TY - JOUR

T1 - Suction bucket foundations under cyclic tensile loading-physical and numerical modeling

AU - Gütz, P.

AU - Achmus, M.

N1 - Funding Information: This study was carried out in scope of the research project “Bearing behavior of suction bucket foundations under tensile loading in non-cohesive soils” (project no. 266046182) funded by German Research Foundation (DFG). The authors sincerely acknowledge DFG support.

PY - 2021/11/1

Y1 - 2021/11/1

N2 - Although suction buckets are believed to be a promising alternative for multipod foundations of offshore wind turbines, the economic and ecological advantages are still limited because of a lack of knowledge regarding the tensile bearing behavior. Major uncertainties exist in terms of the response under cyclic loading and the assessment of the partially drained loading condition, where negative differential pressure beneath the suction bucket's lid contributes to the total tensile resistance. This article presents findings from 1-g model tests of suction buckets in sand subjected to various cyclic tensile loads. The suction bucket was installed via negative differential pressure (suction). The results show a strong effect of the applied load magnitude on the evolution of displacement, plug heave, and suction induced. Greater displacement accumulation is observed for the smaller considered frequency. Monotonic tests with varying displacement rates supplement the cyclic tests and serve for the verification of a hydraulic-mechanic coupled finite element model, which is afterward utilized for the back-calculation of cyclic model tests. Although a rather simple elasto-plastic material law was used for the sand, good agreement was found, indicating that the bearing behavior is mainly governed by the hydraulic conditions and only subordinately by the soil mechanics.

AB - Although suction buckets are believed to be a promising alternative for multipod foundations of offshore wind turbines, the economic and ecological advantages are still limited because of a lack of knowledge regarding the tensile bearing behavior. Major uncertainties exist in terms of the response under cyclic loading and the assessment of the partially drained loading condition, where negative differential pressure beneath the suction bucket's lid contributes to the total tensile resistance. This article presents findings from 1-g model tests of suction buckets in sand subjected to various cyclic tensile loads. The suction bucket was installed via negative differential pressure (suction). The results show a strong effect of the applied load magnitude on the evolution of displacement, plug heave, and suction induced. Greater displacement accumulation is observed for the smaller considered frequency. Monotonic tests with varying displacement rates supplement the cyclic tests and serve for the verification of a hydraulic-mechanic coupled finite element model, which is afterward utilized for the back-calculation of cyclic model tests. Although a rather simple elasto-plastic material law was used for the sand, good agreement was found, indicating that the bearing behavior is mainly governed by the hydraulic conditions and only subordinately by the soil mechanics.

KW - Model tests

KW - Numerical simulation

KW - Offshore foundations

KW - Sand

KW - Soil-structure interaction

KW - Suction bucket

KW - Tensile loading

UR - http://www.scopus.com/inward/record.url?scp=85100892026&partnerID=8YFLogxK

U2 - 10.1520/GTJ20200056

DO - 10.1520/GTJ20200056

M3 - Article

AN - SCOPUS:85100892026

VL - 44

JO - Geotechnical testing journal

JF - Geotechnical testing journal

SN - 0149-6115

IS - 3

ER -