Numerical Analysis of the Single-Directionally Misaligned Segment Behavior of Hydraulic TBM Tunnel

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. In-Text of Figures needs to be increased, graphs and figures should be self-explanatory and clearly readable at 100% zoom which is a text that reader finds while reading papers.

2. Authors have carried out numerical analysis. However, some details of the numerical modelling are missed, such as the method used to determine interface parameters, the effects of mesh density

3. Some figures, such as Figures 7 and 11 are very hard to read. Please revise it.

4. In this study, pure numerical analysis is conducted. Please compare the computed results with others or measured results to verify the numerical model.

5. In Literature review, authors might have forgot to include some important papers related to 3D analysis of tunnel.

Comments on the Quality of English Language

In general, the written of this manuscript is acceptable, but there are still some mistakes. It is highly suggested the author to find a native english to polish the use of language. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

·        The introduction gives a thorough overview of the significance of hydraulic tunnels as well as the typical problems with TBM technology. Still, it can use a more thorough explanation of the particular issues and fixes that have been previously noted in the literature regarding segment misalignment. To make the background section stronger, additional recent studies should be included. Expand on the specific challenges of segment misalignment, incorporating more recent studies to provide a comprehensive background.

·       The research design seems suitable for achieving the goals of the study. To examine the behavior of misaligned segments, a three-dimensional finite element model (3D FEM) is a useful tool. The parameters selected and the different misalignment scenarios taken into account are well-founded.

·       The methods section provides comprehensive and generally clear explanations. Certain aspects, though, could use more explanation, like the rationale behind the particular misalignment parameters selected (5 mm, 10mm, 20 mm, etc.) and the possible effects of various rock conditions. Increasing the transparency of the numerical model's validation would also strengthen the methodology's resilience. Justify the selection of specific parameters and discuss how different geological conditions might impact the results. Consider adding information on the validation process for the numerical model.

·       The results are provided in a clear and concise manner, bolstered by tables and figures. On the other hand, a more thorough discussion of the implications of the major findings and a more condensed summary of them in the text would enhance this presentation. Readability would also be enhanced by making sure that all figures and tables are properly labeled and cited within the text. Summarize key findings more succinctly and discuss their broader implications in greater detail. Ensure all figures and tables are clearly labeled and referenced in the text for improved readability.

·       The conclusions drawn from the given data make sense. The research effectively establishes a connection between the identified stress distributions and possible hazards resulting from segment misalignment and the wider consequences for TBM tunnel safety and building procedures.

 

·       The conclusions are well-supported by the results, but consider discussing potential future research directions and practical applications in more detail.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This article presents valuable insights into the field of tunnel engineering and demonstrates a high standard of writing. I just have a few questions:

 

 

• This paper focuses on misalignment of segments in TBM tunnels, but what other construction issues can cause problems during TBM tunnel construction?
• The study uses a water transfer project as an example. Were there any real-world examples of misalignment causing problems in such projects that motivated this research?
• The study finds a risk of concrete cracking for misalignment over 30mm in C50 concrete. What about different concrete grades? Is there a threshold for them as well?
• This research suggests increased tensile stress on locating pins at misaligned positions. Does the study propose any specific methods for strengthening these pins or mitigating this stress?
• The study focuses on single-directional misalignment. How do the findings change if the misalignment is in multiple directions (e.g., both inward and sideways)?
• It seems that the following numerical research can also be added to the paper:
  https://link.springer.com/article/10.1007/s11709-021-0740-x
  https://link.springer.com/article/10.1007/s42452-021-04770-7

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf