Social care provider the Care Concern Group has appointed main contractor Farrans to replace the old 72-room Clore Manor care home in Hendon with a new six-storey facility with 108 bedrooms and underground parking.
The project takes place on a confined site on the south side of the Great North Way, close to homes and a busy road.
The excavation for the basement car park extends to 4m in depth and measures approximately 50m by 40m, covering almost the entire footprint of the site. The sides of this excavation are lined with a secant-piled retaining wall which is braced with the Groundforce Shorco raking props to transfer lateral loads from the capping beam to concrete thrust blocks located within the excavation down to formation level.
Specialist subcontractor Marney Construction, based in Southend, is carrying out the bulk earthmoving and civils work.
Six Groundforce Shorco MP150 props ranging in length from 7.3m to 10.3m are located along the exposed northern perimeter of the excavation.
On the eastern side, adjacent to the main road, the three MP375 props are supporting the retaining wall above a deeper secondary excavation that will eventually house an attenuation tank to store rainwater runoff from the site as part of the project鈥檚 sustainable urban drainage system.
The MP375 is Groundforce鈥檚 second highest capacity hydraulic ram compatible with tube diameters ranging from 610mm up to 1,220mm diameter. It is capable of supporting loads up to 375t (3,677kN).
Although the MP375 props are capable of supporting high axial loads, absolute capacity was not the primary concern here, explains Groundforce Shorco area manager Ken Sandell.
鈥淭he loads involved here aren鈥檛 especially high but the deflection criteria was quite tight due to surrounding structures and the main road. Franki Piling, who installed the retaining wall and carried out the geotechnical calculations, set a tolerance of plus or minus 10mm of deflection. So we used the MP375s mainly for their stiffness which minimises movement to comply with the deflection limits.
鈥淭he design was developed through close collaboration with our engineers and the client鈥檚 design team.鈥�
Gerard Fennell, Farrans鈥� project manager on this scheme, says: 鈥淭his is a challenging project, with tight constraints due to the close proximity of nearby structures and residents while forming a deep basement.
鈥�Groundforce has been superb on Clore Manor. They have been very professional, approachable and flexible, working closely with our design team and subcontractor to develop a design that is robust and practical.鈥�
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