Experimental Study on the Mechanical Characteristics of Thin-Bedded Rock Masses Due to Water-Absorption Softening and Structural Effects

Round 1

Reviewer 1 Report

This paper is about the mechanical characteristics of rock masses in different strata structures and different water absorption states. Some important conclusions are proposed.

1.The scientific importance of this study are not highlighted. The author should highlight the focus of your research to show how advance or important of your research. Please address this aspect.

2.I think the paper should enrich the references about latest research.

3.The engineering geological background needs to be described in detail.

4.What is the difference between bedding degree and different layer inclination angles in Figure 4.

5.The description is too complex from lines 74 to 87, and it is recommended to simplify.

6.The author should add some captions about Figures 15–17.

7.A revision of the written English is needed.

no

Author Response

1.The scientific importance of this study are not highlighted. The author should highlight the focus of your research to show how advance or important of your research. Please address this aspect.

Thanks for your question. We revised this parts and added relevant literatures. We also rewrite the abstract and the introduction part to be more comprehensive. Please check this two parts.

2.I think the paper should enrich the references about latest research.

Thanks for your question. We revised this parts and added relevant literatures.

3.The engineering geological background needs to be described in detail.

Thanks for your question. We added the engineering geological background. Please check the lines 72-84.

4.What is the difference between bedding degree and different layer inclination angles in Figure 4

Thanks for your question. It is the same. We changed the bedding degree to layer inclination angles. Please check it.

5.The description is too complex from lines 74 to 87, and it is recommended to simplify.

Thanks for your question. We simplified this parts. Please check the lines 100-112.

6.The author should add some captions about Figures 15–17.

Thanks for your question. We added captions on Figures 15–17. Please check the figures.

7.A revision of the written English is needed.

Thanks for your question. We revised the written English through professional english translation agency.

Reviewer 2 Report

The paper is well written and despite some minor mistakes that do not affect the quality of the article, it can be published in this journal after minor revisions.

- The rocks on which the experiments are carried out require more explanations on their nature, their mineralogical compositions. Have petrographic studies already been carried out on these geological formations? These informations are useful for better assessing and validating the results obtained.

- Graphical scales are needed for each photo in figure 1. You must also clearly specify the type of rock here

 

Author Response

1.The rocks on which the experiments are carried out require more explanations on their nature, their mineralogical compositions. Have petrographic studies already been carried out on these geological formations? These informations are useful for better assessing and validating the results obtained.

Thanks for your question. We add this two tables and some explanations. Please check the lines 71-84.

Table 1. Analysis of mineral diffraction of slate.

No.	Mineral content（%）
	Quartz	K-feldspar	Plagioclase	Clay mineral
S1	56.5	/	1.5	42.0
S2	50.3	1.0	1.8	46.9
S3	48.0	0.9	1.6	49.5

Table 2. Relative content of clay mineral.

No.	Clay mineral relative content（%）						Mixed layer ratio（%）
	S	I/S	I	K	C	Py	I/S
S1	2	12	46	8	32	/	5
S2	/	20	37	11	27	5	10
S3	1	15	50	9	25	/	5
S：Smectite； I：Illite； I/S：Illite/Smectite formation； K：Kaolinite；C：Chlorite；Py：pyrophyllite

 

2.Graphical scales are needed for each photo in figure 1. You must also clearly specify the type of rock here

Thanks for your question. It is a good question. However, we ignored graphical scale when took pictures, and we will pay more attention to graphical scale in future studies. We added the type of rock on figure 1. Please check figure 1.

Reviewer 3 Report

1. Linguistic redundancy. Such as, in 2.1, "The dry state is divided into 0°, 30°,45°, 60°, and 90° rock sample groups according to the stratum inclination. The saturated state is divided into 0°, 30°, 45°, 60°, and 90° rock sample groups according to the inclination angle. The natural state is divided into 0°, 30°, 45°, 60°, and 90° rock sample groups according to the inclination angle."

2. The introduction needs to be more comprehensive to allow readers to understand the current research status in this field. Such as, "Many scholars have accumulated rich research results in the study of the mechanical properties of thin-bedded rock masses [4-15]." 

3. The single weak surface theory is not innovative, it is only a simple application.

4. Some figures are indistinct, such as Figure 12, Figure 12(b), Figure 13(b), and Figure 14(b).

5. How does numerical simulation reflect the water absorption softening of rocks? Is it sufficient to have different numerical simulation parameters? Please explain.

6. There needs to be more analysis of the coupling effects of different layers of inclination and water absorption status of rock masses. The authors have not demonstrated novelty in theory or experiment. 

Author Response

1. Linguistic redundancy. Such as, in 2.1, "The dry state is divided into 0°, 30°,45°, 60°, and 90° rock sample groups according to the stratum inclination. The saturated state is divided into 0°, 30°, 45°, 60°, and 90° rock sample groups according to the inclination angle. The natural state is divided into 0°, 30°, 45°, 60°, and 90° rock sample groups according to the inclination angle."

Thanks for your question. We revised the paper as follows:

The rock samples of differernt states are divided into 0°, 30°, 45°, 60°, and 90° rock sample groups according to the stratum inclination.

Please check the line 103- line 105.

2. The introduction needs to be more comprehensive to allow readers to understand the current research status in this field. Such as, "Many scholars have accumulated rich research results in the study of the mechanical properties of thin-bedded rock masses [4-15]."

Thanks for your question. We revised this parts and added relevant literatures. We also rewrite the abstract and the introduction part to be more comprehensive. Please check this two parts.

3. The single weak surface theory is not innovative, it is only a simple application.

Thanks for your question. We want to find a theory to explain the result and apply it to the actual engineering on site. The surrounding rock with the inclination angle between 25°–79° are monitored and supported particularly in Muzhailing Tunnel. Subsequently, we would like to do some creep tests to guide the actual engineering on site.

We added some explainations about this question. Please check the lines 243-246.

4. Some figures are indistinct, such as Figure 12, Figure 12(b), Figure 13(b), and Figure 14(b).

Thanks for your question. We took a re-screenshot. Please check the figures.

5. How does numerical simulation reflect the water absorption softening of rocks? Is it sufficient to have different numerical simulation parameters? Please explain.

Thanks for your question. We added the explaination as follows:

The hypothetical parameters are selected, the experimental results are obtained by numerical simulation method and compared with the indoor mechanical characteristics experiment, the block mechanical parameters and contact surface micro parameters are adjusted by observing the difference between the numerical simulation results and the experimental results, and then the numerical simulation is carried out and compared with the experimental results until the results are more consistent, the numerical simulation parameters are the required parameters, and the parameter calibration is completed.

Please check the lines 279-286.

6.There needs to be more analysis of the coupling effects of different layers of inclination and water absorption status of rock masses. The authors have not demonstrated novelty in theory or experiment.

Thanks for your question. We added Disscusions parts to analyses the coupling effects. Please check lines 355-368. We also added experimental details, completely the results, and describing a comprehensive background to the research in the paper.

Please check the disscusion, abstract, introduction, experiment on the thin-bedded rock masses parts.

Reviewer 4 Report

This is a manuscript with a novel perspective. Considering two influencing factors, the mechanical characteristics of thin-bedded rock masses were studied. The results have practical value for the research on deep buried tunnel engineering. For reference, I suggest accepting this manuscript after making some minor modifications. I have some few comments for the authors:

 

1.There are duplicates in the abstract parts. The abstract needs to be rewritten.

2.Authors should add some relevant literatures, especially the literatures in recent years.

3.Some of the statements in the manuscript should be unified, such as “ inclination angles” and “bedding degree”; “water-bearing states” and “aqueous states”.

4.Authors should indicate why choose rock samples in the saturated state to analyse the shear strength of the rock mass. What about the results of other aqueous states.

5.Formulas (1)-(8) require formula notation description.

6.It is better to add some summary in conclusions parts.

Author Response

1.There are duplicates in the abstract parts. The abstract needs to be rewritten.

Thanks for your question. We rewrite the abstract. Please check it.

2.Authors should add some relevant literatures, especially the literatures in recent years.

Thanks for your question. We added relevant literatures. Please check it.

3.Some of the statements in the manuscript should be unified, such as “ inclination angles” and “bedding degree”; “water-bearing states” and “aqueous states”.

Thanks for your question. We unified the satements. Change bedding degree to inclination angles, and change aqueous states to water-bearing states. Please check it.

4.Authors should indicate why choose rock samples in the saturated state to analyse the shear strength of the rock mass. What about the results of other aqueous states.

Thanks for your question. In the saturated state, the weakening of the rock sample layer is the most obvious. In the actual engineering, the rock in the saturated state is the most dangerous state. So we choose the rock samples in the saturated state to analyse.

5.Formulas (1)-(8) require formula notation description.

We have added the notation description. Please check the paper.

6.It is better to add some summary in conclusions parts.

We have added the Discussion parts. Please check the lines 354-367.

Round 2

Reviewer 3 Report

No comments.

Author Response

We added relevant literatures to let the introduction part to be more comprehensive.