Achieving economy and reliability in piled foundation design for a building project

This paper addresses geotechnical risks in the context of the overall costs for a typical UK building project and summarises the major risks that ought to be addressed by appropriately robust foundation design and construction. The first part of the paper puts geotechnical costs into perspective. It demonstrates that site investigation costs are usually just 2% of the substructure costs or 0.1% of the overall building cost. Yet ground-related problems typically account for about one third to one half of construction programme over-runs, and the average costs of these delays far exceed the original sums expended on site investigation. The second part of the paper draws together the elements that improve the chances of foundations working well and sets out a methodology whereby these elements can be considered together for a particular project to give the required level of robustness.

Tim Chapman, BE, MSc, DIC, CEng, MIEI, FICE
Associate Director, Ove Arup & Partners Ltd

Alain Marcetteau, ENSM, CEng, MICE, FConsE
Director, Ove Arup & Partners Ltd