Abstract:
The question of the continued suitability of existing foundations arises when the function of the
superstructure changes. This can occur when the superstructure is replaced or when the existing
structure is expanded, leading to higher loads on the existing foundation.
Quite often it is a challenge to define the suitability (with respect to integrity, bearing capacity or
both). The lack of information on the existing foundation (such as pile dimensions, installation
records, original soil investigation, design calculations, etc.) makes it frequently seemingly impossible
to assess whether the foundation or foundation elements can be re-used.
The paper outlines the tools available to an engineer to evaluate existing foundation piles for
potantial re-use. The paper illustrates the application of these tools through a few case studies in The
Hague and Amsterdam, The Netherlands, incl. the evaluation of a 400 years old bridge foundation to
address increasing traffic loads.