Pile setup in sand – the "PAGE" joint industry project
File(s)SW2022Keynote1Cathie.pdf (3.05 MB)
Published version
OA Location
Author(s)
Cathie, David
Jardine, RICHARD
Silvano, Rui
Kontoe, Stavroula
Schroeder, Felix
Type
Conference Paper
Abstract
The reliability of long-term axial capacity predictions for large, offshore-scale, piles is uncertain. Current databases of static load tests include very few entries with diameters ≥ 1m, and none >2m. Also, most of the available tests were conducted at relatively early ages after driving. The PAGE Joint Industry Project addressed this knowledge gap by collating and analysing dynamic driving data from 25 offshore piles with 1.6 to 3.4m outside diameters and contrasting these with dynamic re-strike tests conducted between 1h and 1 year after driving. Systematic signal matching was performed with two independent codes that applied different soil models and the outcomes were compared with predictions from modern CPT-based static capacity design methods. Additional supporting analyses were performed on other piles, where static and dynamic tests had been conducted, to help assess the relationships between statically and dynamically measured resistances. Piles with 0.3 to 3.5m outside diameters followed broadly common trends over
the first 30 days after driving, with shaft capacities approximately doubling. While smaller (<1m) diameter piles driven at onshore/nearshore sites display marked further capacity growth, larger offshore piles showed little additional
capacity gain after 30 days. The CPT-based Unified offshore pile design method offered conservative predictions for long-term shaft resistance, while no bias was apparent with the ICP-05 approach. An inverse relationship was identified between long-term shaft setup and diameter, which is ascribed to enhanced dilatancy applying at the pile-sand interface. The base capacities interpreted from dynamic analyses consistently fell far below the monotonic loading capacities predicted by current design methods and showed no significant trend to increase over time.
the first 30 days after driving, with shaft capacities approximately doubling. While smaller (<1m) diameter piles driven at onshore/nearshore sites display marked further capacity growth, larger offshore piles showed little additional
capacity gain after 30 days. The CPT-based Unified offshore pile design method offered conservative predictions for long-term shaft resistance, while no bias was apparent with the ICP-05 approach. An inverse relationship was identified between long-term shaft setup and diameter, which is ascribed to enhanced dilatancy applying at the pile-sand interface. The base capacities interpreted from dynamic analyses consistently fell far below the monotonic loading capacities predicted by current design methods and showed no significant trend to increase over time.
Date Issued
2022-09-20
Date Acceptance
2022-07-01
Citation
Proceedings of the 11th International Conference on Stress Wave Theory and Design and Testing Methods for Deep Foundations (SW2022),, 2022
Journal / Book Title
Proceedings of the 11th International Conference on Stress Wave Theory and Design and Testing Methods for Deep Foundations (SW2022),
Copyright Statement
© 2022 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
License URL
Source
11th International Conference on Stress Wave Theory and Design and Testing Methods for Deep Foundations (SW2022),
Publication Status
Published
Start Date
2023-09-20
Finish Date
2022-09-23
Coverage Spatial
Rotterdam, The Netherlands