Foundations for the future

For the past 50 years civil engineers have been filling the ground under our towns and cities with, among other things, bored concrete piles. In London Clay in particular, such piles are a quick, quiet and cost-effective method of supporting ever-taller buildings and structures. But, unlike the shallower footings of old, today's deep foundations are almost impossible to remove when the building reaches the end of its life and the site needs to be redeveloped. The easiest solution—but one that is clearly not sustainable—is to fill up the space in between with even bigger piles. This paper argues that reuse of existing piles is the real answer and discusses the changes needed in our approach to designing, building and paying for foundations in the future.