The tunneling machines are manufactured by Herrenknecht AG (Germany). The principle of earth-pressure balance shield operation is that the excavated ground is used as support medium enabling to avoid soil elevation or settlement. The force of the push cylinders is transferred via the pressure bulkhead onto the earth slurry in the excavation chamber. Foaming admixtures are used as plasticizers fed into the excavation chamber; the pressure is controlled by the sensors located on sustaining wall and screw conveyor.
For transportation of materials and personnel we use diesel locomotives of Schema production. The train includes diesel locomotive, ground transporting cars with capacity of 5 and 10 cub.m., mortar mixing car, cabin for transportation of personnel and cars for transportation of materials.
Continuity of work performance process, which is very important for tunnelling, is provided by standby electrical power system. With this purpose three Krauter diesel generators with transformers of 0.4/10 kV and capacity 1250 kVA have been installed for EPB shields d 6.250 m. and with capacity of 800 kVA for EBP shield d 3.000 m.
Ventilation and cooling systems provide for supply of cooled air to the shield complex as well as cooled process water needed for shield operation.
Tunnelling machines are equipped with navigation system enabling to display the information about the exact shield location on the monitor in the real time mode. Surveying staff is defining the shield location using the computer, compares the route with the programme, makes necessary calculations and gives instructions to the shield driver regarding the route.
Self-launching, four-section, telescopic, 20-meter long formwork for arrangement of monolithic reinforced concrete lining in a 3-meter diameter tunnel. This formwork system enables to conduct concreting of straight and arch sections.
Four-section, 20-meter long formwork for concreting the splitter wall of a 3-meter diameter tunnel. This structure is used along with the form lining.
Mixer for transporting the concrete mixture in the tunnel and unloading it into the concrete pump charging bin or into another mixer. The bin volume is 4m3.
Vehicle manipulator for concrete laying. Has telescopic swinging boom and jointed steel pumpcrete pipe.
Self-launching tunnel formwork with handling device for concrete spreading manufactured by “CIFA” (Italy) is used for installation of in-situ secondary lining and invert in the tunnel with inside diameter of 5,4 meters. The formwork consists of 4 sections. The length of each section is 4.5 meters. The total length of the tunnel formwork is 18 meters.
Production facilities for manufacturing rings of reinforced concrete lining with carousel-type technology and capacity of 90 000 m3 per year.
Lining of the tunnels with outside diameters 3.5 m and 6.0 m is assembled of universal form rings to provide the tunnel curve. The rings are of 1.0 m and 1.2 m width correspondingly. High accuracy blocks are manufactured of water-resistant concrete using formwork made by Bernold-Ceresola (Switzerland). The sides of the blocks are equipped with waterproof rubber sealants produced by Phoenix (Germany).