Excursion for students of the Faculty of Civil Engineering of the Czech Technical University in Prague on the site of the Považský Chlmec Tunnel

The excursion was attended by the total of 18 students, mainly undergraduates working on their diploma theses and bachelors from the Department of Geotechnics, and 3 professors from the same department. The daylong challenging programme started early – at 6.43 a.m. with departure from the Prague Main Railway Station by a Pendolino train. After arrival in Žilina, a fast bus transfer to the offices of the supplier joint venture followed, where the students were welcomed by the Project Manager Vít Pastrňák who familiarized them in his presentation not only with the progress of construction of the Považský Chlmec Tunnel that had been performed by HOCHTIEF CZ, but also with the whole project of construction of a stretch of the highway bypass of Žilina, D3 Highway Žilina (Strážov) – Žilina (Brodno) that the tunnel is a part of.  

After the introductory lecture, the students were “clad” in the required protective equipment and eventually set out for the tunnel. The role of guides was taken by our experienced tunnel “matadors” – Ladislav Štefan, Libor Mařík and Viktor Petráš. These took the students from the central pit to all tunnel tubes, first to the Eastern, then to the Western portal. During this more than a four-kilometre trip through the tunnel excavated with the NATM, there were several technological stages of the construction to be seen – the whole construction sequence from profiling of primary lining, through placement of blinding concrete under the strip foundation, concreting of the foundation, concreting of the vault including a set of rigs for installation of interjacent insulation, installation of reinforcement, the shoring rig itself and also a rig for treatment of the final lining concrete after removal of the formwork. This exacting journey through the tunnel was after more than three hours finished back at the central pit, from which the students returned to the offices of the joint venture. After that, there was only the long way back to Prague, spiced up at the very beginning by a flat tyre of the bus that was taking the whole group to a railway station in Žilina.