In a solemn ceremony with our engineers, workers and representatives from the general contractor and the client Euro Alliance Tunnels celebrated the completion of the Rasa Ahonmäki tunnel in South-Eastern Finland near Russian border.
Both tubes, each 202 m long and with approximately 124 m2 cross section were excavated using the drilling and blasting method. Additionally one cross cut - 11 m long, cross section 25,5 m2 and one vertical shaft - 15 m deep, 9 m2 cross section were excavated.
Total mass of excavated rock is 53.000 m3. For the primary lining sprayed concrete with steel fibres is used as additional strengthening.
The excavation of both tubes, the cross-cut and the shaft were followed by construction of additional structures: over 40 wells, 900 m channels, 3.600 m cable canals, approximately 1.300 m3 drainage. Precast concrete collision elements on both sides of the tubes were installed with total length 936 m.
Finally the assembling of the secondary lining structure begun: after drilling holes and screwing stubs into the ceiling steel mats were fixed and finally strengthen with sprayed concrete with plastic fibres. The whole shell structure with 8.820 m2 has been complemented by heat insulation and holders for the lighting system.
Rasa Ahonmäki tunnel is a highway E18 road tunnel connecting UK/Norway/Sweden/Finland with Russia.
