Use of underground space and geo-information in Helsinki

Helsinki (population 0.56 million/surface area 185 km2) is concentrated on a narrow peninsula, as is the main public administration and business management of Finland (population 5.2 million). As many ordinary citizens also wish to live in the same area, there is high demand for land suitable for building, even though there is plenty of empty space outside the city. In addition, as the city plan does not permit high-rise buildings, construction has tended to go downwards, into the bedrock. Fortunately the city's Precambrian bedrock is hard and well suited to tunnelling. For 50 years, Helsinki has made versatile use of its bedrock resources. The Finnish Tunnelling Association published three books between 1986 and 1997 on rock engineering in Finland, available in Finnish and English (www:mtry:org/). These books have contributed much to the state of knowledge, particularly concerning tunnelling in the Helsinki area. The geotechnical database (www:hel:fi/kv/geo/) maintained by the City of Helsinki (for nearly 50 years) has provided city planners and citizens with comprehensive information about the city's underground resources, which has led to a constant flow of proposals for the utilisation of the bedrock and the building of tunnels. This in turn has led to more tunnelling. Sustainable development and environmental pollution have been much discussed topics recently and tunnelling has often come up. Helsinki sees tunnelling as a cost-efficient additional resource in city construction. Though tunnels pose great environmental risks during their construction, no accidents have occurred. For this reason Helsinki's 2002 agenda for sustainable development (Local Agenda 21, www:hel:fi/ymk/agenda/index_agenda:html) took a positive view of tunnelling, with any objections being mainly related to city traffic policy. Bedrock tunnels have a long life span and their costs are reasonable. Tunnelling also frees land suited for residential building and decreases environmental emissions. Thus extensive tunnelling has great importance for the sustainable development of Helsinki. The current situation regarding tunnelling is as follows: (i) Helsinki's energy and water management is for the most part already located in bedrock tunnels. (ii) Every citizen can be housed in an underground shelter in the event of a major crisis. (iii) The Helsinki metro operates in tunnels in the city centre. (iv) Most car parking facilities in the nuclear centre are located underground, half of them in bedrock tunnels. (v) Good mineral aggregate for construction is obtained from spaces/tunnels made in the bedrock. From the experience gained in Helsinki we can say that what makes a modern city "unbeatable" is an efficient infrastructure, with its major elements being located in bedrock tunnels. The future of tunnelling in Helsinki looks good, as the bedrock underneath the city provides unlimited possibilities and the city's very useful geotechnical database allows easy access to city planners and citizens alike. (A) "Reprinted with permission from Elsevier". For the covering abstract see ITRD E124500.

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  • Authors:
    • KORPI, J
  • Publication Date: 2004-7


  • English

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  • Accession Number: 01011559
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 19 2005 3:17PM