Employer: Koridori Srbije, d.o.o. (LTD) Belgrade
Contractor: Integral inženjering a.d. (PLC) Laktaši
Value of the works: 69.6 million BAM or 35.6 million EUR

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 stabilization of the slope of the Cut 5 is executed in two phases, by constructing three supporting structures (walls) – K1, K2 and K3. 

In the first phase, the construction of K1 of length l = 411.48 m was performed. The structure K1 contains 181 RS piles ø = 1.500 mm, of length l = 16.18 and 20 m, laid out in two rows. All piles are connected by capping beam (slab) of thickness of 1.2 m and width of 6.0 m. On the slab, the wall of height of 5.92 m with buttresses at every 2.25 m was constructed.

The stability of the structure K1 is ensured by incorporation of 361 permanent electro-insulated prestressed anchors (8Ø15.2 mm), of length l = 40.00 m. Anchors are placed in two rows. In the lower row on the pile capping beam, 180 anchors were installed at distances of λ = 2.25 m. In the upper row on the RC wall, 181 anchors were installed at distances λ = 2.25 m, so that they run through the buttresses of the wall. The construction of the structure K1 was completed in October 2018. 

In the second phase, which is ongoing, the supporting structures K2 and K3 are being built. 

The structure K2 is of length l = 363.70 m, and it contains 161 RC piles ø = 1.500 mm, of lengths l = 26 and 36 m, alternately placed in two rows at the distance s = 4.50 m.

The structure K3 is of length l = 205.22 m, containing 91 RS piles ø = 1.500 mm, of lengths l = 21 and 36 m, alternately placed in two rows at the distance s = 4.50 m.

Additional stability of structures K2 and K3 is provided by installation of permanent electro-insulated geotechnical anchors (5Ø15.7 mm).