Bujanovsky tunnel - proposal for reconstruction of the longest double track railway tunnel in Slovakia

An effort to integrate railway system in all EU countries has led Slovak Republic Railways (ZSR) to modernizing selected rail tracks. These railways include 10 old tunnels, most of them have passed the date of their technical life span and their spatial arrangements do not fulfil requirements for express rail corridors. One of those is also Bujanovsky Tunnel - the longest double track tunnel in Slovakia. Operating since 1955 and 3 410 m long. Tunnel is build on railway no. 180 Zilina - Kosice, which is part of old Kosice-Bohumin railway, today 1st main route Cadca-Zilina-Kosice-Cierna nad Tisou. Tunnel route is under the hill Suchy, vrch and Bujanov, in rocky environment of wart granite and gneisses, which show several tectonic disturbances. Because it is being considered to increase the speed from current 70-80km/hr to 160 km/hr it is necessary to proceed with reconstruction of the tunnel in order to fulfil requirements resulting from increased usability and project safety. Tunnel usability is limited by the tunnel age, progress of construction and also by material used for construction. During tunnel inspection held in 2008, the tunnel lining was assessed mainly as suitable. No deformations were found in tunnel arch neither any major structural cracks. Stone tunnel portals are also in good condition. Remedying works, which can be carried out only after processing detailed analysis of disturbances causes, are necessary due to various levels of tunnel lining degradation, caused by water seepage. Sizable construction works will be required in order to fulfil safety requirements in accordance with new legislation. Therefore it is necessary to build escape corridor next to the existing tunnel, provide tunnel fire main, build approach areas in front of the portals and to replace rail track bedding. Translated submission are include remedying works, proposed to provide the longest possible failure free tunnel serviceability and to fulfil as much as possible current legislation requirements for railway tunnel safety.