Effects of Water-Soaking Height on the Deformation and Failure of Coal in Uniaxial Compression
Round 1
Reviewer 1 Report
The manuscript studies the impact of water level on coal/pillar properties. AE, UCS and water saturation of samples at different conditions were measured and compared. The paper is overall written well; however, it needs some revisions before its acceptance.
The major shortcoming of the paper is lack of information about the coal being studied. The authors mentioned that the coal was "lean coal”, this is not enough. Authors need to provide information about coal rank and lithotypes, as coal rank and lithotype are so crucial in defining coal properties, see Ramandi et al., 2016, 2017. Dull coals generally contain fewer fractures than bright coals which significantly impact their properties.
The authors need to clearly explain the novelty of the work.
Authors need to explain the coring direction, was it parallel to face cleat, butt cleat, or bedding?
Line 94, why the max and min are removed? Are they outliners? Is there any scientific reason behind this? Can you cite a high-level work to back up what you did?
Line 131, authors dried the coal samples in 135 degrees. The temperature is too much and likely had changed coal internal structures. I think the ASTM for coal drying is 40 degrees Celsius.
In line 139 authors said that the samples were taken out every 12 hours, how come the first reading in line 160 is after 8 hours?
Figure 6, “fit cure”, do you mean ‘curve’?
Authors need to explain the scale/size effect in their study, how the small samples are comparable with coal pillars?
There are minor editorial issues, I suggest reading the manuscript carefully and fix these issues.
Some of the texts are almost fully copied from other works, for example below text is from Liu et al. 2018. I suggest going through the paper and fix all of these.
“with 50-mm diameters and 100-mm heights (see the sample pictures in Figure1 )were used according to the standard suggested by the International Society for Rock Mechanics[23]. The specimens were grinded using a grinding machine to control the non-parallelism of both ends within 0.05mm. The ends of the specimens should be flat to within 0.02mm and should not depart from perpendicularity to the axis of the specimens by more than 0.25°. The diameter deviations along the sample axis should be within 0.3mm. A total of twenty-five specimens were divided into five groups, each group have five specimens.”
Author Response
We have tried our best to improve the manuscript and made some changes in the manuscript according to the Reviewer’s comments. These changes will not influence the content and framework of the paper.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
The response please see the attachment.
Once again, thank you very much for comments and suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The comments can be found on the attached file.
Comments for author File: 
Comments.pdf
Author Response
We have tried our best to improve the manuscript and made some changes in the manuscript according to the Reviewer’s comments. These changes will not influence the content and framework of the paper.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Please see the attachment.
Once again, thank you very much for comments and suggestions.
Author Response File: Author Response.docx
