELLING around the world faces higher steel prices resulting from turmoil in the Chinese market. Freezing conditions in January caused havoc in a country that is no newcomer to heavy winters.

The resulting surge in the demand for coal prompted the authorities to urge industry to cut back production in a bid to save electricity for domestic heating and essential services. Several mills did cut back, some even shut for an unspecified period but it seems it will take some time for production to get back to normal levels. Laiwu Steel in Shandong province, Eastern China, was asked to reduce its energy consumption by 100,000kWh to match that being saved by the city.

At the time of writing, rebar and steel rod have hit 70-100/t in the UK. But a freezing winter does not necessarily cause higher steel prices on its own and other factors have conspired to cause the rise in Chinese steel prices. Higher Chinese taxes on long product exports, for instance, like rebar, rod and sections, encouraged by heightened EU and US political pressure aimed at curtailing Chinese exports are partly to blame. International pressure to strengthen the RMB currency has also not helped.

To make matters worse, the rise of the euro by 10% against the UK pound and the US dollar has served to heighten the crisis. All of this may mean higher construction costs for tunnelling, and it is unclear how long the situation will last.

WT to catch chill from Chinese steel woes?

China

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EXCAVATION work has begun on the Hindhead Tunnel in Surrey, England, which will take the main A3 dual carriageway beneath the Devils Punch Bowl at Hindhead.

Transport Secretary Ruth Kelly witnessed the start of excavation works for the 1.9km-long, twin bore tunnel that will become the UKs longest under-land road tunnel and will do much to enhance an area of outstanding natural beauty. Work first started on the project in January last year.

Projected to take around 30,000 vehicles daily, the tunnel is part of a 371 million, 6.5km dual carriageway upgrading and will eradicate all traces of the existing road from the landscape, not least eliminate the notorious traffic light bottleneck at Hindhead.

Tunnelling has began at the northern portal and also should start at the southern end in April, with the two tunnels meeting up in early 2009. Excavation through the

predominantly Hythe Bed sandstone formations will be carried out by three Liebherr 944 excavators, with at least two operat-ing at any one time. Also used will be Liebherr L566T wheeled loaders, Meyco Potenza Logica15 shotcrete robots, ITC TE210 electric tracked excavators and Sandvik Axera 8 (two-boom and basket) drilling jumbos. A conveyor will evacuate the spoil but at the southern end it will be taken through the tunnel to the northern end to avoid using the A3 road.

Initially, the heading will be excavated in 1-2m lengths, then supported using steel fibre-reinforced shotcrete. Excavation of the bench will take place around 100m away from the heading, and be followed by the excavation of

the invert. When completed, the tunnel will receive a secondary concrete lining to provide a smooth finish and a fire-resistant layer.

Work will be carried out on a 24/7 basis, until excavation is completed by March 2009. In 2011, when the tunnel opens to traffic, the existing A3 will be closed and restoration can begin to restore the site to its former natural state.

Congratulating the Highways Agency, Mrs Kelly said: The new tunnel will bury the road deep beneath this protected landscape and ease congestion at this notorious bottleneck improving journeys on the vital Portsmouth to London route.

TUNNELLING professionals from all over the world will convene in Munich, Germany, for an international tunnel safety conference entitled Fire Suppres-sion in Tunnels, from April 2-3.

Aimed at consultants, safety engineers, tunnel operators, government bodies, fire brigades, insurers and manufacturers, the conference will focus on fixed fire suppression systems and will also cover related topics such as detection, reliability and cost.

Presentations will be in English and /or German.

Experts from government, research bodies and the fire protection industry will be presenting their latest findings and there will also be a get-together on April 1, where participants are encouraged to join informal, first off-topic discussions at Hof-brhaus.

International Tunnelling Association (ITA) President Martin Knights said of the conference:

ITA recognises safety is the key operator in existing and new tunnel infrastructure. Conferences like this that allow government, designers and engineers the opportunity to view the latest developments can only be a good thing.

More details from: www.iwma.net

Cross-section through the

proposed Hindhead

Tunnel

Germany

Conference on fire suppression

03-04,06,08-09WT0803.indd 4 25/2/08 11:06:30

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Untitled-3 1 21.2.2008 14:22:54

March 2008

6NEWS

Supermarket tunnel ready for rebuildUK

UK SUPERMARKET giant Tesco looks set to resume work on its 2,300m2 Gerrards Cross store, following the collapse in 2005 of the tunnel onto which the proposed structure was being built.

The original plan envisaged a new store and car park to be built over the railway cutting carrying the Chiltern Line. This necessi-tated a 300m-long segmental concrete arch structure that would also create a tunnel. But on June 30 2005, part of the tunnel being built by main contractor Jackson collapsed, necessitating a halt in the works and causing a seven week closure of the line.

Since the disaster, a thorough investigation by contractor Costain and design engineer Scott Wilson of what went wrong has been conducted, although Tescos Michael Kissman was unable to divulge any details due to legal

reasons. But he told WT that everything

was in place for work to start on dismantling the original building frame as a new tunnel design had been developed with Costain and Scott Wilson. This involved an additional reinforced concrete arch over the original segmental arch to bear the load of the store. Back ll material surrounding the tunnel would be removed and the existing tunnel elements structure would be strengthened. Tescos website

hails the new design as substan-tially more robust than other proposed options.

Costains Mike Sawyer said : We will construct a new reinforced concrete arch over the top, using the existing units as permanent formwork. That will create a more robust structure that doesnt depend on the back ll for strength and increases the factors of safety for the structure. The new store is scheduled to open in March 2010.

A new reinforced concrete arch will support the supermarket

IT LOOKS like a new motorway and tunnels will bring new life to the west of Cyprus, after the Kinyras consortium was named preliminary preferred bidder for the 30-year PPP deal.

Leading the consortium will be local infrastructure company J&P (45%) in alliance with the French infrastructure company Vinci Concessions (40%) and Cybarco (15%). Comprising 31km of motor way, three tunnels and nine viaducts, the contract includes the nancing, design and operation of the motorway linking the well-developed western resort of Paphos with the

hitherto-undev eloped northwest of the island.

The US$682 million project will come as a blow to environ mentalists, given the Akamas regions hitherto special status as the islands last extensive area of outstanding wildlife habitats.

This is Cypruss rst Public-Private Partnership contract for road infrastructure. Due to last four-and-a-half years, the work will be carried out by a consortium comprising J&P (60%), VINCI Construction Grands Projets (20%) and Cybarco (20%).

Motorway, tunnels to open up AkamasCyprus

APTLY named Tatuzo (Big Armadillo), the megashield TBM that is boring Line 4 of Sao Paulos metro has now reached the proposed Oscar Freire station. Between now and the middle of

March, the TBM will undergo a period of inspection and maintenance, after which it will be heaved to the end part of the station to start boring the tunnel from Paulista station.

A UNIGROUT mobile grouting unit, claimed to be the largest in the world, has been supplied by Atlas Copco to Swedish contractor Veidekke Entrepreneur AS, for use on the new Norra Lnken road tunnel project in Stockholm.

An all-in-one automated grouting plant that mixes, pumps and records the grouting process, the unit is primarily designed for tunnelling applications where leakage and in ux of water may be a problem; or where ground water levels are not allowed to vary.

Constantine Spinos, Veidekkes tunnelling contract manager in Stockholm, said: We lose money if the equipment malfunctions so we are dependent on the grouting units ef ciency and reliability.

Sweden

Largest mobile grouter on Stockholm tunnel

Armadillo progressing well in So PauloBrazil

03-04,06,08-09WT0803.indd 6 25/2/08 11:06:58

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Atlas Copco.indd 1 25/2/08 09:50:38

Robbins TBM digs deep Down UnderAustralia

NEWS

March 2008March 2008

FOLLOWING the recent signing of a contract between Yarra Valley Water and John Holland Construction last year, a new 3m-diameter Robbins double-shield TBM will excavate a 3.2km-long sewer tunnel beneath Melbournes northern suburbs as part of the Northern Sewerage Project Stage 2. It is expected to start excavation in late August 2008, having been built at Robbins Ohio, US facility.

Launched from a 35m-deep shaft, the TBM will be armed with

17in cutters to bore through basalt rock, ranging from 60 to 270MPa UCS. As it excavates, full muck cars will be hoisted up the shaft

and side-dumped into a spoils bin for removal by rubber-tired vehicles. However, the proximity of houses has necessitated site modifications that include vibration monitoring and an acoustic shed to dampen noise.

Ken Muir, project manager for John Holland Construction, said: Most civil tunnel works in

Australia in recent years have been undertaken using road headers and soft or mixed ground TBMs.

This is an opportunity to demonstrate how hard rock TBMs can perform.

Overall, the entire Northern Sewerage Project is worth around US$582 million and involves the construction of 13km of sewer ranging from 1.6-2.5m diameter id Stage 2 involves 4.5km of tunnel and is scheduled for completion by 2012.

The Newlands Road Shaft will provide the launching point for a 3.0m Robbins TBM in Melbourne

ONE of Europes largest construc-tion groups, Strabag of Austria, has acquired in its entirety the Italian construction group Adanti Spa.

Strabag claims the Bologna-based company operates in all areas of Italian construction as well as specific know-how of tunnelling.

Strabag itself is no stranger to tunnelling. It is hoping to position Adanti as one of the leading construction companies in Italy.

Adanti generated revenues of

160million in 2007 and currently has 370 employees.

STRABAG SE CEO, Hans Peter Haselsteiner, said: Adanti fits into the group excellently. Its high technological competence and market position gives us the opportunity to develop our business in Italy in all sectors. Backed by our corporate structure, we want to turn Adanti into one of the leading construction companies in Italy in the medium term.

NFM Technologies continues its progress in China following its recent announcement that it has received an order for two 5.75m diameter, hard-rock tunnelling machines for use on the project to divert the Tahoe River, a tributary of the Yellow

River. Delivery should take 11 months.

Worth about US$23 million, the contracts cover design, construction, delivery and commissioning of the two machines.

The first, a single shield

TBM, is for the China Railway Tunnel Group Company (CRTGC); the second, a telescopic shield TBM, is for Sino-Italian group CMC Ravenna and Synohydro Engineering Bureau 4.

Diverting the Tahoe is part of the Yintao project begun in 2006 which aims to bring drinking water to Gansu

province in the northwest of the country. TBMs T7 and T9 are expected to excavate 17.2km and 18.2km respec-tively during the first phase of the work.

NFM has stated that with the 15 machines sold in China during the last 18 months, it has orders worth over US$190.1 million.

NFM wins two more China ordersChina

Strabag acquires AdantiAustria

Strabag was involved on the Copenhagen Metro, completed in 20021 603 448 [email protected]

Data Acquisition Systemsfor automated monitoring of instrumentation in tunnelling projects.

Vibrating WireNATM Stress Cells

03-04,06,08-09WT0803.indd 8 25/2/08 11:07:31

March 2008

NEWS

AMBITIOUS plans to locate a significant amount of Amsterdams infrastructure underground were unveiled recently by civil engineering group Strukton.

Owned by Dutch Rail, the Group envisages facilities such as cinemas, shops, gyms and the household waste disposal system to be buried in the citys clay soil, while multi-storey car

parks could be built under the citys canals. Expected to cost US$14.7 billion, the project will aim to alleviate Amster-

dams traffic problems and improve city air quality, as well as make the city more economically attractive to residents. It is envisaged it would take up to 20 years to complete.

Life underground in Amsterdam The Netherlands

An 11m-diameter, 9.2km-long TBM-driven tunnel that will be the first part of a three-stage scheme in the Buenos Aires area is part of a project commis-sioned to the Nuevo Sarmiento consortium, which submitted the lowest bid. The line will link the capital to the western Greater Buenos Aires suburbs of La Matanza, Morn, Castelar and Moreno.

Comprising the Argentine company Iesca, the Brazilian firm Odebrecht, Spains Grupo Comsa and Italys Ghella, the consortium is tasked to build

the first phase to drive underground 9.2km of the Sarmiento line between Caballito and Liniers stations for US$1.35 billion. It will have to be completed in 36 months and will include a series of ramps, six stations and a maintenance workshop. The larger scheme is worth US$3.35 billion and will see 32.6km of tunnel excavated under the existing tracks.

Tunnelling the line underground is seen as one of the biggest-ever rail projects carried out in the capital.

PROPOSALS for a new road and rail tunnel under the River Thames are being examined by the Dept for Transport and the Environment Agency, following the unveiling of plans by business consortium Metrotidal.

The multi-billion-pound scheme envisages an immersed concrete tube tunnel laid in a trench between Medway and Canvey Island, east of London on the borders of Essex and Kent.

If built, the tunnel would

facilitate the governments overall development plan for the Thames Gateway area.

A spokesman for Medway Council, in whose area the proposed tunnel would lie, told WT that it had received no proposals from Metrotidal but in any case would not view sympathetically any development that might disrupt the Cliffe Marshes an important bird habitat of special scientific interest.

UK

New tunnel could open Thames gateway

Italy

Italian headrace tunnel will get a summer startJUNE will see the start of tunnelling for the 9.15km-long headrace tunnel at the Crevola Toce III hydropower scheme, awarded recently by Enel to a joint venture led by Monti and Giacomini Comm. Alberto and also including Seli.

With outer and inner diameters

of 4.2 and 3.9m respectively and a cross section of 13.85m2, the tunnel will be excavated using a combination of TBM (8,589m) and drill and blast (565m).

Along the tunnel alignment are an assortment of fine grain granitic gneiss, metasediments, marble, dolomite and calcareous clayey

schists, anhydrite and micashists.Seli has designed the double

shield TBM to be compact, easy to transport, assemble and operate, while at the same time maintain productivity and keep costs down.

Manufactured at Selis Aprilia factory in Italy, the DSU Compact TBM System will be kitted-out to

allow the installation of traditional support methods that include rockbolts, welded mesh, steel arches, shotcrete, fibre-glass rods and steel bars, depending on the geology encountered.

Tunnelling is scheduled to be completed by September 15, 2010.

Argentina

Mega rail project commissioned

A LOVAT RME257SE Series 23100 TBM recently broke through at Kirazli Station in Istanbul, Turkey, thereby completing 1,307m of its first drive on the current phase of the citys metro project.

The third Lovat machine delivered to the Gulermak-Dogus JV, the TBM has encountered predominantly soft ground mainly clays, silts and sands, with EPB pressures of up to 5 bar.

Istanbul metroTurkey

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Bright idea for Seattle sewersThe 6.4km-long Brightwater project combines TBM- and micro-tunnelling

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BRIGHTWATER West Contract is a 6.4km-long, segmentally-lined sewer tunnel that combines TBM- and micro-tunnelled sections as part of a larger scheme designed to meet Seattles sewerage demands. It is located north of Seattle in the village of Richmond Beach, a part of Shoreline, Washington. The general contractor for the project is the joint venture (JV) of Jay Dee Coluccio Taisei, acting on behalf of King County, Washington state.

The JV is composed of Jay Dee Contractors Inc of Livonia, Michigan, Frank Coluccio Construc-tion Company, Seattle, and Taisei Corporation of Japan. The project was bid in October 2006 with the JV submitting the lowest (US$102.5 million) and awarded in January 2007, with notice to proceed given on February 20.

The project consists of a Point Wells portal site an excavation about 9.14m deep and 12.2m x 59.44m. It will be used as a launch portal for the BT-4 earth-pressure balanced tunnel-boring machine to drive the 6,431m-long, segmentally-lined tunnel with a 3.96m minimum internal diameter. Around 152.4m of the tunnel will comprise 2,130mm inside-diameter micro-tunnelled ef uent sewer. This micro-tunnel will house a 1,830mm-diameter steel pipeline from the main tunnel, the last 762m of which is lined with a 3.05m-diameter steel pipe, through a ow meter vault ending in a receiving pit where it will connect with a marine outfall pipeline that will be constructed under a separate contract.

GEOLOGICAL SETTINGThe geology for Section 4 is broadly the same as for the Brightwater East Contract (WT, December WT, December WT2007, pp10-12). Bedrock lies at depths of 122m to 457m and will not be encountered during construction, but it is overlain by glacial and non-glacial sediments through which the tunnel will be built. One feature that has resulted from depositional glaciation is the sequence of aquifers and aquitards. Due to groundwater movement between upper and underlying aquifers, natural changes in groundwater levels are anticipated throughout the tunnel alignment.

CONSTRUCTIONAs of the writers visit in October 2007, the JV has completed all site set-up and has started the support of the main shaft and micro-tunnel. All utilities are installed, including two pipe-rammed casings

Vacuum pipes from jet-grout carry spoil to the collector units for safe disposal

As of the writers visit in October 2007, the JV

beneath the Burlington Northern Santa Fe railroad (BNSFRR). The job-site eld of ces have been set up and the contractor has moved from the temporary of ces in Shoreline WA.

The site grading, drainage and temporary access roads have been completed. Equipment is being mobilised on site, including a Manitowoc 14000 crane. The JV is installing steel sheeting and jet-grouting the break-out areas for the main

and micro-tunnel operations. All of the jet-grouting return spoil has been contained for disposal to prevent contamination. The receiving shaft for the micro-tunnel is almost to grade and a second jet-grouting set-up is being started.

A Lovat 4.7m-diameter EPB TBM is being manufactured in the Lovat plant in Toronto, Canada, for the tunnel drive and it is scheduled for delivery in March.

The concrete tunnel segments will be made by CSI/Hanson JV, in Tacoma Washington. All 6,431m of tunnel will be driven from the shaft portal at Point Wells in Richmond Beach to the Ballinger Way Shaft being constructed, with freezing of the overburden on the Central Contract where the EPB TBM will break through and be retrieved.

Major subcontractors include Delta Techno-logy Corp for HVAC, J.P. Francis & Associates Inc for plumbing and mechanical, and United States Electrical Corp of Washington for both temporary and permanent electrical work.

Jet grout rigs at shaft site

11WT0803.indd 11 25/2/08 13:02:16

NORTH AMERICA: Contractual procedure

Managing the unforeseenGeotechnical and underground-construction consultant Dr. Peter J. Tarkoy looks at site clauses designed to facilitate the contractual procedure when unforeseen conditions are encountered

March 2008

12

DSC, the differing site condition clause, has been used in US construction since 1926. Global trends have tailored and altered the assignment of risk in construction, consistent with the DSC clause. Our experience of representing owners, engineers and contractors in association with differing site condition claims has led us to discover persistent failings in a system that administers and attempts to resolve these claims.

This paper will address these timely issues associated with the administration of differing site conditions: nElements of entitlement;nGeotechnical baseline reports; nUtilisation of all available information; nReasonable interpretation and assessment of available information;nDispute review boards;nRecommendations for inclusion into contract speci cations.

ELEMENTS OF ENTITLEMENTThe required technical elements to establish entitlement have not changed, but merely become more distinctive. Outlined in Tarkoy (1988, 1998), they are listed for inclusion in contract speci cations with the DSC clause. They are: nThere must be a difference between reasonable anticipated and documented encountered conditions;nThere has to be a difference between reasonable anticipated and documented encountered construction performance;nA cause-and-effect relationship must be demonstrable between the differences in conditions and difference in construction performance;nThere must be a demonstrable impact on time or costs;nContract conditions must be ful lled (reliance, notice, mitigation), andnNo other factors (self-in icted) can have caused the difference between anticipated and encountered performance.

To date, there has not been a direct link between the Elements for Entitlement and the typical DSC clause. The consistency of these elements with a typical DSC clause used by many public agencies is illustrated in the box.

GEOTECHNICAL BASELINE REPORTSGeotechnical baseline reports have been conducive in establishing the baseline from which any differences are measured. Yet, resolutions have been troublesome and plagued with uncertainty as a result of incomplete or unsuitable anticipated properties. For example, test results often do not re ect the full range of known mechanical properties experienced in a locality in the past. In such cases, the geotechnical engineer should extend anticipated conditions beyond the test results with known local experience, preferably quantitatively, as illustrated in diagram 2.

UTILISATION OF ALL DATAIf not all available data is used by a contractor, the baseline and bidding eld is altered. A contractors failure to examine and use all available data is not uncommon. In one case, the rock core was not examined and the contractor failed to comprehend the massive nature of the rock (diagram 3) to be excavated by hydraulic-impact hammer. The encountered rock was just as indicated by the rock core, as

illustrated in photo A. It is well known that excavation of rock by impact hammer relies on such rock-mass properties as fracture frequency, weathering and mass strength (photo B).

REASONABLE INTERPRETATIONOne of the ongoing problems facing adjudicators of differing site-condition claim entitlements is the reasonableness of interpretations of anticipated conditions into material behaviour under construction conditions, selection of means, methods, equipment, and interpretation into construction performance.

Diagram 3 illustrates a massive rock core that was misinterpreted as being easy to excavate because the contractor interpreted foliation to be equivalent to discontinuities. The rock was too massive (closely-spaced discontinuities lacking) for impact-hammer excavation and had to be blasted, as illustrated in photo A. Closely-spaced discontinuities are necessary to excavate in-situ rock with an impact hammer, as illustrated in photo B.

One way to ensure a reasonable interpretation is to require bidders to require the contractor to provide a list of assumptions and methods of interpretation, such as literature and relationships used to interpret: nGround behaviour; nStability of opening;nExcavation behaviour, andnSelection of means, methods, equipment and excavation rates.

Photo A: the encountered rock was just as indicated by the rock core

Diagram 3: a massive rock core that was misinterpreted as being easy to excavate

12-13WT0803.indd 12 25/2/08 10:13:39

March 2008

13NORTH AMERICA: Contractual procedure

DISPUTE REVIEW BOARDS (DRB)As with all other adjudicating bodies, DRBs depend on the knowledge, experience and thinking of the individual members. It is essential that, in addition to experience and understanding of geotechnical, engineering, and construction issues, the board members must recognise the necessity of ful lling all of the six elements necessary for entitlement.

Without a clear pathway and checklist for establishing or denying entitlement, both parties tend to be unhappy with the adjudicating opinions. In the past, the ASCE and DRBF co-sponsored a continuing education course on the elements of entitlement for DSC claims. However, that programme lapsed recently.

RECOMMENDATIONS FOR CONTRACT SPECIFICATIONSIn our experience, total cost claims are often presented that do not address, rely on or establish the underlying cause of increased costs. In other words, total cost claims overlook or avoid establishing entitlement. Too commonly, entitlement is asserted with little or no proof at all. The basis of the claim relies on the quantum conjured up.

In order to ensure entitlement is fully considered, established and con rmed prior to addressing the quantum of the claim, we recommend the addition of speci c conditions for entitlement. First, we recommend that the Elements for Entitlement be included in the speci cations following the differing site condi-

tion clause. In addition, it must be stated that the contractor is required to: nRely on all available geotechnical information; nView all soil and rock samples;nWalk-tunnel alignment; nProvide evidence of reasonable interpretation into material behaviour, andnAnalyse, establish and present entitlement according to the Elements for Entitlement.

These elements are provided in section 1 and have been discussed by Tarkoy (1988, 1998). For more information, visit these web sites: http://www.tbmexchange.com and http://www.geoconsol.com/index.php.

250

200

150

100

50

0

200

9

165

75

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Photo B: closely-spaced discontinuities are necessary to excavate in-situ rock with an impact hammer

REFERENCES:Tarkoy, P. J. (1988) What Claims are Made Of. World Tunnelling 1(3):249-253 (September 1988).Tarkoy, P. J. (1998) Differing Site Conditions. World Tunnelling (March 1998).Dr. Peter J. Tarkoy is a geotechnical and underground construction consultant specialising in preventing and solving problems in tunneling and heavy construction, adjudicating differing site condition claims, reducing cost and risk in tunneling and tunnel boring.

Diagram 2: extending anticipated conditions based on local experienceArticle 106: differing site conditions(a) The Contractor shall promptly, and before such conditions are disturbed, notify the Engineer in writing of: (1) latent physical conditions at the site differing materially from those indicated in the Contract Documents (sometimes referred to as a `Type I Differing Site Condition); or (2) physical conditions at the site, of an unusual nature, differing materially from those ordinarily encountered and generally recognized as inherent in work of the character provided for in this Contract but unknown to the Contractor until encountered during prosecution of the Work (sometimes referred to as a Type II Differing Site Condition). The Engineer shall promptly investigate such condition(s) to determine if the condition(s) constitute a differing site condition as described in sub-clauses (1) or (2) above. Should the Engineer determine that a differing site condition exists which causes an increase or decrease in the Contractors cost of, or the time required for, performance of any part of the Work, the Engineer shall notify the Contractor of same, and within a reasonable time, not to exceed fteen days, Contractor shall provide a detailed Change Order Proposal in accordance with Article 404, Change Order Procedure and Basis for Payment. The Engineers determination shall be subject to review by the Disputes Review Board as set forth in Article 803, Disputes Resolution Procedure.

(b) No claim for an extension of time and/or an equitable adjustment by the Contractor due to a differing site condition under this Article shall be allowed unless: (i) the condition giving rise to such claim could not have been discovered during a reasonable site inspection prior to award (whether or not same was actually conducted) and was not otherwise reasonably foreseeable, and (ii) the Contractor has given the notice required in (a) above, and has met all requirements in Article 205, Extension of Time. In addition, any proposal by the Contractor for additional time and/or compensation due to a Type I Differing Site Condition shall include speci c reference to the relevant section of the Geotechnical Baseline Report or other Contract Document which the Contractor claims gives rise to such entitlement, with adequate explanation and documentation to support its claim to the Engineer, including appropriate documentation that there was a substantial difference in the actual site conditions from a condition stated in the Geotechnical Baseline Report or other Contract Document, that it impacted on the Contractors prosecution of the Work, and that the condition is one for which the negative impact could not have been avoided by reasonable efforts made by the Contractor.

12-13WT0803.indd 13 25/2/08 10:13:40

TECHNOLOGY: Conveyors

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INNOVATION in conveyor design must take into account many parameters, including bore diameter and type of TBM, muck chip size, rock abrasiveness and moisture content, not to mention the tunnel pro le.

DURABLE CONSTRUCTIONAs an alternative to fabric belt, steel-cable belt is becoming important in todays conveyors, thanks to its higher strength and ability to be used with more powerful drives. On longer tunnels, higher power motors greatly reduce the need for booster drives, which, though adding power to the belt along the tunnel length, can be dif cult to install and are often costly to assemble and maintain.

Steel-cable belt was recently used on a large tunnelling project in Liaoning, China. Two 8m-diameter Robbins main-beam TBMs bored the Dahuofang Water Tunnel; a large reservoir-diversion project comprising two tunnel sections of 19.3km and 16km in length. Two steel-cable

belt conveyor systems were designed for the belt conveyor systems were designed for the drives, with multiple-drive motors of 900kW drives, with multiple-drive motors of 900kW each (300kW is typical). The powerful drives each (300kW is typical). The powerful drives eliminated the need for several booster drives. eliminated the need for several booster drives.

However, steel cable belt has limitations. It However, steel cable belt has limitations. It has high tension and cannot be bent on sharper has high tension and cannot be bent on sharper curves, making it ef cient only for mostly curves, making it ef cient only for mostly straight paths. Fabric belt can negotiate curves straight paths. Fabric belt can negotiate curves easily because it does not have the rigidity of a easily because it does not have the rigidity of a steel-cable belt, although additional booster steel-cable belt, although additional booster drives may be needed in curved areas. drives may be needed in curved areas.

GREATER CONTROLGREATER CONTROLVariable-frequency drives (VFDs) are a Variable-frequency drives (VFDs) are a recent innovation and are now the recent innovation and are now the preferred control system over hydraulic preferred control system over hydraulic couplings as they control acceleration couplings as they control acceleration better during start-up. The system better during start-up. The system actively sets the speed and torque that actively sets the speed and torque that a drive contributes to the conveyor in a drive contributes to the conveyor in both single- and multiple-drive set-ups. So, a controlled start-up is possible and

Desiree Willis of Robbins Co outlines how advancing technology has made Desiree Willis of Robbins Co outlines how advancing technology has made todays conveyor systems more versatile, stronger and energy-ef cienttodays conveyor systems more versatile, stronger and energy-ef cient

Part of the conveyor system on the East Side Access TBM project in New York City, US, showing the vertical conveyor rising out of the Queens shaft at the site

14-15WT0803.indd 14 25/2/08 09:33:33

15TECHNOLOGY: Conveyors

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belt tension is kept low to reduce stress, and allow certain types of belt to negotiate tunnel curves.

Variable-frequency drives are more cost-effective and reliable, and require less routine maintenance than hydraulic couplings, explains Butch Riffe, chief engineer for Robbins conveyor systems. The drive systems are much cheaper because they use AC 3-phase motors, which require less maintenance than earlier, DC motors. Newer systems are also digitised, so a separate frequency motor is not needed to control the torque supplied by each drive.

Since their power output is controlled, VFDs are more energy-ef cient than their hydraulic-coupling counterparts. The latter are still used, mainly on single-drive systems and shorter tunnels that do not require a booster drive. These coupling systems offer a smooth start-up for the simpler motors that operate on one speed.

GOING AROUND THE BENDCurved tunnel paths are one of the biggest chall-enges for muck-hauling systems. Self-adjusting curve idlers, patented by Robbins, help to solve the problem by pivoting to accommodate chang-ing load tensions around curves. The pivoting action does not unnecessarily alter the carrying capacity of the conveyor or the belt tension. Self-adjusting curve idlers were used successfully in the crown-mounted position for the Epping-to-

Chatswood conveyor system, which had a curved tunnel path for over 80% of the bore.

New developments in curve idlers have made them even more vital for conveyor design. Recent decreases in the weight of the carrying idler assembly have improved worker safety by making them easier to lift. The reduced weight makes it easier for workers to install idlers through the installation window, which means less possible back injuries, says Riffe.

URBAN TUNNELLINGNew York Citys East Side Access project involves a job site in downtown Manhattan; one of the worlds largest urban centres. An innovative Robbins continuous conveyor system at the site is using every type of commonly-recognised belt conveyor to transport muck 150m away from the tunnel portal. Most notably, the system has been designed with three overland conveyors, the

second of which must cross a busy roadway. The 48m-long conveyor was built with a completely-enclosed box truss about 6m above the roadway and under existing rail lines. As of January, the system has been highly successful, achieving 95% system availability on average.

MUCK HAULING IN LONG TUNNELSTBM projects are becoming more extensive and Indias AMR Project is no exception. The project, for which two 10m-diameter double-shield TBMs are being assembled, will be the worlds longest TBM-driven tunnel without intermediate access. The tunnel, at 43.5km in length, presents unique challenges for conveyors.

The entire continuous-conveyor system will be broken up into short ights with multiple-drive motors, requiring belt to be added inside the tunnel. Two 914mm-wide steel-cable belt conveyor systems, each 22.5km long, will operate from either side of the tunnel as the TBMs bore. On each side, the conveyors will be split into two ights of 11.3km in length. A dual, 300 kW main drive and booster drive will power each conveyor ight. Once the TBMs bore the rst 11.3 km of their respective drives, the xed tailpiece will be installed at the tunnel portal and the belt storage cassette will be moved inside the tunnel, allowing for the continuous addition of belt to the next conveyor ight.

Self-adjusting curve idler

14-15WT0803.indd 15 25/2/08 09:33:40

INTERVIEW: Alfred Haack

ALFRED Haack retired in December 2007 after 41 years at STUVA, the German tunnelling research organisation. Al-though he has given up his management respon-sibilities for retirement, he is still working 12-14 hours a day and will do so for the next few years. His immense experience will not be lost to the industry, at least for the present time.

EARLY CAREER AND STUVAHaack was born in 1940. Having completed a degree in civil engineering, he rst worked on motorway bridges and in January 1967 joined STUVA as a young engineer. Founded in 1960, the non-pro t research organisation specialised mainly in underground construction, but has

since expanded into railway and road transport. Today, it has become the tunnelling research establishment of the western hemisphere.

Under the management of Gunter Girnau, Haacks rst task was to investigate the art of waterproo ng tunnels, a subject that is still one of his two specialities. His other passion is tunnel res and he has become the world authority on this subject. Yet his knowledge and experience in tunnelling extends outside these two areas.

Haacks PhD thesis was on Fire protection during the construction of tunnels, for which he carried out a series of re tests, rst in the open and then underground. The background to the tests and his PhD thesis was a re accident in

Haacks retirement leaves a gap in the sector

Rodney Craig discusses his old friend, Alfred Haack, who recently retired from a long and distinguished career in tunnelling

16

Alfred Haack, who retired last December

16-17WT0803.indd 16 25/2/08 09:43:21

PIARCHaack represented Germany on the PIARC Working Group No. 6 on Fire and Safety since 1988, but has recently resigned following the completion of the last ve-year phase and the publication of its report. Haack had a major in uence in the working groups work, enjoying the meetings and meeting many friends over the period.

Alfred Haack has had a monumental 41 years in the tunnelling industry and all his many hundreds of friends around the world give him their best wishes as he moves slowly into his retirement. But we all look forward greatly to meeting him at some future meeting.

17INTERVIEW: Alfred Haack

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the Munich metro, in which three people died. There was also a second tunnel re in 1972. In both cases, the res were started in areas where bituminous waterproo ng materials were being installed which caused dense smoke and toxic fumes in the tunnels

In my four-hour informal talk with Haack last January, he reminisced at length about his early career. In 1977, when Girnau retired, Haack was appointed managing director of Stuva, a position which he has held for 31 years. In 1995, he was appointed to the Board. In 1996, a separate daughter company STUVAtec was set up to carry out commercial work for the industry, leaving the basic research to the non-pro t side of STUVA. The German Tunnel journal was started in 1982 and shortly after that date, became the of cial journal of STUVA.

During Haacks time at STUVA, he has written an amazing number of reports and lectures. He is responsible for 284 reports and has given 438 lectures at seminars, conferences and other events. He has lectured all over the world, regularly giving more than 20 lectures a year, with a peak of 28 in 2006. His caring, deliberate endeavour to learn and his kindness to others has meant that he has often spoken for at least some of the time in the native language of the country where he is lecturing. In this capacity, he has spoken in 19 different languages.

INTERNATIONAL TUNNELLING BODYIn 1970, Haack and Girnau represented Germany at the OECD Conference in Washington on the future of tunnelling. Since the formation of the International Tunnelling Association (ITA) in 1974 when nations started forming their own tunnelling societies, Haack has been very active in the working groups and has attended more meetings than any other national representative.

Haack took his term of of ce seriously and made it his task to attend as many of the member nations conferences that he could. He loved travelling the world and meeting people and seeing their countries and, whenever possible, he took a few extra days to explore the countries. His presidency included the 25th anniversary meeting held in Oslo, Norway, when he had a private audience with the king.

Haack has been a major part of the ITA for

more than 30 years. His contribution to their meeting has been enormous, initially represent-ing Germany on the executive council, as president and past president, and recently as elder spokesperson.

Sir Alan Muir Wood, the ITA Honorary President, said of Haack: Alfred was a tower of strength, indefatigable, loyal and always with good ideas for future development. His contribution to tunnelling extended well beyond his period of presidency and as a member of the executive council.

In his tribute to Haack in Tunnel Magazine, ITA president Martin Knights said: Alfred stands out as the supreme mentor, a role model, a leader, a beacon of good standards, someone to go to for advice, a lighthouse where he attracts attention; he warns and advises; he guides you; and weathers every storm.

16-17WT0803.indd 17 25/2/08 09:43:30

TECHNOLOGY: Tunnelling segments

THE 17km-long San Vicente Aqueduct Pipeline tunnel is being constructed using precast concrete rings to act as preliminary ground support through two sections of bored tunnel with lengths of 2.9km and 10.27km. The six-segment, bolted, trapezoidal ring is made from a combination of steel bre-reinforced concrete and self-compacting concrete in vertical moulds.

The segment manufacturer for the San Vicente Second Aqueduct Pipeline Project (SVP) decided to use simpli ed, precasting methods to produce over 66,000 segments, to be used for the primary lining of the tunnels. The methods examined and adopted included the use of steel bre to replace traditional reinforcement bars, vertical moulds to minimise surface nishing, and self-compacting concrete to minimise vibration and compaction effort.

THE SCHEME The SVP consists of a water-transmission pipeline running from the San Vicente Pump Station to the Rancho Penasquitos pressure control and hydroelectric facility. Forming part of the system required to ensure water supply to the San Diego region in the event of supply interruptions, it region in the event of supply interruptions, it is being constructed predominantly in the 17.3km-long tunnel that is bored through mainly sedimentary rock.

Various tunnelling methods are being adopted along the route to suit the local geology, with a bored tunnel and segmental lining adopted as the primary support for about 2.9km of bored tunnel through Reach 2, and

10.27km through Reach 4. The ground in these sections is mainly weaker, sedimentary form-ations and conglomerates between higher-strength granitic rock either side of the two Reaches. A raw water-transmission pipe will be placed through the tunnel, which will form the long-term support for the ground loads and internal water pressure. The precast concrete lining maintains suitable support to the ground lining maintains suitable support to the ground until the permanent support can be installed.

The tunnel is being built with a six-segment, trapezoidal, segmental lining with an internal diameter of 3.2m and a thickness of 178mm. Each ring has a length of 1,219mm and a taper of 19mm across the diameter. Two spear bolts are used across each longitudinal joint and the ring has 12 dowels across the circumferential joint.

Blind-end grout sockets are cast into the centre of each segment, which are being erected behind open-face shields, manufactured by CTS. The design of the segmental lining is based on the use of steel bre-reinforced concrete (SFRC), with the performance requirements listed in Table 1.

SELF-COMPACTING CONCRETESelf-compacting concrete (SCC) is concrete that will ow and consolidate under its own weight to completely ll the form void while main-taining homogeneity, without the need for an external, vibrating energy source. The advantages in terms of noise reduction, health, safety and cost savings on equipment, operation and maintenance are obvious. There can be quality advantages as poker-vibrated concrete may look well-compacted, but the effort can be uneven through the section and poor compac-tion may occur around congested reinforce-ment, or within complex form details, or there ment, or within complex form details, or there could be reinforcement displacement due to excessive effort.

STEEL FIBRE-REINFORCEDSteel bre-reinforced, self-compacting concrete has many similarities with normally-compacted SFRC with the requirements for strength and toughness being unchanged for design purposes.

Also assumed is a suitable mix design, effectively being equal in terms of

being able to achieve the required performance.

MIX DESIGNThe development of the mix design for the segments was

complicated by three of the primary items noted above (vertical segment moulds,

use of SCC and use of steel bre). While these

Segmentally lining the San Vicente aqueduct tunnelSegmentally lining the San Vicente aqueduct tunnelSegmentally lining the San

Mike King of Halcrow Group, London, and Chris Hebert of Traylor Shea Ghazi Precast, Los Angeles, discuss the production of this pipeline in the US

18

March 2008

Vacuum-lifting the newly-cast segment Vacuum-lifting the newly-cast segment

Stacking for trucking to site

18-19WT0803.indd 18 25/2/08 12:51:06

19TECHNOLOGY: Tunnelling segments

March 2008

materials and processes are not new, none had been employed at the segment casting facility in Littlerock, CA, and combining all three is a rst for the segment industry.

In addition to meeting the required design parameters, the concrete had to provide the high-early strengths dictated by the production schedule and casting process, and had to be robust enough to deal with the variability inherent in the local materials and in any high production casting facility. The design strength parameters developed by Halcrow that had to be met are in Table 1.

The materials incorporated into the mix were fairly standard. The decisions that had to be made related to the steel bres, the high-range water reducing admixture (HWRA), and the mix proportioning. The choice of steel bres was largely based on the experience of other projects using bre-reinforced segments, such as the CTRL project in the UK, and also on the recommendations of the technical departments of the bre suppliers.

During the trial mix testing, the steel- bre concrete was tested to ensure it met the exural and tensile requirements set forth by the design. A dosage of 30 kg/m3 proved to be optimal, and the bre used was the Dramix RC 80/60 BN, as supplied by Bekaert. This bre is 60mm long, 0.75mm in diameter, and has a tensile strength of 1,050 N/mm2. It also has hooked ends and comes glued in bundles. Each pound of bre contains about 2,087 bres, so each yard of concrete has over 100,000 bres (130,000 bres/m3).

The HWRAs tested were of the polycarboxy-late family, and were designed to be used speci cally for SCC concrete. Viscocrete 2100 provided by Sika was selected, and the dosages tested ranged from 5-10 ounces per hundred weight (oz/cwt) of cementitious material. Further testing narrowed the ideal range for this application down to 5.5-8.5 oz/cwt. The use of a viscosity-modifying admixture (VMA) was suggested, and tested, but the bene ts observed in the testing did not justify the additional cost.

Field trials began seven months before segment production. Fifty batches of concrete were produced, of which 33 were sampled and tested. The experience gained from these trial batches proved invaluable to the success of the project.

TESTINGThe testing regime included the standard tests for concrete, and some additional testing dictated by the use of the steel bres. Table 2 below lists the test, the required result, and the average result.

The bre content was tested weekly by taking a random sample from the production concrete, lling a 1/4 cubic foot bucket, and then washing out all the non- bre materials. This was done on an inclined table with a magnetic plate at the bottom to collect the steel bres. The bres were then dried, weighed, and compared to the required amount for the sample size.

CASTINGSegment production was undertaken at a twin carrousel plant located near Los Angeles, California. One of the carrousels was dedicated to the San Vicente Project, and the other serviced other projects. The moulds and carrousel were provided by CBE of France, and the concrete batch plant was supplied by ACT/Wiggert. The facility was originally constructed in 2001 for the NOS-ECIS project, and has since been updated and modi ed for various projects.

The segments were cast vertically, with two moulds per trolley. There were a total of 144 moulds on 72 trolleys. The moulds were lled with concrete from an overhead bucket that traveled from the on-site batch plant into the casting building. The segments were steam cured and demoulded with a vacuum lifter, and were produced on a two shift/day basis, ve days/week. Average daily production was 48 rings, and there were approximately 11,000 rings required for the project. Casting was nished in April 2007.

CONCLUSIONSThe use of steel bre-reinforced self-compacting concrete in vertical segment moulds provided some unique challenges. Applying these technologies, whether individually, or as in this case, combined, must be considered carefully against the design requirements of the project, the concrete production capabilities, and the casting process. While there were some hurdles to overcome, combining these three technolo-gies was successful and enabled the project to meet the structural, schedule, and commercial goals. It also produced a nished product suited to its intended nal use.

REFERENCES:1. Burke J., The Saviour at San Vicente, Tunneling and Trenchless Construction, December 20062. Klein S., Hopkins D., McRae M., Ahinga Z., Design Evaluations for the San Vicente Pipeline Tunnel, RETC 2005 Proceedings, Ed. Hutton D., Rogstad W D.3. Interim Guidelines for the Use of Self-Consolidating Concrete in Precast/Prestressed Concrete Instituted Member Plants, Precast/Prestressed Concrete Institute, TR-6-03

Table 1: concrete performance requirementsParameter StrengthCharacteristic compressive cylinder strength 41.3N/mm2 (6,000psi)Characteristic exural strength at rst crack 4.2N/mm2 (610psi)Characteristic residual (post-crack) exural strength 3N/mm2 (440psi) Characteristic tensile strength 2.8N/mm2 (420psi)Early-age (stacking) compressive strength 9.6N/mm2 (1,400psi)

Table 2: test resultsTest Design requirement Actual average resultSeven-day compressive strength None speci ed 40.8N/mm2 (5,930 psi)28-day compressive strength 41.3N/mm2 (6,000psi) 50.7N/mm2 (7,360 psi)56-day compressive strength None speci ed 64.9N/mm2 (9,430 psi)

Flexural strength at rst crack 4.2N/mm2 (610psi) 8N/mm2 (1,162 psi)Residual exural strength 3.0N (440psi mm2) 3.7N/mm2 (536 psi)Tensile strength 2.8N/mm2 (420psi) 5.4N/mm2 (780 psi)Fibre content 30kg/m3 (50lbs/yrd3) 31.7kg/m3 (53.3 lbs/yrd3)

Result from a limited sample of 48 cylinders taken over the rst two months of production

Project owner: San Diego County Water Authority Project engineer: Jacobs Associates Contractor: Traylor Brothers and JF Shea CompanySegment manufacturer: Traylor Shea Ghazi Precast Segment designer: Halcrow Group

Credits

Preparing vertical moulds for casting

18-19WT0803.indd 19 25/2/08 12:51:13

EQUIPMENT: Support & haulage vehicles

The vital support vehiclesSupport and haulage vehicles is an equipment category that is as huge as it is varied. George Demetri grapples with a selection of what is on offer

March 2008

20

WHEN it comes to underground support vehicles, Sandvik offers a large range, partly due to its huge size and partly to the companies it has acquired over the past 20-odd years. This includes: Hughes Mining tools (1987); MGT (1987); Mission Drilling (1988); Eimco (1989); Tamrock(1990), which itself acquired Toro in 1987), Voest-Alpine (1996) and Drillmaster (1997). In 1998, Tamrock and Sandvik Rock tools merged fully to form Sandvik Mining and Construction. The same year, the company established the four product areas of Sandvik Tamrock, VA-Eimco, Sandvik Materials Handling and Driltech Mission.

Consequently, these mergers and takeovers have resulted in a wide range of Sandvik products that re ect the diverse origins of these various companies. However, as of January, the rm wisely decided to consolidate the myriad brands under the Sandvik banner and ensure the rainbow of coloured products would conform to its blue house colour.

Lars Josefsson, president of Sandvik Mining and Construction, said: I believe that doing business under one brand will clarify Sandviks total offering and make it even easier for our customers to do business with us. This is also a natural consequence following the reorganisation of our company last year. Our customers will only have to call one number for sales, support and servicing for all Sandvik equipment, irrespective of what kind of equipment it is.

Sandviks range of underground support vehicles is very wide and covers underground loaders (LHD) and trucks, and MPVs (multi-purpose vehicles). The companys load-haul dumpers (LHDs) have tramming capacities of 1-21t, while the loaders, also low-pro le, come in either diesel or electric variants.

Sandviks underground loaders (LHD) have FEA-optimised frames, four-wheel drive, articulated steering, advanced drive-train technology and an ergonomic design. Rugged and highly-manoeuvrable, they have tramming capacities of 1-21 metric tonnes and are available in both diesel and electric versions.

Typical of these is the LH625E, which, at over 14m long and 3m high, is claimed to be the biggest-ever underground loader, designed for underground production and large-scale developments. With a tramming capacity of

around 25,000kg, the unit does not produce exhaust fumes and features the patented Toro cable-reeling system.

But, perhaps the most visionary development to have come out of Sandvik for a long time is AutoMine; an automated loading-and-hauling system that has been designed for underground mining, which the rm is now seeking to apply to tunnelling. If that happens, it will be a positive development that could bolster productivity.

Adaptable for small-scale operations, as well as larger block-caving applications, AutoMine

allows an operator (who would otherwise have driven a single vehicle underground) to control and monitor several vehicles from the comfort of an air-conditioned of ce above ground. In this way, it is possible to monitor the movements of a eet of driverless loaders or trucks that are hundreds of metres underground.

Also based in Sweden, Gia has manufactured locomotives for the tunnelling industry since 1950. The company claims its range of 2-456t locomotives can provide high productivity, have a high traction force, can reach relatively high speeds and are easy to customise. They are available in different engine sizes.

Gia also makes three utility service trucks: the articulated GIA 111 and 211, and the rigid TT24. All four-wheel drive, the trucks are designed to operate on steep gradients. All models can come equipped with boom and basket, scissor

platforms for ANFO charging, scaling and other kinds of installation works. Further versatility comes from the fact that the trucks can be used for other applications, such as small dump trucks or shotcreting. By having different equipment on the cassette, one track can serve numerous applications. Gia claims its utility/service trucks can boost productivity and safety, and have low investment and service costs, as well as being made of well-known components.

ROAD VEHICLESA shorter wheel base and greater ground clearance makes Volvos recently-introduced FM340 6X4 Tipper usable for tunnelling

applications. Indias experience in this respect is an interesting one. Volvo India says that,

prior to the introduction of the FM340 6x4 Tipper, dumpers were mainly used in tunnelling, but their lack of manoeuvrability in congested spaces saw many customers resort to 6x4 and 4x2 trucks. Yet, these very vehicles, although good in congested spaces, suffered from low power-to-weight ratios and other concerns, such

as cab safety and visibility levels.Volvo says its FM340 bridges the gap

between the two types with its claimed manoeuvrability, and ability to handle

gradients, dif cult terrain and congested spaces. Equipped with a six-cylinder, in-line diesel engine that is heat stabilised, the FM340 has a power output of 340HP at 1,6001,900rpm, as well as a 14M3 body with complete steel construction, sub-frames and a sandwich oor, made from Hardox 400 steel. It also features a rock breaker.

SPECIALIST VEHICLESShotcreting deep into a tunnel can have special demands; for instance, how do you get the concrete, ready mixed, to where it is needed? One way is to use a bizarre-looking, concrete bullet car made by Cifa, which combines a mixer and transporter.

Peter Remnant of UK-based Specialist Plant told WT: These vehicles can be rubber-tyred, but are usually mounted on small bogeys for track gauges of 750mm, 900mm or 1,000mm. The units are rather big, ranging in length from 5.5-7.2m and come in six different capacities to suit the loading gauge; the largest being the

The ITC Superloader combines excavator and rear conveyor belt

20-21WT0803.indd 20 25/2/08 09:46:15

21EQUIPMENT: Support & haulage vehicles

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MC100, which can take 10m3 of concrete for the largest tunnels. Higher capacities can be achieved if needed by linking the bullet cars together, coupling the male and female ends. Drum-rotation speeds range from 11-12 rpm.

Putzmeisters self-propelled Tunnel-Kreter SP 40 is designed for large shotcreting applications for tunnel construction. The kinematics of its specially-designed spraying arm and oscillating nozzle increase spraying speed. The unit is armed with a 3m-long lance, which can be aligned parallel to the tunnel wall and set to travel at variable speeds, automatically back and forth, enabling the operator to cover a 3m section of the tunnel by simply controlling the main boom.

Another specialist vehicle that is just as intriguing comes from UK-based AFC Tunnelling. Its Pipe Utility Vehicle (PUV) is designed to move both people and equipment in and out of tunnels easily. Comprising working platforms at the front and rear for simultaneous load carrying, the plat-forms can also be folded away for maximum manouverability. PUV was developed for the UK water industry and is designed to move through circular tunnels, including sewers and storm drains. It features an on-board carousel, which, on a job for Thames Water, carried 3x6m pipe sections with a combined weight of 1.5t.

Tunnelling-machine specialist ITC (part of the Terex group) has been supplying the tunnelling

industry with excavators for more than 40 years, but it also produces other types of utility vehicle to aid tunnel production. One newly-launched machine is the ITC Superloader, combining an excavator and rear conveyor belt, which can be linked to a dump truck or other conveyor for spoil evacuation.

Made in Germany, the Superloader, like all the companys tunnel-loaders, is built on a modular basis to allow it to be con gured to individual circumstances. Designed to speed up mucking (minimising the cost of conventional drill-and-blast tunnelling), it is aimed at non-homogeneous soft-to-medium hard rock (with erratic blocks) that demands exible equipment.

With a working height of 4.7m and a width of 2.75m, the Superloader comprises a basic chassis on a crawler with a 1m-wide, integrated, heavy-duty conveyor. It is notable for having

both diesel and electric drives for emission-free working at the face, with a cable reel and robust mucking-boom equipment. ITC claims the machine makes it easy for the operator to reach loading capacities as high as 8-10 m3/min in extremely hard and abrasive rock. This means it takes only two minutes to load a 20m3 dump truck. Easy maintenance and very low running costs are also claimed by the manufacturer.

A smaller version of the Superloader is also available. The ITC 312 SL was used recently on the Breidalsoverfringen 15km-long transfer tunnel to the Raudalsl power plant in west Norway, where it achieved an average weekly advance rate of 90m, with a peak value of over 100m, including the support works.

The classic wheel loader has evolved into a highly-manoeuvrable and versatile piece of equipment that is at home in large or con ned spaces. Caterpillar has produced these highly-mobile units for many years. Take the 944F, which is the worlds largest wheeloader with bucket capacities ranging from 14-36m3 and a net power output of 1176kW (1,577 hp). With its reduced engine noise, lower emissions and good fuel ef ciency, the 944F proves that big does not necessarily mean environmentally unfriendly. With a standard, rated payload of 35.4t, Caterpillars able monster has a colossal operating weight of just over 194t.

Volvo FM340 6x4 tipper

20-21WT0803.indd 21 25/2/08 09:46:20

TECHNOLOGY: Innovation222222

Rugged notebook for rugged environmentsRugged notebook for rugged environmentsRugged notebook for

GETACS newly-launched P470 notebook is designed as a secure and rugged notebook for use in tough, wet and dirty environments. The design takes into account the need for a rugged data storage solution when out of the of ce, reducing, so the manufacturer claims, the risk of data theft and accident.

Weighing less than 3kg, the unit features a magnesium alloy casing that provides an overall weight reduction of around 25%, as well as increasing the strength of the chassis by 50%. This, it is claimed, allows the notebook to survive the small drops that can sometimes occur on site. Robustness is further enhanced by the shock-mounted HDD and LCD TFT screen, thereby allowing the unit to withstand vibrations and other shock conditions that can result in electronic damage and loose connections. In addition, the G-sensor is said to protect data from drops and accidents. Furthermore, solid particles and moisture are prevented from entering the unit, thanks to the sealed I/O caps and doors, making it suitable for use in more extreme environments.

If stolen, a range of measures will keep the notebooks data safe from hackers. This includes a biometric ngerprint reader designed to constitute a secure and reliable authentication device for log-in or for accessing sensitive device for log-in or for accessing sensitive

GETACs P470 notebook is a rugged little number with 14.1in hi-res TFT screen

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232323TECHNOLOGY: Innovation

information. This also eliminates the need to remember those easily forgotten or hacked passwords. Second, a Trusted Platform Module (TPM 1.2) or Root-of-Trust, a chain of trust procedures monitors every step, from pre-boot to OS load, to guard against unauthorised tampering from physical theft or software attack.

As would be expected, the unit offers a range of wireless connectivity facilities, including built-in Wi-Fi and Bluetooth 2.4G to allow secure connection to other Bluetooth devices; Wide Area Network GPS to record the P470s location, and 3G technology. The built-in 1.3 Mega Pixel camera can be used as a webcam for video conferencing.

www.getac.com

Robot unveiled at concrete gatheringCONJET AB recently unveiled its latest demolition robot, the compact hydrodemolition 322 Robot, the smallest unit in the companys range of high-pressure water-jetting equipment designed to remove weakened and damaged concrete from numerous structures.

Designed for good manoeuvrability, the unit is compact and manoeuvrable and is claimed to be ideal for use in con ned spaces: it has been designed to pass through openings 0.8-1m wide, depending on the attachment tool used, which means it can be used in tunnels as small as 1.7m in diameter. The robot operates with a reaction force from the water of 1,400N.

Comprising a self-contained, crawler-mounted undercarriage, the electrically-powered robot has an integral control system that allows progress of hydrodemolition to be remotely and safely controlled, as well as monitored away from the hazardous cutting area. When in operation, the robot can adjust its undercarriage width to improve stability and is equipped with a single oscillating nozzle mounted on a traversing cradle that runs back and forth along a 1.5m-long feed beam. For safety, a protective shroud covers the nozzle assembly.

While in operation, the unit ensures that only those weakened or damaged areas of concrete are removed, in what the manufacturers describe as a continuous, uniform and safe operation to a predetermined depth above or below any steel reinforcement which, if exposed, is also cleaned of rust.

A control box, wireless or cable-connected, allows the unit to be controlled remotely. But if contact is lost with the robot, the units emergency stop feature is activated and both robot and pump will shut down automatically.

www.conjet.com

Revamped excavator continues tradition?Revamped excavator continues tradition?Revamped excavator

LIEBHERR recently launched its completely-redesigned R 944 C Tunnel Litronic excavator which replaces the R 934 B Tunnel. Weighing in at 41t, the new R 944 C Tunnel Litronic is not only much heavier than its predecessor, but has an output of 190kW/258 hp and offers 31% more engine power. The new excavators dimensions are compact to suit its purpose.

Powered by a Liebherr six-cylinder, in-line engine producing an output of 190kW/258hp at a nominal speed of 1,800rev/min, the R 944 is designed to reduce particulate emissions; as an optional extra, it can be tted with the new Liebherr particulate lter system certi ed in accordance with the CERT standard (Curtailing Emissions from Real Tunnel-building Machinery). Comprising a closed catalytic-coated lter made from cordierite, a pre- lter and an electronic monitoring unit, the system regenerates passively via the continual oxidation of the particulate. The modular design allows the central module (comprising lter muf er and silencer) to be demounted easily for ash removal.

FOPS and FGPS come as standard on the tunnel cab for protection. Polycarbonate windows on the right and rear are provided for their high impact resistance and good visual qualities but, on special request, the entire cab can be tted with polycarbonate windows. Other aspects of the R 944 Cs robust speci cation include a slewing arm with 2 x 45 slewing areas and a 4.5m bucket stick. The optional mechanical qu