Dear Dr. Zhang,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 11 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Jiaolong Ren

Academic Editor

PLOS ONE

Journal requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. In the online submission form, you indicated that [Data will be made available on request].

All PLOS journals now require all data underlying the findings described in their manuscript to be freely available to other researchers, either 1. In a public repository, 2. Within the manuscript itself, or 3. Uploaded as supplementary information.

This policy applies to all data except where public deposition would breach compliance with the protocol approved by your research ethics board. If your data cannot be made publicly available for ethical or legal reasons (e.g., public availability would compromise patient privacy), please explain your reasons on resubmission and your exemption request will be escalated for approval.

3. When completing the data availability statement of the submission form, you indicated that you will make your data available on acceptance. We strongly recommend all authors decide on a data sharing plan before acceptance, as the process can be lengthy and hold up publication timelines. Please note that, though access restrictions are acceptable now, your entire data will need to be made freely accessible if your manuscript is accepted for publication. This policy applies to all data except where public deposition would breach compliance with the protocol approved by your research ethics board. If you are unable to adhere to our open data policy, please kindly revise your statement to explain your reasoning and we will seek the editor's input on an exemption. Please be assured that, once you have provided your new statement, the assessment of your exemption will not hold up the peer review process.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

Reviewer #1: Yes

Reviewer #2: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

Reviewer #2: Yes

**********

Reviewer #1: Experimental study on water-heat-salt migration and deformation characteristics of subgrade filler during freeze-thaw cycles

Abstract

• The abstract provides a broad summary of the study, covering the motivation, methodology, and findings. However, the structure is imbalanced. The rationale (arching in culverts due to freeze-thaw cycles) is introduced well, but the objective is not clearly stated as a standalone sentence.

• The methods are implied but not concisely defined (e.g., freeze-thaw tests on soil columns).

• The findings are detailed, but too verbose for an abstract. Quantitative data is partially presented but would benefit from clearer summaries (e.g., numerical deformation values, migration rates).

• Clearly identify the research objective and condense findings into 2–3 data-backed sentences.

• Clearly articulate the objective of the study as a standalone sentence.

• Condense the description of findings; include only the most critical quantitative results.

• Maintain balance by briefly mentioning the methodology and limiting excessive detail in the findings.

Introduction

• The hypothesis and aim are implied but should be explicitly stated at the end of the section.

• Streamline the literature review by focusing on studies most relevant to multilayer subgrade behavior.

• Show the quantitative data of previous works and how they differ from your study.

• This study suggested to be used:

Saleh, S. A., Ismael, R. S. ., & Abas, B. S. . (2024). Effect of Soil Stabilization on Structural Design of Flexible Pavement. Journal of Studies in Civil Engineering, 1(1), 36–54. https://doi.org/10.53898/jsce2024113

Experimental Materials and Scheme

• Include a summary table detailing the freeze-thaw cycle parameters (temperature range, duration, number of cycles).

• Clarify the rationale for choosing specific cement stabilization percentages across materials.

• Mention whether replicate tests were conducted to ensure reproducibility.

Experimental Results and Analysis

Temperature Variation

• Support observed trends (e.g., temperature lag) with statistical validation or replicating data.

• Highlight how the findings align or contrast with existing models of thermal migration in soils.

Moisture Content

• Provide a comparative table summarizing moisture change across materials and cycle numbers.

• Consider discussing the implications of water redistribution on structural integrity more directly.

Salt Content

• Expand discussion on the practical impact of upward salt migration, especially in upper structural layers.

• Include statistical ranges or error bars in salt content measurements for clarity.

Deformation Analysis

• Present residual deformation results in tabular form for quick comparison across materials.

• Discuss how the four-stage deformation process informs design recommendations for embankments in similar regions.

Microanalysis

• Quantify microstructural features where possible (e.g., pore sizes, crystal dimensions).

• Consider correlating SEM/XRD findings more directly to macro-scale deformation behaviors.

• Specify the representativeness of the samples analyzed (e.g., selection criteria).

Conclusion

• Condense the list of findings and focus on the most impactful results.

• Add a final paragraph summarizing engineering implications and potential field applications.

• Briefly mention any limitations of the study and suggest future research directions, such as long-term field validation or model development.

Reviewer #2: Title and Abstract

The title is informative but could be more specific. For example, mention the geographic context (e.g., "in Northwestern China") or emphasize the sulfate erosion aspect more clearly.

The abstract is dense and includes too many technical details without sufficient explanation of their significance.

Can the abstract be revised to clearly define the research problem, methods, key findings, and implications in a more reader-friendly format?

What is meant by “arching disease” in the abstract? Consider defining this for readers unfamiliar with the term.

2. Introduction

The introduction provides a solid literature foundation but lacks a concise statement of the knowledge gap and hypothesis.

The "arching disease" is mentioned but not well contextualized.

Can the authors clearly articulate the specific research questions or hypotheses that this study seeks to answer?

What distinguishes this study from the numerous prior studies cited on water-salt migration and sulfate erosion?

Can the mechanism or definition of “arching disease” in transition sections be illustrated with a figure or schematic?

Experimental Materials and Scheme

The rationale for selecting the specific filler types and stabilization percentages is not explained.

Moisture contents appear unusually low (e.g., 3–5%). Clarify if this refers to dry densities or actual field conditions.

What criteria guided the selection of 3% and 5% cement contents? Are these field-validated values?

Why was 7 cycles chosen for the multi-layer test and 3 for the single-layer? Is there a theoretical or practical justification?

Is the 96-hour cycle duration realistic compared to field freeze-thaw rates?

Results and Analysis

Temperature Variation

Figures 2 and 3 are helpful but need better labeling and scale uniformity (legends? The numbering should be defined).

The description of "temperature lag" lacks quantification.

Can the authors quantify the temperature lag across sensors and compare it with model predictions or literature values?

Were thermal properties of the materials (e.g., thermal conductivity) considered in interpreting the lag?

Moisture Content Variation

The “high-low-high” water distribution is interesting but not fully explained.

The concept of "water lag" and "lid effect" is not defined clearly.

What mechanisms contribute to the “high-low-high” pattern: capillarity, thermal gradient, or osmotic flow?

How does the presence of salts affect freezing/melting behavior and water redistribution?

Salt Content Variation

Salt migration is well documented but would benefit from mass balance or modeling discussion.

The observed salt redistribution appears counterintuitive in later stages.

Can the authors provide a salt mass balance over cycles to show conservation or net accumulation?

How do salt precipitation/dissolution dynamics (e.g., solubility curves) explain the observed redistribution?

Deformation Analysis

The division into four freeze-thaw stages is insightful.

Deformation behavior is mainly described qualitatively.

Can the axial displacement be correlated with water/salt content or microstructural changes?

How repeatable or statistically significant are these deformation measurements?

Microanalysis

XRD and SEM results are interesting but poorly integrated with mechanical behavior analysis.

No discussion of quantitative phase analysis or crystal orientation/density.

What is the estimated amount of ettringite and gypsum formed, and how does this relate to observed swelling?

Is there any SEM or EDS evidence showing salt crystallization blocking pore throats?

Discussion (Missing/Underdeveloped)

There is no dedicated discussion section to synthesize findings or relate them to broader engineering practice.

What are the practical implications of these findings for high-speed railway subgrade design in saline soil regions?

How can the insights on moisture/salt migration inform predictive modeling or mitigation strategies?

Conclusion

The conclusions are mostly restatements of results.

Lacks discussion on limitations and future work.

Can the authors highlight the main engineering recommendations derived from this study?

What are the main limitations (e.g., lab scale vs. field scale, duration, boundary conditions)?

References and Style

The citation style is inconsistent (e.g., use of Chinese references with limited access).

Some citations appear repetitive or too many from the same group.

Can the authors diversify references with more international studies or review papers?

General/Editorial Suggestions

Improve language clarity: Terms like "occurres" and “slowes” suggest grammar and spell-checking is needed.

Add schematics of the experimental setup and sensor arrangement.

Ensure all figures are legible with consistent scales and labels.

**********

what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy

Reviewer #1: No

Reviewer #2: Yes:  Fidelis Odedishemi Ajibade

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step.

Dear Dr. Zhang, 

plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Jiaolong Ren

Academic Editor

PLOS ONE

Journal Requirements:

If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. 

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

Reviewer #1: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions??>

Reviewer #1: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #1: N/A

**********

4. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #1: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

**********

Reviewer #1: Thank you for revising the manuscript and for carefully responding to the reviewers’ comments. The revision is appreciated. However, I would like to suggest two points for further improvement:

1. In the response to each comment, it would be better to indicate the page and line numbers where the modifications have been made in the revised version. This will help the reviewers easily identify the changes and avoid any confusion.

2. The number of references should be increased where appropriate. Strengthening the literature support will improve the overall quality of the manuscript. I recommend adding the following references in the revised version:

o Saleh, S. A., Ismael, R. S., & Abas, B. S. (2024). Effect of Soil Stabilization on Structural Design of Flexible Pavement. Journal of Studies in Civil Engineering, 1(1), 36–54. https://doi.org/10.53898/jsce2024113

o Shirmohammadi, M., Hakimi Asiabar, S., and Peyrovi Cheshnasar, M. (2025). Dual Transitional Floors and Soil-Structure Synergy: A Paradigm Shift in Seismic Resilience for Hybrid High-Rise Systems. Advances in Civil Engineering and Environmental Science, 2(2), 62-71. doi: 10.22034/acees.2025.508498.1021

**********

what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy

Reviewer #1: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org

Experimental Study on Water-Heat-Salt Migration and Deformation Characteristics of Subgrade Filler during Freeze-Thaw Cycles in Northwestern China

PONE-D-25-25268R2

Dear Dr. Zhao,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager®  and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support .

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Jiaolong Ren

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: