Deutsche Nationalbibliothek 4. Erweiterungsbau in Leipzig

The German National Library in Leipzig - 4th extension - Special features of the underpinning and safety measures of inventory.

At present the 4th extension of the German National Library in Leipzig is under construction. The new building is near the existing buildings and was founded in 6 to 8 m below the existing foundations. The ground is liable to subsidence due to a 4 m thick coal seam. This had to be specially considered in the planning.
To protect the existing buildings against settlements, cracking and misalignment extraordinary safety measures were implemented:
-·tensioning arrangement of buildings by means of tension bars
-·strengthening of vulnerable areas by timber trussed bond
-·using a special technology of grouted underpinning
With these measures, non-uniform settlements and cracks could be largely avoided.