Within the construction works of the South Portal access, a critical construction milestone has been successfully reached: the new Inbound Ostfold Line (IØL) track is now free from the obstruction offered by the E18 bridge pier.
The completion of the south tunnel access involved an accurate definition of all the construction stages in order to avoid any (even temporary) bridge traffic interruption. Displacement, pressure and strain sensors have been also provided to guarantee a real-time monitoring and the highest level of safety of the site.
Here is a brief description of the designed solution: the whole bridge load is carried by two massive concrete blocks, post-tensioned toward the pier on both sides (see picture below); the two blocks are then supported by a filler-beam deck, whose steel beams are encased in tubular steel profiles, drilled in rock; on the other side the deck support is offered by a 10m-high concrete wall.
Construction stages have been completed thanks to the coordination between BaneNOR, the contractor, and SWS Norway engineering team, headed by Michele Civiero.
Pictures below give comparison of the site between the first and last construction stages.
For a complete description of the project take a look here.