Non-Destructive Methods for Assessing the Condition of Reinforcement Materials in Soil
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper is well written and can be accepted in its current form.
Comments on the Quality of English LanguageThe English language is good.
Author Response
I would like to express my sincere gratitude for taking the time to review my manuscript.
Thank you once again for your time and effort.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript presents innovative non-destructive methods for evaluating the condition of reinforcement materials in soil. While the research holds promise, the manuscript requires significant revisions before it can be reconsidered for publication. The following comments outline key areas that need attention:
1. The introduction currently lacks a discussion on the status of research regarding performance monitoring methods for reinforced earth retaining walls. I recommend providing a succinct overview of existing methods to establish a baseline for comparison. Highlight how the research methods presented in this manuscript contribute uniquely to this field. This will help underscore the novelty and relevance of the work.
2. There appears to be a discrepancy between the description in the text and the data presented in Figure 8. It is crucial that the figure accurately reflects the textual description to maintain the integrity of the data presented. Please review and rectify any inconsistencies to ensure that the figure and text are harmonious.
3. The difference in strain results for geosynthetic materials measured by optical fibers and strain gauges is noted in Figure 8, attributed to differing measurement distances. However, the explanation provided lacks depth and clarity, making it unconvincing. Please elaborate on how these differences in measurement techniques could contribute to the observed results, potentially discussing any relevant literature or theoretical frameworks.
4. There are errors and unclear explanations in some of the images in the paper:
l Figure 1: The usage of aramid fibers needs to be introduced and explained in the text since they are depicted in the figure.
l Figure 8: Correct the spelling from 'strip gauge' to 'strain gauge' to avoid any confusion.
l Figure 11: Please review and correct the annotations as they seem to contain errors. It is imperative that all figures are clear and correctly annotated to support the data they represent.
5. The manuscript currently lacks a detailed analysis of both indoor and field test results. For example, the strain results of geosynthetic materials at different heights of the reinforced earth walls should be compared and analyzed to provide insights into the behavior under varied stress conditions. Adding this comparison could significantly enhance the depth of the study and provide a more comprehensive understanding of the materials' performance in different conditions.
Comments on the Quality of English LanguageExtensive editing of English language required.
Author Response
Comments 1: The introduction currently lacks a discussion on the status of research regarding performance monitoring methods for reinforced earth retaining walls. I recommend providing a succinct overview of existing methods to establish a baseline for comparison. Highlight how the research methods presented in this manuscript contribute uniquely to this field. This will help underscore the novelty and relevance of the work.
Response 1: Thank you for pointing this out. We agree with this comment. Therefore, We have added a discussion in the introduction on the current state of research regarding performance monitoring methods for reinforced earth retaining walls. The revised section provides a succinct overview of existing methods, establishing a baseline for comparison. Additionally, We have emphasized how the research methods presented in this manuscript offer unique contributions to the field. This inclusion aims to underscore both the novelty and relevance of the work as per your recommendation.
The additional description can be found from line 42 on page 1 to line 56 on page 2.
A reference [5] showing the current status of inspections has been added.Subsequent references have been renumbered accordingly.
Comments 2: There appears to be a discrepancy between the description in the text and the data presented in Figure 8. It is crucial that the figure accurately reflects the textual description to maintain the integrity of the data presented. Please review and rectify any inconsistencies to ensure that the figure and text are harmonious.
Response 2: Thank you for your valuable feedback. Upon review, we identified an inconsistency between the textual description and Figure 8. We have now corrected the description in the text to align with the data presented in the figure. Specifically, we have updated lines 177 to 178 on page 6 to read: “The results for a reinforcement material 6.0 m in length, placed at a height of 2.25 m from the base of the reinforced earth wall, are shown in Figure 8.” This update ensures consistency between the figure and the text. We appreciate your careful review and apologize for any confusion caused.
Comments 3: The difference in strain results for geosynthetic materials measured by optical fibers and strain gauges is noted in Figure 8, attributed to differing measurement distances. However, the explanation provided lacks depth and clarity, making it unconvincing. Please elaborate on how these differences in measurement techniques could contribute to the observed results, potentially discussing any relevant literature or theoretical frameworks.
Response 3: Thank you for your valuable feedback. We acknowledge the difference in strain results measured by optical fibers and strain gauges, and we believe this is due to the difference in measurement intervals between the two techniques. We have revised the manuscript to clarify this point:
“It can also be seen that the distribution of strain measured using a strain gauge and the distribution profile obtained using optical fibers are slightly different. Strain gauges measure local strain over a small area of approximately 10 mm and are spaced 1.5 m apart, meaning they cannot capture strain changes between the gauges. In contrast, optical fibers measure the average strain over continuous 1 m intervals, with data points recorded every 0.2 m. This difference in the measurement intervals and spatial coverage is likely responsible for the variations in the strain distribution profiles.”
Comments 4: There are errors and unclear explanations in some of the images in the paper:
l Figure 1: The usage of aramid fibers needs to be introduced and explained in the text since they are depicted in the figure.
l Figure 8: Correct the spelling from 'strip gauge' to 'strain gauge' to avoid any confusion.
l Figure 11: Please review and correct the annotations as they seem to contain errors. It is imperative that all figures are clear and correctly annotated to support the data they represent.
Response 4: Thank you for your valuable feedback. We have addressed your comments as follows:
1. Figure 1: We have introduced and explained the use of aramid fibers in the text.
The correction is on page 2, lines 77 through 81.
"As shown in Figure 1, this geosynthetic consists of a high-elasticity aramid fiber covered in a grid pattern with high-density polyethylene, with the strength provided by the aramid fiber. By replacing one of the aramid fibers with an optical fiber, it becomes possible to measure the strain occurring in the geosynthetics."
2.Figure 8: We have corrected the spelling to “strain gauge”.
3.Figure 11: The vertical axis of the graph shows absolute values. The maxima are + values and minima are negative values, and the graph plots their absolute values. We have modified the graph to avoid any misunderstanding.
Comments 5: The manuscript currently lacks a detailed analysis of both indoor and field test results. For example, the strain results of geosynthetic materials at different heights of the reinforced earth walls should be compared and analyzed to provide insights into the behavior under varied stress conditions. Adding this comparison could significantly enhance the depth of the study and provide a more comprehensive understanding of the materials' performance in different conditions.
Response 5: Thank you for your comments. Based on the reviewer's comments, we will add a detailed analysis of the test results. Please allow 10 days for the additional details.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper proposes two non-destructive methods for assessing the condition of reinforcing material in reinforced earth walls: a method for assessing the geosynthetic material and the other for steel plates.
The method for assessing the geosynthetic material is proposed based on some results of a published case study. While the method for assessing the steel plates is proposed based on results of a laboratory and field experiments.
General Comment:
The first method which is proposed for assessing the condition of geosynthetic material based on some results of a published case study, was previously proposed in 2009 in the paper titled “A new optical fiber sensor to assess the stability of geogrid-reinforced soil walls” by Yashima et al. in “Geosynthetics International”, 2009, 16, No. 4. Even in the previously published investigation, detailed results of 3 case studies were utilized. One of those three case studies was the same as that mentioned in this manuscript, however, in more comprehensive way.
Other Comments:
11. Some parts of the text need reference to be added. For example, it was stated in the sentence in Lines 70 and 71 that a strain gauge lasts from 2 to 3 years in soils, a reference for such a statement should be provided.
22. In Line 77, some results of only one case study were shown, therefore, “cases” should be changed to “case”.
33. In Line 120 and Figure 2, the corrosion accelerant used should be mentioned.
44. Section 2.2.2 should be re-written to make it clear that there was more than one experiment conducted in the field, and that the two types of steel samples were used in the buried samples study not in the study performed on samples on the ground surface.
55. Under Section 3, Subsections 3.1 and 3.2 have the same headings. The heading of Subsection 3.2 should be related to the results of the magnetic survey study.
66. In Figure 8, there were only 5 strain gauges, there were no strain gauges at 6 m. The strain gauges symbols should be removed from distance 6 m.
77. Discussion on Figure 8 indicates that measurements for 0.2 m were taken but the average along 1 m distance was used. It can be seen from Figure 8, that the values per 0.2 m are used not the average value per 1 m.
88. In Line 175, “performed field” should be changed to “performed in the field”.
99. In Line 189, it is not clear what is meant by “located field”.
110. The results shown in Figure 10 is for the third plate. This should be clearly indicated in the text and in the figure itself.
111. In Line 222, “will impossible” should be changed to “will be impossible”.
112. The conclusion in Lines 223 to 225 related to the durability of the optical fiber sensor was not addressed in the paper. Conclusions should be on results addressed in the paper.
113. Results of magnetic flux intensity shown in Figure 12 is for plate arrangement that is different from that shown in Figure 6. The correct arrangement should be shown in both figures. If there were more than one arrangement, then both of them can be shown.
114. Results of the magnetic survey on buried plates show that the flux intensity fades quickly with depth. At a depth of one meter, practically there was no difference. Does that mean that this method is only useful for very shallow layers of reinforcement?
Comments on the Quality of English Language
Corrections as mentioned above are required.
Author Response
Comments 1: Some parts of the text need reference to be added. For example, it was stated in the sentence in Lines 70 and 71 that a strain gauge lasts from 2 to 3 years in soils, a reference for such a statement should be provided.
Response 1: Thank you for your valuable feedback. I appreciate your point regarding the need for a reference to support the statement made in Lines 70 and 71 about the lifespan of strain gauges in soils. Based on my experience, I believe that the lifespan is approximately 10 years, particularly in moisture-rich soil environments. I have updated the text accordingly, as follows:
"Strain gauges have traditionally been used to measure the strain in geosynthetics. A strain gauge measures changes in electrical resistance. However, in moisture-rich environments within soil, the durability of a strain gauge is limited to about 10 years at most due to issues like wiring corrosion and adhesive degradation. Based on my experience, failures can occur even sooner."
Since there is no specific literature to cite, I have relied on my professional observations to support this assertion. I will continue to pay attention to such details to enhance the quality of the manuscript. Thank you again for your guidance.
Comments 2: In Line 77, some results of only one case study were shown, therefore, “cases” should be changed to “case”.
Response 2: Thank you for your valuable feedback. We have carefully reviewed Line 77 and agree with your suggestion. We have revised the text to change ‘cases’ to ‘case’ as recommended.
Comments 3: In Line 120 and Figure 2, the corrosion accelerant used should be mentioned.
Response 3: Thank you for your valuable comment. We have revised the manuscript to include the mention of the corrosion accelerant used. Specifically, in Line 120 and Figure 2, we have now added details regarding the use of an inorganic halides aqueous solution with a 10% concentration as the corrosion accelerant.
"Figure 2. States of corrosion due to corrosion accelerant. (using a 10% aqueous solution of inorganic halides)"
Comments 4: Section 2.2.2 should be re-written to make it clear that there was more than one experiment conducted in the field, and that the two types of steel samples were used in the buried samples study not in the study performed on samples on the ground surface.
Response 4: Thank you for your valuable feedback. In response to your comment, we have revised Section 2.2.2 to clarify the distinction between the field experiments and the types of steel samples used. Specifically, we have made it clear that two types of reinforcement materials—one with anti-corrosion treatment (zinc galvanization) and one without—were used in the buried samples study, not in the study performed on the ground surface. The revised section now clearly distinguishes between the experiment conducted on the ground surface and the experiment involving buried samples at various depths.
"2.2.2. Field experiment
Based on the data of the laboratory experiment, we conducted the field experiment to reproduce a state of corrosion. Portions of the steel reinforcement (1160×60×4 mm) were subjected to defects or severing, as shown in Figure 4. These were placed on the ground surface, and the magnetic field (magnetic flux density) was measured directly above the steel along the survey line using the Optically pumped magnetometer (Geometrics, G-858G) (Figure 5). The objective was to compare the magnetic fields of new reinforcement and reinforcement with defects simulating corrosion, in order to understand the relationship between corrosion and the magnetic field.
Additionally, new reinforcement materials were buried at different depths (0.5, 0.75, and 1.0 m) underground (Figure 6), and the magnetic field was measured from the surface. The objective was to determine whether it is possible to measure the magnetic field in buried conditions and to establish the effective measurement range. Two types of reinforcement materials—one with anti-corrosion treatment (zinc galvanization) and one without—were buried at the same depths. Regular measurements will be conducted in the future to compare and verify the results based on the presence or absence of anti-corrosion treatment over the long term."
Comments 5: Under Section 3, Subsections 3.1 and 3.2 have the same headings. The heading of Subsection 3.2 should be related to the results of the magnetic survey study.
Response 5: Thank you for your feedback regarding the headings in Section 3. We have corrected the title of Subsection 3.2, which was previously incorrect. The new title is now “Change in magnetism caused by corrosion in steel reinforcement materials,” which more accurately reflects the results of the magnetic survey study.
Comments 6: In Figure 8, there were only 5 strain gauges, there were no strain gauges at 6 m. The strain gauges symbols should be removed from distance 6 m.
Response 6: Thank you for your valuable feedback. Upon review, we identified an inconsistency between the textual description and Figure 8. We have now corrected the description in the text to align with the data presented in the figure. Specifically, we have updated lines 177 to 178 on page 6 to read: “The results for a reinforcement material 6.0 m in length, placed at a height of 2.25 m from the base of the reinforced earth wall, are shown in Figure 8.” This update ensures consistency between the figure and the text. We appreciate your careful review and apologize for any confusion caused.
Comments 7: Discussion on Figure 8 indicates that measurements for 0.2 m were taken but the average along 1 m distance was used. It can be seen from Figure 8, that the values per 0.2 m are used not the average value per 1 m.
Response 7:Thank you for your valuable comment regarding the discussion on Figure 8. To clarify this point and avoid any misunderstanding, we have added the following explanation:
“It can also be seen that the distribution of strain measured using a strain gauge and the distribution profile obtained using optical fibers are slightly different. Strain gauges measure local strain over a small area of approximately 10 mm and are spaced 1.5 m apart, meaning they cannot capture strain changes between the gauges. In contrast, optical fibers measure the average strain over continuous 1 m intervals, with data points recorded every 0.2 m. This difference in the measurement intervals and spatial coverage is likely responsible for the variations in the strain distribution profiles.”
Comments 8: In Line 175, “performed field” should be changed to “performed in the field”.
Response 8: Thank you for your careful review and for pointing out the phrasing issue. We have made the necessary correction by changing “performed field” to “performed in the field” . We appreciate your attention to detail, which has helped improve the clarity of the manuscript.
Comments 9: In Line 189, it is not clear what is meant by “located field”.
Response 9: Thank you for your valuable feedback. I acknowledge that the term “located field” was unclear. I have removed this expression from the manuscript.
Comments 10: The results shown in Figure 10 is for the third plate. This should be clearly indicated in the text and in the figure itself.
Response 10: Thank you for your constructive feedback. To clarify that the results shown in Figure 10 pertain to the third plate, I have added the following sentence to section 3.2.2:
"Measurements were taken using three reinforcement materials, and similar trends were obtained. Figure 10 shows the results for the third plate. Defects of varying sizes were simulated on the three reinforcement materials."
Additionally, I have revised the figure caption to read: “Figure 10. Magnetic field (magnetic flux) of 3rd plate.”
Comments 11: In Line 222, “will impossible” should be changed to “will be impossible”.
Response 11: Thank you for your feedback. I have reviewed the suggested section, and the sentence has been revised to “will be impossible.” I appreciate your helpful comment.
Comments 12: The conclusion in Lines 223 to 225 related to the durability of the optical fiber sensor was not addressed in the paper. Conclusions should be on results addressed in the paper.
Response 12: Thank you for your feedback. To address your concern, I will remove the section related to the durability of the optical fiber sensor from the conclusion. I appreciate your careful review and suggestion.
Comments 13: Results of magnetic flux intensity shown in Figure 12 is for plate arrangement that is different from that shown in Figure 6. The correct arrangement should be shown in both figures. If there were more than one arrangement, then both of them can be shown.
Response 13: Thank you for your valuable feedback. To avoid any confusion, I have revised Figure 6 to ensure clarity and consistency with Figure 12. I appreciate your attention to detail.
Comments 14: Results of the magnetic survey on buried plates show that the flux intensity fades quickly with depth. At a depth of one meter, practically there was no difference. Does that mean that this method is only useful for very shallow layers of reinforcement?
Response14: Thank you for your insightful comment. The results of the magnetic survey on buried plates indicate that the flux intensity fades quickly with depth. At a depth of one meter, there is practically no difference observed. This suggests that this method may only be useful for very shallow layers of reinforcement. In my view, while this method is effective for shallow layers, we need to consider its limitations regarding deeper applications. To address this point, I will be adding a conclusion section to elaborate on my thoughts. These revisions will be completed by October 18.
Response 14: Thank you for your insightful comment. As you have pointed out, the results of the magnetic survey indicate that the magnetic flux intensity fades rapidly with depth, and at a depth of one meter, there was practically no difference. This suggests that the method may indeed be more suitable for very shallow layers of reinforcement. I am currently preparing an additional section in the conclusion to include my thoughts on this matter, and I will complete these revisions by October 18.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have adequately addressed the sugestions and comments made by the reviewers in the revised manuscript.
Comments on the Quality of English LanguageNone
Author Response
I would like to express my sincere gratitude for taking the time to review my manuscript.
Thank you once again for your time and effort.
Reviewer 3 Report
Comments and Suggestions for Authors*Authors' replies to the reviewer's comments are satisfactory.
*In Line 112 (last sentence in second paragraph of Section 2.2), what is meant by "tempe"? Is it "temperature"? Correction should be made.
Comments on the Quality of English Language
Good quality
Author Response
Comments 1: In Line 112 (last sentence in second paragraph of Section 2.2), what is meant by "tempe"? Is it "temperature"? Correction should be made.
Response 1: Thank you for pointing out this oversight. ‘Tempe’ was indeed intended to mean ‘temperature.’ We have corrected the text accordingly in the revised manuscript.
Author Response File: Author Response.docx
