Piling proves the economical solution
Client: The property owner/occupier
Sandringham Road Bromley, Kent
A new foundation piled raft provided an economical alternative to deep trench foundations for this extension to a semi detached property.
The contract involved the construction of a piled raft foundation for a new extension to the side of the property.
Purkelly had installed a pad and beam underpinning system to the front wall of the property some time previously. Whilst no site investigation work was carried out prior to piling, it was known that the strata was generally firm to stiff clay for at least 3.0 m depth.
It was assumed that the clay would be susceptible to shrinkage and heave and Purkelly's economical pile and slab design for the scheme took this into account. Deep trenched foundations were a more expensive option.
Varying pile loads were calculated in the design and Purkelly installed a total of 11 No. 250 mm diameter auger bored piles to depths between 7.0 m and 11.0 m. The top 3.0 m of the piles were sleeved. The RC foundations consisted of a 250 mm thick flat slab constructed on a 250 mm cellcore heave protection.
