A residential and hotel complex is currently under construction on the project site, which covers approximately 9,000 square metres on Fanny-Zobel-Straße in the Alt-Treptow district of Berlin. On behalf of Agromex GmbH, PORR special civil engineering was responsible for excavating the construction pit between the Treptower and TwinTowers development projects.

Sealing slabs were installed using the jet grouting method (DSV) to waterproof the base of the excavation and prevent buoyancy. This enabled dry construction despite the immediate proximity to the water. In addition, the team constructed diaphragm walls with a total area of around 7,000 square metres and installed 89 bored piles with a diameter of 1,200 millimetres. To prevent buoyancy, a total of 795 micro piles of various diameters were installed. Temporary internal steel bracing, anchors as well as residual dewatering completed the excavation system.

Particular challenges arose from the strict environmental and water protection requirements. The directly adjacent River Spree necessitated close coordination with the relevant authorities. Regular measurements and continuous monitoring of the neighbouring embankment wall ensured safety throughout the entire construction process.

The extensive preparatory work also included the decontamination of the site, which had previously been used for industrial purposes, as well as the excavation of more than 70,000 cubic metres of earth. Despite the challenging conditions, the excavation was completed on schedule and handed over to the client in the summer of 2025.

The project demonstrates PORR special civil engineering’s expertise in implementing complex excavation solutions in an inner-city environment. Quality, adherence to the schedule and cost-effective execution were the focus of the collaboration with the client.