Hamburg

Zollkanal

Micro piles for the rehabilitation of the quay wall in the UNESCO World Heritage Site, Speicherstadt

Quay wall renovation in Hamburg’s Speicherstadt

The Speicherstadt is one of Hamburg’s most significant historic buildings. The quay walls, built between 1880 and 1920, are being renovated in sections to preserve the existing waterfront infrastructure. One sub-project involved the repair of the quay wall in front of Warehouse P, between Kornhausbrücke and Jungfernbrücke on the southern Zollkanal. The existing quay wall exhibited, amongst other things, deformation, cracks, damp damage as well as damage to the existing timber sheet pile walls. As part of the rehabilitation, a new water-facing sheet pile wall with a reinforced concrete beam was constructed as a facing structure.

101 micro piles for back-anchoring the sheet pile walls

To secure the new sheet pile wall, PORR special civil engineering installed a total of 101 micro piles with lengths of up to 40 m. The micro piles serve to back-anchor the structure and transfer the loads into the subsoil. The detailed design, including the structural calculations for the micro-grouted piles, was carried out by PORR special civil engineering planning. The design and execution were adapted to the constraints of the historic structure and the local infrastructure.

3D modelling for the design of the anchoring

In the area of the rear anchoring, there were several existing structures and underground installations. These included, as well as other things, a district heating tunnel as well as existing micro piles from the wall frame system. A three-dimensional model of the subsoil as well as the existing underground structures was created to plan the anchoring works. The modelling served to coordinate the anchoring positions and to take existing structural elements into account during construction.

Work subject to tidal influence on the Zollkanal

The micro piles were installed under conditions of tidal water levels in the Zollkanal. At high tide, some of the drilling starting points were submerged, whilst at low tide the work platform could not be repositioned. The micro piles were first installed and, following the installation of the new sheet pile wall, extended towards the water side using sleeve couplings. They were then connected to the bracing of the new embankment structure.

Restoration of the quay wall

Once the specialist civil engineering works had been completed, the new structure was supplemented with a reinforced concrete quay head and a facing wall. The works formed part of the rehabilitation of the quay walls in the area of the Zollkanal and the Speicherstadt.

Foundation for the rehabilitation of a historic harbour structure

The installation of 101 micro piles laid the foundation for the rear anchoring of the new sheet pile wall structure on the Zollkanal. The specialist groundworks form part of the ongoing rehabilitation measures on the historic quay walls of Hamburg’s Speicherstadt.