Construction pit at Rosenthaler Strasse in Berlin

A residential and commercial building with 45 rental apartments and twelve office units is being built at Rosenthaler Strasse 43-45 in the Mitte district of Berlin. The new structure consists of three distinct buildings and provides space for local businesses on the ground floor.

Business optimization during planning

In June 2018, PORR was assigned the contract for all work on the construction pit for the new building. Despite the existing on-site approval planning, PORR commissioned PORR Spezialtiefbau Planung GmbH to optimize on-site planning in order to achieve savings during implementation.

Construction pit enclosure

Work on the construction pit enclosure included almost all the trades involved in specialist civil engineering. In the area of the boundaries without direct development and towards the street, free-standing soldier pile walls were planned on the upper meters. The walls were then secured more deeply with cast in-situ concrete diaphragm walls, supported with temporary anchors or corner reinforcements.

An anchored jet grouted underpinning will be used in the area of building no. 46. A jet grouted sealing base was used to seal the construction pit from below against the groundwater. In some areas of the later buildings, micropiles were planned to protect against buoyancy.

Conclusion

Despite the existing, verified approval planning, PORR Spezialtiefbau Planung was able to save 10% on the required building materials.

Optimised subsections:

• Soldier pile wall
• Reinforcing steel in the cast in-situ concrete diaphragm wall
• Steel reinforcement, two-layer
• Jet grouted sealing base