Lemminkainen announced last week that it had been awarded the EUR 22M (USD 32.75M) construction contact for the Koivusaari section of the Helsinki West Metro in Finland. The contract covered excavation of the Koivusaari station and Katajaharju shaft as well as a 2km tunnel from the shaft to the border of Espoo, on Helsinki’s western border.
The metro will be partially built under the sea. The plan included an emphasis on technically challenging dredging works for the foundation and construction of a blasted rock embankment in the sea.
Rock quality in bordering Otaniemi, a southeastern district of Espoo, varies generally between good and poor (Q-classification) with limited zones of very poor rock, according to a spokesperson for Poyry, a designer on the West Metro project.
“This challenging project provides an excellent opportunity for us to combine Lemminkainen’s strengths in both rock engineering and foundation engineering,” said Risto Kupila, vice president, rock engineering of Lemminkainen.
Excavation will begin in June after the completion of preparatory works; the metro tunnel and station should be completed in early 2013.
