Study on Stope Stability in Continuous Mining of Long-Dip, Thin Orebody by Room–Pillar Method
Round 1
Reviewer 1 Report
Dynamic change of surrounding rock stability with mining depth is interesting and important for mining safety. However, conclusions of this paper presented are meaningless. So my suggestion is reject for publicaiton.
Author Response
Modification instructions
Dear reviewer：
I am very grateful for your comments on the manuscript. According to your advice， we have extensively modified the original manuscript.
1. Dynamic change of surrounding rock stability with mining depth is interesting and important for mining safety. However, conclusions of this paper presented are meaningless. So my suggestion is reject for publicaiton.
Thank you very much for your comments in our manuscript. In order to analyze the stability of stope under continuous mining with room-pillar method for a kind of orebody with long inclination but not deep mining, this paper takes room-pillar method for continuous mining of long inclination orebody in Mengnuo Lead-Zinc Mine, Yunnan Province as the research background. In mines that use room and pillar method for mining, even if all stopes use the same mining technology and parameter layout, as mining depth increases, the equivalent values of surrounding rock stress, displacement and plastic zone will show different characteristics and rules. Therefore, on the basis of the analysis of stope mechanical model of long inclined thin orebody with room and pillar mining, based on numerical simulation, the nature of the change in stresse, displacement and the plasticity zone of the roof and pillar during continuous mining along inclination are systematically analyzed. The research results are of great significance for the reasonable setting of stope structural parameters and the safety of deep mining with room and pillar method. We have reorganized and combed the contents of the conclusion to make it meaningful.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article submitted for review is devoted to actual issues of studying the stability of the rock mass around the stope in the room-and-pillar method of mining a thin ore body. The stability of the roof, the safety of workers and the efficiency of ore mining depend on the choice of rational sizes of room and pillars.
The solution of these geomechanical problems is well achieved by numerical simulation. With an adequate formulation of the problem by numerical simulation, sufficiently reliable results are achieved. This article solves a specific problem of studying the stability of the stope roof and pillars for the thin ore body of the Mengnuo Lead-Zinc Mine.
The material of the article corresponds to the thematic areas of the journal Sustainability.
I read the article in detail and I had questions and comments, the elimination of which will improve the quality of the manuscript.
1. It is recommended to add numerical simulation to the keywords. The main part of the article is devoted to numerical modeling.
2. In my opinion, it is necessary to expand the introduction and give more references to the latest scientific works of scientists in the field under study. The introduction contains outdated literature and there is absolutely no analysis of new literature.
It is especially recommended to consider and analyze the following articles:
Chen, T., & Mitri, H. S. (2021). Strategic sill pillar design for reduced hanging wall overbreak in longhole mining. International Journal of Mining Science and Technology, 31(5), 975–982. https://doi:10.1016/j.ijmst.2021.09.002 Bazaluk, O., Petlovanyi, M., Zubko, S., Lozynskyi, V., & Sai, K. (2021). Instability Assessment of Hanging Wall Rocks during Underground Mining of Iron Ores. Minerals, 11(8), 858. https://doi:10.3390/min11080858 Takhanov, D., Muratuly, B., Rashid, Z., & Kydrashov, A. (2021). Geomechanics substantiation of pillars development parameters in case of combined mining the contiguous steep ore bodies. Mining of Mineral Deposits, 15(1), 50–58. https://doi:10.33271/mining15.01.050 Garza-Cruz, T., Pierce, M., & Board, M. (2019). Effect of Shear Stresses on Pillar Stability: A Back Analysis of the Troy Mine Experience to Predict Pillar Performance at Montanore Mine. Rock Mechanics and Rock Engineering, 52(12), 4979–4996. https://doi:10.1007/s00603-019-02011-3
In some of these articles, the authors also studied the stope stability and the effect of mining depth. It is recommended to study them and indicate in the introduction.
3. Fig. 1 bad quality. The clarity of the drawing needs to be improved.
4. For a general understanding, it is necessary to indicate in section 3 what and how ore is mined in the mine with the room-and-pillar mining method.
5. In section 3, indicate what rocks are represented by the hanging and footwall of the deposit.
6. It should be indicated where the geological data of the deposit and the physical and mechanical properties of the massif were taken from. This applies to Fig. 1 and table 1.
7. Section 5.1 is recommended to be renamed into "Justification of the geomechanical model". This subsection also reveals the research methodology.
8. In section 5.1, what is the angle of dip of the deposit taken during modeling.
9. It is recommended in section 5.3 to pay attention and note the sufficiency of the accepted dimensions of the model, according to the distribution of the stress field. Are there edge effects?
10. It is necessary to show the location of the monitoring points (Section 5.3.2) for better understanding earlier on the sheme (for example, in Section 5.1).
11. In section 5.3.2. the results of the study of displacements are not described at all. After Figure 10, it is necessary to describe the results of the study obtained in the graph.
12. The authors in the annotation state that "the evolution law of stress, displacement and plastic zone of stope roof and pillar during continuous mining along inclination are systematically analyzed. There are no law in the article by the authors. Probably, this should be called the nature of the change in stresses, displacements and the plasticity zone of the roof and pillar. Or you need to give specific patterns.
13. The plastic zone is poorly described in Figure 11. There are no blue and red symbols. They need to be shown and explained. Also describe quantitatively how the plastic zone changes. As it was done in the analysis of the stress field.
14. In section 6 How exactly do the authors propose to change the stope parameters? How much to increase or how much to decrease. Need to be more specific.
15. Conclusions are encouraged to present specific quantitative results. How many times did the stress change with depth? This is described in Section 5, but not shown in the conclusions. Also about the plastic zone. The conclusions do not fully reveal the results obtained.
16. As noted above, the article contains a lot of outdated literature and not enough new literary sources. It is recommended to increase them on the basis of the proposed scientific articles.
Author Response
Modification instructions
Dear reviewer：
I am very grateful for your comments on the manuscript. According to your advice, we have extensively modified the original manuscript.
1. It is recommended to add numerical simulation to the keywords. The main part of the article is devoted to numerical modeling.
Thank you very much for your comments in our manuscript. We have added numerical simulation to the keywords.
2. In my opinion, it is necessary to expand the introduction and give more references to the latest scientific works of scientists in the field under study. The introduction contains outdated literature and there is absolutely no analysis of new literature.
Thank you for your valuable comments on our manuscript. We have reorganized the introduction part of our manuscript to refer more the latest scientific works of scientists in the research field. We have carefully analyzed some of the articles you suggested, and explained them in the introduction of the manuscript.
3. Fig. 1 bad quality. The clarity of the drawing needs to be improved.
According to your suggestion, we have further processed Figure 1 to improve its clarity.
4. For a general understanding, it is necessary to indicate in section 3 what and how ore is mined in the mine with the room-and-pillar mining method.
My sincerest thanks for your suggestions for our manuscript. We have explained how to mine the orebody by the room-and-pillar method and what orebody to mine in the mine at the corresponding position in section 3.
5. In section 3, indicate what rocks are represented by the hanging and footwall of the deposit.
The hanging and footwall of the deposit is lamellar limestone. We have accurately described it in the corresponding position in section 3.
6. It should be indicated where the geological data of the deposit and the physical and mechanical properties of the massif were taken from. This applies to Fig. 1 and table 1.
We sincerely thank you for your suggestions for our manuscript. The geological data of the deposit is obtained from the geological survey report provided by the enterprise. The physical and mechanical properties of the massif are obtained by reduction and correction the physical and mechanical parameters of rock through Hoek-Brown strength criterion based on the physical and mechanical parameters of rock obtained from laboratory tests and the RMR value of rock quality evaluation. We have explained in the corresponding positions of section 3 and section 5.1.
7. Section 5.1 is recommended to be renamed into "Justification of the geomechanical model". This subsection also reveals the research methodology.
Thank you for your valuable comments on our manuscript. According to your suggestion, we have renamed the title of section 5.1 as "Justification of the geomechanical model."
8. In section 5.1, what is the angle of dip of the deposit taken during modeling.
In section 5.1, the angle of dip of the deposit is 50° during modeling. We have explained it in the corresponding position of section 5.1.
9. It is recommended in section 5.3 to pay attention and note the sufficiency of the accepted dimensions of the model, according to the distribution of the stress field. Are there edge effects?
My sincerest thanks for your suggestions for our manuscript. To eliminate the edge effect of the calculation model in the process of modeling, we extended the left and right boundaries of the model outward by a certain distance. Therefore, the size of the calculation model is acceptable, and the calculation results are not affected by the edge effect.
10. It is necessary to show the location of the monitoring points (Section 5.3.2) for better understanding earlier on the sheme (for example, in Section 5.1).
Thank you for your valuable comments on our manuscript. We have added a diagram of monitoring point layout at the corresponding position in section 5.3.2 for better understanding earlier on the sheme.
11. In section 5.3.2. the results of the study of displacements are not described at all. After Figure 10, it is necessary to describe the results of the study obtained in the graph.
We sincerely thank you for your suggestions for our manuscript. We have carefully examined the contents in section 5.3.2, and we have added the results of displacement analysis in section 5.3.2
12. The authors in the annotation state that "the evolution law of stress, displacement and plastic zone of stope roof and pillar during continuous mining along inclination are systematically analyzed. There are no law in the article by the authors. Probably, this should be called the nature of the change in stresses, displacements and the plasticity zone of the roof and pillar. Or you need to give specific patterns.
According to your suggestion, we have carefully checked the content you mentioned, and we have revised the content to "the nature of the change in stresses, displacements and the plastic zone of the roof and pillar."
13. The plastic zone is poorly described in Figure 11. There are no blue and red symbols. They need to be shown and explained. Also describe quantitatively how the plastic zone changes. As it was done in the analysis of the stress field.
My sincerest thanks for your suggestions for our manuscript. We have added blue and red symbols to the corresponding figure to better describe the plastic zone.
14. In section 6 How exactly do the authors propose to change the stope parameters? How much to increase or how much to decrease. Need to be more specific.
As the result of this research is a regular result, our propose for stope parameters is a certain trend change. For the accurate and specific adjustment of stope parameters, we think that need to combine the actual situation on site to accurately adjust.
15. Conclusions are encouraged to present specific quantitative results. How many times did the stress change with depth? This is described in Section 5, but not shown in the conclusions. Also about the plastic zone. The conclusions do not fully reveal the results obtained.
We sincerely thank you for your suggestions for our manuscript. According to your suggestion, we have reorganized the contents of the conclusions to show more specific quantitative results.
16. As noted above, the article contains a lot of outdated literature and not enough new literary sources. It is recommended to increase them on the basis of the proposed scientific articles.
Thank you very much for your comments in our manuscript. In the introduction, we have added some relatively novel references on the basis of the original references.
Author Response File: Author Response.pdf
Reviewer 3 Report
This study consider stability of stope under continuous mining room-pillar method. It has to include surrounding rocks or shallow mining.
It is better to demonstrate each result in reference introduction in Section 1 Introduction.
Equation (2), what is E ??
Line 182
Do you estimate the deformation according to compressive stresses.
Line 203
Please describe some comments.
Figure 11
Please would you like indicate some symbol or color categories.
Author Response
Modification instructions
Dear reviewers：
I am very grateful for your comments on the manuscript. According to your advice， we have extensively modified the original manuscript.
1. This study consider stability of stope under continuous mining room-pillar method. It has to include surrounding rocks or shallow mining.
My sincerest thanks for your suggestions for our manuscript. In fact, the mine in our manuscript is not strictly deep mining, and we use the room-pillar method of shallow mining for research. For surrounding rock, the stress and displacement of pillar and roof are analyzed in this manuscript, which can also reflect the change of surrounding rock stress and displacement to a certain extent. The state change of pillar and roof is very important for mine safety.
2. It is better to demonstrate each result in reference introduction in Section 1 Introduction.
Thank you for your valuable comments on our manuscript. According to your suggestion. We have added the demonstration results of the references in the introduction of section 1.
3. Equation (2), what is E.
In Equation (2), E is the elastic modulus of roof rock. We have added the corresponding description in the section 4 of the manuscript.
4. Line 182. Do you estimate the deformation according to compressive stresses.
My sincerest thanks for your suggestions for our manuscript. We did not estimate the deformation according to the compressive stress. In section 5.3.2, we determined the deformation of the stope roof and surrounding rock through displacement analysis.
5. Line 203. Please describe some comments.
Thank you very much for your comments in our manuscript. We have added some descriptions of displacement analysis in section 5.3.2.
6. Figure 11. Please would you like indicate some symbol or color categories?
We appreciate your comments on our manuscript. According to your suggestion, we have added symbols to the corresponding figure to illustrate the contents of the figure.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
I carefully reviewed the updated version of the article. The recommendations were taken into account. The authors have done a good job. The article is recommended for publication.
