Variation Mechanism and Prediction of Soil–Water Characteristic Curve Parameters of Low-Liquid-Limit Silty Clay under Freeze–Thaw Cycles
Round 1
Reviewer 1 Report
Review comments attached.
Comments for author File: 
Comments.pdf
Author Response
Dear Editor and Reviewer,
Thank you very much for giving us an opportunity to revise our manuscript entitled “Variation Mechanism and Prediction of Soil-Water Characteristic Curve Parameters of Low Liquid Limit Silty Clay under Freeze-Thaw Cycles” (applsci-1857427) by Xiaohan Luan and Leilei Han for publication in Applied Sciences.
We appreciate your hard work in pointing out the important revisions needed in the paper. We have seriously taken these comments into account. What we have changed in response to the reviewers’ comments are given point by point in the following pages attached in this letter.
We hope that all these changes fulfill the requirements to make the manuscript acceptable for publication in Applied Sciences.
Looking forward to hearing from you soon.
Yours Sincerely,
Leilei Han
Response to the Reviewer #1’s comments:
We appreciate for your valuable suggestions. We have revised the manuscript according to the reviewer’s comments, and hope that the revised manuscript can be better than the original one. Thanks very much.
Q1: The paper explains the SWCC of silty clay soil, but the authors presented the typical SWCC with parameters details. Draw the soil water characteristics curves for the given three different densities of soil.
Response: The purpose of the typical SWCC given in this paper is to explain the meaning and calculation method of the SWCC graph. In this part, this study discusses the SWCC changes before freeze-thaw and after different freeze-thaw cycles at three dry densities from the perspective of eigenvalues. The purpose is to comprehensively discuss the parameters in the following section, and this discussion is quantitative.
Q2: Authors need to draw the SWCC for the initial state of soil (before freezing and thawing of soil), mention the saturated, residual moisture contents and Air Entry Value (Air Entry Suction).
Response: The saturated, residual moisture contents and Air Entry Suction of the soil initial state have been given in detail in Table 2.
Q3: The water holding performance of soil during the freezing and thawing processes should be discussed. This is a significant topic in unsaturated SWCC subjected to freezing and thawing.
Response: Thanks for your professional suggestion. It is indeed an important topic, which is also one of the goals of our research group in the future. However, the objective of this paper is to predict SWCC characteristic parameters and its microscopic mechanism after the freeze-thaw cycle. The change of soil water holding capacity in a single cycle needs an independent research topic, because SWCC focuses on expressing the relationship between matric suction and water content, and does not consider the time factor.
Q4: The soil from permafrost and seasonally frozen regions' performance can be determined from the soil-freezing characteristic curve (SFCC). Even though the SWCC and SFCC are physically similar for the soil, and both discuss the porewater pressure of soil, the authors need to briefly mention in the manuscript the SFCC of frozen soils.
Response: Thanks for your professional suggestion. As you said, SFCC is a mathematical description of the relationship between unfrozen water content in frozen soil and negative temperature, which is quite important for soil. However, this paper focuses on the comparison of SWCC changes before and after the freeze-thaw process. The detailed description of SFCC will be presented in the subsequent research.
Q5: Variation of matric suction during thawing and freezing needs to be plotted and discussed in detail.
Response: This paper focuses on the prediction of soil indicators after freeze-thaw cycles, rather than the monitoring of soil indicators during freeze and thaw processes. As answered Q3 & Q4, freezing and thawing within a single cycle is also one of the future goals of our research group. In the future, this research will be carried out as an independent topic.
Q6: Though the authors measured matric suction using filter paper, there are advanced methods like potentiometer, tensiometers etc. It is suggested to use any one advanced method and compare their results from filter paper.
Response: Thank you for your suggestion. As you said, the common SWCC measurement method include tensimeter method, potentiometer method and so on. These methods are faster for SWCC measurements and even allow for in situ measurements. However, limited by the experimental conditions, we finally used the filter paper method for measurement, and did not invest too much resources in the comparison of measurement results of various methods. We believe that the data measured by the filter paper method can provide effective support for the main purpose of this study.
Q7: Line no: 77 authors mention about natural factors? Explain what are the natural factors? (need to mention the factors that are affecting unsaturated soil behaviour).
Response: Thanks for your valuable suggestion, made me realize something was missing in this part of the expression. Descriptions of natural factors affecting unsaturated soil behavior have been added to this section.
Q8: In materials and methods section authors mentioned the properties of soil. Figure 1 (a) shows the grain size analysis curve, which standard was used for the testing and which standard for classification of soil. authors need to mention the soil type and group symbol of that soil.
Response: The reference standard notation and description of this section have been added
Q9: The Authors write in Table 1 that the optimum moisture content of soil was 15.38%. However, it is not mentioned by what method this OMC value was determined.
Response: The indicators in the table are all based on [33] Institute of Highway Science, Ministry of Communications. Code of Geotechnical Test for Highway: JTG E40-2007. People's Communications Publishing House, 2007. The OMC is obtained by compaction test. Sorry it wasn't marked here before, it has now been added in the revised manuscript.
Q10: Authors need to discuss the soil sample preparation for the test elaborately (sample preparation standards references).
Response: Thanks for your comments, the content and standard reference for soil sample preparation has now been supplemented.
Q11：The section “Effect of F-T cycles on the micro-structure of soil samples” (Starting from line 217) was not clear should rewrite elaborately. In line 217 – “A new soil particle structure is gradually formed”- what is the meaning of this sentence? What is the new structure and how authors confirmed the new structure of soil particles? Authors give more details about IPP analysis (i.e., how many photographs are analysed for the determination of pores in soil samples).
Response: Sorry for the lack of clarity in this section, this section has been rewritten and IPP more details are provided on p7-224. The expression "a new soil particle structure is gradually formed" is inaccurate, the author The original intention is to express that the soil microstructure after freezing and thawing is significantly different from the previous one.
In a word, thank you very much for your professional comment, which is very helpful to improve the quality of the article. I have learned a lot. Thank you again for your hard work.
Author Response File: 
Author Response.doc
Reviewer 2 Report
The abstract and conclusions fully correspond to the results of the conducted experiments.
The experiments are well described and the presented results are significant.
The information is easy to understand.
Research is important from both a scientific and a practical point of view.
But the formatting of manuscript can be better (ex.: title of figures must be in the same page as the figure)
Author Response
Dear Editor and Reviewer,
Thank you very much for giving us an opportunity to revise our manuscript entitled “Variation Mechanism and Prediction of Soil-Water Characteristic Curve Parameters of Low Liquid Limit Silty Clay under Freeze-Thaw Cycles” (applsci-1857427) by Xiaohan Luan and Leilei Han for publication in Applied Sciences.
We appreciate your hard work in pointing out the important revisions needed in the paper. We have seriously taken these comments into account. What we have changed in response to the reviewers’ comments are given point by point in the following pages attached in this letter.
We hope that all these changes fulfill the requirements to make the manuscript acceptable for publication in Applied Sciences.
Looking forward to hearing from you soon.
Yours Sincerely,
Leilei Han
Response to the Reviewer #2’s comments:
Thank you very much for your high evaluation and recognition of this work. We will continue to do follow-up research. Thank you again for your hard work.
Author Response File: Author Response.doc
Reviewer 3 Report
It is interesting research work presented well. The authors may consider reducing acronyms and improve the resolution of the images in the manuscript.
Author Response
Dear Editor and Reviewer,
Thank you very much for giving us an opportunity to revise our manuscript entitled “Variation Mechanism and Prediction of Soil-Water Characteristic Curve Parameters of Low Liquid Limit Silty Clay under Freeze-Thaw Cycles” (applsci-1857427) by Xiaohan Luan and Leilei Han for publication in Applied Sciences.
We appreciate your hard work in pointing out the important revisions needed in the paper. We have seriously taken these comments into account. What we have changed in response to the reviewers’ comments are given point by point in the following pages attached in this letter.
We hope that all these changes fulfill the requirements to make the manuscript acceptable for publication in Applied Sciences.
Looking forward to hearing from you soon.
Yours Sincerely,
Leilei Han
Response to the Reviewer #3’s comments:
Thank you very much for your high evaluation and recognition of this work. We will continue to do follow-up research. Thank you again for your hard work.
Author Response File: Author Response.doc
Reviewer 4 Report
Minor
- Please change micro-structure to microstructure.
- Please change "matrix suction "to "matric suction"
- Table 1 and Figure 1 can be separated.
- Fig. 1 (b): a scale can be added to the photo.
- Line 117 or Fig. 2: please add more information about the thermostatic chamber (manufacturer, model, etc).
- Equation 1: use log instead of lg
- Line 147: use × instead of *
- Equation 5: change s2 to s2 (subscript)
Author Response
Dear Editor and Reviewer,
Thank you very much for giving us an opportunity to revise our manuscript entitled “Variation Mechanism and Prediction of Soil-Water Characteristic Curve Parameters of Low Liquid Limit Silty Clay under Freeze-Thaw Cycles” (applsci-1857427) by Xiaohan Luan and Leilei Han for publication in Applied Sciences.
We appreciate your hard work in pointing out the important revisions needed in the paper. We have seriously taken these comments into account. What we have changed in response to the reviewers’ comments are given point by point in the following pages attached in this letter.
We hope that all these changes fulfill the requirements to make the manuscript acceptable for publication in Applied Sciences.
Looking forward to hearing from you soon.
Yours Sincerely,
Leilei Han
Response to the Reviewer #4’s comments:
We appreciate for your valuable suggestions. We have revised the manuscript according to the reviewer’s comments, and hope that the revised manuscript can be better than the original one. Thanks very much.
Q1: Please change micro-structure to microstructure.
Response: Thanks for your professional suggestion. The “micro-structure” has been revised.
Q2: Please change "matrix suction "to "matric suction".
Response: Thanks for your professional suggestion. The “matrix suction” has been revised.
Q3: Table 1 and Figure 1 can be separated.
Response: Thanks for your professional suggestion. Table 1 and Figure 1 has been separated in the revised manuscript.
Q4: Fig. 1 (b): a scale can be added to the photo.
Response: Thanks for your professional suggestion. The scale has been added to the photo.
Q5: Line 117 or Fig. 2: please add more information about the thermostatic chamber (manufacturer, model, etc).
Response: Thanks for your professional suggestion. The information has been added.
Q6: Equation 1: use log instead of lg.
Response: Thank you for your suggestion. The mistake has been corrected.
Q7: Line 147: use × instead of *.
Response: Thanks for your valuable suggestion, the mistake has been corrected.
Q8: Equation 5: change s2 to s2 (subscript).
Response: Thank you for your suggestion. The mistake has been corrected.
In a word, thank you very much for your professional comment, which is very helpful to improve the quality of the article. I have learned a lot. Thank you again for your hard work.
Round 2
Reviewer 1 Report
Most of the technical questions are not answered properly.
