A SERIES of heavy-duty, hydraulically-operated tubular struts have been provided by shoring specialist, Groundforce Shorco, to support a 60m long retaining wall at the development of £45m new headquarters for City of Edinburgh Council.
The 80-tonne capacity struts were supplied to support an eight-metre high, 600mm diameter contiguous piled retaining wall at the northern boundary of the development near the city’s Waverley Station within eight metres of the main Edinburgh-London railway line.
As the excavation is well within the designated rail support zone it was essential to provide adequate support with a system which would minimise inward deflection of the piles to reduce the risk of any significant settlement within the heavily rail-tracked area.
The propping system was designed in-house by civil engineers, Carey Group Plc, with some technical input from the technical department at Harrogate-based Groundforce Shorco, a division of leading specialist plant equipment hire company Vp Plc.
The solution was to install the 11.6m long tubular struts at approximately 6m centres raking between a purpose-designed, high-modulus waling beam of twin universal beam sections about 12 metres long and substantial mass-concrete thrust blocks founded on rock. The horizontal force on the wailing beams was 11.5 tonnes per metre run.
Carey Group Plc engineering manager, Andrew Richards, says: “As the wall is so close to the main railway line, the results of failure or excessive defamation are so horrendous as to be beyond contemplation. Therefore it was absolutely crucial for us all to get it exactly right. We were pleased with Groundforce Shorco’s technical advice and input to this scheme.”
Groundforce Shorco technical manager, Tony Gould, says: “Although we were not involved in the detailed design work on this scheme, it illustrates how an excellent relationship developed during a long period between a customer’s own in-house engineering department and our own technical team creates an effective, speedy economical solution to the satisfaction of all involved.”
The main contractor for the development, due to for completion in September 2006, is Britain’s largest privately-owned construction, development and house builder, Miller Construction
