The transformation of steel production at thyssenkrupp Steel continues to progress. With the construction of the first direct reduction plant (DRI plant) on the site in Duisburg's southern port of Walsum, the company is taking an important step towards climate-neutral steel production by 2045. Instead of coke in traditional blast furnaces, hydrogen will be used as a reducing agent to produce pig iron in a direct reduction plant. The project is one of the world's largest industrial decarbonisation projects and will enable up to 3.5 million tonnes of CO2 to be saved per year.
Frankipfähle combine many benefits
The contract for the execution of the special civil engineering works for the DRI plant has been awarded to the DRI plant special civil engineering consortium, consisting of PORR Spezialtiefbau and Implenia Spezialtiefbau. The consortium's tasks include pile foundations, the construction of CMC concrete columns, the construction of the main floor slab for the 140-metre-high DRI tower, as well as extensive earthworks.
On 15 January 2024, the early start of construction was approved. In April 2024, work began on the pile foundations, which have already made considerable progress. PORR's special civil engineering division is installing a total of around 1,100 Franki piles with a diameter of 71 cm and lengths between 9.5 and 12 metres. By mid-September 2024, 561 piles had already been manufactured, with around 5,100 m³ of concrete having been processed. The Frankipiles replace a large proportion of the originally planned fully cased bored piles with diameters of 1.2 m to 1.8 m. This change brings significant benefits in terms of sustainability and cost savings.
The use of Franki Piles reduced the concrete volume from 13,750 m³ to 4,750 m³ and saved around two-thirds of the required reinforcement. In addition, the displacement method eliminates the need for drilling, which further reduces CO2 emissions. ‘This method has provided significant benefits for both the project and the customer. On the one hand, the process is very economical. In addition, the use of Frankipiles results in significant time savings compared to fully cased Kelly bored piles. The driven pile foot of the Frankipiles makes it possible to carry larger loads with a slimmer cross-section and improved settlement behaviour. The smaller diameter means that we save a considerable amount of construction material, especially concrete, which also reduces CO2 emissions,’ says Alexander Belz, site manager at PORR Special Civil Engineering, Düsseldorf branch, listing the benefits.
Logistical challenges and future work
The subsoil of the plant site presented particular challenges, as the terrain had been used for decades to store heavy steel products. This led to increased pile-driving resistance, which was, however, successfully overcome. Half of the pile foundation work has already been completed, and further major construction phases, including the construction of a deep construction pit with diaphragm walls, are still to come.
With the DRI plant, thyssenkrupp Steel is sending a strong signal in favour of climate protection and the transition to climate-neutral steel production. The plant is scheduled for completion in 2027.
