Gotthard railway systems now being installed and the Ceneri is on course
Posted: 1 August 2012 | | No comments yet
Since the second final breakthrough on 23 March 2011, fitting-out of the Gotthard Base Tunnel has made rapid progress, and since September 2011, installation of the railway systems has been taking place from the north. Elsewhere in the Ceneri Base Tunnel, work has begun on the main drives from the intermediate heading at Sigirino. The inward drives from both portals have already been completed.
Status of work on the Gotthard Base Tunnel
Installation of the railway infrastructure systems from the north is progressing rapidly and the ballastless track is currently being laid from Erstfeld.
Along the overground approach line to the Gotthard Base Tunnel, various constructions such as underpasses, bridges, passages and retaining walls are being built. This work is already at an advanced stage.
In the autumn of 2010, work began on the northern railway installations site at Erstfeld. The site occupies approximately 65,000m2 and large halls, workshops and offices have been erected as the logistical base for installation.
Since 5 December 2011, all railway traffic on the Gotthard line has been travelling over the newly built single-track east line from Erstfeld to Altdorf. This single-track phase is necessary to allow work on underpasses and bridges on the west side of the approach section. During the next 12 months, the two former main-line tracks of Swiss Federal Railways (SBB) will be upgraded to high-speed tracks. SBB is equipping the railway line with the tracks, overhead wire, cable systems and points heaters. The tracks, which are designed for train speeds of up to 200km/h, are equipped with ETCS Level 2 (cab display without trackside signals).
In the railway systems building at the north portal, the interior work and outdoor work are complete.
Both tubes of the cut-and-cover tunnel are joined to the underground portal. Backfilling of the cutand- cover tunnel is complete and the surface has been profiled. The concrete plant on the installation site has been removed and all buildings have been demolished and dismantled. Lining work in both tubes was completed in February 2012.
In September 2011 at the north portal of the Gotthard Base Tunnel, the general contractor, Transtec Gotthard, began installation of the railway systems in the east tube. The Erstfeld– Amsteg–Sedrun East section will be the first to receive the railway infrastructure systems. Work will start with pulling-in cables and installing temporary systems. The ballastless permanent trackbed will then be concreted.
In February 2012, ballastless track laying began and is taking place in phases. After the sleepers and rails have been laid in the tunnel, the track will be exactly aligned. Only then can the sleepers be permanently concreted into place. This takes place with a mobile concrete plant on rails – a 500m-long concrete train which was specifically developed for the Gotthard Base Tunnel. This allows fresh concrete to be produced directly at the laying site and allows approximately 220m of track to be laid in the tunnel per day.
Installation and commissioning will take a total of seven years. The only available access points for bringing the infrastructure equipment into the tunnel are via the two portals. Therefore, virtually all transportation takes place by rail from the two installation sites in the north and south.
In the electric power feed-in cavern near the lowest point at Amsteg, structural work on the rooms for the railway infrastructure systems is complete. The inner linings of the west tubes of the Erstfeld and Amsteg sections have been joined and the benches have been installed.
On the installations site, dismantling and removal work has been in progress since summer 2011. The concrete plant, the belt conveyors of the spoil management systems, the gravel plant and the visitor trail have been demolished, and the retention basin of the water-treatment plant has been removed.
In parallel with the railway systems, final work on the concrete shell is in progress. By May 2012, all of the cross galleries had been equipped with end-doors, ventilation and other systems. The inner lining of the multifunction stations at Sedrun and Faido will be completed by the summer and autumn of 2012 respectively.
AlpTransit Gotthard Ltd has signed the work contract for the hoisting systems for the two 800m-deep shafts at Sedrun which will be used for inspection and maintenance work. Installation will start in August 2013.
Shortly before Christmas 2011, the first of four track-crossover doors was transported into the tunnel and installed in the north of the multifunction station at Sedrun. The technical inspection took place at the end of February 2012.
In summer 2011, work began on reculti – vation of the Claus Surrein landfill site. In June 2012, the bathing lake on the landfill site, a project of the Tujetsch municipality, was opened. The belt conveyors on the Val Bugnei landfill site have been dismantled and the belt conveyor bridge in the Tgaglias temporary storage site has been demolished. On the installations site, construction of a railway systems building has begun and when it becomes operational, it will be used to accommodate various railway system installations.
In the east and west tubes of the Faido section, almost 22km of lining have been concreted. Therefore, both inner linings are now joined to the Sedrun section. In November 2011 in the transverse cavern, work began on the twostorey railway systems building.
In mid-2012, fitting-out of the multifunction stations at Faido and Sedrun will begin and the works includes the execution planning and development of the entire mechanical and electromechanical equipment of the two multifunction stations, the ventilation centres and the railway systems buildings at Sedrun and Faido. It also includes their manufacture, installation and commissioning. The central element is the ventilation system of the under ground railway systems building in which all of the systems are housed.
In the Faido–Bodio West section, the railway infrastructure systems have been installed and test runs for speeds of up to 230km/h will take place on this approximate 16km-long section from 2013. These will allow the complex interfunctionality of all of the railway infra – structure systems in the Gotthard Base Tunnel to be extensively tested. The logistical base for installation of the railway infrastructure in this section of the tunnel is the Installation Site (South) at Biasca.
Work on the connection between the AlpTransit line and the SBB main line on the south overground section between Biasca and Osogna has been in progress since May 2011. Important structures for the Nodo della Giustizia junction have been constructed. Construction is in progress of the bridge over the Froda Canal, the cut-and-cover tunnel at Giustizia, and a retention basin for the Stabiello stream.
The focus of the construction work will increasingly transfer to the railway installations. In the autumn of 2011, installation of the railway systems from the north portal of the Gotthard Base Tunnel began. In the last six months in this section, work on the construction shell, electromechanical equipment and railway systems proceeded in parallel.
The interfunctionality of all of the railway infrastructure systems that have been installed will be tested during a test phase starting here in 2013. The findings will have signal value for the commissioning and commercial opening of the Gotthard Base Tunnel. At the beginning of 2016, the interfunctionality of the technical installations in the Gotthard Base Tunnel will be tested in test operations with trains. At the end of May 2016, AlpTransit Gotthard Ltd will hand over the tunnel to SBB ready for operations. In the optimal case, scheduled train services will be possible from December 2016.
Status of work on the Ceneri Base Tunnel
On the Ceneri Base Tunnel, almost 50% of the total 39.78km of the tunnel has now been excavated and the drives at the portals in the north and south are complete.
Work on the Nodo di Camorino has been in progress since 2006. The new four-track railway bridge over the A2 motorway will replace the existing two-track bridge. To avoid interference with railway operations, two tracks of the new structure will first be built alongside the existing bridge. This will allow diversion of the two tracks for demolition of the old and construction of the second half of the new bridge. During the nights of 5-6 November 2011, the bridge was lowered by almost two metres onto the supports. During this work, the A2 was closed and road traffic was diverted. The bridge has been handed over to SBB for the provisional relocation of the main railway line and demolition of the old bridge began in March 2012.
The first section of the bridge over the Morobbia is already in operation and the old bridge and the pedestrian walkway have been demolished.
For the 1km-long Lugano-Bellinzona viaduct, the foundation work for various columns is in progress and implementation of the first field of the viaduct has begun. For the 400m-long Bellinzona-Lugano viaduct, work is in progress on the installations site and realisation of the foundations of the first pillars.
A further important phase in the construction of the Ceneri Base Tunnel has already come to an end. On 21 December 2011, the last blast took place in the north drive at Vigana. To date, 670m of the 15.4km-long Ceneri Base Tunnel have been excavated by blasting from Vigana. At the beginning of 2012, lining of the tunnel began.
The invert is being concreted and the expansions for the jet fans are being blasted. The vault is being sealed, and preparations are being made for the invert in the area of the east tube.
Excavation of both tubes entirely by con – ventional drilling and blasting has been in progress since 2010. Driving is taking place in the east and west single-track tubes both northwards and southwards. For logistical supplies to the driving areas, four hanging platforms have been installed. The excavated rock is transported on belt conveyors out of the tunnel to the landfill site at Sigirino. In May 2011, the drive to the south entered the Linea della Val Colla geological fault zone. Here, the work was performed mechanically, without the use of explosives. In February 2012, the geological fault zone was overcome and conditions are improving again. Behind the blasted drive, work on the invert is progressing in both directions. The systems required for this purpose are regularly advanced to keep pace with the drive. Ventilation of the construction sites is provided by the respective jet fans.
On 20 May 2011, at the south portal in Vezia, the last blast took place allowing driving of the inward drives in the south to be com – pleted. For some of the time these drives were very challenging, because the south portal is situated immediately adjacent to the SBB main line, the A2 motorway, the new road tunnel of the Lugano bypass, and the heritage-protected Villa Negroni. At the end of March 2012, concreting of the invert was completed in both directions. In the east tube, work on sealing and concreting the vault is in progress.
Modifications are now being made to the SBB main line. These are necessary because no new overground line to the Ceneri Base Tunnel is being constructed at Vezia. At a later stage, a 170m-long cut-and-cover tunnel will be constructed in the preliminary cutting, which will link the underground portal to the main line.
From the start of 2012, excavation of the Ceneri Base Tunnel has been proceeding only from the intermediate heading at Sigirino. Respective work is scheduled to be completed in 2016, after which the railway systems will be installed. Invitations for tender will be published in 2012. The Ceneri Base Tunnel is scheduled to open for commercial operations in December 2019.
About the author
Renzo Simoni has been CEO of AlpTransit Gotthard Ltd since 1 April 2007. His previous employment included assignments with Helbling Beratung + Bauplanung AG, Ernst Basler + Partner AG and Gruner AG. Renzo studied civil engineering at the Swiss Federal Institute of Technology (ETH), Zurich, followed by a postgraduate diploma in spatial planning and a doctoral thesis at the ORL Institute.