Münzviertel residential district, Hamburg

Nord Project and Stiftung Auszubildendenwerk are constructing a new residential development, designed to house around 650 people, near Hamburg’s central railway station. PORR was contracted to construct the approx. 5,000m² construction pit and manufacture the necessary pile foundations. The site’s inner-city location and adjacent residential buildings meant the pile foundation, consisting of 650 Atlas piles ranging from 10m to 20m in length, had to be constructed with limited noise and no vibration.

Challenging inner-city soil conditions

A tailored solution was required to deal with the non-homogeneous site soil – sandy and silty, with clay underneath some sections, backfill close to the surface, and deeper layers consisting of load-bearing sand and alluvial marl – plus a 3m height difference between the northern and southern edges of the site.

Secure construction pit execution

Soldier pile walls were found to be sufficient on the northern section of the site.

Existing buildings were secured with tangential and back-anchored bored pile walls. The southern part of the site was conceived as a trough construction pit. We made the specific proposal to execute the sealing walls as inserted sheet pile walls. Where particularly high loads were generated by adjacent buildings, an additional 1,600m² of in-situ concrete diaphragm wall in thicknesses of up to 80cm was installed. Finally, the construction pit walls were securely anchored with grouted anchors.

Economically sound and environmentally friendly pile foundations

During the excavation process, the construction site team uncovered remnants of old foundations and numerous old piles. As these piles were to remain in the soil, the plans produced by Spezialtiefbau Planung GmbH had to be constantly updated. We were able to install the new Atlas piles in between the old piles.