Market heat in Finland plus more strengthening works than anticipated have inflated the cost of the road and rail tunnels on the Vuosaari Harbour infrastructure project, T&TI has been told.
Tunnel construction costs have increased by US$32.5M, which is nearly a third of the overall rise in construction costs on the entire project. Estimates put the latest cost for the scheme at US$376M from US$207M five years ago (2002 currencies) – but while the jump was about 40% in local currencies, ignoring inflation, the gulf is wider in US dollars due to loss of parity in exchange rates over the period.
Pekka Kontiala, project director, told T&TI that more strengthening works had been required on the tunnels than expected, which contributed to the higher costs. However, he added that construction cost inflation of some 20% since 2002 had added US$58.5M to costs.
When the project was planned in 2000 there was relatively little tunnelling activity in Finland, he said. Much more tunnelling works have got underway in the last five years, driving up demand and therefore costs in the country.
Excavation recently finished on the project, having ended late 2006 on the 13.5km single bore Savio rail tunnel and in April last year on the twin 1.7km tubes for the Porvarinlahti road tunnel. On the former, concrete lining works are underway for completion in April and the tunnel is to open late 2008. On the latter, tunnel fit-out is due to finish in May for the road’s scheduled opening in October. All tunnels were excavated by drill and blast, mostly in granite.
On the Savio rail tunnel the rock was “mainly good”, said Kontiala, except for a 200m stretch of fractured rock requiring much more primary lining support. Excavation began at the start of 2005, taking just over 20 months and tunnelling at depths up to 60m, and was costed at US$92M. Contractors were YIT Construction, Lemcon and Kalliorakennus-Yhtiot, and the designer JP-Suoraplan.
A contract for the final lining, four access tunnels and three vertical shafts was awarded late last year to Lemcon for US$30M. The total, completed cost of Savio rail tunnel is put at just over US$160M against the original price tag of US$133M (2004 currencies), which represents an increase of 23% in local currencies, ignoring inflation. Tunnelling works accounted for two-thirds of the budget, or US$86M (2004 currencies).
Tunnel excavation for the Porvarinlahti road tubes ran simultaneously from October 2004 to last April, encountering a little limestone but mostly granite. The bores are 9m high by 12m wide. Excavation costs – which included the 600m long Labbacka rail tunnel on this section of the project – had been budgeted at about US$29M (2004 currencies). The contractor was Skanska Tekra, the designers Finnmap Infra and Kalliosuunnittelu Oy Rockplan. The project began in 2003.
