Creep Behaviours of Argillaceous Sandstone: An Experimental and Modelling Study
and Yu Zhang 3Round 1
Reviewer 1 Report
Comments to the Authors:
In the manuscript titled "Creep behaviours of argillaceous sandstone: an experimental and modelling study”, the authors discuss a case-study regarding the mechanical characteristics of argillaceous sandstones. The latter were investigated both experimentally and numerically through laboratory tests and a new nonlinear creep model. The experimental investigation was carried out through multi-stage creep tests on several samples subject to different confining pressures. The nonlinear creep model was embedded in the FLAC3D software. The collected results showed that confining pressure improve the creep failure strength of sandstones.
The argument in the manuscript is reasonable and adequate with the topics published in the Applied Sciences journal.
The manuscript shows interesting results but in this current form cannot be published in the Applied Sciences Journal and there are some issues to be worked out. Thus, I retain that the manuscript needs a moderate Revision.
The main criticism of the manuscript consists in the absence of a real discussion of the achieved results. Indeed, in the manuscript a “Discussion Data” section is missing. In this section, the authors are invited to enhance the discussion of the collected results and to compare them with other relevant researches in worldwide. Furthermore, the authors should explain the limits of the adopted approach, which are its strengths and weaknesses and to emphasize what is new in their research and what is already known to the international scientific community. Thus, the authors should make an effort to better stress these aspects.
[Minor items]
- 2 lines 54-55, the authors assert: “…the creep behaviours of AS under different confining pressures have not been well documented”, here, specific references about the existing knowledges on the topic are needed.
- 2 line 83 in the section 2.1. AS sample, the authors assert: “…the deformation of the roadway continues to increase with time”, it would be interesting to know both the rate of road deformations and how they were measured.
- 3 lines 101-102: in the Figure 2 the authors should distinguish the Fig. 2A from Fig. 2B and comment them in the relative caption separately. The same considerations regard figures 10 and 12.
- Pag. 3 line 105: in the caption of Table 1 there is a Chinese character, please correct it.
- Why did the authors choose to examine only 3 samples and how they were selected?
- 21, line 496: the Figure 13 cited in the text is missing. The authors are invited to correct this mistake.
I wish that my notes can be useful to the authors to improve their manuscript and to bring it up to publication standards.
Author Response
Comment 1：
The main criticism of the manuscript consists in the absence of a real discussion of the achieved results. Indeed, in the manuscript a “Discussion Data” section is missing. In this section, the authors are invited to enhance the discussion of the collected results and to compare them with other relevant researches in worldwide. Furthermore, the authors should explain the limits of the adopted approach, which are its strengths and weaknesses and to emphasize what is new in their research and what is already known to the international scientific community. Thus, the authors should make an effort to better stress these aspects.
Response: Thanks for your suggestion, The strengths of the adopted approach are given by the end of Section 1 and the weaknesses of this adopted approach is given by Section 5 (4). Furthermore, we add some latest papers in the introduction part.
Comment 2：
lines 54-55, the authors assert: “…the creep behaviours of AS under different furthermore confining pressures have not been well documented”, here, specific references about the existing knowledges on the topic are needed.
Response: We have modified this part of our paper. Two references on creep tests of argillaceous sandstone were added to the paper, which were the only research results on this research direction that the author could find, so we say that the research references about creep test of AS under different confining pressures were really limited.
Comment 3：
line 83 in the section 2.1. AS sample, the authors assert: “…the deformation of the roadway continues to increase with time”, it would be interesting to know both the rate of road deformations and how they were measured.
Response: Thanks for your suggestion. We have completed defect part in Section 2.1.
Comment 4：
lines 101-102: in the Figure 2 the authors should distinguish the Fig. 2A from Fig. 2B and comment them in the relative caption separately. The same considerations regard figures 10 and 12.
Response: Thanks for your careful review. We have corrected all similar mistakes in this paper, please see the corresponding sections of the newly submitted manuscript.
Comment 5：
Pag. 3 line 105: in the caption of Table 1 there is a Chinese character, please correct it.
Why did the authors choose to examine only 3 samples and how they were selected?
Response: We are very sorry for the mistake you mentioned. We have deleted the Chinese character in the new Table 1. For the second question, the longitudinal wave velocity of all samples is tested by wave velocity meter and the sample with similar wave velocities are selected for experiment. we selected the samples with similar wave velocities for the experiment.
Comment 6：
line 496: the Figure 13 cited in the text is missing. The authors are invited to correct this mistake.
Response: Thank you for this comment. We are sorry for the careless mistake, and we have revised it in the newly submitted manuscript.
Reviewer 2 Report
The authors tackled a very interesting topic. The creep behavior of sandstone is related not only to the stress but also to the confining pressure. The findings could be very interesting to the readers. The title and abstract accurately reflect the paper content. The reviewer recommends the manuscript be revised to address the reviewer’s comments prior to publication in the journal.
1) I suggest updating the cited literature to newer ones related to study on sandstone creep properties.
2) At the end of the introduction, the novelty of the research should be given.
3) The caption of Figure 3 is not correct. What does represent by 1-a, 1-b,…etc.
4) The Caption of Figure 6 – It will be more clear if authors give what are the corresponding confining pressures for a) to f) in the caption.
5) It is difficult to relate the differences in Figure 10a) and 10b).
6) The implementation of the model does not contain any novelty or any new integration scheme. The challenging point is the prediction of the real failure modes. Can it be integrated into the model?
Author Response
Comment 1：
I suggest updating the cited literature to newer ones related to study on sandstone creep properties.
Response: Thank you for your suggestion and we have revised it in the newly submitted manuscript.
Comment 2：
At the end of the introduction, the novelty of the research should be given.
Response: Thank you for your comment. We have modified this part of our paper.
Comment 3：
The caption of Figure 3 is not correct. What does represent by 1-a, 1-b,…etc.
Response: Thank you for your meaningful comment, we have revised the caption of Figure 3 in our newly submitted manuscript.
Comment 4：
The Caption of Figure 6 – It will be more clear if authors give what are the corresponding confining pressures for a) to f) in the caption.
Response: I’m sorry for our carelessness, we have revised it in our new manuscript.
Comment 5：It is difficult to relate the differences in Figure 10a) and 10b).
Response: On the one hand, we can see that the accelerated creep stage shows different changes under different confining from Figure 10a) and 10b). The accelerated failure stage of the pattern is shorter when the confining pressure is 12MPA, comparing with the result of the test when he confining pressure is 6MPA. On the other hand, under different confining pressures, the strain values of corresponding stages are different from Figure 10a) and 10b). So these should be the differences between Figure 10a) and 10b).
Comment 6：
The implementation of the model does not contain any novelty or any new integration scheme. The challenging point is the prediction of the real failure modes. Can it be integrated into the model?
Response: Thank you for your command. As you said, it’s a challenge to integrate the real failure modes into the model. It requires a clear failure criterion, We need to determine more parameters to refine the model with this function. We are working vigorously to conduct the work, and this question will be exhibited in our next paper.
