Reloading Mechanical Properties and Particle Flow Simulation of Pre-Peak Confining Pressure Unloading Sandstone
Round 1
Reviewer 1 Report
The present manuscript reports mechanical laboratory tests of sandstone samples investigating the relation between confining pressure and strength. The experimental results are compared with a two-dimensional particle flow simulation. I am not very familiar with tri-axial loading tests and the present manuscript did not really help me to familiarize myself with the topic. Certainly the experiments and the simulation have been performed in a suitable manner but the text appears hard to be followed by a reader who is not working with a ‘Thermo-hydro-mechanical–chemical multi-field coupled triaxial rheological test system’. Even though it is possible to find more information in the referred literature in my opinion it would be helpful to add some more basic information. For example Figure 1 could be supplemented with a schematic presentation of the components indicating the directions of the applied loadings. It is also not absolutely clear to me how the tri-axial compressive strength is determined from the confining pressure and the axial pressure. Can you provide a formula? I have another question concerning the Triaxial unloading test (2.1.1). I am not sure if I understood this right but I would have expected that the confining pressure was unloaded and not loaded (l. 117). Concerning the numerical model I could not follow how the three dimensional cylindrical models were modeled as two-dimensional rectangular models. I guess that symmetries were used but this should be explained. How do the particle shape, size and their variation affect the simulation results and how are material properties of components in a sandstone matrix considered? The modeling part will need some more information.
In general, I would suggest editing and rephrasing of the text so that it is easier to be read, by cutting long sentences in part, avoiding long sequences of terms and adding articles.
Author Response
Thank you for your comments.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments: applsci-2358052
In the current exploration, the authors investigate Reloading Mechanical Properties and Particle Flow Simulation of Pre-Peak Confining Pressure Unloading Sandstone. This work seems to be interesting, original, and also well-developed. Figures are included for better improvisation. I recommend the publication after minor changes. My suggestions are listed below:
· Please add some very recent papers to enhance the introduction related to your study especially from the Applied Science Journal.
· What is the main contribution addressed by you regarding the field?
· Add Tables to show the obtained data.
· Add qualitative results in the abstract.
The methodology should be explained precisely. The authors did not discuss methodology. Which method is used to calculate the results?
Minor editing of English language required.
Author Response
Thank you for your comments.
Author Response File: Author Response.docx
Reviewer 3 Report
Overall paper is well formatted and has novelty. But, language is poor, it need massive polish from native speaker before resubmission.
Language issue.
Author Response
Thank you for your comments.
Author Response File: Author Response.docx
