Work has started on the first stage of the 4.3km-long Presov northern bypass, part of the R4 speedway in eastern Slovakia.
The consortium of Vahostav-SK and TuCon has the contract worth around €143 million with part European Union financing. The road is expected to be open by 2023.
The schedule includes a 1.1km twin-tube Bikos Tunnel, a 700m-long anti-noise wall and three bridges, all less than 1km in length. The tunnel will be constructed using the New Austrian Tunneling Method (NATM) and have concrete road surfaces.
NATM, also known as the sequential excavation method or sprayed concrete lining method, gained attention first in the 1960s based on the work of Ladislaus von Rabcewicz, Leopold Müller and Franz Pacher in Austria between 1957 and 1965. The fundamental difference between this new method as opposed to earlier methods comes from the economic advantages having the inherent geological strength available in the surrounding rock mass to stabilise the tunnel during construction.
The R4 stretch on the west side of Presov will be connected to the D1 motorway.
Construction of the 7.9km south-west Presov bypass on the D1 motorway has been underway since summer 2017 and is scheduled for completion by summer 2021. It is being built by the consortium of Eurovia SK, Metrostav and Doprastav for around €356 million.
