Small-scale testing of laterally loaded monopiles in sand

K. Thomassen, H.R. Roesen, L.B. Ibsen, S.P.H. Sørensen

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Deep Foundations

ABSTRACT: In current designs of offshore wind turbines, monopiles are often used as foundation. The behaviour of the monopiles when subjected to lateral loading has not been fully investigated. In this paper, the behaviour of two non-slender piles in sand subjected to lateral loading are analysed by means of small-scale laboratory tests. Six quasi-static tests are conducted on piles with diameters of 40mm and 100mm and a slenderness ratio, L/D, of 5. To minimise scale effects, the tests are carried out in a pressure tank at various stress levels. From the obtained load-deflection relationships it is revealed that the uncertainties of the results for the pile with a diameter of 40mm are large. The load-deflection relationships normalised as H/(L2D™) and y/D indicate that the lateral load, H, is proportional to L2D. Comparison of the normalised load-deflection relationships for different stress levels shows that small-scale tests applied with overburden pressure are preferable. PRESENTACIONES TÉCNICAS En el diseño actual de turbinas eólicas marinas, mono-pilas son normalmente usadas como cimentación. El comportamiento de las mono-pilas cuando están sometidas a cargas laterales no ha sido completamente investigado a fecha de hoy. En este artículo, el comportamiento de dos mono-pilas no esbeltas instaladas en arena sometidas a cargas laterales es analizado mediante tests de laboratorio a escala reducida. Seis tests cuasi-estáticos son realizados sobre mono-pilas con diámetros de 40mm y 100 mm y relación de esbeltez de 5. Para minimizar los efectos de escala, los tests son llevados a cabo en un tanque de presión a diferentes niveles de presión. De la relación fuerza-desplazamiento obtenida, se puede concluir que las incertidumbres de los resultados de la mono-pila con diámetro de 40 mm son mayores. Las relaciones fuerza-desplazamiento normalizadas como H/(L2D™) y y/D indican que la carga lateral H es proporcional a L2D. Una comparación de las relaciones fuerza-desplazamiento normalizadas para diferentes niveles de presión muestra que los tests a pequeña escala con presión extra aplicada son preferibles.

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Cite this article:
K. Thomassen; H.R. Roesen; L.B. Ibsen; S.P.H. Sørensen (2011) Small-scale testing of laterally loaded monopiles in sand in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper1099,author = K. Thomassen; H.R. Roesen; L.B. Ibsen; S.P.H. Sørensen ,title = Small-scale testing of laterally loaded monopiles in sand,year = 2011}