Investor: Koridori Srbije, d.o.o. (LLC) Belgrade
Contractor: Integral inženjering a.d. (PLC) Laktaši
Value of works: 37.7 million BAM or 19.3 million EUR
General information on the project:
Corridor 10 is one of the most significant Pan-European transport corridors that run through Serbia. The program of the construction of Corridor 10 through Serbia is implemented through four projects that are divided into sections, and sections into lots (contracts).
Integral inženjering a.d. is the main contractor on the section Caričina Dolina – Vladičin Han, LOT 5: Roads and bridges on the subsection Caričina Dolina – tunnel Manajle.
The contractor on the section Grdelica (Gornje Polje) – Caričina dolina, LOT 1: Road and bridges from Grdelica to the tunnel Predajane is the Joint Venture (JV) “Azvi SA (Spain) and Taddei SpA (Italy)”.
Due to especially complex conditions, the Investor allocated the part of works on the new stabilization of the Cut 5 on the section Grdelica (Gornje Polje) – Caričina dolina, LOT 1: Road and bridges from Grdelica to the tunnel Predajane to the company “Integral inženjering”.
Design solution and contents of works:
Permanent landslide stabilization and protection of the motorway route in the zone of the Cut 2 will be realized by constructing the protective structure (covered gallery on piles) and three independent structures from piles Ø = 2.000 mm, of lengths l = 25 and 30 m.
Protective covered gallery, of the total length l = 150 m, is founded on bored piles Ø = 1.500 mm, of lengths l = 15-21 m on distances of s = 3 m. The piles are connected with the capping beam of length l = 151.80 m. Above piles on the left and in the middle of two pavement profiles, RC columns of diameter d = 1.20 were built at the distance of s = 3 m, that are connected at the top with bearing beams. The piles on the right side are connected by the capping beam, and there are RC walls between piles. The works were completed at the end of April 2019.
The first and the second structures that are made of piles are planned on the first and third berm looking from below, and the structure is made of bored piles Ø = 2.000 mm, of length = 25 m, which are placed at distances s = 5.0 m. The piles are connected by the capping beam of dimensions 2.50 x 1.20 m, of length of about l = 130 m.
The third structure made of piles is planned on the sixth berm looking from below, and it is composed of bored piles Ø = 2.000 mm, of length l = 30 m, placed at distances s = 5.0 m. The piles are connected by the capping beam of dimensions 2.50 x 1.20 m, of length l = 105.57 m.
Additional stability of protective structures that are made of piles is provided by the two rows of pre-stressed anchors at each structure. The design planned permanent pre-stressed anchors made of 6 cables Ø = 15.7 mm, of bearing capacity Fpk (kN)=1593 kN, of length ls = 30+10 = 40 m. Anchors for both structures are installed on the capping beam, in two rows at the distance s = 2.5 m.
Relieving of excavation will be performed at several levels of height of approximately 10 m with inclination 1:1, i.e. from above downwards. Between each two levels, the berm of width of about 5 m is planned and each berm will carry the channel for drainage of surface waters from the slope. The distance of the lowest, i.e. the first berm from the planned gallery is about 20 m. After each level is excavated, it will be permanently protected by installation of flexible system of composite mesh and SN anchors Ø =32 mm.