Page 8 - TunnelTalk Annual Review 2010 Preview

10 years from the original project timeline. The original plan, set in 1998, was to have the baseline railway operating in 2007. As it is, TBM excavation of the longest drives for the main tunnels started from the Bodio portals in 2001 with drill+blast work starting from the base of the deep access shaft at Sedrun in 2002. Work on the shorter TBM drives from the north Erstfeld portals started in 2006. The project is now scheduled to open at the end of 2017.
opens in 2017, travel time between Zurich and Milano will be shortened by one hour. In addition, freight trains will be able to travel the straight, flat tunnel alignment with twice the load and at twice the speed. People and goods will cross the Alps faster, more safely and in a much more environmentally friendly way. The breakthrough of the first running tunnel of the twin tubes through the base of the Alps is a historic and record-setting achievement.
The last of the four Herrenknecht TBMs that have excavated much of the total underground works was working towards the very last breakthrough for the entire project in March 2011. n
References
• Breakthrough milestone for Gotthard Base Tunnel - TunnelTalk, September 2009
• Gotthard TBM safely across the Piora
Mulda - TunnelTalk, Nov 2008
• Bodio tunnel lining wurms - Switzerland -
When the Gotthard Base Tunnel
TunnelTalk, Dec 2004 Concrete contributions to a mammoth undertaking
During the course of realising the massive Gotthard Baseline project, many different contractors and engineering firms, many thousands of workers, and legions of different suppliers and equipment manufacturers contributed to the effort. Three construction contracts were let for the main tunnels and their passages and chambers.
• At Sedrun, the consortium of Implenia/ Frutiget/Bilfinger Berger/Pizzarotti completed 11km of drill+blast headings at the bottom of the two 800m deep access shafts.
• At the south, TAT, the Tunnel AlpTransit Ticino JV comprising Implenia/ Alpine Bau/CSC Impresa/Hochtief/ Impregilo completed two lots and operated two Herrenknecht TBMs running parallel for about 14km from the Bodio portal initially and then carrying on into the 11km long drives from the Faido access adit to breakthrough into the Sedrun drill+blast work.
• From the north, the AGN, Arbeitsgemeinschaft Gotthard- Basistunnel Nord JV of STRABAG AG of Switzerland and Austria, managed the two further Herrenknecht TBMs on the project for the initial 10.7km of tunnel from the Amsteg
adit to breakthrough with the Sedrun drill+blast work and then the 7.1km parallel drives from the Ersteld portal to Amsteg.
Herrenknecht AG supplied four gripper rock TBMs of 8.8m to 9.5m diameter to the consortia for the north and south lots. The machines excavated a combined total of 85km of the 2 x 57km long twin tube complex. For development works and the central Sedrun drill+blast excavation, fleets ofAtlasCopcoandSandvikjumboswere used with their support systems.
Muck haulage behind the advancing TBMs was via long continuous conveyors suppliedbyH+ELogisticsbutthesupply- line rail-bound workhorses of the long- distance headings teamed once again the familiar duo of SCHÖMA locomotives and Mühlhäuser rolling stock. SCHÖMA supplied more than 125 powerful locomotives to the project. Mühlhäuser delivered more than 500 units to the different contractors including wagons, concrete remixers, flat cars, man-riders and specialised ambulance cars to assist in any emergency.
Concrete admixtures, shotcreting machines and a fire protection mortar were contributions by BASF MEYCO to the different construction contracts.
DELVO® Crete Stabilizer 10 slowed
down cement hydration to ensure an open
® time of four to six hours while GLENIUM
superplasticizers maintained workability after long distance transportation and exposure to the high temperatures in the interior of the mountain. The combination was used for cast final lining as well as shotcrete. MEYCO® SA 160 accelerator was added to shotcrete for fast solidification.
MEYCO® Fireshield 1350 fire protection mortar was supplied to protect the concrete liningsfromspallingdamageintheevent of an in-tunnel fire in the Bodio tunnel section while MEYCO® Potenza and Oruga shotcreting robots were delivered in numbers totheErstfeldandSedrunheadings.
To the effort Bekaert supplied volumes of Dramix® steel fibre for shotcrete reinforcement as well as its Duomix® M6 Fire protection polymer fibres.
Many different sets of formwork were supplied to the project, several of the specialist pieces by Doka of Austria. For the Erstfeld lot its equipment lined the two large span Y-branch crossover caverns.
The congratulations of all in the international tunnelling industry goes to the workers, suppliers and all the managers involved who teamed together to bring the project to its successful end- of-excavation milestone. n
Among principle suppliers (clockwise from top left): Herrenkneckt gripper TBMs; Schöma locos and Mühlhäuser concrete remixer cars; Doka formwork; Bekaert steel and polyfibre as well as BASF MEYCO concrete admixtures
8
TunnelTalk AnnuAl Review 2010 www.TunnelTalk.com
MEGA PROJECTS
PREVIEW