Study of the Evolution of Water-Conducting Fracture Zones in Overlying Rock of a Fully Mechanized Caving Face in Gently Inclined Extra-Thick Coal Seams
Round 1
Reviewer 1 Report
The paper investigates the caving of overlying strata and the development height of water-conducting fracture zone caused by mining in working face, by using similar simulation experiment, microseismic monitoring system, numerical simulation, theoretical analysis and engineering practice.
There are severeral points to be considered before acceptance:
1. Introduction: the novelties need to be listed and discussed in order to demonstrate the originality of the paper and the contributions against the existing literature.
2. Introduction: This sentence needs to be expanded: "the analysis of the height of water-conducting fracture zone is influenced by many factors": what are these factors and how the fracture zone is influenced?
3. Introduction: the last paragraph should describe the structure of the paper.
4. Section 3.1: This sentence " According to the similarity theorem" needs to be expanded: what does the similarity theorem say? Please cite some specific references.
5. Figure 2: how the measures were calibrated? Please explian how the model is representative of the case study.
6. Figure 5 needs to be re edited to make it more readable.
7. Section 3.4: This sentence: "Most of the energy of microseismic events is 0-50J and 50-100J." needs to be demonstrated with citations.
8. Section 4.1 the numerical model needs to be described in more details. for example: how the mesh was validated? How the dimensions of the element were calibrated? What are the boundary conditions?
Author Response
Thank the reviewers for their valuable comments. According to the relevant opinions, the author has carefully improved it. See the annex for details.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript analyzes the caving of overlying strata and the development height of water-conducting fracture zone caused by mining in working face. By using the research methods of similar simulation experiment, microseismic monitoring system, numerical simulation, theoretical analysis and engineering practice, the law of overburden caving and the development of water-conducting fracture zone are mutually verified.
The research design is appropriate. The methodology is very well explained. The title of the paper "Study on Evolution Law of Water-conducting Fracture Zone in Overlying Rock of Fully Mechanized Caving Face in Gently Inclined Extra" reflects its content.
I would be beneficial if major goals and objectives of study usage as well as it's future application areas will be more discussed by the authors (further research).
Author Response
Thank the reviewers for their valuable comments. According to the relevant opinions, the author has carefully improved it. See the annex for details.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear author,
I read the response to my observations and they are interesting. However, I saw no changes in the paper.
1. Please add your comments inside the test.
2. Also, this new sentence:
"Except that the upper surface of the model is not bounded, the allowable deformation of the other five boundary surfaces is set to be 0.1m to limit the lateral and bottom displacement of the model."
Is not clear. Do these boundaries assume shear beam conditions in order to reproduce the shear effect between the two materials?
Please refer to this literature with similar cases:
Coleman JL, Bolisetti C, Whittaker AS (2016) Time-domain soil-structure interaction analysis of nuclear facilities, Nuclear Engineering and Design 298 (2016) 264–270
Forcellini D (2016) "3D Numerical simulations of elastomeric bearings for bridges" Innov. Infrastruct. Solut. (2016) 1:45 DOI 10.1007/s41062-016-0045:4
Mina D, Forcellini D. Soil–structure interaction assessment of the 23 november 1980. Irpinia Basilicata Earthquake Geosciences 2020;10:152. https://doi.org/ 10.3390/geosciences10040152. 2020.
Author Response
Thank the experts for their valuable opinions again. This is of great help to the perfection of the paper again. The author has carefully improved it in strict accordance with the requirements of experts. See the annex for details.
Author Response File: Author Response.pdf
