Challenges Related to the Transformation of Post-Mining Underground Workings into Underground Laboratories

Round 1

Reviewer 1 Report

The manuscript is well written and I have no substantive objections.

I just have a few minor comments: 

line 112 - in EU coking coal mines will work  after 2050,

Line 120 –the references should be indicated in table headers,

Table 1 - several countries are missing, e.g. Ukraine, Turkey, why?

Figure 2 – why part of countries has green background,

Line 173 - closing parenthesis is missing, 

Line 185 – BARBARA should be changed on Barbara,

Line 187 - lack of references number, 

Line 250 – I can't find this worksheet on https://bsuin.eu , could you provide a more accurate link, 

Line 252 - interesting is the number of respondents participating in the surveys, can you provide it. 

Author Response

The authors would like to thank Reviewer #1 for the effort in a very detailed review of the article and for the positive feedback. All comments of the reviewer were very valuable, therefore we made every effort to satisfactorily address them in the revised version of the article. The detailed response for each comment can be found below as well as in the revised version of the paper.

General Comments: The manuscript is well written and I have no substantive objections. I just have a few minor comments.

Comment 1. Line 112 - in EU coking coal mines will work after 2050,

Ad.1. According to the reviewers’ comment, the sentence in line 112 was clarified. After revision, this part of the article looks as follows:

“It is connected to the energy transformation into carbon-neutral energy and assumes that in 2050 there will be no energy or steaming coal mines in the present form in any of the EU countries. Only coking coal mines will be still opened after EU energy transition.”

Comment 2. Line 120 –the references should be indicated in table headers,

Ad.2. The change in article has been made accordingly. The caption of Table 1 after revision looks as follow:

Table 1. Number of main active underground mines in Europe

Comment 3. Table 1 - several countries are missing, e.g. Ukraine, Turkey, why?

Ad.3. In the first version of the manuscript approach there were chosen countries belong to the European Union and also which have the potential to access in the near future (10-15 years) like Albania, Bosnia, and Herzegovina as well as Serbia. On the other hand, some countries were avoided like Turkey (problem with political issues).  Ukraine has declared access in 2022 (also a political issue). UK was also added as a former member of EU.

We fully agree with the reviewer that such an approach was unclear, hence to make the table more consistent to the chapter and Green Deal facet, which is the initiative of the European Union, the table and text were modified accordingly. In the revised version of the manuscript, only EU countries with Norway and United Kingdom was included (Norway is a member of the European Economic Area and there is a close cooperation with EU within Green Deal and UK as former member).

Comment 4. Figure 2 – why part of countries has a green background,

Ad.4. The map covered the BSR region that was covered by the Interreg BSR program, and was additionally marked with the location of the Hagerbach test galley from Switzerland. However, we agree with the reviewer that the map may have been unclear. Therefore, figure 2.  has been replaced with a new map with markings

Comment 5. Line 173 - closing parenthesis is missing, 

Ad.5. The change in the article has been made accordingly.

Comment 6. Line 185 – BARBARA should be changed on Barbara,

Ad.6. The change in the article has been made accordingly.

Comment 7. Line 187 - lack of references number, 

Ad.7. The change in the article has been made accordingly. After revision, this part of the article looks as follows:

As pointed out by Pactwa et al. [16], underground space is also suitable for sustainable food production.

Comment 8. Line 250 – I can't find this worksheet on https://bsuin.eu, could you provide a more accurate link?

Ad.8. According to the reviewer comment, the more accurate link was attached to the paper. https://bsuin.eu/2021/01/08/bsuin-final-reports/. In some browsers, reports needs to be opened by clicking title of the report with right mouse button and then choosing the option, open in a new tab.  

Comment 9. Line 252 - interesting is the number of respondents participating in the surveys, can you provide it. 

The surveys were organized as part of a workshop aimed at identifying challenges that stand in the way of attempts to build underground facilities for non-mining activities. Unfortunately, risk issues and “weak” aspects of activity are issues that companies are reluctant to share. In order to avoid a situation in which survey participants indicate a complete lack of problems, we organized a survey that is anonymous, but in which respondents specify the unit they come from. In such a situation, if the survey contained controversial/ unreliable answers, then we could confront it with representatives of individual units. Such situations happened only once when one of the Underground facility operators indicated a complete lack of problems and risk in their site, while in the past some accidents occurred in their site. In connection with the above, public disclosure of the survey, will require obtaining permission from each of the representatives. Of course, we can apply for such consent, but certain procedures must be followed.

Reviewer 2 Report

his paper analyses the challenges and threats related to setting up an underground laboratory in the post-mining area. The topic is very interesting. Some suggestions are follows:

(1) Rock mechanics research related to the post-mining area is necessary. Which rock mechanics problems will be involved? The problems should be clarified in paper.

(2) What geological disasters will be faced in the post-mining area? such as water and gas disasters. Some papers related to geological disasters and rock mechanics related to the post-mining area furtherly should be reviewed. For example,  

Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria

Study on the physicochemical characteristics and dust suppression performance of new type chemical dust suppressant for copper mine pavement

Instantaneous discharge characteristics and its methane ignition mechanism of coal mine rock damage

Coupled seepage-damage effect in fractured rock masses: model development and a case study

Evolution and modeling of mine water inflow and hazard characteristics in southern coalfields of China: A case of Meitanba mine.

Author Response

The authors would like to thank Reviewer for the effort to review deeply of the article and for the valuable and positive feedback. We are convinced that the substantive comments raised by the reviewer enabled us to present the problem in a more factual and accessible way for the reader. All revisions have been placed in the appropriate places in the text of the article, however, answers to comments can also be found below.

General Comments: This paper analyses the challenges and threats related to setting up an underground laboratory in the post-mining area. The topic is very interesting. Some suggestions are as follows:

Comment 1. Rock mechanics research related to the post-mining area is necessary. Which rock mechanics problems will be involved? The problems should be clarified in the paper.

Ad. 1. We fully agree with the reviewer's comment. we drew similar conclusions from the analysis of respondents' answers (mining operators, scientists, and representatives from underground laboratories). As shown in section 4, Results and discussion safety issues are the most often mentioned challenges during the transformation of post-mining areas. Then According to Figure 8, based on the risk evaluation results, it came up that most hazardous risk categories are associated with ground control problems and seismic activity, which are resulting from rock mechanic issues.

 In the category of ground control problems there were 16 risks included:

1. Geologic discontinuities occurrence
2. Unsupported roof
3. Spalling of wall
4. Roof Failures
5. Workings instability
6. Overburden caving
7. Long term creep effect
8. Too high In-Situ Stress
9. Ground Movement
10. Collapse of surface
11. Mine collapse
12. Lack of monitoring devices of workings stability
13. Cave-in
14. Swelling
15. Squeezing

While in the seismic activity category there were 9 identified hazardous events:

1. High frequency of tremors occurrence
2. Strain bursts
3. Pillar bursts
4. Fault slip bursts
5. Earthquakes
6. Seismic magnitude of tremors > 3 ML
7. Seismic magnitude of tremors > 4 ML
8. Seismic magnitude of tremors > 5 ML
9. Lack on

It has to be stated that risks presented above are observed only in facilities which were included in the project. Analysis in different site requires additional implementation of risk identification and end evaluation procedure.

Finally, we would like to state that the rock mechanical risk was included in the analysis as indicated by the reviewer, however, we also want to emphasize that this article is not aimed at conducting a risk assessment, but at identifying challenges that potential UL manufacturers face and which must be identified before starting new non-mining activity (Rock mechanic risk is just one of the challenges). A detailed report on risk assessment in EU underground laboratories prepared by the authors of this paper is available at :    
https://bsuin.eu/wp-content/uploads/2021/01/WP4_HS_and_facility_improvement_Report.pdf

Comment 2. What geological disasters will be faced in the post-mining area? such as water and gas disasters. Some papers related to geological disasters and rock mechanics related to the post-mining area furtherly should be reviewed. For example:

• Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria
• Study on the physicochemical characteristics and dust suppression performance of new type chemical dust suppressant for copper mine pavement
• Instantaneous discharge characteristics and its methane ignition mechanism of coal mine rock damage
• Coupled seepage-damage effect in fractured rock masses: model development and a case study
• Evolution and modeling of mine water inflow and hazard characteristics in southern coalfields of China: A case of Meitanba mine.

Ad.2. During the workshops on Health and Safety in underground facilities, the participants pointed out such threats as:

In the group of water hazards:

1. Water ingress
2. Chemical leakage into water
3. Problem with surface waters associated with depression craters
4. Gassing of underground waters
5. Deep bedrock water pockets
6. Flood

Hazards related with Gases

1. Toxic gases occurrence after blasting works
2. Exceedances of sulphur dioxide (SO2) limits
3. Exceedances of hydrogen sulphide (H2S) limits
4. Exceedances of nitric oxide (NO2), other nitrogen oxides (NO) limits
5. Exceedances of hydrocarbons (HC) limits
6. Exceedances of carbon monoxide (CO) limits
7. Exceedances of carbon dioxide (CO2) limits
8. Exceedances of radon gas limits
9. Exceedances of Methane (CH4) limits
10. Gas explosion
11. Fluid (gas and / or liquid) eruption, including hydrogen sulphide

However, we would like to emphasize once again that risk assessment in underground conditions is not the main subject of this article. This is one of the elements included in the analysis, along with legal, political, economic and social issues (which is clearly indicated in chapter 4-figure 7).  A detailed report on risk assessment in EU underground laboratories prepared by the authors of this paper is available at :          
https://bsuin.eu/wp-content/uploads/2021/01/WP4_HS_and_facility_improvement_Report.pdf

What was indicated in the paper.

Additionally, after getting acquainted with the articles presented by the reviewer, we conclude that, despite their high level, they are not directly related to the subject of our study,

Reviewer 3 Report

This paper has presented interesting results of analyses the challenges and threats related to setting up an underground  laboratory in the post-mining area.

The research content of this paper is novel, focused, and the research method is systematic. However, in my opinion, the manuscript does need minor revision before being accepted for publication.

Below are some comments and suggestions:

1/ In Section 3 (Materials and Methods) Subsection 3.2 the risk matrix method was adopted. The manuscript would be much better if other methods of risk analysis were also analyzed. It is not clear why the risk matrix method was chosen.

2/ In Section 4 (Results and discussion) a fairly large amount of representative data has been statistically processed at a simple level. For example not explained has an assessment been made of the degree of coherence of the connected ranks are available. Deep statistical analysis would make the manuscript much more authoritative.

I regret that the authors didn't mention about the degree of coherence of the connected ranks, factor analysis, cluster analysis and other commonly accepted methods of data analysis. For example, risk assessment in mines using different methods of analysis is given in papers:

 

Ghasemi, E., Ataei, M., Shahriar, K., Sereshki, F., Jalali, S.E., & Ramazanzadeh, A. (2012). Assessment of roof fall risk during retreat mining in room and pillar coal mines. International Journal of Rock Mechanics and Mining Sciences, (54), 80-89. https://doi.org/10.1016/j.ijrmms.2012.05.025

Sakhno, I., Sakhno, S. and Vovna, O. (2020): Assesing a risk of roof fall in the development mine workings in the pro-cess of longwall coal mining in terms of Ukrainian mines. Mining of Mineral Deposits,14, 1, 72-80 https://doi.org/10.33271/mining14.01.072

Ameri Siahuei, M. R., Ataei, M., Rafiee, R., & Sereshki, F. (2021). Assessment and Management of Safety Risks through Hierarchical Analysis in Fuzzy Sets Type 1 and Type 2: A Case Study (Faryab Chromite Underground Mines). Rudarsko-geološko-Naftni Zbornik, 36(3). https://doi.org/10.17794/rgn.2021.3.1

Author Response

The authors would like to thank Reviewer 2 for the effort to review deeply of the article and for the valuable feedback. We are convinced that changes in the article, in accordance with the reviewer's recommendations, positively affected on the quality of the manuscript. All comments have been placed in the appropriate places in the text of the article, however, answers to comments can also be found below.

General Comments: This paper has presented interesting results of analyses the challenges and threats related to setting up an underground laboratory in the post-mining area. The research content of this paper is novel, focused, and the research method is systematic. However, in my opinion, the manuscript does need minor revision before being accepted for publication. Below are some comments and suggestions:

Comment 1. In Section 3 (Materials and Methods) Subsection 3.2 the risk matrix method was adopted. The manuscript would be much better if other methods of risk analysis were also analyzed. It is not clear why the risk matrix method was chosen. In Section 4 (Results and discussion) a fairly large amount of representative data has been statistically processed at a simple level. For example not explained has an assessment has been made of the degree of coherence of the connected ranks are available. Deep statistical analysis would make the manuscript much more authoritative. I regret that the authors didn't mention the degree of coherence of the connected ranks, factor analysis, cluster analysis and other commonly accepted methods of data analysis. For example, risk assessment in mines using different methods of analysis is given in the papers:

• Ghasemi, E., Ataei, M., Shahriar, K., Sereshki, F., Jalali, S.E., & Ramazanzadeh, A. (2012). Assessment of roof fall risk during retreat mining in room and pillar coal mines. International Journal of Rock Mechanics and Mining Sciences, (54), 80-89. https://doi.org/10.1016/j.ijrmms.2012.05.025
• Sakhno, I., Sakhno, S. and Vovna, O. (2020): Assesing a risk of roof fall in the development mine workings in the pro-cess of longwall coal mining in terms of Ukrainian mines. Mining of Mineral Deposits,14, 1, 72-80 https://doi.org/10.33271/mining14.01.072
• Ameri Siahuei, M. R., Ataei, M., Rafiee, R., & Sereshki, F. (2021). Assessment and Management of Safety Risks through Hierarchical Analysis in Fuzzy Sets Type 1 and Type 2: A Case Study (Faryab Chromite Underground Mines). Rudarsko-geološko-Naftni Zbornik, 36(3). https://doi.org/10.17794/rgn.2021.3.1

AD.1. This article is focused on the identification of challenges that may be an obstacle to the use of underground workings for non-mining activities. The purpose of the article is not to conduct a thorough, quantitative risk assessment, but only to highlight problem areas that prospective UL operators should pay attention to (including political, social, economical and environmental issues as well). Therefore, the risk assessment method based on the risk matrix seems to be the optimal solution for the purposes of this analysis, as it allows you to easily identify hazard categories and pre-assign appropriate probability and severity ranges. of course, the risk matrix, as a qualitative method, is only an initial stage, giving guidance on which categories of hazards should be analyzed in more detail using qualitative methods.

Other risk assessment methods have not been analyzed as they are not the subject of this study. Our goal was to identify challenges and determine way of further works for future UL operators.

Considering that the analysis used data from 7 underground objects, the authors are even convinced that carrying out a joint quantitative analysis for 7 different objects located in different geological and mining conditions would be a critical methodological error, unacceptable from the scientific point of view.

Still, we agree with Reviewer that some clarification should be included in the paper, there fore in section 3 we have included the following statement:

“It has to be highlighted here that the risk matrix method is a very general approach and should be used to determine risk categories which have to be evaluated in more detail (quantitative) way. For example in case of roof fall risk may be analysed with use of nu-merical methods or systematic approach of risk assessment presented by Ghasemi et al., in paper [51] or in paper by Sakhno et al., [52]. In case or more general analyses, not focused at only one group of hazard hierarchical analysis may be performed Siahuei et al. [53].”

Reviewer 4 Report

Dear authors!

The post-mining is usually the subject that is well known but there are few positive cases in the world that are reflecting what is possible with the underground spaces after the mining is done. Although your article is well structured, and your theme is interesting, there is a need for minor corrections:

-        Line 103 and 105: you are using “reclamation” that is usually used if the mine will be replanted so the expression “repurposing” is more suitable like in the whole article

-        Line 117: the reference is missing for the source

-        Line 133: since the abbreviation “DULs” is stated in the line before, there is no need for the full text

-        Line 153: stated the abbreviation so that the abbreviation in the line 155 is clear

-        Line 177 to 180: you are stating the whole reference text that is not adding to the article so just the MDPI way of referencing is in order

-        Line 188: to be consistent with the rest of the article the expression “repurposing” should be used instead of “readaptation”

-        Line 206: state the reference to the webinars and workshops

-        Line 243: at least the basic information about the risk matrix should be stated in the article

-        Line 249: you are stating that “a risk evaluation worksheet with a list of all 106 risks…” is in the reference but some basic information should be stated in the article

-        Line 224: chapter 3.2 Preliminary risk evaluation is not complete and should be rewritten in the form that is stating the necessary elements for a scientific article (methodology key elements of are missing)

Best regards.

Dear authors!

Consistency of the expressions should be used in the whole article.

Best regards.

Author Response

We would like to thank Reviewer for detailed review of our paper. We appreciate the time and effort that you and the reviewer dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated all of the suggestions made by the reviewer. Those changes are highlighted within the manuscript. Moreover, please find below our response to the reviewer’a comments

General Comments: Dear authors! The post-mining is usually the subject that is well known but there are few positive cases in the world that are reflecting what is possible with the underground spaces after the mining is done. Although your article is well structured, and your theme is interesting, there is a need for minor corrections:

Comment 1. Line 103 and 105: you are using “reclamation” that is usually used if the mine will be replanted so the expression “repurposing” is more suitable like in the whole article

Ad.1. The change in article has been made accordingly.

Comment 2. Line 117: the reference is missing for the source.

Ad.2. The change in article has been made accordingly. After revision the reference was added :

“On the other hand, the mines excavating Critical Raw Materials are strongly supported by the EU in order to achieve independence from the global raw material dynamics and supply chain challenges [25]”

Comment 3.  Line 133: since the abbreviation “DULs” is stated in the line before, there is no need for the full text.

Ad.3. The change in article has been made accordingly.

Comment 4.  Line 153: stated the abbreviation so that the abbreviation in the line 155 is clear

Ad.4. The change in article has been made accordingly.

Comment 5. Line 177 to 180: you are stating the whole reference text that is not adding to the article so just the MDPI way of referencing is in order

Ad.5. The change in article has been made accordingly. After revision:

The requirements for the overburden and the hall sizes put enormous pressure also for the rock mechanical engineers to mitigate the risks coming from the share rock mass induced gravitational pressure and any horizontal pressures. See, e.g. [40].

Comment 6.  Line 188: to be consistent with the rest of the article the expression “repurposing” should be used instead of “readaptation”

Ad.6. The change in article has been made accordingly. In whole article reclamation was substituted by term repurposing.

Comment 7.  Line 206: state the reference to the webinars and workshops

Ad.7. Most of the workshops were carried out by partners of the BSUIN and EUL project consortia and were held stationary at the headquarters of the organizers of the meeting among the project partners. However, at the end of the EUL project, a hybrid webinar was also organized, in which participants from the project consortia could also participate. Therefore, according to the reviewer's suggestion, reference no. 50 was added to the article.

50. EUL webinar - MANY FACES OF UNDERGROUND LABORATORIES, Helsinki, 27 January 2022. https://bsuin.eu/2022/01/19/eul-closing-webinar/

Comment 8.  Line 243: at least the basic information about the risk matrix should be stated in the article

Ad.8. The change in article has been made accordingly. After revision additional paragraph was added to section 3.2. Preliminary risk evaluation

“Then each risk has been analysed qualitatively using the risk matrix method. As it was pointed out in [19] risk matrix method is one of the most commonly utilized approach in establishing risk severity. There are many types of risk matrix but so-called two-dimensional risk matrix is most commonly used due to the ease of its preparation and results interpretation. Such approach allows not only to determine the impact of each event but also identify how the risk is affected by its probability or consequence. This information is of high importance, during the process of mitigations procedures development. The risk assessment method based on a risk matrix for ULs can be applied already at the design stage of a given facility. Still it is crucial that evaluation must be carried out exclusively by specialists in a particular field t o achieve reliable results. The biggest advantage of proposed approach is the possibility implementation of appropriate preventive and risk minimisation measures already at the design stage, just after preliminary evaluation. At the same time, there are no technical limitations to use it as the basic method of classifying selected events as part of the periodic risk assessment of the operation of underground facilities throughout their entire life cycle

 

 For purpose of this analysis, the risk evaluation worksheet has been developed and sent to researchers, scientists, and UL users. In the risk matrix method, the risk may be defined according to the formula:

RISK = R_p  R_i                         (1)

 

where:
R_p  – the probability of unwanted event occurrence,      
R_i – expected/predicted consequences of the event.

Comment 9. Line 249: you are stating that “a risk evaluation worksheet with a list of all 106 risks…” is in the reference but some basic information should be stated in the article

Ad.9. In the opinion of the authors, a detailed description of all 106 risks in the article is not an optimal solution, due to the need to significantly increase the content of the article. Therefore, only the main groups of threats that were included in the analysis are presented in order to give the reader a general overview of the scope of the work carried out. The description of the individual groups and the methodology of performing the analysis are presented in section 3. However, to satisfy the potential readers, references have been added to the report (available in open access), which describes in detail the process of identifying threats and lists all 106 analyzed events. new reference is [51] BSUIN WP4 Report: “Health & Safety in Underground Environment” By: Fuławka K., Pytel W., Szumny M., Mertuszka P., Joutsenvaara J., Shekov V. and Bubunova T., Wrocław, KGHM CUPRUM, R&D, (2020)

Comment 10.  Line 224: chapter 3.2 Preliminary risk evaluation is not complete and should be rewritten in the form that is stating the necessary elements for a scientific article (methodology key elements of

Ad.10. Risk evaluation with use of Risk Matrix was improvement according to previous comment of reviewer. Still Authors would like to point out that this article is focused on the identification of challenges that may be an obstacle to the use of underground workings for non-mining activities, not on risk evaluation solely. The purpose of the article is not to conduct a thorough, quantitative risk assessment, but only to highlight problem areas that prospective UL operators should pay attention to (including political, social, economical and environmental issues as well). Therefore in Authors opinion only basic information about risk analysis should be provided to the reader, while this is not the main scope of the paper.