Paper contribution

Validating Large-Diameter Bored Pile Design in Danian Limestone via Testing

Anna Wudzka; Adriana Hernandez-Guardado; Francesco Petrella

Proceedings
EUROCK 2026
Pages
605-610
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

This paper presents the case history of preliminary piles tested in Danian limestone as part of the design validation for large-diameter bored piles supporting the Kronprinsesse Marys Bro bridge crossing the Roskilde Fjord in Denmark. The project involved extensive geotechnical investigations and static load tests on two preliminary piles to assess shaft and base resistance in weak, highly variable limestone. The piles, with diameters up to 1.19 m and rock sockets of 5–8 m, were tested using bi‑directional O‑cell systems, providing direct measurement of load transfer and resistance mobilisation. A statistical analysis of more than 300 UCS tests revealed a significant strength variability, highlighting the importance of site‑specific characterisation. The findings demonstrate that bored piles socketed in Danian limestone can achieve higher shaft and base resistances than currently permitted by the Danish National Annex to Eurocode 7. The proposed methodology enables the derivation of representative design parameters, advocating the use of percentile‑based UCS values and empirical correlations tailored to local rock conditions. This case history provides valuable insights for practitioners and regulators, supporting the revision of Annex L of the Danish National Annex to Eurocode 7 to incorporate robust methods for estimating shaft and base resistance in soft rock.

Contributors

Authors

  1. Anna Wudzka Ove Arup & Partners Danmark A/S, Denmark, Denmark ORCID 0009-0003-3540-4507
  2. Adriana Hernandez-Guardado Ove Arup & Partners Danmark A/S, Denmark, Denmark; Department of Civil and Architectural Engineering, Aarhus University, Aarhus, Denmark. ORCID 0000-0001-8518-8310
  3. Francesco Petrella Ove Arup & Partners Danmark A/S, Denmark, Denmark ORCID 0009-0005-9952-908X

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References

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