Customer case

SSAB Large diameter piles in deep and steep Norwegian fjords

September 27, 2023 6 min read

Pile installation, Norwegian fjords, electric ferries, terminal extension, steel pipe piles,drilled steel piles, ferry termninal

Case details

Product RR® and RD® large diameter piles

Country Norway

Company GEO fundamentering & bergboring AS

Industry Building structures and infrastructure

Green shipping has long been a goal for Norwegian transportation. This has led to heavy investments in electric and hybrid transportation ferries. These ferries are used to allow road traffic to pass over the huge number of fjords along the Norwegian coast line. In 2021, 70 ferries out of a total 200, more than 1/3, had been replaced by electric ones. This transition has been backed by national funding and has also triggered demand for infrastructure development.

Case details

Product RR® and RD® large diameter piles

Country Norway

Company GEO fundamentering & bergboring AS

Industry Building structures and infrastructure

The new ferries are bigger, and heavier and have greater transportation capacity. But they are also longer and more slender than the previous ones. These changes have been made to optimize the use of energy. The changes to the ferries have also affected the ferry terminals. The terminals need to be extended and upgraded to withstand the new forces. Charging stations in the terminals are a new functionality, but the charging stations also set totally new forces. Every charging station has a suction force, which alone means a force of 400 tonnes. There are 2 charging stations in each terminal. This only gives a new potential horizontal load of 800 tonnes.

GeoFundamentering & Bergboring has already had 12 of these terminal extension projects, stretching all the way from Stavanger in the Southwest to Lofoten in the North of the country. A total of 622 pile points with a total of 11, 480 meters of steel pipe piles have been installed. This means 2 700 tonnes of steel for these piling structures. On top of this, also some steel cores and anchoring braces have been used.

Pile installation, Norwegian fjords, electric ferries, terminal extension, steel pipe piles,drilled steel piles

Typical ferry terminal design (on Kjøpsvik). 10 axes, approx. 100 meters long, 31 piles and 18 fender piles.

Drilled steel piles are used instead of driven ones for several reasons, the most common of which are:

In some places the ground conditions make driving unsafe or very difficult
Noise and disturbance to the surroundings are lower with drilled piles
High pile precision is very important and can be achieved more easily with drilled piles
When piles are drilled into the bedrock, load transfer from the pile to the bedrock is safe
Piles face both vertical and tensile forces, drilling of piles into the bedrock and use of anchors through the piles offer more safety
With drilling there are fewer possibilities for broken piles during installation.

These challenges are often related to installation in great depth.

Cleaning a pile from inside can be difficult when the pile is long. It is important to have a clean starting point before casting the pile with reinforced concrete. The photo above is from a video inspection of the bedrock surface below the pile toe.

Sliding of pile on top of bedrock while starting drilling. With water depth up to 50 meters, it can be difficult to get a good starting point for pile drilling. Especially when there is no soil on top of the bedrock. As the picture above shows, the pile can slide off from the correct position on the rock surface several times before it attaches.

SSAB has a long, good cooperation with GeoFundamentering og Bergboring, formerly Hallingdal Bergboring. Project-specific pile sizes, lengths, and on-time deliveries to the site are crucial to creating good project progress and cooperation between the supplier, contractor, and project owner

Geo fundamentering og bergboring AS is a leading supplier of piling and sheet piling work also covering installation of bracing and achoring. They carry out foundation installations for all types of buildings and facilities across Norway both onshore land and offshore in all types of ground conditions. They also deliver geotechnical engineering drilling of water and energy wells.

The world's first hydrogen-fueled transportation ferry is operated at the Hjelmeland-Nesvik terminal.