Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article is interesting and presents an approach that is little explored in the literature, which is the injection of grout while maintaining the tensile force in the bar, thereby bonding the pre-stressed reinforcing bar to the surrounding ground through the hardened grout. The topic is relevant and current, and may be important to the public. However, for the article to be accepted and published, it needs greater scientific rigor. The following items should be revised:
- The introduction is clear and broad, but still generic and with few citations. It lacks greater contextualization. The authors should deepen the introduction, providing more information on types of grouts, types of injection, among others. Figure 1, which shows the early-stage prestressed reinforcing bar insertion method, should not be in this item, but in the method section. Furthermore, the author should better explain this method and what tests were done to prove its efficiency;
- Item 2 is well explained, but why was the injection angle limited to only 35 degrees? And it needs to characterize the grout and not just state that it is ultra-rapid-hardening cement with a water–cement ratio of 30%, to which 1.3% of SikaCem admixture was added. What are the mechanical properties of this grout?
- Item 3, numerical analysis, should be completely revised, better explaining the parameters used, especially those in Table 2.
- Item 3.2, Analytical Result, seems to be item 4, correct? And it only has 1 page of results? There are few results in this article, making it a small contribution. In addition to few results, the analysis is very superficial and does not compare with other works in the area. For example, in Figure 8, Axial stress contour of the hardened grout body, there is no analysis. They just threw the figure at the end of the article and that's it.

I suggest a complete reformulation of the method, results, and analyses of the article.

Author Response

Thank you very much for your valuable review comments.
Please find the revised manuscript attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Good job. Below is the technical reviewer report for Geotechnics manuscript titled “Construction Test and Numerical Analysis on Reinforcing Bar Insertion Method Prestressed before Grout Hardening.”

Some minor comments:

1. The abstract clearly outlines both the experimental and numerical parts but remains mainly descriptive. To emphasize novelty, highlight that this study provides the first field verification of an early-stage prestressing technique for reinforcing bars. You could also add quantitative data such as the achieved residual tensile force (≈700–800 µ strain corresponding to ~42 kN) and the confirmed compressive stress in the grout body. Ending the abstract with a brief statement on potential applications for slope stabilization or anchor systems would strengthen its practical impact.
2. The introduction is thorough in describing slope-stabilization practices in Japan but should more clearly position this work relative to conventional post-tensioned methods. A concise paragraph identifying the key innovation, introducing prestress before grout hardening to induce compressive pre-stress in the grout, would help readers grasp its engineering significance. Linking this approach to known challenges (limited elongation in hardened grout, delayed stress transfer) would emphasize that the study contributes a realistic, constructible improvement to established ground-reinforcement techniques.
3. Again the introduction should go beyond Japan. As an example here [DOI: 10.1016/j.engfailanal.2024.108282] you can suggest also that “numerous damages and slope failures of natural and cut slopes have been reported” worldwide.
4. Figures 5(a)–(b) effectively summarize the strain evolution. The text could highlight more explicitly that the maintained strain of ~700–800 µ demonstrates successful residual prestress transfer. When discussing long-term changes, a short quantitative estimate of the 30-day loss rate (e.g., 5–10 %) would help contextualize time-dependent relaxation effects. The authors may also comment briefly on whether observed diurnal fluctuations correlate with measured temperature variations to reinforce the environmental interpretation.
5. A general comment is that the text is always short. More technical comments are suggested.
6. The six-step simulation sequence is logically organized. To improve clarity, briefly explain the physical rationale behind each parametric case: Case 2 (weakened grout), Case 3 (delayed prestress), Case 4 (no prestress). A comparative summary table showing maximum compressive stress in the grout and residual bar tension for each case would succinctly convey the results. Noting that Case 1 reproduces field data within ±10 % validates the modeling accuracy; this achievement deserves emphasis as a methodological benchmark.

Author Response

Thank you very much for your valuable review comments.
Please find the revised manuscript attached.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

SUMMARY
The presented article is relevant and relates to the subject of the Geotechnics magazine. The relevance of the study is due to the injection of the solution while maintaining the tensile force of the rod, which binds the prestressed reinforcing rod to the surrounding soil through the hardened solution.
Ultimately, the main goal is to increase the stability of the mortar in the soil to tensile loads. The authors conducted field tests, as well as numerical analysis, and obtained important scientific and practical results. 
The reviewer believes that the article has scientific novelty and practical significance, but recommends correcting some comments. 

COMMENTS

This study examines improving the resistance of soil mortar to tensile loads. The main idea is to connect prestressed reinforcement bars to the surrounding soil through hardened mortar.
 
I consider the topic original and relevant to this field. This is due to the need to improve the resistance of soil mortar to tensile loads. This is an important engineering challenge in geotechnics. The author's proposed approach is original. Therefore, this article fills a specific gap in this field. It adds new theoretical knowledge due to the fact that the authors conducted field tests. Their numerical analysis allowed them to propose new engineering solutions for improving the resistance of soil mortar to tensile loads. Thus, the article adds to the subject area in both scientific and practical terms.
 
Regarding methodology, the authors need to improve the structuring of their approach; a methodological framework for the study is needed. I have already written about this in detail in my comment #7.
 
To ensure that the conclusions are consistent with the presented evidence and arguments, the results obtained need to be discussed in more detail. I have already described this in detail in my comment #8.
 
The references provided are appropriate, but their number should be increased. Otherwise, the article appears too brief and does not fully reflect the state of the art of the problem under consideration.
1. The name doesn't look good enough. It is not clear from the name that we are talking about a solution for fixing soils. The author probably needs to add this so that the title of the article more clearly reflects the journal's focus.
2. The abstract lacks formulations of the scientific and technical problems to be solved. This should be added to the beginning of the annotation. The author immediately says that a new method has been proposed for installing a prestressed reinforcing rod at an early stage. However, it is necessary to start the annotation with the formulation of the problem.
3. There is also no quantitative expression of the result in the annotation. The author must show by how many percent or in what numerical ratio the proposed scientific and technical solutions are better than the existing ones. This should also be added.
4. The author gave only 3 keywords, and one of these words is "Numerical analysis", which is essentially just a well-known term that refers to absolutely any engineering article. In other words, the keywords were chosen unsuccessfully. The author needs to work with keywords. First, the word "Numerical analysis" should be removed, and the total number of keywords should be at least 7. This will be more correct, otherwise interested readers will not be able to find this article in the future.
5. The literature review is not large enough. The author needs to work in more detail with the scientific literature and provide a broader overview of the current state of the problem. The author analyzed an insufficient amount of scientific literature in the "Introduction" section. I would like the author to analyze at least 10 additional sources of literature over the past 5 years. The issues of fixing soil and solutions to contain tensile forces have been conducted in quite a large number of studies. Engineers and scientists all over the world are constantly solving problems on this topic. The description of the current state of the problem should be expanded.
6. It is methodologically incorrect to end the "Introduction" section with Figure 1. The formulations of the scientific applied problem, the purpose and objectives of the study should be placed here.
7. I would like to see the methodological scheme of the study in graphic form. This can be a flowchart containing variable studied factors and determined totals.
8. There is a missing section discussing the results. A comparative table should be provided between the previously proposed methods and the method proposed by the author. The advantages, disadvantages, risks and limitations of the received engineering proposals should be clearly analyzed and reflected. 
9. The list of references, as already mentioned, needs to be supplemented. It currently contains 30 sources, but it would be more logical to show at least 10 more sources on the research topic. Otherwise, the article looks too short and insufficiently informative.

Author Response

Thank you very much for your valuable review comments.
Please find the revised manuscript attached.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Manuscript Title: Construction Test and Numerical Analysis on Reinforcing Bar Insertion Method Prestressed before Grout Hardening

The manuscript addresses a technically and scientifically relevant topic in geotechnical engineering related to slope stabilization using reinforcing bar insertion techniques. The proposed method—“early-stage prestressing before grout hardening”—represents a novel construction approach aimed at enhancing system performance against tensile loads induced by slope movements.

The study combines a field construction test with a three-dimensional numerical analysis using PLAXIS 3D to reproduce the observed behavior. The manuscript is generally well structured and clearly written.

The abstract correctly states the objective and the overall methodology, yet it presents several important limitations:

It does not include key quantitative results (e.g., magnitude of prestressing, degree of agreement between measurements and simulations). At least some reference values are expected to provide context to interested readers.

The author uses general statements without numerical support.

The introduction adequately contextualizes slope failure mechanisms and motivates the development of the new method. However, to strengthen the problem statement and clarify the existing scientific gap, I recommend both specific and general improvements:

The manuscript lacks a theoretical discussion explaining why the compressive state induced in the grout prior to hardening would enhance tensile resistance.

No explicit hypotheses or research questions are formulated.

Regarding the methodology, the description of the site, materials, and construction procedure is detailed and clear. Nonetheless, several methodological limitations require deeper consideration in the manuscript:

The study appears to rely on a single reinforcing bar, which severely restricts the generalization of the results.

The grout hardening time was validated only through an air-curing test, not under real in situ conditions.

Environmental effects (temperature, humidity) were neither controlled nor reported, despite the later mention of thermal fluctuations.

Strain measurements were collected at only four points, limiting the interpretation of the stress gradient along the bar.

Most geotechnical parameters were estimated from N-values or typical reference values, without justification of the correlations or associated uncertainties.

Boundary conditions and interface formulations—critical aspects in anchor simulations—are not described in adequate detail.

The use of elastic–perfectly plastic constitutive models may be insufficient to capture the nonlinear behavior of the grout. The author should formally justify this modeling choice.

The results show reasonable agreement between simulations and measurements at three of the instrumented points, with a significant discrepancy near the ground surface. The proposed explanation—insufficient grout hardening—is plausible but remains unverified.

The discussion of stress evolution in the grout is clearly presented, showing the compressive state after prestress release. However, the manuscript does not quantify the benefit of prestressing (e.g., percentage increase in compressive stress or stiffness).

The conclusions appropriately reflect the study’s findings. However, they do not fully acknowledge the study’s limitations (lack of replication, parameter uncertainties, numerical simplifications, among others). Including a Limitations and Future Work section would strengthen the manuscript, especially regarding long-term performance and the need for additional tests.

With respect to the references, the list is extensive and includes recent literature. Nevertheless:

The bibliography is heavily focused on Japanese studies, limiting its international perspective.

Some cited works are conference proceedings with limited dissemination.

Editorial and Formatting Issues

The author’s email address is missing.

Maintain the hierarchy of headings and subheadings according to the journal’s instructions.

Figure 1: Three subfigures are indicated using letters. According to the journal’s format, each subfigure must be described in the figure caption.

Figure 2: Units of measurement must be indicated.

Figures 3, 4, 5, 7, and 8: Apply the same recommendation as for Figure 1.

Figure 6: Apply the same recommendation as for Figure 2.

Tables 1 and 2: The formatting does not follow the journal’s style.

In the references, adopt the journal’s required format and carefully review each entry, especially author names. Include DOIs for all scientific articles to facilitate quick access for readers.

Author Response

Thank you very much for your valuable review comments.
Please find the revised manuscript attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The article is interesting and therefore deserves to be published. There are still points we can discuss in the work, but they are no longer possible to revise due to research decision issues. The authors did an excellent job of correcting the first version, and so I believe the article is ready for publication. Congratulations.

Author Response

Thank you for your kind review.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have taken into account the reviewer's comments and made the necessary adjustments to the manuscript. The revised manuscript demonstrates significant improvements in both scientific and visual aspects.
The reviewer no longer has any comments, and the manuscript can be published in the journal as it is.

Author Response

Thank you for your kind review.

Reviewer 4 Report

Comments and Suggestions for Authors

Adapt Tables 1, 2, and 3 to the journal's format.

The author must carefully review the bibliographic references to ensure they meet all the journal's requirements. For example, the initial review requested that the DOI of each article be included. A simple review of the current version revealed that the first reference has a DOI, but it was not added. Proceed with all references corresponding to journal articles.
The publication year of the articles should be in bold.

Author Response

Thank you for your review. Regarding the references, I revised the method of identifying DOIs and have added most of the missing DOIs. I also made the publication years bold and corrected the formatting of Tables 1–3. The revised sections are highlighted in yellow.