Hamburg
Pile foundations for the A7 motorway cover
Hamburg, Germany / 02.2017 - 07.2017
Im Zuge des Ausbaus der Bundesautobahn A7 entstehen auf Hamburger Stadtgebiet mehrere Lärmschutztunnel. Für den rund 1.970 m langen Abschnitt in Hamburg-Stellingen wurde die Bietergemeinschaft aus PORR Spezialtiefbau und HOCHTIEF Infrastructure GmbH mit den Gründungsarbeiten beauftragt. Für den ersten Bauabschnitt des Autobahndeckels übernahm PORR Spezialtiefbau die Herstellung von Teilverdrängungsbohrpfählen, Großbohrpfählen sowie statischen Probebelastungen. Die Gründungsarbeiten erfolgten bei laufendem Autobahnverkehr.
Facts & Figures
Company
PORR Spezialtiefbau GmbH
Type
Foundations
Runtime
02.2017 - 07.2017
Partial displacement bored piles for the noise barrier tunnel
Special civil engineering for the motorway cover
The motorway cover forms a key part of the extension of the A7 motorway in Hamburg. Extensive deep foundation works were required to construct the structures, in order to safely transfer the loads from the tunnel and civil engineering structures into the subsoil. The foundations were designed to meet the site’s geotechnical conditions as well as the requirements of the structures’ future use.
1,300 Partial displacement bored piles for the foundations
A total of 1,300 Partial displacement bored piles were constructed for the foundations of the structures. The piles have a diameter of 78 cm, were designed for design loads of up to 2,811 kN and reached lengths of up to 14 m. The Partial displacement bored piles transfer the loads from the structures into the load-bearing soil layers and form an essential part of the foundation concept.
Supplementary large-diameter bored piles
In addition, 37 large-diameter bored piles with a diameter of 120 cm and lengths of up to 8 m were used. The large-diameter bored piles were installed in areas where the structural requirements of the buildings necessitated a corresponding foundation solution. Together with the Partial displacement bored piles, they form the load-bearing structure of the foundation.
Test loads to verify load-bearing capacity
Before the final pile foundation was constructed, a total of seven static pile load tests were carried out. The load tests served to verify the load-bearing capacity as well as the deformation behaviour of the planned foundation elements and formed the basis for the subsequent construction.
Foundations for the tunnel and civil engineering structures
The various foundations were tailored to the load requirements of the structures as well as the local ground conditions. The combination of Partial displacement bored piles and large-diameter bored piles enables the loads from the planned structures to be transferred into the load-bearing soil layers.
Foundation for the A7 motorway extension
The installation of 1,300 Partial displacement bored piles as well as 37 large-diameter bored piles, as well as the preceding load tests, laid the groundwork for the construction of the tunnel and cover structures. The specialist civil engineering works thus form an essential foundation for the realisation of the motorway cover in Hamburg.
