Imminent Problems that Conventional Piling Will Face in Highly Developed Towns and Cities

Foundations are typically left in-situ when a superstructure is decommissioned as towns and cities undergo cycles of redevelopment and regeneration. This presents challenges for the next developer and as the cycle continues the ground becomes increasingly congested. Existing piled foundations are particularly difficult to manage as methods of investigating their structural integrity are necessarily intrusive, time consuming, costly and, ultimately, often inconclusive. The piling industry could continue to construct piles as it has done for the past 60 years and develop innovative methods to remove obstructions from previous generations of foundations. Alternatively, the industry could instigate action to re-design piles to mitigate the challenges presented by underground obstructions. With increased pressure for sustainable construction it is vital that every element of a development is economically designed to add value.

The hollow pile idea is presented, which is currently being jointly developed by Keltbray Piling and City, University of London, to optimise design and construction. This paper discusses the implementation of the hollow pile and the benefits it could potentially provide to accelerate project delivery, reduce material usage and minimise volumes of construction waste sent to landfill. A case study for a potential project is reported based on outcomes from a recent hollow pile field trial whilst potential uses for the pile void are also outlined.