Berlin

Kurfürstenstraße

Diaphragm walls, sealing slabs and bored piles for a new quarter

A new quarter in the heart of Berlin

A complex of buildings serving various purposes was constructed on the site, which covers an area of approximately 2,940 m². Even before the building constructions became visible, the groundwork for the future structures was laid beneath the surface. The first phase of construction involved enclosing the excavation pit as well as securing the adjacent existing buildings. This was followed by the construction of the DSV sealing slabs, the pile foundations and the earthworks.

Diaphragm walls in an inner-city setting

For the excavation enclosure, around 4,000 m² of diaphragm walls with a wall thickness of 80 cm and depths of up to 21 m were constructed. The construction pits were stabilised using a total of around 2,000 m of temporary wire anchors. In addition, the neighbouring buildings were stabilised using jet grouting. Around 300 m³ of grout was injected for this purpose. These measures formed the basis for the subsequent work within the construction pit and enabled the construction of the deep foundations within the constraints of a densely built-up urban neighbourhood.

Bored pile foundations for the building construction

A total of 110 bored piles, with a diameter of 88 cm and lengths of up to 35 m, were installed to bear the future loads of the buildings. The drilling work passed through thick layers of clay and marl, as well as through areas containing embedded boulders. The piles transfer the loads from the future building construction into load-bearing soil layers and form the basis for the foundations of the new building complex. The work was carried out using two rotary drilling rigs, which were operated in parallel on the construction site.

Work between existing and new building construction

The construction work took place in a densely built-up inner-city environment. Existing neighbouring buildings were directly adjacent to the construction site, whilst at the same time the various specialist civil engineering works were co-ordinated. Diaphragm walls, underpinning, DSV sealing slabs, pile foundations and earthworks were carried out in several successive construction phases and together formed the basis for the subsequent building construction work.

The foundation for the new building complex

Even before the residential tower, office tower and residential blocks came to define the cityscape, the foundations for the new quarter on Kurfürstenstraße were laid beneath the ground surface. With the completion of the construction pit and the bored pile foundations, the groundwork was laid for the subsequent construction phases. Nestled between existing buildings, inner-city infrastructure and new forms of building construction, this marked another milestone in Berlin’s urban development.