ABSTRACT
Reinforced concrete deep foundations are typically abandoned after a building is demolished. This is a particular problem in highly developed cities, such as London, as they undergo redevelopment cycles. Many London sites are now in their third generation of deep foundations. The previous foundations present significant economic, environmental and safety challenges for subsequent developers, as the ground is increasingly more congested with piles; this is clearly not sustainable. Reuse of existing piled foundations is particularly difficult as insurance cannot be easily obtained. The piling industry has adopted construction methods to core out existing piles, only to replace them with larger diameter or deeper concrete piles. This paper explores the use of the Giken Gyropiler to overcore and remove concrete piles in their entirety. This technique, combined with more sustainable foundations could rehabilitate sites that have been polluted with piles, and has the potential to improve the value of brownfield sites.
