Railway Tunnel Ejpovice
The improvement of the railway track between Rokycany and Pilsen is part of the modernisation of the Czech National Railway Transit Corridor III. Construction of two single-track tunnel tubes at Ejpovice, with a length of 4,150 metres each, which are part of the new railway line, begun in early 2015.
If everything continues to unfold according to plan, the tunnel will be ready by the end of 2017. Trains will then be able to pass through this section of the railway corridor at speeds of up to 160 kilometres per hour, and the journey time between Prague and Pilsen will drop to less than one hour.
Unique in the construction of the tunnel are the use of a giant 110-metre, 1,800-tonne tunnel boring machine, as well as the method of reinforcing the walls of the tunnel using only precast concrete reinforced with steel fibres. The lining of the tunnel is a ring made from concrete with an outer diameter of 9.5 meters and internal diameter of 8.7 metres. The segmental lining rings are manufactured near the construction site. Each ring is 2 metres long, consists of eight segments (7 basic components and one additional – binding component) and weighs 60 tonnes. 4,000 rings are required for both tubes. The rings are connected by plastic anchors (longitudinal direction) and steel rods (pulled out after injection). The injection mortar (mixture of cement, bentonite, fly ash, and water), which is transported via pipeline up to the boring shield, is injected into the approximately 10 cm between the concrete ring and the rock.
HeidelbergCement’s subsidiary Ceskomoravský cement is supplying the cement for the entire modernisation project.
