Experimental Study on the Electrical Resistivity Characteristics of Uniformly Graded Calcareous Sand

Round 1

Reviewer 1 Report

The article discusses the properties of known sand, which has high resistivity, which can be used as protective materials, as well as determining the relationship between resistivity and mechanical properties of sand. The basis of the research was a series of experiments aimed at studying the influence of temperature, water, and density on winter resistivity. In general, this area of research is very promising and interesting, as it allows us to answer a number of fundamental questions in this area. The article was prepared taking into account the basic requirements of the journal and corresponds to the topics of the stated research. In general, this work can be accepted for publication after the authors answer a number of questions that the reviewer had while reading it.

1. In the abstract, the authors should provide numerical values of changes in resistivity depending on external factors, in particular, when the fraction varies, the authors report changes in the resistivity value, but no numerical values are presented. This should be addressed in the revised version.

2. The authors should reflect in more detail the experimental conditions in Table 2, as well as exactly how they varied, in what range, etc., not only describe the fraction sizes.

3. For all studied quantities, it is necessary to provide not only the curves describing the dependences, but also the measurement errors, since data with errors can have a significant impact on the description of the observed quantities.

4. The authors should combine Figures 1 and 3 into a general experimental design, and also provide data on the filling density of the boxes.

5. It is not clear how exactly the experiments were carried out to determine the effect of water on the change in resistivity; the authors should provide more details on these experiments.

6. On technical notes. Authors should provide links to all calculation formulas used, in accordance with the basic citation requirements.

Author Response

1. In the abstract, the authors should provide numerical values of changes in resistivity depending on external factors, in particular, when the fraction varies, the authors report changes in the resistivity value, but no numerical values are presented. This should be addressed in the revised version.

Thank you for the reviewer's feedback. Modifications have been made in the paper.

2. The authors should reflect in more detail the experimental conditions in Table 2, as well as exactly how they varied, in what range, etc., not only describe the fraction sizes.

Thank you for the reviewer's feedback. The main purpose of this article is to study the effect of a single particle size change on the resistivity of calcareous sand. The test plan in Table 2 is the test plan for each single particle size sample under different influencing factors.

3. For all studied quantities, it is necessary to provide not only the curves describing the dependences, but also the measurement errors, since data with errors can have a significant impact on the description of the observed quantities.

Thank you for the reviewer's feedback. Modifications have been made in the paper.

4. The authors should combine Figures 1 and 3 into a general experimental design, and also provide data on the filling density of the boxes.

Thank you for the reviewer's feedback. Table 2 has provided the density of each sample. The testing method of the experimental instrument has been added in Figure 1.

5. It is not clear how exactly the experiments were carried out to determine the effect of water on the change in resistivity; the authors should provide more details on these experiments.

Thank you for the reviewer's feedback. Corresponding descriptions have been added in the paper.

6. On technical notes. Authors should provide links to all calculation formulas used, in accordance with the basic citation requirements.

Thank you for the reviewer's feedback. Relevant citations have been added to the paper.

Reviewer 2 Report

File attached.

Comments for author File: Comments.docx

Readable.

Author Response

1. The abstract section should be rewritten, in a progressive way including the need and critical finding of the work.

Thank you for the reviewer's feedback. The abstract section of the paper has been rewritten in response to the reviewer's comments

2. In introduction section, the general information can be reduced and target the research gap through discussing the relevant literature.

Thank you for the reviewer's feedback. Corresponding descriptions have been added to the paper

3. Some latest work needs to be introduced in the content and discuss.

Thank you for the reviewer's feedback. Corresponding descriptions have been added to the paper

4. The advantages/ background of the material should be discussed in introduction section, clearly.

Thank you for the reviewer's feedback. Modifications have been made in the paper

5. What are the advantages of this work over published literature, results should be compared.

Thank you for the reviewer's feedback. Corresponding descriptions have been added to the paper

6. References that are more than 7 years should be reduced.

Thank you for the reviewer's feedback. Modifications have been made in the paper

7. The overall presentation of work is weak. There are some language errors and description errors in the article, which can be modified to make the article more beautiful. 

Thank you for the reviewer's feedback. Modifications have been made in the paper

Reviewer 3 Report

This article focuses on “Experimental Study on the Electrical Resistivity Characteristics of Uniformly-graded Calcareous Sand.” This manuscript is well organized. However, some minor issues need to be addressed before publication.

1、It is suggested to update the research background.

2、Explain the reason for choosing tap water as the pore fluid for most experiments.

3、The reason why the resistivity of calcareous sand increases with increasing relative density.

4、The number of decimal places should be consistent, as shown in line 281.

5、The wording regarding particle size in the text should be consistent, particle group/particle fraction.

6、The conclusion should be re-written and made briefer to show the major findings of the study and conclusions drawn.

7、Some latest literature review on the data analytic methods on the energy systems is suggested to be included in the Introduction to enrich the state-of-the art review. See “Machine Learning and Data-Driven Techniques for the Control of SmartPower Generation Systems: An Uncertainty Handling Perspective”

major

Author Response

1、It is suggested to update the research background.

Thank you for the reviewer's feedback. The research background in the paper has been updated

2、Explain the reason for choosing tap water as the pore fluid for most experiments.

Thank you for the reviewer's feedback. (1) The cost of using tap water as pore water is low; (2) When pure water is used as pore water, the resistivity of the sample is relatively high, while when salt solution is used as pore water, the resistivity is too low, so tap water is chosen as pore water.

3、The reason why the resistivity of calcareous sand increases with increasing relative density.

Thank you for the reviewer's feedback.There is already a relevant description in the text, see lines 343-346

4、The number of decimal places should be consistent, as shown in line 281.

Thank you for the reviewer's feedback. Modifications have been made in the paper

5、The wording regarding particle size in the text should be consistent, particle group/particle fraction.

Thank you for the reviewer's feedback. Modifications have been made in the paper

6、The conclusion should be re-written and made briefer to show the major findings of the study and conclusions drawn.

Thank you for the reviewer's feedback. Modifications have been made in the paper

7、Some latest literature review on the data analytic methods on the energy systems is suggested to be included in the Introduction to enrich the state-of-the art review.

Thank you for the reviewer's feedback. Modifications have been made in the paper

Reviewer 4 Report

Title and author of paper

Reviewer comments on “Experimental Study on the Electrical Resistivity Characteristics of Uniformly-graded Calcareous Sand” from Heying Hou, Wei Han, Tianxiang Li, et, al.

Comments

• The three photos in Figure 2 are all too blurry. Please provide clearer photos.

• How many readings are taken on the same sample during resistance measurement? As is well known, the values obtained from a single resistance measurement have great randomness. How to eliminate measurement errors?

• “dried at 105~110 ℃ for at least 8 hours” at line 107-108. Will the drying temperature of 105-110 ℃ cause changes in some components of calcareous sand, and what method is used to determine the complete drying of calcareous sand after 8 hours?

• Please add pictures of the electrical resistivity testing process in the article.

• Some of the legends in Figure 13 exhibit stacking phenomenon. Please present the results in a clearer form.

• Please pay attention to adjusting the format of the references. Some references such as "References 6-8, 12" have formatting issues.

Recommendations

The research is systematic and complete, and it is recommended to publish it after modification.

Minor editing of English language required

Author Response

• The three photos in Figure 2 are all too blurry. Please provide clearer photos.

Thank you for the reviewer's feedback. The image in Figure 2 has been replaced with a clearer photo

• How many readings are taken on the same sample during resistance measurement? As is well known, the values obtained from a single resistance measurement have great randomness. How to eliminate measurement errors?

Thank you for the reviewer's feedback. The description of data reading has been supplemented in the text

• “dried at 105~110 ℃ for at least 8 hours” at line 107-108. Will the drying temperature of 105-110 ℃ cause changes in some components of calcareous sand, and what method is used to determine the complete drying of calcareous sand after 8 hours?

Thank you for the reviewer's feedback. According to the soil test specifications and research results of relevant scholars, calcareous sand can be dried for more than 8 hours at 105~110 ℃, and this temperature does not change the composition of calcareous sand.

• Please add pictures of the electrical resistivity testing process in the article.

Thank you for the reviewer's feedback. The resistivity test image that has been added in Figure 1.

• Some of the legends in Figure 13 exhibit stacking phenomenon. Please present the results in a clearer form.

Thank you for the reviewer's feedback. Figure 13 shows the electrical resistivity of calcareous sand with different particle sizes and relative densities. Although stacking appears in the figure, a general trend can be observed.

• Please pay attention to adjusting the format of the references. Some references such as "References 6-8, 12" have formatting issues.

Thank you for the reviewer's feedback. Modifications have been made in the paper.

Reviewer 5 Report

This paper presented a fundamental study of electrical resistivity of calcareous sand considering many influential factors. The contents are comprehensive and the experimental data have good potential of usage. Generally, this work is well presented, and there are some comments for authors to consider:

1)     Usually the electrical resistivity characteristics include both DC case and AC case, each case has its own engineering applications. The authors are suggested to explain the reason to use AC instead of DC. And also some differences between AC and DC are suggested to be discussed. Some related literatures are: W. Elkey, E.J. Sellevold, Electrical resistivity of concrete, (1995).; Construction and Building Materials 363 (2023) 129830.; Structural Concrete 24(1) (2023) 374-388.; Journal of Advanced Concrete Technology 14(2) (2016) 35-46.

2)     For the sand after compaction, there is still large volume of space between particles, how to consider this factor in the resistivity analysis? Since the electric current transport mainly through the contacted surface between two particles.

3)     Fig. 3, it is suggested to add some photos with sand in the box.

4)     Fig. 7, the vertical axis might use log scale.

5)     Also Fig. 10, not sure the resistivity is constant or not within 60% to 100% saturation, maybe log scale can be clearer.

6)     If possible, it is suggested to show a general empirical model covering all the important parameters at the end of Chapter 4.

None

Author Response

1) Usually the electrical resistivity characteristics include both DC case and AC case, each case has its own engineering applications. The authors are suggested to explain the reason to use AC instead of DC. And also some differences between AC and DC are suggested to be discussed. Some related literatures are: W. Elkey, E.J. Sellevold, Electrical resistivity of concrete, (1995).; Construction and Building Materials 363 (2023) 129830.; Structural Concrete 24(1) (2023) 374-388.; Journal of Advanced Concrete Technology 14(2) (2016) 35-46.

Thank you for the reviewer's feedback.There are already relevant explanations in the paper. Using an AC power source for testing could eliminate measurement errors caused by electrode polarization effects

2) For the sand after compaction, there is still large volume of space between particles, how to consider this factor in the resistivity analysis? Since the electric current transport mainly through the contacted surface between two particles.

Thank you for the reviewer's feedback. For saturated calcareous sand, current is mainly conducted through pore water in the pores, and the presence of intergranular pores is a necessary condition for current conduction.

3)  Fig. 3, it is suggested to add some photos with sand in the box.

Thank you for the reviewer's feedback. Figure 3 is mainly to highlight the size of the box, so there is no additional photo of sand in the box.

4)  Fig. 7, the vertical axis might use log scale.

Thank you for the reviewer's feedback. The author attempted to use logarithmic and linear coordinates for the vertical axis, and after comparative analysis, it was found that linear coordinates have a better effect.

5) Also Fig. 10, not sure the resistivity is constant or not within 60% to 100% saturation, maybe log scale can be clearer.

Thank you for the reviewer's feedback. The author attempted to use logarithmic and linear coordinates for the vertical axis, and after comparative analysis, it was found that linear coordinates have a better effect.

6) If possible, it is suggested to show a general empirical model covering all the important parameters at the end of Chapter 4.

Thank you for the reviewer's feedback. Because there are many influencing factors, it is difficult to include all factors in one formula.

Reviewer 6 Report

The following modifications are suggested:

1.       Line 16-20: The abstract should contain the main result values.

2.       Introduction: Many references used in the study are outdated, such as 2004, 2005, 2007 etc. Author needs to cite most recent related references.

3.       Section 2.3 The schematic diagram of the experimental setup must be provided for better understanding.

4.       Abbreviation list is missing.

5.       The details of the equipments used in this study should be provided such as equipment name (mode, company, country).

6.       Section 4. There must be a paragraph of the result and discussion before section 4.1.

7.       The authors checked the effect of different parameters such as: temperature, resistivity, saturation, density. Can the author explain which parameter has more effect?

Author Response

1. Line 16-20: The abstract should contain the main result values.

Thank you for the reviewer's feedback. The abstract section in the article has been reviewed

2. Introduction: Many references used in the study are outdated, such as 2004, 2005, 2007 etc. Author needs to cite most recent related references.

Thank you for the reviewer's feedback. The references in the article have been updated.

3. Section 2.3 The schematic diagram of the experimental setup must be provided for better understanding...

Thank you for the reviewer's feedback. Relevant descriptions have been added in section 2.3 of the text

4. Abbreviation list is missing.

Thank you for the reviewer's feedback. Modifications will be made in the future according to the requirements of the journal.

5. The details of the equipments used in this study should be provided such as equipment name (mode, company, country).

Thank you for the reviewer's feedback. The model of the testing instrument used in this article has been added to the corresponding positions in the text

6. Section 4. There must be a paragraph of the result and discussion before section 4.1.

Thank you for the reviewer's feedback. Corresponding content has been added before section 4.1

7. The authors checked the effect of different parameters such as: temperature, resistivity, saturation, density. Can the author explain which parameter has more effect?

Thank you for the reviewer's feedback. From the data in the text, it can be seen that saturation has a significant impact on the resistivity of calcareous sand in terms of numerical changes in resistivity.

Round 2

Reviewer 1 Report

The authors answered all the questions posed, the article can be accepted for publication.

Author Response

Thank you to the reviewer.

Reviewer 2 Report

The author has addressed the comments satisfactorily.  

Readable.

Author Response

Thank you to the reviewer.

Reviewer 5 Report

None

None

Author Response

Thank you to the reviewer.

Reviewer 6 Report

The authors have revised accordingly. 

Author Response

Thank you to the reviewer.