Transiently Loaded Bucket Foundations in Saturated Dense Sand - Demonstration of the Boot Effect

Søren Dam Nielsen, Lars Bo Ibsen, Benjaminn Nordahl Nielsen

Research output: Contribution to journalJournal articleResearchpeer-review

3 Citations (Scopus)

Abstract

The mono bucket foundation is a cost-effective foundation for offshore wind turbines. During a storm, these foundations are exposed to large wave loads of short duration. This paper investigates the effect of increased loading rate on the bearing capacity of two mono bucket foundations installed in dense sand inside a pressure tank. The foundations had aspect ratios (skirt lengths [L] relative to the diameters [D]), L/D, of 0.5 and 1.0, respectively. Foundations were brought to failure with varying loading rates, resulting in drained, partly drained, or undrained behavior. Increases in bearing capacity were observed as the loading rate increased. This behavior was caused by a combination of dilative soil behavior and suction created by upward movement, known as the boot effect. For mono bucket foundations, the boot effect resulted in an increased bearing capacity that was 18 to 25 times higher than the drained capacity. Furthermore, the boot effect also led to an increase in stiffness. The stiffness of the partly drained response is measured up to four times higher compared with drained behavior.
Original languageEnglish
JournalGeotechnical Testing Journal
Volume40
Issue number6
Number of pages14
ISSN0149-6115
DOIs
Publication statusPublished - 2017

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Demonstrations
Sand
bearing capacity
sand
Bearing capacity
stiffness
wind turbine
suction
Stiffness
Offshore wind turbines
effect
Aspect ratio
cost
rate
soil
Soils
Costs

Keywords

  • Bucket Foundations
  • Transiently loaded
  • The boot effect

Cite this

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title = "Transiently Loaded Bucket Foundations in Saturated Dense Sand - Demonstration of the Boot Effect",
abstract = "The mono bucket foundation is a cost-effective foundation for offshore wind turbines. During a storm, these foundations are exposed to large wave loads of short duration. This paper investigates the effect of increased loading rate on the bearing capacity of two mono bucket foundations installed in dense sand inside a pressure tank. The foundations had aspect ratios (skirt lengths [L] relative to the diameters [D]), L/D, of 0.5 and 1.0, respectively. Foundations were brought to failure with varying loading rates, resulting in drained, partly drained, or undrained behavior. Increases in bearing capacity were observed as the loading rate increased. This behavior was caused by a combination of dilative soil behavior and suction created by upward movement, known as the boot effect. For mono bucket foundations, the boot effect resulted in an increased bearing capacity that was 18 to 25 times higher than the drained capacity. Furthermore, the boot effect also led to an increase in stiffness. The stiffness of the partly drained response is measured up to four times higher compared with drained behavior.",
keywords = "Bucket Foundations, Transiently loaded, The boot effect, Bucket Foundations, Transiently loaded, The boot effect",
author = "Nielsen, {S{\o}ren Dam} and Ibsen, {Lars Bo} and Nielsen, {Benjaminn Nordahl}",
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Transiently Loaded Bucket Foundations in Saturated Dense Sand - Demonstration of the Boot Effect. / Nielsen, Søren Dam; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl.

In: Geotechnical Testing Journal, Vol. 40, No. 6, 2017.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Transiently Loaded Bucket Foundations in Saturated Dense Sand - Demonstration of the Boot Effect

AU - Nielsen, Søren Dam

AU - Ibsen, Lars Bo

AU - Nielsen, Benjaminn Nordahl

PY - 2017

Y1 - 2017

N2 - The mono bucket foundation is a cost-effective foundation for offshore wind turbines. During a storm, these foundations are exposed to large wave loads of short duration. This paper investigates the effect of increased loading rate on the bearing capacity of two mono bucket foundations installed in dense sand inside a pressure tank. The foundations had aspect ratios (skirt lengths [L] relative to the diameters [D]), L/D, of 0.5 and 1.0, respectively. Foundations were brought to failure with varying loading rates, resulting in drained, partly drained, or undrained behavior. Increases in bearing capacity were observed as the loading rate increased. This behavior was caused by a combination of dilative soil behavior and suction created by upward movement, known as the boot effect. For mono bucket foundations, the boot effect resulted in an increased bearing capacity that was 18 to 25 times higher than the drained capacity. Furthermore, the boot effect also led to an increase in stiffness. The stiffness of the partly drained response is measured up to four times higher compared with drained behavior.

AB - The mono bucket foundation is a cost-effective foundation for offshore wind turbines. During a storm, these foundations are exposed to large wave loads of short duration. This paper investigates the effect of increased loading rate on the bearing capacity of two mono bucket foundations installed in dense sand inside a pressure tank. The foundations had aspect ratios (skirt lengths [L] relative to the diameters [D]), L/D, of 0.5 and 1.0, respectively. Foundations were brought to failure with varying loading rates, resulting in drained, partly drained, or undrained behavior. Increases in bearing capacity were observed as the loading rate increased. This behavior was caused by a combination of dilative soil behavior and suction created by upward movement, known as the boot effect. For mono bucket foundations, the boot effect resulted in an increased bearing capacity that was 18 to 25 times higher than the drained capacity. Furthermore, the boot effect also led to an increase in stiffness. The stiffness of the partly drained response is measured up to four times higher compared with drained behavior.

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KW - Transiently loaded

KW - The boot effect

KW - Bucket Foundations

KW - Transiently loaded

KW - The boot effect

U2 - 10.1520/GTJ20160339

DO - 10.1520/GTJ20160339

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JO - Geotechnical Testing Journal

JF - Geotechnical Testing Journal

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ER -