Construction of two tunnels for pedestrians below the railway line Kraków-Balice
At the end of 2013 we started a new project, the construction of two tunnels for pedestrians below the railway line in Krakow connecting Kraków Główny railway station and Balice airport. The tunnels, designated as 2.7.1 and 2.7.5, were erected by the Contractor and subcontractor- Astaldi and Infrares.
The tunnel 2.7.1 is an underground passage leading to railway platforms of the local station Kraków-Łobzów, located along Wroclawska street. The tunnel consists of two separate parts, between which there is an old, existing railway viaduct, planned for renovation in the future. Because of this, the geometry of the tunnel had to incorporate the existing underground infrastructure (sewage pipes, gas pipe, electric cables) and include two extra exits, leading up towards railway platforms. That is why we had to include 4 “holes” in the walls, for staircases and lift shafts. The tunnel has no bottom slab, it is founded on concrete, drilled piles. The total length of two parts of the tunnel is 13,9+11,12m, and the cross section is a rigid frame on piles. The width of the structure is 5,0m, the vertical clearance is 3,0m.
The tunnel 2.7.5 is a passage under the railway, connecting two sections of Katowicka street. It has the total length of 50m, its horizontal clearance is 3,5m and vertical one is 2,5m. The entrances are designed as separate buildings, with staircases and ramps for disabled people and a roof made of steel trusses with plexiglass filling.
Interesting facts
The 2.7.1. initially had driven piles, but because of a close proximity of a gas and sewage line, the piles were changed to bored ones. In the original design, between the entrances to staircase and lift shaft, a pillar was designed, which – as we discovered – had a too small cross section to bear all loads. We had to change it to ensure the safety of the structure.
< Our designs
