Housed in the magnificent congress and concert palace Finlandia Hall, the show will run from 20 to 26 May, following the main theme: ‘underground spaces in the service of a sustainable society’.

The Finnish Tunnelling Association (FTA) boasts an impressive range of presentations for the show. Not all have been confirmed as T&TI goes to press. The deadline for the registration fee is the end of March, but the remarkable acceptance list of 153 oral and 81 poster presentations should ensure that this WTC really has something for everyone.

Keynote speakers have been named, with mayor of Helsinki Pekka Sauri speaking on the importance of underground spaces in the urban environment, Timo Alkas of Posiva presenting on the disposal of spent nuclear fuel and Professor Hakan Stille of the Royal Institute of Technology of Finland.

The Muir-Wood lecture, held in memory of the death of Sir Alan Muir-Wood, first and honourary president of the ITA, will kick off the talks. It will be presented by Robert Mair, professor at Cambridge University, with the topic: tunnelling in urban areas and effects on infrastructure – advances in research and practice.

Besides the conference, the FTA has arranged a series of technical site visits for the more hands-on attendees. These include:
– The energy and multi-utility tunnel network of Helsinki.
– The Itakeskus underground swimming centre.
– The Viikinmaki underground wastewater treatment plant.
– West Metro Project.
– KEHU – City Service tunnel for delivery vehicles.
– Underground coal storage and district cooling.
– Ring Rail Line Keharata.
– Parking and service tunnels for Finlandia Hall and new Music Centre, Helsinki.
– The underground research hall of VTT

Technical Research Centre of Finland. The city of Helsinki is itself a bright spot in the Scandinavian tunnelling industry. The airport transit link currently under construction (see page 19) and the recently agreed expansion to the metro stand amongst many other projects in the Nordic region.

“Work is available and on the increase,” says Pekka Sarkka, president of the Finnish Tunnelling Association (FTA). “There’s good competition between the companies. The industry was not really affected by the global depression. Maybe work isn’t as widespread as in an outright boom–but it isn’t low at all.”

Trends
“Without speculating on why, Swedish companies used to win contracts for hydroelectricity jobs all over the world and now not so much,” says Bengt Ljung, chairman of the Swedish Mining and Tunnelling Group.

As for back home, the majority of work in Sweden is around Stockholm, with impressive projects like the SEK 16bn (USD 2.49bn) Citybanan, which involves many of the large firms in Sweden, such as Sandvik, ABB and others. The Citybanan will improve the traffic situation in central Stockholm.

“In Finland, rail traffic accounts for the majority of tunnelling work,” says Sarkka. “And almost 100 per cent excavated with drill and blast.”

He explains that the flat profile and good rock of Finland—recent glaciation has stripped the land of much of its soil—allows for shallow, flat tunnels, in contrast to the steep, fjord-bypasses of Norway. It also allows for the construction of lots of access tunnels, which compensates for the slower rate of excavation associated with drill and blast.

There is a very clear focus in Norway towards developing infrastructure, especially road tunnels, according to Eivind Groev, president of the Norwegian Tunnelling Society (NFF). A scattered population in a country that presents many challenges to cohesive infrastructure is a priority for a government responsible for reaching rural areas.

“There is an upcoming project—a 20km rail tunnel south of Oslo that is currently being discussed,” says Groev. “We are deciding whether to use TBM or drill-and-blast. If TBM is the decision, it will be the first use since the early 90s.”

The prevalence of drill-and-blast is a result of the need for road tunnels, which do not necessarily need a circular bore-section, making TBM use obviously inefficient.

Challenges
The Ring Rail Line in Helsinki has experienced a unique problem under the Helsinki-Vantaa Airport runway. The glycol de-icer used to protect the planes has seeped through the bedrock and supports the growth of concrete eating microbes. Sarkka anticipates that this has resulted in a half-year delay on the project.

The Helsinki Metro western extension has been similarly delayed, though in its case by permit issues, rather than voracious, chemically enhanced, tunnel-destroying microorganisms.

Norwegian tunnelling has been almost without incident in the past decade, according to Groev.

The last major incident occurred in the late 90s with the accidental draining, by tunnel works for the Romerike project, of several small lakes on parkland east of Oslo and damage to houses. This caused political tension with the resulting public protest, but as Groev points out: “Lessons are always learned from such situations.” Water inflow to the tunnel reached 3000 litres per minute and was eventually stopped with Rhocal-Gil, which was followed by concrete when the potentially poisonous sealant was banned in Norway in 1997.

The Stockholm Citybanan has problems relating to delicate and valuable buildings along the alignment. “The path of the tunnel requires that we blast under a small island covered in 17th Century churches, it is effectively an island-museum – there is a need to be very careful,” says Ljung.

Future
In the past, notably the ‘60s, ‘70s and ‘80s, Norway was heavily involved in tunneling for hydroelectric projects, the fruits of which provide for the majority of Norway’s power requirements today.

“In future I think hydroelectricity will become more of a focus again,” says Groev. “We are exporting and importing with Europe depending on the season. In the next 20 years we will be getting back in to hydropower.”

In Finland, Posiva has been responsible for research into the permanent storage of nuclear waste material underground. The Onkalo project has driven down to a depth of 420m to perform a suitability study and ascertain the nature of the bedrock. This will also enable the testing of a final disposal scenario under real world limitations.

“The nuclear storage project in Finland, the first of its kind in the world, has been the focus of a lot of research for 30 years now,” says Sarkka. “I cannot foresee any obvious problems with it because of this level of work and investigation.”

These and many other quirks of the Scandinavian tunnelling industry, and wider, will be presented at WTC Helsinki. Pekka Sarkka and the FTA invite you to join them as they work eagerly towards a bright future for the tunnelling industry!


Finlandia Hall Glycol de-icer created an ideal environment for concrete-eating microbes at the Helsinki airport link project WTC visitors will have the chance to visit blasting work is underway on the Rail Ring Line