SPECIAL TUNNELLING - Razel-Bec

SPECIAL

TUNNELLING

03

RAZEL-BEC TUNNELLING

This abstract of our magazine gives a general overview of RAZEL-BEC Tunnelling division’s activity.No less than 10 projects are under process on 2012.Obviously, RAZEL-BEC tunnelling department is a leader in the French tunnelling market.

Reading through these different projects covers, you will notice three main characteristics of RAZEL-BEC:

• RAZEL-BEC is expert in difficult and highly technical sites, demonstrating the capacity of the team to adapt to the environment and overcome the difficulties, specifically in case of adverse geological conditions.

• RAZEL-BEC considers all its colleagues to be of major importance, through their competences and team spirit; they allow RAZEL-BEC to meet all its challenges.

• Establishing a trustworthy partnership with its clients is for RAZEL-BEC the essential element for the outcome and success of tunnelling projects.

RAZEL-BEC was recently confirmed in its client’s confidence, with the start of two new projects: Fréjus emergency tunnel, this time on the Italian side (6.5 km) and the water supply gallery for the LNG terminal in Dunkerque (5 km, dia. 3.5 m).

Laurent FAYAT

Chief Executive Officer

Jean GUILLAUMEManaging Director Majors Projects

02 > RAZEL-BEC > Tunnelling

interview...0504 > RAZEL-BEC > Tunnelling

With over 150km of excavated galleries and tunnels throughout France and abroad, RAZEL-BEC is a key player in the tunnelling industry on a large range of projects such as:• Road and railway tunnels,• Metro tunnels and underground stations,• Hydraulic pipes and galleries, • Sewages and shafts, • Tunnel refurbishments.

Working with a team of 260 permanent staff, the Tunnelling department masters every aspect of tunnel building, including support and reinforcement technologies, and can adapt them to any type of ground, from mountainous hard rock to highly developed urban sites in soft ground.With their own estimators, structures and methods engineers, the Construction team is capable of designing, developing and planning any type of underground construction no matter which technique the contracting authority desires to employ.A highly capable and well-resourced team, RAZEL-BEC can take over any point of the project, from conception to delivery.

Today, there are no less than 10 tunnelling sites currently under their leadership.

Let’s meet RAZEL-BEC tunnelling department.

Razel-Bec, civil engineering construction company, is leading the way in Underground construction...Patrick Ramond. - Underground construction and RAZEL-BEC go back a long way. Since we bought Pico, French leader in underground construction and large-scale works in 1980, RAZEL-BEC has not stopped expanding in this field. For RAZEL-BEC and Fayat Group, this is an important area of development in France as well as abroad. The consequences are an increase of turnover, and also in skilled and competent workforce. The Tunnelling department is made up of 260 highly skilled personnel, with its own estimating team, design section and geotechnicians. Always seeking to deepen our knowledge in the field, RAZEL-BEC has a permanent need to integrate new people.

What does represent the underground construction market for Razel-Bec?P. R. - RAZEL-BEC is committed to this sector for the long haul, and our market share is always growing on the French territory, even though the public demand, which is our key market, fluctuates somewhat. In 2010, for a total turnover of 405 million Euros, the Tunnelling department took in 70 million, which is 17% of the company’s earnings. This result is in constant progress. For example the recent deal signed for the emergency gallery of the Fréjus road tunnel on the Italian side, after securing the contract for the French side in 2009. This recent success has ensured the position of RAZEL-BEC as a key player in the sector.

How is Razel-Bec positioned in the context of the markets and the competition?P. R. - Today, in terms of deals signed in the tunnelling industry, RAZEL-BEC ranks in the top five businesses. The technical prowess necessary for the development in this sector

requires a huge investment and superior know-how, which only the major construction firms have developed in France.RAZEL-BEC approaches the traditional markets like the conception-construction type markets. The company works independently, like on the Line 4 metro prolongation worksite in Paris, and in partnerships, like the contract for the Toulouse metro, or the VL9 sewage system section 2 and also on the La Bussière and Chalosset tunnels on the A89 motorway. Our team can work on urban and on alpine sites as our steady activity in Savoie testifies. Our international partnerships are also important for our input as added expertise of our teams like on the Fréjus tunnel in Italy.

What is Razel-Bec attitude towards the global market?P. R. - Export is crucial to gain the momentum we need to keep afloat in terms of technological development. The other virtue of the international markets is having young professionals trained in these techniques, which represents an area of progress for the company. In more concrete terms,We have signed agreements in Australia. Asia, with its rapidly developing market, is a continent we must approach. We are also looking for partners on smaller-diameter tunnels, in water-¬treatment, for "key-in-hand" projects with local partners. This could plausible in the USA, for example. The search for "niches"could provide a rich well of projects that could establish a firm base for export-led growth.

Patrick Ramond Director of Razel-Bec Tunnelling department

Our development echoes with an increase of turnover, and an equal increase in the quality of

our workforce.


At the end of 2012, the Parisian metro Line 4 will become part of the “Ile-de-France”, and will put the inhabitants of Montrouge within 2 minutes of Paris, and half an hour from the Clignancourt’s Gate. The works have been separated into two distinct sections. On the Montrouge side, the new station 100 meters long, which will be in the form of a 13.5 meter arched tunnel, as well as the stations back-tunnel (the finished section will be 7.4 meters), which will serve as a technical area for the RATP, and may constitute, in the future, the first part of the final extension towards Bagneux. The whole project is being constructed under the Avenue de la République, a very busy road lined with 19th century houses of varying quality.

a "multi-shaft" siteEach of the installation areas designated for the site have been reduced to the minimum possible size. All the shafts were excavated are at the base of 5- to 6-storey buildings, on the edge of their foundations. The stations back-tunnel, of which the civil engineering phase was finished in autumn 2010, has been constructed in a traditional way, by excavating from two initial shafts. A layer of shotcrete was systematically applied as the tunnel excavation advanced, before traditional supports were installed.The lining of the invert and the vault was done as close as possible to the excavation of the tunnel so that the gap was no less than 27 meters between the rock face and the last part of the tunnel lined. The works took place at a depth of 15 meters, completely above water

table, in a classic Ile-de-France geological landscape: backfill, Beauchamp sand, shale and stones, rough limestone.The Mairie de Montrouge station, of which the top head of the tunnel was bored on the 18th of January 2011, was also traditionally excavated from two initial shafts following a complicated phasing process, notably because of the reinforcement of the quarries.

Quarry reinforcement and ground injection to the south of the stationOne of the most delicate points of the project came from the presence of old quarries, which we couldn’t visit prior to the commencement of the worksite (probably mined between 150 and 200 years ago during the Paris city extension works), which affected a large part of the zone to the south of Paris, right at the site of the station. To limit as much as possible the risks of surface settlements and their potential repercussions on neighbouring buildings, the project required, before the real excavation started, large-scale ground consolidation."Unfortunately, these measures turned out to be insufficient because of the highly decompressed state of the ground discovered at the site of the quarry", explains Jean-Claude Durand, site Director. Technical discussions held directly after the discovery of the unstable nature of the ground concluded, at the beginning of 2009, that it was necessary to grout the surrounding ground adjacent to the quarry. This technical decision was later confirmed to be well-founded and justified by the presence

Spoil evacuation in the station. The Stations back-tunnel.

The RATP project allows the Line 4 extension of the Paris metro into the heart

of Montrouge. It has taken three years to complete this huge construction of

the new section: 1470 meters long, with the new station, Mairie de Montrouge.

The lot number 2 entrusted to RAZEL-BEC, which alone represents 800 meters of

traditional excavation, required a huge amount of site preparation work and also

some very delicate ground reinforcement works due to the presence of former

underground limestone quarries.

line 4

a delicate project in a confined urban site

What is Xelis’s role?christophe Blouet. - Xelis oversees the project management of the conception and construction of the line 4 extension on which Razel-Bec is working. It is a complete project management, of all fields unconnected to the railway system, and not just on the large-scale works. Xelis manages the works contracts by ensuring quality control, the follow-up of its implementation, and

contractual and financial aspects. On this project, Xelis also oversees the ScMc (Scheduling, construction Management and co-ordination).

and what does that consist of?c.B. - The role of the ScMc consists of co-ordinating all parties and anticipating planning problems in order to avoid mistakes and minimise their impact on the works’ delivery dates. Keeping to the start-up date of the extension is always a major objective for the Project Manager.

What are the constraints of this site?c.B. - We were confronted by two types of hazards. The first is to do with the urban context. The traffic on the surface, the reduced size of the site installations, the numerous intricate services (notably gas, electricity and telecommunication) were

heavy constraints at the beginning of the works. Steps taken by the Montrouge Town authorities and the Hauts-de-Seine General council allowed us to overcome them, but these constraints naturally generated delays and costs consequences.

What were the other types of constraints the site was confronted with?c.B. - Geology, by definition, always has a huge impact on the construction of underground works. and yet, on this project, although we knew about the underground quarries, their presence on a large part of the site led to some major geotechnical constraints, due to a much greater instability of the adjacent shale and rocks than anticipated. This required another phase of ground treatment to overcome these difficulties.Here, the injections were carried out from top head gallery in order to limit the impact of the excavation on the surface buildings.

Was the station itself affected?c.B. - Yes. as a wide-open gallery, the station was a very delicate work to carry out, due to its location next to the building’s foundations. So, we injected the ground on the southern half of the works, in the quarry zone, and underground in order to reduce to a minimum the impact on traffic and on the surface activities. In these conditions, the slightest difficulty can have large consequences, and the role of Xelis is to anticipate these as much as possible, and to work in close collaboration with the construction companies in order to overcome any problem.

The words of...

of grouted empty spaces, discovered during excavation.

an educational projectApart from the fact that no accident occurred on a site housing up to 200 people during three years of works, Jean-Claude Durand notes that "this was a great project in terms of its peculiarity technical nature which allowed us to train many motivated young workers".The surface constraints, unique to an urban site and particularly delicate on this project, necessitated that we adapt our methods to the unique geological environment which is typical to the outer edges of Paris, degraded by the presence of old quarries located right next to the most enormous structures.

Contracting authority: RATPProject management and SCMC: XELIS

Station, excavation of access passages.

excavation of the station.

christophe Blouet, Xelis, Project Manager


Didier Simonnet Director of the SFTRF, Project Owner.

can you recall the context of the Fréjus tunnel?Didier Simonnet. - The Maurienne valley has always been a key trade route between France and Italy via the Northern alps. The Mount cenis pass, which climbs higher than 2000 meters, has been the quickest route to cross the mountainous barrier of the alps for a very long time. The boring of the Fréjus rail tunnel, opened in 1871, quickly opened up a new way of crossing the alps.

When was the road tunnel first considered?D.S. - at the end of the Second World War, transalpine trade intensified and a growing number of cars and lorries crossed the Mount cenis pass. But the pass road, which is frequently the site of serious accidents, is difficult to drive in winter. Since the end of the forties, a road tunnel became the most obvious solution, and would also help economic development in the Savoie.

What is the SFTRF?D.S. - The SFTRT, or French Fréjus Tunnel Society company, was created in 1962 by Pierre Dumas, then the Mayor of chambery and State Secretary of civil engineering Works, Territorial collectivities

The words of... Hard rock tunnelling for the Fréjus emergency tunnel

The excavationThe excavation of the tunnel is broken down into two parts. The first 650 meters of the gallery are excavated in a traditional way, with explosives, bolts and shotcrete support. The average rate of excavation is 4.2 meters per day. The final lining is made up of an invert and an arched of 45 cm thick, casted in situ.The remaining 5,795 meters up to the Franco-Italian border are dug by a mechanical excavating machine, called a "hard rock" tunnel borer.In the aim of protecting the environment and reducing transport, part of the material extracted is being crushed and reused, the rest of the rubble is sent to a dump site in an old quarry in the vicinity of the tunnel.

After the Mont Blanc tunnel fire of the 24th of March 1999, road tunnel safety

legislation has undergone some significant changes. The construction of the Fréjus emergency tunnel conforms

entirely to the new rulings. RAZEL-BEC has been entrusted by the

French Fréjus Tunnel Society Company (SFTRF) the construction of the

entire 6,495 meters of the emergency tunnel on the French side of the border.

The emergency tunnel parallel to the existing Fréjus tunnel, located 50 meters from the existing tunnel and linking Piemonte to Savoie has an internal diameter of 8 meters. RAZEL-BEC is undertaking the 6,495 meters of the contract for the French side.The two tunnels (safety tunnel and main tunnel), 12,875 meters long, will be connected by 34,100m2 emergency shelters. The creation of 5 by-passes suitable for motor vehicles will allow emergency services and their vehicles access from the road tunnel and also from the emergency tunnel. The works will also cover 8 technical substations and 2 ventilation units, allowing equipment upgrades. Half of these works are to be carried out in the context of a contract signed between the French Fréjus Tunnel Society Company (SFTRF) and RAZEL-BEC.

Prefabricated segments Emergency

Inter-tunnel distance 50m

Emergency tunnel Existing road tunnel

Under floor services systems

Ventilation

Shelter Airlock

Fresh air entryCurrent emergency access

Air exhaust

FRéjus: after France, RAZEL-BEC wins the contract on the Italian side.RAZEL-BEC has just secured the construction

of the Fréjus emergency tunnel on the Italian

side. One more success for the company after

securing the Fréjus emergency tunnel of the

French side on the 28th of April 2009.

RAZEL-BEC Tunnelling has thus signed the two

contracts (Franco-Italian) for the construction

of the Fréjus emergency tunnel linking Savoie

and Piemonte.

Contracting authority: SITAF — Societa Italiana

Traforo Autostradale Fréjus Project

Management: I3S Group — Inexia / SNCF

Engineering / SWS/ SEA

Leading contractor: Group Itinera

The Order to start the works is dated from the

12th of July 2011 for 1,350 working days.

and of Socio-economic groups in the Rhone-alpes, and notably Savoie. The project came from the willingness to defend the Savoie-Piemonte road tunnel project, which succeeded with the opening of the Fréjus road tunnel in 1980 and then the construction and opening of the Maurienne motorway, between 1993 and 2000.

The Fréjus emergency tunnel is a major safety project for the SFTRF and the tunnel users... D.S. - Of course, but the safety of the Fréjus Tunnel has for a long time been a permanent preoccupation of all the subsidiary companies. To this aim, almost 70 million euros have been invested since 2000 to improve the tunnel safety.The tunnel is under 24 hour surveillance by 241 cameras relayed directly to the central control Post (Pcc), which ensures a permanent real-time surveillance. also, 16 Tunnel Safety Firemen are on call 24 hours a day, 365 days a year in the two stations installed inside the tunnel, ready to respond to any emergency. Finally, the binational emergency services organisation in the event of an accident is charted in the Binational emergency Plan (PSB).

Disc Cutter Cutting wheel

Muck

Muck conveyor

Shield

Thrust cylinders Concrete segments

Segment erector

Probe Drill

Backup gantries

Contracting authority: French Fréjus Tunnel Society Company (SFTRF) Project management: I3S Group — Inexia / SNCF Engineering / SWS / SEA

The tunnel segment factory has been erected since June 2010 at St-Étienne-de-Cuines, around 40km from the site. "It produces the tunnel lining that constitutes the support and final lining for the Fréjus tunnel", explains Hugo Le Fol, Works supervisor. "The tunnel lining requires precise dimensions, which we achieve thanks to moulds with a margin of error of only 0.3 mm.The factory is mostly automated, with a conveyor system which allows the moulds to pass from one station to another (demoulding, greasing, concrete pouring...), a soundproof concreting booth with automatic mould hoods and a direct link to the concrete mixing station, which brings the concrete

with a shuttle skip. It’s also equipped with an exit line, which allows for the reversal and storage of the segments.A subcontractor also takes care of part of the factory which manufactures reinforcement cages, using a new system com-posed of conveyors for the transfer of moulds and welding robots (they weld 300 times in 4 minutes)".Right now, we have produced a total of 800 rings, which means 5,600 segments. From mid October, we will raise up the production time to two shifts in order to produce 10 rings per day, advancing the tunnel by 18 meters. Production is schedu-led to finish by October 2012.

The tunnel borers christening


Anne is the name given to the tunnel boring machine on the Fréjus emergency tunnel site, christened according to tradition on Monday the 4th of July in the presence, of Patrice Raulin, the President of the SFTRF, the Prefect Christophe Mirmand and the RAZEL-BEC Tunnelling department team.

At the Fréjus’ tunnel borers christening ceremony, Jean Guillaume, RAZEL-BEC Assistant General Director, hailed "the site team for their work and their perseverance these last two years. I also congratulate them for their engagement in the Safety process put in place by the company. The results are here today: 70,000 continuous working hours on the site without serious accident. It’s a promising start, the fruits of the work carried out to improve safety by the team since the beginning of the project. We must now continue, because when it comes to safety, there is always work to do".

The tunnel boring machineThe tunnel boring machine that we selected is a rock borer constituted of a single shield (see the diagram) and 10 trailers, on which are positioned the hydraulic and electric systems needed to operate the machine. These trailers also allow us to ensure all the logistics, in particular the handling of the segments and the annular void filling mortar as well as the ventilation. The tunnel boring machine is 170 meters long. It was assembled in an underground chamber located around 650 meters from the tunnel entrance.

The nominal shield diameter is 9.46 meters. It is characterised by a distinctive conical shape to protect against the risk of convergence*.The retained average progress rate of excavation is 15 meters per day. The ground is mostly composed of limestone shale which will be crushed by disc cutters mounted on the head of the tunnel borer. They are spaced on average every 10 cm on the diameter. The cutting wheel turns from 1 to 6 rpm maximum, and is fitted with 8 electric motors, of which the total power installed is 7,800 KVA.

*A convergence characterises the natural tendency of the ground to close up behind the excavation, and is a result of tectonic forces present in the massif and/or the pressure exerted by the weight of ground applied vertically upon the tunnel (over head). To face this constraint, and prevent the tunnel borer from becoming trapped, a possible enlargement of the wheel diameter is planned, from 10 cm in the first instance up to 20 cm.

The tunnel Segment factory

Vital statisticsn concrete volume: 65,000 m3

n Total reinforcements: 6,000 tonnes

n Production time: 26 months

n Rings required: 3,272 rings, 5,890 meters

n 1 ring = 7 segments = 50 tonnes

a few statisticsn Initial project time: 45 months, of which

6 were preparation

n Personnel: around 120 people working on site including 15 representatives

n More than 120,000 m3 of spoil excavated (by explosive or bored)


In the context of transferring water from the East to the West of La Réunion Island for

irrigation and drinking water, RAZEL-BEC is constructing an 8.5 km hydraulic tunnel for

the General Council of La Réunion. This site, started up in 1998, has crossed

4 major aquifers which have posed major challenges for the tunnels progression.

After boring is completed, we have a little more than two years of work to do.

ILO... these 3 letters represent more than 30 km of tunnels bored through basalt over a period of nearly 30 years. ILO means West Coast Irrigation (Irrigation du Littoral Ouest), and consists of 3 major parts: the irrigation of more than 7,000 hectares of farmland (97 million m3 per year), bringing additional fresh water to 5 municipalities (Le Port, La Possession, Saint-Paul, Trois Bassins and Saint- Leu), and refilling the water table at Rivière des Galets.The upstream Salazie tunnel is one of four tunnels that make up this ambitious project (Mafate tunnel, Sainte Suzanne tunnel, downstream Salazie tunnel, upstream Salazie tunnel). With an internal diameter of 3.2 m and a length of 8,531 m, the upstream Salazie tunnel stretches between the Rivière des Pluies and the intake on the Mât River, with the intake on the Yellow Flower river en route. It will allow us to pump 4.4 m3/s of water towards the

irrigation zones. We are boring with a "hard rock" TBM, baptised Jacqueline. "Last May, 12 years after the Order to start work was issued, the tunnel boring machine finished boring the 8,500 meters of the upstream tunnel", announced Pascal Baraté, Project Director.

"Sub-marine" episodesThis tunnel crossed 4 major aquifers* which hindered its progression. We intercepted the first aquifer right at the start, before the TBM was erected, while we were excavating the access tunnel. The TBM could only start boring at PM 773.We reached the second aquifer at PM 1238, and the TBM reached it in October 2001. It could only restart in July 2009 at PM 3600, after almost 8 years of being immobilised, blocked by a dyke and 300 meters of water flowing at 400 liters per second. This was followed by a period of traditional excavation, during

* An aquifer is a water reservoir localised in a ground layer or rock, sufficiently porous (that can hold water) and permeable (so the water can flow freely) to hold a subterranean water table.

which, notably, we needed to try and treat the ground in order to hold and diminish the water flow, create a chamber so we could remove the TBM, excavate with explosives a tunnel parallel to the one already bored, deepen the existing tunnel in order to insert a guttering system to cope with the water inflow, and continue the tunnel excavation until we reached the third aquifer. This aquifer was reached between PM 3000 and PM 3600, and we crossed it in a traditional way, with explosives, which we’ve been doing since the TBM got blocked. At the end of this aquifer, the TBM was able to start again in July 2009.Finally the fourth aquifer, between PM 4760 and 5260, was crossed with the TBM which was modified specially by the site team to cope with 1,200 liters per second with a load of 300 meters! "In the strongest water inflow, the flow reached 1.5 m3/s. These aquifers can take months, even years before the flow can

be stabilised", explains Pascal Baraté.This summer, at the same time of the dismantling of the TBM, the concrete lining started. It will take another two years to line the zones that couldn’t be bored with the TBM.

a few dates n 15th December 1998:

Order to start work.

n 2nd august 2001: start-up of the TBM at PM 773.

n 21st October 2001: TBM stopped at PM 1238 after exceptional water inflow.

n 15th September 2004: tunnelling restarted with drill and blast from PM 1203.

n June 2007 to May 2009: creation of a second shaft, labelled upstream of the upstream.

n excavation of 800 meters of tunnel in traditional method with drill and blast.

n October 2007 to april 2009: crossing an aquiferous zone between PM 3000 and 3600 (traditionally, with drill and blast).

n July 2009: start-up of the TBM at PM 3619.

n October 2009 to august 2010: crossing a new aquiferous zone (with the TBM).

n 13th May 2011: tunnel boring machine Jacqueline bores through to Salazie.

Downstream Salazie tunnel: upstream injections. Upstream Salazie tunnel: TBM blocked at PM 1238. May 2011: the TBM finishes the 8,500 meters tunnel, started in 1998.

Contracting authority: Reunion DepartmentOperation supervision: Food, Agriculture and Forest Department Project Management: BRL / SCP / SECMO

la Réunion Island

a 13 year old site: a long project for the Salazie pipeline

Patrick RamondDirector of the Underground

Construction department

Let’s congratulate the personnel and the client

for their unswerving courage and will to finish

this project.

a few statisticsn Project time: 45 months, including 6 months

for preparation.

n Start-up: 15th of July 2008.

n Personnel: between 60 and 80 people are working on the site depending on the phase of construction.

n almost 70,000 m3 of muck excavated (in drill and blast or with a TBM).

n 15 tonnes of explosives.

n 220 tonnes of iron framework.

n 11,000 m3 of concrete lining.


To meet increasing Corsican demands for energy (3% per year), the current

electrical grid requires new production equipment development. The construction

of the Rizzanèse hydroelectric station is designed to meet these needs.

The Rizzanèse hydroelectric power station, built on the steepest part of the river, is a groundbreaking project and will provide 12% of the electricity generated in Corsica. It is made up of four parts: the dam, the underground tunnels, the penstock, the hydroelectric power station.The RAZEL-BEC business group (representative), BEC (manager) and Bilfinger Berger, are in charge of the construction of the underground tunnels. This will require the construction of:• the supply tunnel, 3.5 meters in diameter and

5,816 meters long (of which 150 meters have been excavated in a traditional way, with drill and blast);

• the access tunnel, 403 meters long (of which 282 meters had already been excavated as a probing tunnel several years beforehand);

• a surge shaft, 90 meters deep (of which 66 meters with a 7 meters diameter and the last 24 meters with a 2.4 meters diameter) linked to the supply tunnel by an 8 meter long branch;

• a coating of concrete on the steel lined tunnel between the surge shaft and the open-air zone, around 440 meters);

• partial concrete lining of the supply tunnel (around 20% of the tunnel);

• a place to install a valve and several concrete blocks to support the penstock.

a complex geologyThe delivery tunnel for the Rizzanèse project was dug into an essentially granitic and dioritic massif. The excavation of the tunnel ran into some unexpected difficulties, so several experts were called on the site.They discovered that the difficulties were a result of the near-absence of fractured rock in the massif, revealed after the TBM had passed through, and also of the constraint tensor anisotropy, generating a resistance to the compression on the axis of the tunnel higher than that measured on the sample.

The final conclusions also brought to light an atypical behaviour of the rock, characterised by a higher micro cracking limit than is normally encountered in granite-type rocks, which was an aggravating factor in the difficulties we had in cutting through the rock.At the beginning of summer, the site had finished 30% of the ancillary works and the lining of the supply tunnel. It is to be said that, the lining of the tunnel is carried out by blocks (one block represents 12 meters of lined tunnel). Of the whole of the tunnel, only 20% will be lined, principally the areas corresponding to where the rock was altered.Also, the triple point lining has started.The site team, directed by Bernard Morland, will also have to carry out the casting of the watertight door (the door positioned at the end of the access tunnel), bonding injection, ground filling and consolidation, and of course, the removal of the site installations.

Contracting authority: EDFProject management: EDF

Water supply tunnel from the Rizzanèse dam

excavation in atypical rock

While performing Quality Control on the air inside the tunnel, the site Safety team uncovered rates of radon which required greater than normal precautions in the tunnel. With more than 4,000 Becquerels regularly detected in the tunnel, special precautions were necessary, such as improved ventilation and holding dosimeters made compulsory...

Radon is a naturally-occurring radioactive gas, produced by the decomposition of radium, itself a product of the decomposition of radium present in the Earths crust. It is odourless and colourless. It is present everywhere on the Earths surface, but especially in granitic and volcanic substrata. In open air, the concentration is low, as it is dispersed by the wind. In confined spaces it can accumulate and reach high concentrations.After the works were started, there was a change in the legislation governing the actions to be taken if the concentration increased beyond a certain level.

Radon on the Rizzanèse site>

a few statisticsn Project time: 52 months (including 10.5 months

for preparation).

n Personnel: between 50 and 55 people are working on the site.

The waste water collectorn 3,200 meters of tunnel lined with rings made

up of 6 concrete segments, 1.1 meters long and 25 cm thick.

n Internal diameter: 3 meters.

n excavation diameter: 3.72 meters.

n 3,200 m3 of mortar filler.

n 36,000 m3 of muck carried away by barges on the River Marne.

n 17 months of excavation (not counting work phasing interruptions).

The shafts n 1 shaft, 8 meters in diameter and 24 meters

deep, to be excavated within a diaphragm wall enclosure.

n 4,000 m3 of excavated muck.

n 2,300 m3 of casted concrete.

n 4 shafts to be completed in civil engineering and fit with automations, gates, trapdoors and water-tight doors.

n 1 technical station to build.


The work on the 2nd section of the new "VL9" intake on the waste-water transport

system in the South-East of Paris started in autumn 2010, on behalf of SIAAP,

Contracting Authority.Notably, section 2 of the "VL9" project

was entrusted to RAZEL-BEC as technical supervisor and manager.

This intake breaks down into 3 tunnel lots (lot 1: 1,200 meters; lot 2: 3,200 meters; lot 3: 1,600 meters), and several access shafts are spread out along the tunnel. The lot number 2 which connects Maisons-Alfort and Créteil (Val-de-Marne) is the central part of the 6 km "VL9" intake which, in 2014, will complete the Ile-de-France water treatment system. Using gravity, the waste-water will flow faster and more economically from the pumping station at Charenton-le-Pont to the treatment centre at Seine-Amont in Valenton, in the same county.

Huge constraintsThe project, entrusted to RAZEL-BEC as technical supervisor and manager, is to carry out 3,200 meters of tunnel 3 meters wide and 23 meters deep, an access shaft 24 meters deep, a second optional access shaft that was not consolidated because of a land access problem, the civil engineering and the equipment of 4 shafts as well as a technical station.With an overburden of 20 meters above the whole tunnel, the intake is installed underneath a public area. It is mostly located (2,500 meters out of 3,200 meters of the tunnel) in an SNCF zone of influence* on the Paris/Lyon line. This

heavy constraint required the installation of a continuous topographical surveillance system of the railway lines, with alert levels that could lead, ultimately, to a disruption of railway traffic.The geological profile shows great variations in the typical features of the Parisian basin, alternating slate, sandstone and limestone massifs. The project runs through a sensitive environment for much of its route.

Good progress for the TBMThe tunnel is excavated with an earth pressure balance tunnel boring machine, christened Anne. It is lined with concrete segments, which are sent from the shaft P1 at Maisons-Alfort up to shaft P3 located near the Pompadour crossroads in Créteil (Val-de-Marne). The intake diameter for excavation is 3.72 meters. The TBM is almost 10 meters long, weighs 110 tonnes and has a total thrust of 1,200 tonnes (a power of 630 KVA)."In Autumn 2010, the first crossing underneath the SNCF railway, carried out with no interruptions, was completed successfully (250 points installed on the railway sleepers were monitored with a frequency of 1 measure every 20 minutes) and the tunnel boring machine

Contracting authority: SIAAP - Large Works Department - Network ServicesProject management: SIAAP - Large Works Department - Project Management Services

collector Vl9

lot number two entrusted to Razel-Bec

* Zone of influence: theoretical zone determined by the sNCF which sets a certain distance from one side to the other of a railway track, in which the ground settlement must remain below a certain level. This zone is calculated, and takes specifically into account the geology between the works carried out and the railway track.

proceeded according to expectations", explains Denis Vialle, Site Director. The access shaft has been excavated and the interior civil engineering is being carried out now.


Built for the ASF, the Bussière and Chalosset tunnels on the A89

motorway are carried out in the context of the extension of the A89 motorway, between Balbigny (Loire) and La Tour

de Salvagny (Rhône). In the group, RAZEL-BEC is the representative for

the Chalosset tunnel and manager for the La Bussière tunnel.

The extension of the A89 motorway, conceived by the operating company ASF (Southern French Motorways), is characterised by a 50 km route (32 km in Rhône, 18 km in Loire) and 3.5 km of link road to the Arbresle road. A dual carriageway with an enlargement to 3 lanes between Tarare East and the Tour de Salvagny, it crosses 22 municipalities. With 16 million m3 of excavation, 83 standard civil engineering structures, 8 viaducts, 6 interchanges and one junction, the A89 also houses 3 tunnels, of which the Bussière and Chalosset have been entrusted to RAZEL-BEC by the ASF. Located between the Tarare East and West slip roads, they bypass the town of Tarare on the South side. The tunnels are mono directional twin tunnels with linking routes for pedestrians and emergency vehicles. The excavated section varies between 83 m2 and 98 m2, depending on the supports installed.The traditional excavation method, drill and blast or mechanical, is used, with the final

lining made up of reinforced concrete and a watertight membrane seal on the outside of the concrete lining. A concrete plant dedicated to the two sites has been set up.The site is progressing rapidly. The four tunnels have been bored. The excavation is finished. Only the excavation for the invert is still to be finished. The sealing and lining works are under way. The network installation works in the tunnel (fire, fresh and waste water, multitubing etc) has just started.

Safety charter "Towards zero accidents"The contracting authority has taken some ambitious steps to implement a Safety charter, followed by every company working on the A89. The group is thus provided with a Safety Director, devoted to risk prevention and the good health of the personnel present on our site.

a highly ecologically valuable natural environmentPrior to the start of the project, we had made

Bussière and chalosset Two tunnels for the a89 motorway

other commitments to various environmental- and wildlife-protection societies;Several protected species have been listed: white-clawed crayfish, yellow-throated warbler... Environmental-awareness classes are regularly organised with these organisations. Here too, the group is provided with an Environment Director, tasked uniquely with environmental risk prevention and general site organisation.

commitments made for the workforce and professional reintegrationIn light of their training and their professional re-integration into the workforce, 8 people have been recruited in partnership with Pôle Emploi (the French national job-seeking agency). They received training in the use of explosives on site as well as training to drive large vehicles safely. Today, five people are still working on-site, and give us great satisfaction.

LA BUSSIèRE TUNNEL ChALoSSET TUNNEL

Project time 28 months 24 months

Length excavated952 meters (north tube) and 937 meters (south tube)

646 meters (north tube) and 640 meters (south tube)

Length lined:952 meters (north tube) and 937 meters (south tube)

704 meters (north tube) and 750 meters (south tube)

Exterior works 2 technical stations, 1 fire reservoir, 1 retention tank and 1 smoke ant recycling wall

1 technical station, 1 fire reservoir and 1 retention tank

Provisional geology

Metavolcano sediments, Eyed banded gneiss, siltstone and conglomerates

Rhyo-dacites and volcanic breccias, Eyed banded gneisss, siltstone, pelites and conglomerates

Others 1 pedestrian by-pass 1 pedestrian by-pass and 1 emergency vehicle by-pass

Contracting authority: ASFProject management: Egis Tunnel


In March 2010, the Algerian National Agency for Dams and Transfers (ANBT)

gave the order to start to RAZEL-BEC for the construction of a dam made up of a 1,000,000 m3 of Roller-Compacted

Concrete (RCC) with a 13 km, 4.3 meters diameter supply gallery.

This is a site allows RAZEL-BEC to demonstrate its expertise in dam

construction and underground works.

This hydraulic structure, the fifth largest in the country, in terms of storage capacity (294 million m3), is located in the Jijel Wilaya, a little more than 350 km east of Alger. An important link in the water transfer system up to the high plateaux, this structure is a 1,000,000 m3 dam made of roller-compacted concrete.With a height of 115 meters, 366 meters long and 8 meters deep, it contains a lock free level rise floodgate with a usable width of 60 meters and two temporary diversion tunnels, each 6 meters across and 400 meters long.From the dam, a transfer gallery, 13 km long and 3.5 meters across will ensure the transfer of water to the High Plain of the Setif Wilaya. It will be entirely bored by a tunnel boring

machine (excavation diameter 4.3 meters) which will have to cross variable and little recognized ground (limestone, sandstone, shale and more or less altered schists), explains Michel Kreitmann, Works Director. The 43,000 25 cm thick tunnel linings (four segments per ring) will be prefabricated on-site, next to the tunnel entry, in a tunnel segment factory which is currently under construction. Production should start before the end of 2011, as soon as the Italian-produced moulds are delivered.The tunnel-boring machine is under construction at the in Herrenknecht’s factory, due to be delivered at the end of October 2011. The excavation can then start at the beginning of 2012.

Let’s not forget that in Algeria, RAZEL-BEC built the Koudiat Acerdoune dam, also for the ANBT. After seven years of work, started in 2002, the dam was completed on the 25th of June 2009. More than 1,500 people contributed to the construction of this structure, hugely important for Algeria and for RAZEL-BEC.

Algeria

Diversion tunnel, entry of the Tabellout dam.

Tabellout dam

13 km of tunnels in algeria


France: Paris metro - Line 4 RATPYears: 2009/2010 Ground: Marl and coarse LimestoneLength: 432 mSection: 63 m²

The pre-cutting method with prevault, more commonly called the PERFOREX METHOD, was introduced in the seventies.Initially, the method was developed to create a decompression slot when explosives are used in underground works in order to optimize the blasting effect and minimize the impact to surrounding area.The range of use has then been extended through the concreting of the slot which creates a protective concrete hull ahead of the cutting face.This patented method well proven by numerous contracts in France and abroad has today become a reference for railway and motorway tunnelling work in soft and mi-hard grounds.In these types of ground where a roof support is necessary and more particularly in urban areas, the PERFOREX METHOD allows for the excavation of full section tunnels up to the largest cross sections.

This method is as well considered for underground car parks and underground storage projects.

aDVaNTaGeS

For many underground projects the PERFOREX METHOD proves to be very performent and presents a lot of advantages:Quick installation of a temporary roof support prior to excavation of the face which results in:• limitation of ground decompression around the

tunnel;• considerable decrease of settlements on

surface.Additional safety for:• peronnel and the work under construction;• surrounding structures.

simple mechanisation and industrialisation of the job site which results in:• less painful tasks;• adaptability to variable ground conditions;• regular progress allowing for time saving and

programme reliability;• cost control.

>

Czech Republic: Chomutov tunnelYears: 2001/2003 Ground: ClayLength: 850 mSection: 75 m²

England: Ramsgate – Harbour accessYears: 1998/1999 Ground: ChalkLength: 755 mSection: 105 m²

The Perforex Method

an innovative technique for sensitive works

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SPECIAL TUNNELLING - Razel-Bec