Expansion of Overpass K20 – Elbmarsch

Progress at the large-scale project in Hamburg

In Hamburg, the highly frequented motorway A7 south of the Elbe tunnel is expanded from six to eight lanes. SSF was contracted to design the 3.8-kilometre long bridge structure K20 – overpass Elbmarsch. The initial technical final design of the bridge built in the 1970s already left space for a widening between the two carriageways. New calculations came to the result that the existing bridge can still be operated until at least 2045. So, the decision was made to keep the existing bridge and renovate it before the 8-lane expansion.


The widening of an existing bridge is technically demanding and not much experience is available. Thus, in the framework of the preliminary evaluations, a 100-metre long section was erected as pilot project. In terms of traffic management, the project is neither an easy enterprise as traffic has to be maintained during expansion and renovation. Three of the lanes should remain operable during the entire construction period.


Construction began in 2020. Currently the construction phases are at around half time. Renovation of the existing structure was successfully completed – and at the moment works to expand the bridge are under way. The entire project is planned to be completed in mid-2027 and will significantly improve capacity of the transport network south of river Elbe.


SSF Ingenieure is responsible for the following services:

  • structural engineering: approval design (§51 HOAI Lph 4)
  • approval design for the expansion of superstructures incl. substructures
  • approval and final design for new construction of mega piles
  • calculation of bearing forces of existing structure incl. expansion
  • structural consulting during the entire construction period