Chairman of the Finnish Tunnelling Association International Activity Group, Finland
Mr. Ilkka VÄHÄAHO graduated as a Civil Engineer from the Technical University of Helsinki, Finland in 1979. He has 40-year experience in foundation and rock engineering at the City of Helsinki and has been the Head of Geotechnics since 1997.
Mr. Vähäaho is a member of the Advisory Board of the ITA Committee on Underground Space ITACUS and also a ‘Global Perspective Ambassador’ of ITACUS to promote the usefulness of Underground Resources. He has been engaged in the work of numerous National and European Standards and has a strong engagement in the Finnish Geotechnical Society SGY and the Finnish Tunnelling Association MTR-FTA. He is currently the Chairman of the SGY Ground Improvement Committee and the MTR-FTA International Activity Group.
Urban Underground Space - Sustainable Property Development and Current Status of the Helsinki Underground Master Plan
Underground space is a resource for those functions that do not need to be on the surface. The Underground Master Plan of Helsinki shows both existing and future underground spaces and tunnels, as well as existing vital access links to the underground. It also includes rock resources reserved for the construction of as yet unnamed underground facilities, with the aim of identifying good locations for functions suitable for being underground, and which would also reduce the pressures on the city centre’s rock resources. It has been claimed by some non-Finnish experts that the favourable characteristics of the bedrock and the very severe winter climate conditions have been the main drivers for the underground development. While rock material is one of them, there are other more important main drivers than winter, such as the Finnish need to have open spaces even in the city centre, the excellent and long-lasting cooperation between technical units and commercial enterprises as well as the small size of Helsinki. It is among the smallest cities by area and clearly the biggest by population in Finland. Real estate owners may restrict the use of underground space under their lot or get compensation only if the space to be used is harmful or it causes some loss to the owners.
More and more attention is being paid to the attractiveness of underground spaces these days. The planning of underground spaces located in bedrock gives architects an opportunity to utilise the living and versatile rock surface. Structural engineers need to understand and know how to dimension the underground space as a rock framed, self-supporting structure. The outcome is not only cheaper than a concrete framed space, but at least in the opinion of the author of this paper, also far more beautiful.
The capital areas of Helsinki and Tallinn have grown enormously during the last 20 years. The 80-kilometre-wide Gulf of Finland separates the cities and restricts the movement of people and goods. A tunnel between Tallinn and Helsinki would be an extension of the Rail Baltica rail link, a project to improve north–south connections between EU Member States.