A new 12.2km long section of the motorway is being constructed on the outskirts of Prague that will connect the D0 ring road (one of the most significant transport structures in the Czech Republic) with the D10 and D11 motorways, as well as many other major roads connecting the capital to its surrounding areas. A bridge was required at the second-most-important crossroads of this section of the ring road. Therefore, the expertise of Structural Engineer Jan Lamparsky of AFRY CZ was enlisted to ensure it would be delivered successfully.
About the project
The final bridge design has a single span of 43.5 m, with a width that varies from 78.3 m in the middle to 89.6 m at the ends. The supporting structure consists of 23 beams made of post-tensioned prestressed concrete.
The total area of the bridge is 3,800 m2. It is covered in a one-meter thick layer of soil, for which various details of insulation, drainage of the insulation surface, and transition areas were required.
Whereas most bridge traffic is in a longitudinal direction, traffic on this bridge is at a 45° angle.
Engineering challenges
In addition to the difficulty of designing the rear walls and the frame connection to the supporting structure, the biggest challenge for Jan Lamparsky was the foundation of the bridge.
The first design he looked at was a frame bridge, but this would have been very economically inefficient and technically demanding to construct. It would have made it necessary to anchor it to the substructure, requiring connectors to bind reinforcement at the corners, as well as prestressing the retaining walls and frame corners.
Despite the larger number of bearings required, this variant proved the best solution. The walls could be efficiently designed from reinforced concrete. By reducing the number of prestressing cables in the beams, it was possible to design a shallow foundation without the need to anchor it in the subsoil.
Solutions and Results
With its atypical dimensions and shapes, the bridge structure has a single span of 43.5 meters of post-tensioned prestressed concrete. The construction is expected to be completed in 2026, at a total estimated cost of around €400 million.
Learn what the engineer says about the project
Prestressed highway concrete bridge gallery
