Deformation Control Technology of Gob-Side Entry Retaining with Large Volume CFST Roadway Side Support in Top-Coal Caving Longwall and Stability Analysis: A Case Study

Round 1

Reviewer 1 Report

Securing underground excavations in top coal caving metohds is extremely important due to the impact of the hanging roof layers and the impact of the post-mining space. The proposed solution is very interesting both in terms of science and technology, in particular in terms of identifying zones particularly at risk of increased deformations. The application aspect confirms the effectiveness of this type of support and contributes to the reduction of operating losses, which is why it recommends the article for further processing. Below are some comments and suggestions:

1. In the introduction, two/three sentences should be added regarding the thickness of coal released from the roof in the top coal caving methods (range from to);

2. In the subsection 2.1, it should be written what is the compressive strength of coal - whether it is prone to release or whether any technological treatments should be used to make it collapse;

3. Figure 3c, please check the title;

4. For Figure 6, add a unit for stress colors. In addition, please write which arrangement is commonly used in real-world conditions;

5. In the fourth chapter, it should be written whether other types of support were also modeled in the exploitation space, which co-occur: anchors. In addition, please write what was the value of horizontal and vertical stresses adopted in modelling;

6. For Figure 11, write the stiffness or compressive strength of steel tubes filled with concrete;

7. In the subsection 5.3, information on the method of excavation deformation monitoring should be added: what devices were used. In addition, bearing in mind the maintenance of excavations behind the mining front, it should be added that in addition to the proposed solution, wooden cribs are often used (“Decreasing Mining Losses for the Room and Pillar Method by Replacing the Inter-Room Pillars by the Construction of Wooden Cribs Filled with Waste Rocks "; "Comparative Analysis of the Mining Cribs Models Filled with Gangue"), which are filled with various materials - such a reference will also be a form of discussion of the results;

8. Dimensions of steel tubes filled with concrete used in industrial conditions should be added to the conclusions.

Author Response

Manuscript ID: applsci-2411046

Manuscript title: Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study

Dear Editor/Reviewer:

Thank you very much for your letter! Regarding the comments and recommendations of the paper entitled “Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study”.

We appreciated the thorough reviews provided by the journal and the reviewer. We have checked the manuscript thoroughly and revised it accordingly. Enclosed is the revised version of the paper (see ‘Revised manuscript’) as well as a separate file (see ‘Response to the comments_ applsci-2411046’) explaining the changes we have made in response to the comments. In the revised manuscript, some grammar and spelling errors have also been corrected. In the separate file, we responded point by point to the comments and recommendations.

Hope these will make it more acceptable for publication in Applied Sciences.

If you need any other information, please contact me immediately.

Yours sincerely,

Zi-Lu Liu, PhD

Author Response File: Author Response.docx

Reviewer 2 Report

The work describes the subject of securing a roadway in a longwall system, where the roadway remains unobstructed and is not decommissioned after the passage of the longwall complex. This is a very important topic in terms of safety and maintaining the continuity of mining operations.
The article is well written, the chronology of the sections is maintained and it reads well. In the following sections, one can find a comprehensive introduction, an analysis of the conditions in a specific case, a mathematical model describing the relationship between the rock mass and the proposed support type, simulation and tests under real conditions. Although, the article does not describe a complete methodology for the selection of this type of support for different geological conditions, but focuses on one case, in my opinion it makes an important contribution to the development of such a comprehensive methodology.

I have a few minor comments:
The abbreviations referred to, i.e. GER and RBB (Figure 10), should be explained earlier in the text so that the reader does not have to guess.
The description of figure 15 should be revised.
I would improve the quality of figure 3b .

Author Response

Manuscript ID: applsci-2411046

Manuscript title: Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study

Dear Editor/Reviewer:

Thank you very much for your letter! Regarding the comments and recommendations of the paper entitled “Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study”.

We appreciated the thorough reviews provided by the journal and the reviewer. We have checked the manuscript thoroughly and revised it accordingly. Enclosed is the revised version of the paper (see ‘Revised manuscript’) as well as a separate file (see ‘Response to the comments_ applsci-2411046’) explaining the changes we have made in response to the comments. In the revised manuscript, some grammar and spelling errors have also been corrected. In the separate file, we responded point by point to the comments and recommendations.

Hope these will make it more acceptable for publication in Applied Sciences.

If you need any other information, please contact me immediately.

Yours sincerely,

Zi-Lu Liu, PhD

Author Response File: Author Response.docx

Reviewer 3 Report

 

  This article introduces a method of gob-side entry retaining with large-diameter steel tube concrete columns as roadside supports, the deflection curve equation of the main roof rock layer and the load calculation formula of roadside support body were derived, the influence of column spacing on the distribution characteristics of tensile stress in the roof was studied based on the contact characteristics between the support body and the roof. Finally, specific construction techniques were proposed and practiced. Overall, I think that this study is novel and meaningful, so it is recommended to publish in this journal. However, there are some issues that need further improvement before publication. The following are specific review comments: 1. There are some grammatical problems and misspellings need to be corrected; 2. In Figure 3, the steel tube concrete column adopts a concentric nested structure. What are the advantages of using this form of structure? 3. What is the corresponding relationship between the relative comparative numerical relationship of qb in Figure 7 and qu in Formula 11 and the failure form? Suggest further clarification in the article. 4. Why you use the Prandtl foundation model theory? And why is Terzaghi's theory not suitable for studying this problem? 5. The conclusion of the paper is too verbose, and it is recommended to further refine it.

   

Author Response

Manuscript ID: applsci-2411046

Manuscript title: Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study

Dear Editor/Reviewer:

Thank you very much for your letter! Regarding the comments and recommendations of the paper entitled “Deformation Control Technology of Gob-side Entry Retaining with Large Volume CFST Roadway Side Support in Top Coal Caving Longwall and Stability Analysis: Case Study”.

We appreciated the thorough reviews provided by the journal and the reviewer. We have checked the manuscript thoroughly and revised it accordingly. Enclosed is the revised version of the paper (see ‘Revised manuscript’) as well as a separate file (see ‘Response to the comments_ applsci-2411046’) explaining the changes we have made in response to the comments. In the revised manuscript, some grammar and spelling errors have also been corrected. In the separate file, we responded point by point to the comments and recommendations.

Hope these will make it more acceptable for publication in Applied Sciences.

If you need any other information, please contact me immediately.

Yours sincerely,

Zi-Lu Liu, PhD

Author Response File: Author Response.docx