Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil
<p>The bearing behaviour of large-diameter monopile foundations for offshore wind turbines under lateral cyclic loads in cohesionless soil is an issue of ongoing research. In practice, mostly the <span class="inline-formula"><i>p</i></span>–<span class=&quo...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
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| Series: | Wind Energy Science |
| Online Access: | https://wes.copernicus.org/articles/8/327/2023/wes-8-327-2023.pdf |
| _version_ | 1811158147003318272 |
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| author | J. Song M. Achmus |
| author_facet | J. Song M. Achmus |
| author_sort | J. Song |
| collection | DOAJ |
| description | <p>The bearing behaviour of large-diameter monopile foundations for offshore
wind turbines under lateral cyclic loads in cohesionless soil is an issue of
ongoing research. In practice, mostly the <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> approach is applied in the
design of monopiles. Recently, modifications of the original <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> approach
for monotonic loading stated in the API regulations have been proposed to
account for the special bearing behaviour of large-diameter piles with small
length-to-diameter ratios. However, cyclic loading for horizontally loaded
piles predominates the serviceability of the offshore wind converters, and
the actual number of load cycles cannot be considered by the cyclic <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span>
approach of the API regulations. This research therefore focuses on the
effects of cyclic loading on the <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curves along the pile shaft and aims
to develop a cyclic overlay model to determine the cyclic <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curves valid
for a lateral load with a given number of load cycles. A stiffness
degradation method (SDM) is applied in a three-dimensional finite element
model to determine the effect of the cyclic loading by degrading the secant
soil stiffness according to the magnitude of cyclic loading and number of
load cycles based on the results of cyclic triaxial tests. Thereby, the
numerical simulation results are used to develop a cyclic overlay model,
i.e. an analytical approach to adapt the monotonic (or static) <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curve to
the number of load cycles. The new model is applied to a reference system
and compared to the API approach for cyclic loads.</p> |
| first_indexed | 2024-04-10T05:19:27Z |
| format | Article |
| id | doaj.art-b0879dcaa8a247cf9fbafdf7421a07b3 |
| institution | Directory Open Access Journal |
| issn | 2366-7443 2366-7451 |
| language | English |
| last_indexed | 2024-04-10T05:19:27Z |
| publishDate | 2023-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Wind Energy Science |
| spelling | doaj.art-b0879dcaa8a247cf9fbafdf7421a07b32023-03-08T11:54:08ZengCopernicus PublicationsWind Energy Science2366-74432366-74512023-03-01832733910.5194/wes-8-327-2023Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soilJ. SongM. Achmus<p>The bearing behaviour of large-diameter monopile foundations for offshore wind turbines under lateral cyclic loads in cohesionless soil is an issue of ongoing research. In practice, mostly the <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> approach is applied in the design of monopiles. Recently, modifications of the original <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> approach for monotonic loading stated in the API regulations have been proposed to account for the special bearing behaviour of large-diameter piles with small length-to-diameter ratios. However, cyclic loading for horizontally loaded piles predominates the serviceability of the offshore wind converters, and the actual number of load cycles cannot be considered by the cyclic <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> approach of the API regulations. This research therefore focuses on the effects of cyclic loading on the <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curves along the pile shaft and aims to develop a cyclic overlay model to determine the cyclic <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curves valid for a lateral load with a given number of load cycles. A stiffness degradation method (SDM) is applied in a three-dimensional finite element model to determine the effect of the cyclic loading by degrading the secant soil stiffness according to the magnitude of cyclic loading and number of load cycles based on the results of cyclic triaxial tests. Thereby, the numerical simulation results are used to develop a cyclic overlay model, i.e. an analytical approach to adapt the monotonic (or static) <span class="inline-formula"><i>p</i></span>–<span class="inline-formula"><i>y</i></span> curve to the number of load cycles. The new model is applied to a reference system and compared to the API approach for cyclic loads.</p>https://wes.copernicus.org/articles/8/327/2023/wes-8-327-2023.pdf |
| spellingShingle | J. Song M. Achmus Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil Wind Energy Science |
| title | Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil |
| title_full | Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil |
| title_fullStr | Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil |
| title_full_unstemmed | Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil |
| title_short | Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil |
| title_sort | cyclic overlay model of i p i i y i curves for laterally loaded monopiles in cohesionless soil |
| url | https://wes.copernicus.org/articles/8/327/2023/wes-8-327-2023.pdf |
| work_keys_str_mv | AT jsong cyclicoverlaymodelofipiiyicurvesforlaterallyloadedmonopilesincohesionlesssoil AT machmus cyclicoverlaymodelofipiiyicurvesforlaterallyloadedmonopilesincohesionlesssoil |