Cementation Skanska starts piling for major open forging project in Sheffield

Sheffield Forgemasters, owned by the Ministry of Defense (MoD), is undertaking a recapitalization program at its Brightside Lane site. It includes the construction of a 13,800m² building to contain a new 13,000 t forging press, furnaces, tempering pits and cranes.

Sheffield Forgemasters awarded Vinci Building a £138m contract to deliver the new open die forging facility earlier this year. The main contractor has in turn subcontracted the £12.1m piling and earthwork package to Cementation Skanska.

Following the completion of a demolition and remediation program on site, Cementation Skanska has now commenced substructure work for the new building.

The piling contractor, working closely with Vinci Building, is constructing a 200m long secant pile wall for the new forge, supporting an 8-10m deep excavation. 1,300 piles will also be installed, of which 300 will be drilled rotary, and the rest will be installed by the continuous flight auger (CFA) method. In total, 1,500 pilots will be needed for the project.

Sheffield Forgemasters head of engineering for the recapitalization program said Richard Malam GE: “Sectant piles were chosen to create the perimeter of the large underground pit needed to accommodate the new press. These secant piles combine temporary and permanent works and help control groundwater during pit excavation.”

Cementation Skanska is also using basalt reinforcement instead of conventional steel in retaining walls, following a successful trial as part of its work at High Speed ​​​​2 in London. Basalt rebar is 4.5 times lighter than conventional steel rebar, making it easier to transport and for operators to move around the site – reducing manual handling injuries. In addition, the contractor explained that no sparks are produced when cutting, meaning no hot work permit is required. It also does not corrode or rust, he added.

“In other areas, deep foundations consist of a combination of rotary bored piles and CFA, selected based on soil conditions and ease of installation,” said Malam.

Skanska Cementation Managing Director, Andy Entwistle, commented: “We have developed a truly collaborative working relationship with Vinci Building and Sheffield Forgemasters, which has helped us to reduce program timelines and costs.

“We revised the initial design assumptions and through further analysis and testing, reduced the number of rotary bore piles, replacing them with CFA piles. They are quicker and cheaper to install and also reduce carbon emissions. It really shows the benefits of bringing design and construction capabilities together from the early stages of a project.”

Previous phases

In August 2021, Sheffield Forgemasters was acquired by the Ministry of Defence, which plans to recapitalize defense critical installations and equipment at the site. As part of this, Sheffield Forgemasters is investing in forging and machining facilities to support the growing demand for defense work.

Between November 2021 and February 2022, consultancy firm Tetra Tech conducted ground investigations at the site in two phases. Investigation methods included wireline drilling, windowless sampling, dynamic sampling and rotary drilling, exploring approximately 50m below ground level.

“The geology of the site comprises variable and substantial terrain covering alluvium with occasional pockets of glacial till,” Malam said. GE.

“The bedrock consists of the Pennine Middle Coal Measures (PMCM) Formation, at depths of between 7m and 10m below ground level. PMCM can be further classified into mudstone, sandstone and coal.”

Tetra Tech then carried out further studies to assess the potential for shallow groundworks in the area, while groundwater specialist WJ Groundwater carried out in situ testing to develop a groundwater control proposal.

Vinci Building has also been on site for two years, delivering a package of enabling works.

Over the past seven months, on-site demolition and remediation work has included removing interior steel structures, stabilizing the ground, removing contaminants, processing over 25,000 m³ of prey and crushing 4,500 m³ of old concrete to clean up the site.

“In light of the historical use of the site, substantial land preparation efforts were made during the initial phase of the project,” Malam explained.

“These efforts involved excavating the earth to a depth of 3m below the surface to remove buried historic structures. In certain areas, the excavation was extended due to the identification of pits and deep wells. As part of our soil remediation strategy, extensive groundwater and surface water testing has been conducted.”

Vinci Building also partnered with testing, inspection and certification firm Socotec to set up an on-site laboratory to speed up the testing process.

Turner & Townsend is also a supporting partner for the Sheffield Forgemasters project.

completion

The forging line is scheduled to be operational in the summer of 2027. It will be complemented by a new machining facility, which is currently being expanded, containing several versions of the world’s largest five-axis vertical turning lathe .

The new steel forging facility is intended to serve defense and commercial work in sectors such as civil nuclear power.