Mont Sion Tunnel to Start Imminently in French AlpsThe A41 north stretch is the missing link on the A41 between Villy-le-Pelloux / Saint-Martin-Bellevue and Saint-Julien-en-Genevois in the popularly area called Upper Savoy in the French Alps. The section will complete a major regional highway link which, via the A43 and A41, will link up the main cities in the alpine furrow (Grenoble, Chambery, Annecy and Geneva). This key segment to connect the regional transport networks will shorten the distance between Annecy and Geneva to less than half an hour by road and will provide a fast access through Bellegarde to the Paris-Dijon high speed line that crosses the Upper Bugey. It will also facilitate access to the Lyon and Geneva airports. View maps here. The financing, design, construction, operation and maintenance of this 18.8 km section has been commissioned to ADELAC on 27th October, 2005. A 55-year concession agreement was signed, with the concession starting from the next day. ADELAC is the subsidiary of several partners. Its shareholders are highway operator AREA (Group APRR), who controls 49.9% of the company; four businesses of Bouygues Construction, i.e. Bouygues Travaux Publics (23.05%), GFC Construction (8.75%), DTP Terrassement (6.9%) and Losinger Construction (0.50%); and Group Bouygues' Colas (6.9%); Caisse d'Epargne et de Prevoyance des Alpes (2%) - a financial institution - and engineering firm Setec (2%). GIE Constructeurs A41 is the JV of building companies responsible for the construction, namely the four above-mentioned Bouygues Construction companies and Colas. Click fr/56. French Minister for transport Dominique Perben during the christening ceremony on 9th October, 2006 of the TBM dubbed 'Adelaide' ADELAC has commissioned to AREA the operation and maintenance of the A41 North. AREA operates a network of 384 km of highways in Rhone-Alps, whereof a hundred kilometres situated in mountainous areas (A43, A48, A41, A51N). The network has several tunnels, in particular the 2 x 3,150 m L'Epine tunnel which is very similar to the Mont Sion tunnel, backbone of the A41 North. Click fr/60.i-Lac, formed by Setec and Bouygues TP, has been entrusted with the project engineering. i-Lac designed the tunnel and subcontracts the tunnel engineering to Bouygues TP. The A41 North has a total cost of EUR871.5 million, of which 76.5% allocated to the project development and construction. The A41 North will be completed in 38 months (9 months for development and 29 months for building it). Design and construction amounts to EUR595 million. Entry in service is foreseen for 28th December, 2008. The scheme requires to mobilize more than 150 earthmoving vehicles (diggers, bulldozers, scrappers, graders, dumpers...), to move 7 million cubic metres of earth, to build a precast concrete segment plant at the north portal in Presilly and to install seven base camps and four plants to produce the asphalts (two fixed facilities and two mobile ones) to construct the highway. At its peak, up to 900 people will be employed. In addition to four viaducts (264 m, 270 m, 212 m and 360 m), the section requires also a cut-and-cover tunnel in Le Noiret and a twin bored dual-lane tunnel under the Mont Sion. The 3.1 km Mont Sion tunnel is the key component and major structure of the A41 North. The base camp at the tunnel's north portal, in Presilly, is the biggest of all worksites. The site gathers, in reality, a 3,000 sq m precast concrete segment factory, the TBM platform, the power systems necessary for the functioning of the machine, the warehouses and maintenance workshops for equipment, offices and a temporary dump site to store the muck. This is the operational and logistics base from where the TBM will start its warm-up as early as mid-October prior to digging in eight months the first, west tunnel. The TBM will then be brought back to the north portal, by road for the cutting head and through the just completed tunnel for the 11 trailers that make up the trailing gear. About three months will be necessary to prepare the machine for the second drive. Excavation of the second, east tube will last seven months. Altogether, construction of the tunnel will be achieved in 18 months, the date of completion being March 2008. The four tunnel portals (30 m to 120 m) are built by a Paurat roadheader machine which excavates the top heading under an umbrella vault, then steel arches are installed and shotcrete is sprayed. There is a slight cover of 5 metres above the portal areas, that are in ground where molasse meets glacial moraines. Visit www.wirth-europe.com/roadheaders/paurat.htmThe Mont Sion tunnel has been christened on Monday 9th October, 2006 during a ceremony presided by Dominique Perben, French minister for transport. The TBM is dubbed 'Adelaide', in reference to the name of the concessionaire ADELAC and Adelaide of Susa who, in the XIth century, contributed to the expansion of the Duchy of Savoy. Built by Herrenknecht, the biggest TBM in service in France is 12 m in diameter m, 220 m long and weighs 2,200 tonnes. It is an exceptional machine composed of a cutting wheel and 11 trailers that supply the 4.8 MW power logistics, are used as supports for the assembly of the concrete rings (approx. 18,000 segments of 15.5 tonnes each), and allow for the mucking-out and lengthening of the conveyor belts and pipes. It is a hard rock TBM in open mode, a real moving factory that constructs the tunnel as it progresses. An average daily advance of 23 to 24 metres is expected. Under the joint effect of a 4 rpm rotation and a thrust of up to 82 megaNewtons, i.e. 8,200 tonnes, exercised by 24 jacks moved by 16 motors of 160 kW each, the disc cutters laid on the cutterhead chew through the ground. Thanks to the loading buckets, the rock (2 x 340,000 cu m) is evacuated outside by a belt and trucked to final dump sites. The TBM will dig in consolidated molasse, with a strength of up to 120 MPa, following an upward gradient from the north portal in Presilly. The machine will bore in a first stage the lower half of the cross section at the portals before moving to full face tunnelling phase, due to commence by mid-November 2006. View pictures here. Visit www.herrenknecht.comThe segment moulds and the carousel plant are supplied by Herrenknecht. The segments will be installed according to the so-called Swiss method, which means that instead of erecting the segments one after the other, a complete ring is assembled in the shield's tail skin. By its own weight, the ring stands in the tail skin and is then transferred to be placed in its final position. The key is located always at the same place at the invert.Geologists and hydrogeologists expect little water. The extrados will be filled with gravels, which will create a seal which will drain the possible water and provide watertightness above the traffic clearance. There are therefore no rubber gaskets between the segments and the rings.Designed to fulfil today's highest security standards, the Mont Sion tunnel includes seven cross passages to enable communication between both tubes in case of emergency. Four will be for pedestrians while three will be for rescue vehicles. These seven cross passages will be excavated, after cutting the segments, by a rotating head or hydraulic hammer.Fifteen safety niches equipped with fire gates and emergency call telephones will be installed in every tube. The longitudinal ventilation system, comprising 38 reversible fans (20 in the east tunnel and 18 in the west tunnel) will quickly fight smoke formation in case of fire. Read E-News Weekly 2/2006. Visit www.adelac-a41.com 43/06.