Groundforce Shorco hydraulic propping equipment is once again helping to streamline construction of a large basement in Scandinavia.
Working for the first time for main contractor Skanska, Groundforce has supplied its MP150 modular hydraulic props in a raking configuration to support the large basement excavation on the Valand Quarter 6 project in Kungsbacka, a few kilometres south of the Swedish city of Gothenburg.
The project, for local developer Aranäs, comprises an office building with a deep basement housing a car-park, a restaurant and other leisure facilities.
The large footprint of the building is approximately 50m x 50m. With such distances between the piled retaining walls, it was clearly impossible to brace the excavation across its width.
Groundforce reputation on other Scandinavian projects (notably the massive “Barcode” project in Oslo) brought the company’s expertise to the attention of the Skanska team. Consultation with the main contractor soon resulted in a bespoke solution for the project.
Groundforce specified its 150-tonne capacity MP150 raking props to support the sides of the excavation, with the loads transferred to steel upstand supports driven into the ground.
“None of the props are perpendicular to the waling beam, so corbel connections were needed at the top to connect the props onto the waling beam,” explains Groundforce European Sales Manager, Sam Oldroyd.
The location of each upstand, and hence the length of each prop, was determined by the design of the basement and the need to minimise obstructions inside the excavation. “Each prop had to be drawn to establish the overall length,” explains Sam.
In total, 13 of the MP150 props were installed, eight of them positioned in a fan-shape to support a broad curve that forms one corner of the site.
According to Skanska, the standard solution for an excavation of this size would have been a temporary structural steel frame, specially designed and erected piece-by-piece on site – an expensive and very time-consuming solution.
“We decided to use Groundforce Shorco to reduce the need for welding,” explains Skanska’s project engineer Johanna Fridhagen. “Welding in our projects is very demanding and costly, which means that if we can avoid this to a large extent, the project will benefit economically.”
The only pieces of steelwork ultimately used in the design were the steel beams welded across the three remaining corners of the excavation to act as knee-braces.
The equipment was delivered ready for installation on site in February 2017. The basement is expected to be completed later this summer.