New Roads And Bridges

An additional challenge is the ground itself in the new city district. HafenCity’s location on the Elbe marshes is subject to the alluvial influence of the river, which means that the upper layers of soil are made up mostly of clay and glacial sediment. As so-called cohesive layers, they are highly water absorbent, which means they cannot bear heavy weight. Sand, which is load bearing, begins further down

HafenCity's roads and bridges are especially constructed for the requirements of a district<br>nearby the harbour

HafenCity's roads and bridges are especially constructed for the requirements of a district
nearby the harbour (© ELBE&FLUT)

This is why all buildings in HafenCity are built on piles. These are usually driven around 20 m deep into the earth, which transfers the weight to the loadbearing sand layers. In Strandkai neighborhood and southern Überseequartier a departure from pile foundations is taking place for the first time: basements are actually being excavated down to the loadbearing sand level, in some cases to 7 m below mean sea level

For road building, preloading is used to raise the level temporarily to around 11–12 m above sea level: the weight of heaped up sand presses any water out of the cohesive layers of ground below, creating a stable foundation suitable for road building. When this process is finished, the sand preload is removed down to the future level of the road, so that piping and conduit can be laid and roads built.

Roads in HafenCity are planned in at an early stage but the realization of road surfacing, pavements, cycle lanes, tree-planting or parking bays only takes place gradually and in close coordination with construction firms. Because road surfaces would be largely destroyed during structural engineering, almost all carriageways are given a temporary surface. After completion of the surrounding buildings, the final surface is then laid and finished, together with ancillary surfaces, cycle paths/strips and tree planting. 

Through the city by car

Four road bridges currently connect HafenCity with the city center. Central northern access is via Am Sandtorkai/Brooktorkai. From here traffic fans out to the south; primarily via Shanghaiallee and Osakaallee. The northern extension continues across Kornhausbrücke bridge following on from the so-called “Domplatz axis”. The most important and easternmost access is Versmannstrasse, which is being rebuilt as a four-lane, raised avenue, in parallel with extension of the U4 subway line to Elbbrücken; part of the road runs directly above the subway tracks.

The temporary traffic diversion runs over Baakenhafen bridge and alongside the Elbe to the Elbe bridges. When operations recommence, traffic can be channeled back to Versmannstrasse, and the Elbe embankment will be relandscaped as a broad green promenade with sidewalks and cycle paths.

The job of renewing and widening Zweibrückenstrasse bridge was satisfactorily completed in summer 2016. In the process, the sharp northern bend of Zweibrückenstrasse was modified and the street directly joined onto Baakenwerderstrasse. The new works have not only provided a wider thoroughfare and better paths for cyclists and pedestrians, its sustainable pump and drainage system is now much better protected against flooding.