Back to overview
Foundations

Pile foundation for motorway cover (First BA), Hamburg

Hamburg, Germany / 02.2017 - 07.2017

Three noise protection tunnels are planned along the A7 motorway in Hamburg. The aim is to "merge" the Schnelsen, Stellingen, Othmarschen and Bahrenfeld neighbourhoods and protect residents from road noise. The motorway will be widened to eight lanes to improve traffic flow. The bidding consortium PORR Spezialtiefbau/Hochtief Infrastructure GmbH won the public tender organised by DEGES for the 1,970 m long Stellingen section of the motorway.

 

2,620 piles for motorway cover in Hamburg-Stellingen

Contrary to the original planning with jacket-grouted large bored piles (d = 120 cm), the PORR special civil engineering special proposal will be realised with Partial displacement bored piles. In the area of the 900 m long tunnel section, sands and boulder clay are present in varying layer thicknesses and heights. The piles are set in the sands. In order to optimise the embedment length in the sands, several static test loads were carried out in advance. This resulted in a minimum embedment depth of one metre in the load-bearing sands. The so-called cover in Stellingen is deeply founded with a total of 2,583 piles. In order to be able to absorb horizontal loads during construction, the piles are inclined.

Photo: During the expansion, the motorway continues on a narrower road directly next to the construction site. The pile foundation methods are carried out only a few metres from the running traffic.

Facts & Figures

Company

PORR Spezialtiefbau GmbH

Type

Foundations

Runtime

02.2017 - 07.2017

Principal
DEGES

Pile production with flowing traffic on the A7

Special challenge due to construction site location

Construction site logistics and occupational safety posed a particular challenge during construction. In addition to the construction site traffic, the activities of other trades and subcontractors also had to be taken into account on the closed carriageway. However, motorway traffic with a distance of just two metres in front of the equipment was also not a daily occurrence. In July 2017, work on the northbound carriageway was completed on time and without any accidents. 

Some large bored piles were installed at a limited working height due to a culvert and an existing bridge.

Services 1st construction phase:

1,300 Partial displacement bored pilesd = 78 cm, Nd ≤ 2,811 kN, L ≤ 14.0 m    
7 static test loads      
37 large bored pilesd = 120 cm, L ≤ 8.0 m

What ultimately counts in the construction business is successfully completed projects. PORR has many of these.

Photo: During the expansion, the motorway continues on a narrower road directly next to the construction site. The pile foundation methods are carried out only a few metres from the running traffic. Photo: The pile driver works a few centimetres from the railing of “Kieler Straße” bridge. Photo: The first piles are installed on the floor staggered with little distance between them. In the front area the covered VB pile heads can be seen. The short ends of the steel reinforcement stand out. Behind that are the uncovered ones, which still need to have their excess removed. The road traffic is redirected directly next to the construction site during the construction works.