Study on the Effectiveness of Reinforcing Bar Insertion Work with a Circular Pipe

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Reviewer report – “Study on The Effectiveness of Reinforcing Bar Insertion Work with A Circular Pipe”
By Kakuta Fujiwara, Lichao Wang

This research proposes an earth reinforcement, namely a system of reinforcing bar insertion processes that uses pipes as a construction method. The study supposed several series of model experiments, including lift-up and water sprinkling tests.
The research is interesting, the manuscript is well written, and there are more major observations.
1. The formula for lateral force acting on a pile per unit depth appears to be correctly structured and consistent with the principles of soil mechanics. However, it has limitations, particularly in cases involving surface failure. The text explicitly mentions that the formula does not account for surface failure mechanisms, limiting its applicability in scenarios where surface deformations are present. The development of passive resistance around the pile is not explicitly accounted for. A slippage or deformation between the pipe and the core bar can redistribute the lateral forces, affecting the overall structural integrity.
2. Authors should numerically simulate the experiments using the finite element method, bypassing the need for a simplified formula that I find inapplicable to this situation.
3. Implementing this earth reinforcement system can be expensive. The authors could explain how this reinforcement can be implemented in an existing earth structure.
The authors' interesting research is worthy of publication if it includes an explanation of previous observations.
Kind regards,
The reviewer.

Author Response

Dear Reviewer

Thank you very much for your valuable review.
We have attached the revised manuscript and a point-by-point response to the reviewers’ comments.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Overall Evaluation

This manuscript presents a laboratory investigation into a new slope stabilization method that utilizes circular acrylic pipes in conjunction with reinforcing bar insertion to enhance resistance against slope failures triggered by static loading and rainfall. Two model test series—lift-up and water sprinkling experiments—are conducted, and the results indicate that increasing the number and diameter of pipes raises the slope failure angle and prolongs the time to failure under rainfall conditions. The study addresses a relevant and urgent topic in geotechnical hazard mitigation and provides a straightforward experimental setup with systematic variation of parameters. The manuscript’s strengths include its practical focus, logical progression from hypothesis to experiment, clear visual documentation of failure processes, and a reasonably comprehensive reference list. However, several significant technical and scientific issues, ambiguities, and omissions undermine the current manuscript’s rigor, generalizability, and value for the broader research community, as detailed below.

Key Points to be Addressed:

1. Experimental Detail and Reproducibility

-How were sand placement, compaction, and moisture control ensured and measured in each experiment? What steps were taken to guarantee initial uniformity and test repeatability?

-Define all geometric and mechanical parameters (D, D1, D2, “gap,” “core bar,” etc.) explicitly and use consistently in both text and figures.

2. Interpretation and Field Applicability

-To what extent can the model-scale results be extrapolated to real slopes, given the scale, 1-g modeling, simple sand, and boundary conditions? Provide a critical discussion on scaling effects and limitations.

-How does the imposed water sprinkling rate correspond to realistic field rainfall intensities and infiltration? Justify its selection and relevance for real hazard scenarios.

3. Mechanistic Understanding and Analytical Modeling

-The analytical approach assumes full transfer of lateral load from pipes to core bar; is this assumption physically justified under all observed failure modes (surface vs. pass-through failure)? Discuss possible deviations, and clarify the conditions for valid use of the load estimation formula.

4. Data Presentation and Statistical Rigor

-Raw data underlying the summarized figures (e.g., failure time, bending strain) should be made available, or at minimum, error ranges must be presented.

5. Figures and Image Quality

-Several figures (photographs, diagrams, time histories) lack sufficient resolution, clear labeling (units, axes, timestamps), and necessary annotations (e.g., failure modes, scale bars).

6. Literature Review and Contextualization

-The literature review is largely descriptive. Where does this work stand in relation to the state-of-the-art in reinforced slope stabilization (including advanced modeling approaches, field studies, or hybrid systems)? More critical analysis is needed.

To enhance the manuscript's integration within the broader research context and to substantiate the methodologies employed, it is recommended that the authors include additional citations of pertinent literature. Such citations will not only fortify the paper's foundational context but also demonstrate a comprehensive engagement with contemporary studies in the field:

Optimal Plastic Analysis and Design of Pile Foundations Under Reliable Conditions, (https://doi.org/10.3311/PPci.17402).

7. Discussion of Limitations and Broader Implications

-Identify and openly discuss all limitations inherent to the experimental design (scaling, boundary effects, material selection, drainage, etc.) and provide clear boundaries for where conclusions are valid.

Author Response

Dear Reviewer

Thank you very much for your valuable review.
We have attached the revised manuscript and a point-by-point response to the reviewers’ comments.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all the comments.

The manuscript is well written, and the topic is interesting. 

Reviewer 2 Report

Comments and Suggestions for Authors

I recommend accepting the paper.