Cyclic overlay model of <i>p</i>–<i>y</i> curves for laterally loaded monopiles in cohesionless soil

Song, Junnan; Achmus, Martin

doi:https://doi.org/10.5194/wes-8-327-2023

Articles | Volume 8, issue 3

https://doi.org/10.5194/wes-8-327-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/wes-8-327-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 8, issue 3

Research article

|

08 Mar 2023

Research article |

| 08 Mar 2023

Cyclic overlay model of p–y curves for laterally loaded monopiles in cohesionless soil

Junnan Song and Martin Achmus

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Final revised paper (published on 08 Mar 2023)
Preprint (discussion started on 23 Dec 2021)

Interactive discussion

Status: closed

RC1: 'Comment on wes-2021-160', Anonymous Referee #1, 29 Nov 2022

The paper gives a good overview of guidelines and standards, problems with them, and earlier emendations (to the standards). The final section, “5 Model application and discussion” is excellent, setting the developments in perspective. Finally, the paper is very well-written, in general. Thus, the present reviewer has no hesitation is recommending the paper for publication “as it is”.

Citation: https://doi.org/10.5194/wes-2021-160-RC1
RC2:
'Comment on wes-2021-160', Anonymous Referee #2, 30 Dec 2022
The manuscript studies the effect of lateral cyclic loading of larger-diameter to-length monopiles surrounded by cohesionless soil (sand) used as a foundation for a wind turbine. The manuscript, based on the subject and quality, is publishable in its present form in the Wind Energy Science journal. Nevertheless, some small modifications and clarifications may improve the quality even more, as listed below.

In it non-typical to include references in the abstract as it should be possible to read and understand the abstract without access to the reference list. Please modify this.

Some of the symbols include a ()’, it is unclear the meaning of this.

The z-term has the unit [m]. If p_us and p_ud both have the unit N/m, then C_1, C_2 can not have the same unit as C_3 (or both set be dimensionless). Please correct equation (2).

In the figures, it may be shorter to just write the unit as [-] and [mN/m^3] instead of using the untypical term “in 1”, …

Line 191, und -> and

Line 196, exemplary -> examples

Section 4.2 should include some more details on the FE model used. 3D model, boundary conditions, type of elements, …

On page 13, a number of ranges are presented in a non-typical way. Either use the mathematical definition L/D \in [5,8], etc., or just write L/D=5 -- 8, or …
Citation: https://doi.org/10.5194/wes-2021-160-RC2
- AC2:
  'Reply on RC2', Junnan Song, 23 Jan 2023
  We thank the referee for your effort and positive evaluation of our paper.
  We will address the small modifications suggested by your comment, since we think that this will indeed further improve the quality of the paper. Below, our response to the particular comments is given:
  References in the abstract will be excluded.
  
  In geotechnical engineering, the ()’ marks quantities referring to effective stresses.
  
  Equation (2) has a typo which will be corrected.
  
  We will change the axis denotations in Fig. 2 accordingly.
  
  The typo in line 191 will be corrected.
  
  “exemplary” will be replaced by “as an example”.
  
  The paragraph in section 4.2 will be extended as follows:
  
  “The simulations were conducted with the finite element code Abaqus (Abaqus 2016) using 8-noded volume elements (C3D8). Only one half of the three-dimensional cylindrical system was modelled, hereby utilizing symmetry conditions. The sufficient size of the model domain and sufficient fineness of the finite element mesh was proven by preceding sensitivity analyses. For instance, the model for the pile with 5 m diameter and a length of 25 m had a width of 100 m (dimension in direction of the horizontal load), a breadth of 50 m and a depth of 50 m. At the edges of the domain, horizontal supports were considered for the nodes in the vertical planes and vertical supports for the nodes in the bottom plane.”
  We will change the presentation of ranges accordingly: L/D = 5 – 8, e/L = 0 – 1 etc.
  
  Citation: https://doi.org/10.5194/wes-2021-160-AC2
AC1:
'Comment on wes-2021-160', Junnan Song, 23 Jan 2023
We thank the referees for their effort and their positive evaluation of our paper.
We will address the small modifications suggested by referee #2, since we think that this will indeed further improve the quality of the paper. Below, our response to the particular comments of referee #2 is given:
References in the abstract will be excluded.

In geotechnical engineering, the ()’ marks quantities referring to effective stresses.

Equation (2) has a typo which will be corrected.

We will change the axis denotations in Fig. 2 accordingly.

The typo in line 191 will be corrected.

“exemplary” will be replaced by “as an example”.

The paragraph in section 4.2 will be extended as follows:

“The simulations were conducted with the finite element code Abaqus (Abaqus 2016) using 8-noded volume elements (C3D8). Only one half of the three-dimensional cylindrical system was modelled, hereby utilizing symmetry conditions. The sufficient size of the model domain and sufficient fineness of the finite element mesh was proven by preceding sensitivity analyses. For instance, the model for the pile with 5 m diameter and a length of 25 m had a width of 100 m (dimension in direction of the horizontal load), a breadth of 50 m and a depth of 50 m. At the edges of the domain, horizontal supports were considered for the nodes in the vertical planes and vertical supports for the nodes in the bottom plane.”
We will change the presentation of ranges accordingly: L/D = 5 – 8, e/L = 0 – 1 etc.
Citation: https://doi.org/10.5194/wes-2021-160-AC1

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Junnan Song on behalf of the Authors (06 Feb 2023) Author's response Author's tracked changes Manuscript

ED: Publish as is (11 Feb 2023) by Lars Pilgaard Mikkelsen

ED: Publish as is (17 Feb 2023) by Athanasios Kolios (Chief editor)

AR by Junnan Song on behalf of the Authors (17 Feb 2023)

Short summary

In this research, a cyclic p–y overlay model for monopiles in sand soils could be developed via comparison of numerical simulations of monopile behaviour: once under monotonic and once under cyclic loading with a defined number of load cycles (utilizing the stiffness degradation method). The new cyclic overlay model gives plausible results and can be applied to any monotonic p–y approach for monopiles in sand.