Issue link: http://read.dmtmag.com/i/653001
I DA U N I V E R S A L M a rc h -A p r i l 2 0 1 6 20 interceptor, a 25km long sewage overfl ow storage and transport tunnel, 7.2m diameter running up to 65m deep, mostly underneath the river. It will eliminate storm overfl ow into the river from 34 existing sewers. e seven-year construc- tion starts next year, overseen by specially-created indepen- dent company Balzagette Tunnel for utility company ames Water. Contrac- tors selected include major European fi rms BAM Nuttall, Ferrovial Agroman, Balfour Beatty, Costain and Vinci Construction. Second largest e second largest project in Europe is the Stuttgart 21 underground station and rail scheme in Germany, and the associated Stuttgart-Ulm high-speed rail project, both of which involve multiple tunnels. Taken together, they are costing around €10 billion. Both are now signifi cantly into construction a er years of controversy and protest. e city project is building a new central station, under- ground in the heart of the city, with eight tracks running at 90º to the orientation of the 15-platform existing station. e client, Deutsche Bahn, said that despite fewer lines, the through nature of the station was quicker and faster than the existing in-out terminus, which funnels into just fi ve exit lines. e project involves recon- fi guring local and regional lines with a series of radiating so ground tunnels in the city, which is enclosed by hills on three sides. Complex work is needed beneath buildings and a river crossing. A new high-speed rail link is also running out south- east through the largest of the tunnels, the 9.5km hard rock Filder tunnel, which is currently being driven. Austrian contractor Porr is working from the southern portal, using TBM drives and a central 1.5km-long section of drill and blast. e drill and blast is needed to pass through anhydrite Keuper gypsum which must be kept dry to avoid expansive reaction with water, which could trap a machine. Special water seals have to be installed around the tunnel bores. Work on the fi rst bore began in autumn last year, using a 10.82m Herrenknecht multimodal machine in EPB mode. Spoil goes to the surface with a Swiss Agir conveyor for immediate loading for truck disposal from a tightly constrained worksite. To save space, segments arrive on a just-in-time basis by train from precast works operated by contractor Max Bögl near Berlin. e fi rst 4.5km is just fi nished, and the TBM is being dismantled and moved to the portal for a parallel drive beginning next spring. Atlas Copco rigs are starting the centre sections. A er its second drive, the TBM will be hauled through the conven- tional sections for two more drives at the far end. At this city end, meanwhile, large NATM (new Austrian tunneling method) caverns are being made for the TBM reception and turn, and for link tunnels into the station. Sophisticated compensation grouting is needed to stop the settlement of buildings above the tunnel. Specialist consultant Professor Walter Wittke is advising on the tunnel and this work. Five tunnels Wittke is also working on the high speed link to Ulm, which continues from where the Filder fi nishes at the airport with another 60km of new line. Some fi ve major tunnels are required, several in construc- tion for the last three years. e biggest are under the Schwabian Alps, a highland national park where two tunnels, totaling 14km, take the line upwards and another, the 5.5km long Albabstieg, descends into Ulm. Tunneling: Going Underground e 15.4km Ceneri tunnel is part of the Alp Transit scheme C Completion of running tunnels for London's huge Crossrail scheme was a major highlight this year, as the last of eight Herrenknecht TBMs (tunnel boring machines) broke through in May, meaning that 21km of new twin bore tunnel has now been threaded through complex cluttered ground beneath Britain's capital. e last TBM, Victoria, completed one of two parallel 8.3km bores from the east to Farringdon Station in central London – the longest drives. Six 7.1m diameter EPBs (earth pressure balances) worked on the project, which also used two slurry type Mixshields for a crossing under the River ames. Work to dismantle Victoria began in the summer. e tunnels are the central element of the overall £14.8 billion ($20.5 billion) project which forms a new 118km-long link from the east to west of London. ere are expected to be 200 million passengers annually. Work continues on station caverns, primarily with spray concrete methods, and fi tting out for both stations and rail. Trains are scheduled to run at the end of 2018. London's tunnelers have another project to occupy them – the huge £4.2 billion ($5.8 billion) ames Tideway