Underwater tunnel in navigation structure C-1 as part of Flood Protection Barrier
The total length of the tunnel is 1961m, including 1189m-long underground section and two 386m-long ramp sections. The deepest section of the road in the tunnel is at a level of -24.3 m (under the marine channel). The underground part is divided into sections, each up to 60m-long.
The cross section of the underwater section of the tunnel is 5-flight frame, the width is 42m and the height is 10m. The tunnel has two main tubes. Each tube carries a 15.25 m wide three-lane carriageway. Also, there is a central tube, which is designed for maintenance systems and evacuation.
The engineering facilities include ventilation, illumination, inside fire suppressing, television observation, automated mechanisms, alarm system, network and evacuation system, automated system of operational management and supervisory control system.
The fill dam of the Flood Protection Barrier is 25.4km-long and is situated in Gulf of Finland. This dam is part of St Petersburg Ring Road.
The dam is equipped with six water sluices B1-B6 and two navigation structures C-1 and C-2, which at the same time leak the water. The total length of the water width is 1536m that is 1.5 times wider than the mouth of the Neva River.
Transmost PLC made a contribution into this project. The company has designed the following structures:
- underwater tunnel in navigation structure C-1,
- vertical lift bridge in navigation structure C-2,
- superstructures in navigation structures B-1 – B-6,
- junction on the Bronka railway station,
- two temporary bridges in dams D-2 and D-7.
All the structures are designed for 6-lane highway.
The opening for traffic was in 2011.