Project description:
As part of the project “Optimization of the railway section – Bridges near Jablunkov – Bystřice nad Olší”, the final lining was completed, and the excavated double-track tunnel was fully equipped, including portal parts of total length of 612 m. The track in the 612 m long tunnel (chainage km 288.702 – 289.314, i.e. TM 0 – 612) goes through a transition, with maximum cant of 23 mm. In this section, the track centre distance also gradually increases from 4.0 m to 4.268 m, and the height difference between Track 1 and Track 2 goes from 0 mm to 89 mm.
The construction of the tunnel included backfilling of the excavated parts of the tunnel, namely by 24 m on both sides. Over 8 000 m3 of material was used for backfilling. The slopes above the portals were reinforced with the GREENSLOPE reinforcement system with a total area of over 1 000 m2. Part of the fire protection was also the construction of a 257 m long escape gallery connected to the new tunnel by a 17 m long cross passage. The original single-track tunnel was used for the escape gallery, in which traffic was terminated with the start of traffic on the new track. The rest of this tunnel was backfilled. The final lining of the upper vault of the escape gallery is built of shotcrete.
The final (secondary) lining of the excavated tunnel is made of monolithic reinforced concrete C25/30, thickness 600 mm. The concreting was carried out into a formwork car in sections (concreting blocks) 12 m long. During construction, the concreting of the final lining and excavation of the core and bottom of the tunnel were concurrent. The length of the excavated part, including two sections made under the false primary, is 588 m.
Waterproof class 0 according to TKP 20, chap. 20.3.8 was required for the tunnel. This waterproofing is ensured in the embossed part by an intermediate foil insulation th. 3 mm, designed in the range of the entire tunnel profile. For the excavated sections, a watertight lining according to TKP 20, watertightness class 0 was used.
