New office complex ATLAS, Munich

A new office complex is being built at Rosenheimer Str. 143A in the east of Munich. The new building will comprise two basement levels and be founded on a base depth of -7.85 metres. A major challenge was securing the construction pit, which was created in parallel with the demolition of the existing buildings.

Most of the existing building was demolished, only the high-rise building was secured at the rear in its gutted state with an overlapping bored pile wall (880 mm) and permanent anchors (5 strands). The pile wall will later be partially used as a building foundation. The southern excavation pit enclosure (Rosenheimer Straße) and the opposite northern side were constructed using soldier pile shoring and timber infill. The shoring was secured in a single layer with three-strand temporary anchors. After completion of the building construction work, the timber shoring will be dismantled.

On the western side of the construction pit, there is the disintegrated bored pile walls, which were constructed with plug-in beams and timber shoring in the upper area and filled with jetcrete in the lower area.

The beams as well as the timber infill are removed and dismantled. The remaining shoring remains anchored back into the subsoil in a single layer. On the eastern side of the construction pit, the neighbouring structure was secured using VdW twin piles (406 mm) and temporary anchors. The pile pairs will be used for load transfer in the final state. In some cases, existing walls had to be underpinned using jet grouting, as their foundation base is higher than the planned excavation base.

The subsoil consists of several metres of backfill material, followed by underlying gravel soils that extend to a depth of around 17 metres. The groundwater is well below the construction pits and therefore has no influence on the shoring.

Some unforeseen existing situations could only be identified after the demolition work had been completed and led to short-term adaptations and changes to the course of the work.