Client
Ředitelství silnic a dálnic s. p. [Roads and Motorways Directorate, state-owned enterprise]
Main contractor:
Joint Venture “Společnost obchvat Náchoda” – EUROVIA CZ, a. s.; Stavba mostů a. s.; Marti a. s.; EUROVIA SK, a. s.
Construction period
March 2025 – 2027
Description of built structures:
This project involves a road-type linear construction that provides a northwestern bypass of the city of Náchod. The aim is to divert transit traffic from the city center, thereby improving road safety, reducing the noise and exhaust burden for residents and increasing travel comfort. The I/33 road is designed in category S 11.5/70 with a total length of 6.465 km, the I/14 road in category S 9.5/80 with a length of 0.923 km. The construction includes a number of other built structures solving the redirection of highways and local roads, bridge structures, cycle paths, accesses to plots of land, operation sets, noise barriers, utility networks, vegetation alterations as well as two tunnel structures: the 100-meter-long Kramolna tunnel and the Dolní Radechová tunnel which will be constructed by Marti a. s.
Construction technology:
The Dolní Radechová tunnel is a single-tube road tunnel of category T – 9.5 with two-way traffic and a design speed of 70 km/h. According to the ČSN 73 7507 standard, it is a short tunnel with a total length of 363 meters.
In terms of geology, the tunnel passes through a Permian rocks environment with a lithological representation of sandstones and conglomerates. In areas with low overlying rock – in the portal sections and in the central part- soils of Quaternary and eluvial cover will reach into the tunnel profile.
In terms of construction technology, the tunnel is divided into excavated and cut-and-cover sections. The structure of the excavated tunnel consists of a two-layer lining (primary and secondary) with an intermediate drainage and protective layer and surface waterproofing. The excavation will be carried out according to the principles of the New Austrian Tunneling Method.
The Kramolna Tunnel is designed as a cut-and-cover, prefabricated structure with a total length of 100 m. Construction pit shall be excavated for the tunnel construction works. The tunnel lining structure is designed from reinforced concrete prefabricated elements made of C50/60 XF4, XA2 concrete with the addition of polypropylene fibres. The tunnel lining thickness ranges from 350 to 370 mm, with each prefabricated segment laterally divided into side sections and a vault. The vault will be protected against groundwater erosion by a multi-layer waterproofing system.
A retaining wall will also be constructed in the area of western portal. It forms part of the Kramolna Tunnel, extending 18 m above the portal and 42 m in parallel to the tunnel. The entire retaining wall is a monolithic structure made of C30/37 XC4, XF4 concrete.
Implemented work:
In addition to the implementation of primary and secondary lining, including the waterproofing layer, the scope of delivery of Marti a. s. also includes the realization of construction pits – portals, the construction of an escape tunnel, the realization of a fire water main, cable ducts, internal structures as well as the construction of the tunnel drainage system.