Calculation Method for Determining the Wall Displacement and Primary Support Bearing Capacity of Tunnels
Round 1
Reviewer 1 Report
The paper must undergo major revisions before considering it for publication. I must state that it is currently unclear to me if the paper consists of any substantial contribution and novelty, as there are already several simplified solutions for tunnel-support interaction. The authors must provide a review of the available methods, and explain what is the novelty of their proposed method. Although a short review and explanation is given in the introduction, many of the available solutions are not referenced, and the explanation of the novelty of the proposed method is not well explained. Available methods include solutions that account for less simplistic assumptions, such as more advanced constitutive models, and non-hydrostatic stress field.
Here are a small sample of papers that should be reviewed:
Brown, E.T., Bray, J.W., Ladanyi, B. and Hoek, E., 1983. Ground response curves for rock tunnels. Journal of geotechnical Engineering, 109(1), pp.15-39.
Panet, M., Givet, P.D.C.O., Guilloux, A., Duc, J.L.D.G.N.M., Piraud, J. and Wong, H.T.S.D.H., 2001. The convergence–confinement method. Press ENPC.
Alonso, E., Alejano, L.R., Varas, F., Fdez‐Manin, G. and Carranza‐Torres, C., 2003. Ground response curves for rock masses exhibiting strain‐softening behaviour. International journal for numerical and analytical methods in geomechanics, 27(13), pp.1153-1185.
Please address the following comments.
1. English writing style- should be improved throughout the entire paper.
2. Abstract- the abstract must be improved. This includes the English writing style, providing a better definition of the problem and simplifying assumptions, the method of calculation, and the novelty compared to current available tunnel-support calculation methods.
3. "However, due to the shortage of engineers' technical level, it is urgent to propose a simple and efficient calculation method." This statement doesn't sound right to me. There are many available methods for tunnel support calculation, including simplistic methods. In any case, a shortage of engineers should not be mentioned in this context.
4. The authors use the term "Large span tunnels" throughout the paper. Is the method not valid for any span?
5. "The Xiabeishan No. 2 tunnel is selected as a verification calculation example". For my understanding, this tunnel is used as an example, and the verification is done via numerical modeling. Hence, the word verification should be deleted from the above sentence.
6. Basic assumptions- it seems that there are additional assumptions, such as hydrostatic stress field, and circular tunnel. Also, how is the effect of distance between support installation and tunnel face (i.e. longitudinal displacement profile) accounted for?
7. What is the novelty of the derivation for the support components (i.e. bolts, steel sets, etc.)? There are other papers that have derived expressions for the tunnel support components.
8. Why are two software programs, Midas and Flac, both used?
9. " the anchor rod is simulated using beam element with 200 iterations". I don't think that iterations is the right term here. Do you mean elements?
10. Verification process- rather than checking the method for a single example, it is much better to conduct a rigorous verification process. This can be achieved by automating the process of the numerical modeling and comparing for a range of input parameters.
I did not detect many English mistakes. However, the writing style must be improved.
For instance, the sentence "It is of great significance to quickly calculate the displacement of tunnel wall and the bearing capacity of primary support for guiding construction and ensuring construction safety" could be simplified as "Calculating tunnel wall displacement and primary support bearing capacity is crucial for guiding construction and ensuring safety."
This is just an example, and there are many sentences that should be revised.
Author Response
Thank you very much for your careful reading and suggestions on the value of the article. We have carefully considered and made revisions to your questions and suggestions regarding the innovation of this article. We have conducted a detailed analysis and cited the three papers you mentioned. We have used methods such as supplementary introduction, abstract, and conclusion to provide additional explanations for your innovative questions. We deeply apologize for the carelessness of our writing. You suggest that we consider non hydrostatic stress fields and other constitutive models. Thank you for your suggestion. This is our future research content. The innovation of this article lies in separately calculating the constraint effect and bearing capacity of anchor rods, sprayed concrete, and steel arches on the displacement of surrounding rock.
Reviewer 2 Report
The paper can no published. Eventually more examples should bê presentes.
Quality of Engl
Author Response
Thank you very much for your careful review. We have made modifications according to your suggestions, as follows. Thank you for your careful review, which has improved the quality of the article.
Author Response File: 
Author Response.docx
Reviewer 3 Report
This paper presents a novel method to calculate wall displacement and support bearing capacity of large-span tunnels. In general, it seems that the paper is interesting and may be adequate in terms of the scope of the Applied Sciences journal. However, several revisions must be addressed by the Authors. Revisions are listed as follows.
1. The Abstract Section must be enriched. It is recommended to improve the ending part of this section. Thus, by the ending part of the Abstract Section, please declare the main findings of the research.
2. In the Introduction Section, around 23 technical papers are discussed. However, it is recommended to discuss more precisely those publications, please try to discuss more in detail the cited papers in the Introduction Section.
3. By the end of the Introduction Section (last paragraph), please declare more in detail the main contribution of this paper to the Applied Sciences Journal.
4. Please justify more precisely the basic assumptions reported in Section 2.1. Are these assumptions reported in any technical paper? If so, please include them.
5. Please explain more in detail the Mechanical model presented in Section 2.2.
6. A more comprehensive justification of the basic assumptions for the bolt must be included in Section 3.1.1. What the Authors are reporting is good. However, a more detailed explanation is required.
7. In Section 3.1.2, please include the proper citation where all the equations are coming from. The same for Section 3.1.3.
8. There are a lot of Equations in Section 3. I am quite sure that some of them are quite popular to be included in the manuscript. Please delete some of the Equations presented in Section 3 which can be considered as less important.
9. By the end of Section 3, please include a flowchart of the theoretical derivations that are necessary as a methodology to extract the results presented in the paper.
10. In Section 4.2, please document more information about MIDAS GTS and FLAC3D software, respectively. Why are these computer programs used? Are they the only option to perform these analyses?
11. Section 4 is very short, please incorporate and discuss more results, this will make the paper more solid and will justify its publication.
12. Conclusions must be improved as well, please be more specific and direct in every reached conclusion.
Author Response
Thank you very much for your careful review. We have made modifications according to your suggestions, as follows. Thank you for your careful review, which has improved the quality of the article.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
It is evident that the authors have invested efforts in improving the paper.
However, it seems to me that there is no novelty in the proposed method.
In the abstract the authors state: "Through comparison with the numerical simulation results, 22 it is proven that the calculation results of the method proposed in this paper are more accurate and 23 have a certain guiding role in the selection of support methods and parameters". This is simply incorrect! Numerical results would definitely be more accurate, as they are capable of accounting for additional effects that are not considered using the simplistic analysis outlined in the paper. Moreover, if engineers wish to quickly calculate tunnel-support response, there are numerous available solutions for this problem. Some of the simplistic solutions account for more complex conditions than the authors.
The authors write: "Compared with the previous studies, this paper considers the displacement of the tunnel wall more carefully, deduces the displacement of the tunnel wall solution after the application of bolts and, the tunnel wall displacement solution after the application of a steel arch frame and shotcrete, and finally gives the calculation method of the bearing capacity of the primary support."
Here too, I cannot see how this can be true. Ultimately, the authors have provided some variation of a convergence-confinement method. Hence, there is no substantial contribution.
The level of English writing could be improved.
Author Response
Thank you for your advises.
Reviewer 3 Report
It seems that the Authors have addressed all the recommendations. Thus, the paper is now in a more suitable form to be published in the Applied Sciences Journal.
Author Response
Thank you for your advises
Author Response File: Author Response.docx
