Energy-Dissipation Support Technology for Large Deformation Tunnels Based on the Post-Peak Behavior of Steel Plate Buckling: A Case Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I congratulate the authors for this interesting and well-written/investigation manuscript.
The manuscript investigates the energy dissipation for energy in tunnels surrounding rock through support technology. The analysis is supported by testing, FEM, and 3D laser scanning.

1-      Introduction (end of the 2^nd paragraph), section 2.1, and other sections there is  “Error! Reference source not found”. Correct these figures captions please.

2-      In figure 1 caption, please mention location and country.

3-      Can you add a figure of the FEM model at different loading stages

4-      Please comment on the effect of the yielding point of the steel.

Author Response

Thanks for the reviewers' careful review and valuable recommendations. Details of the changes are in the word document.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have presented a real-time issue related to structure stability and tried to analyze the possible reasons for failure. The following observations may be helpful to improve the manuscript.

1. The support structures as subjected to complex directional loadings (as mostly they are arc structures). The possible ways of analyzing these structures can be added in introduction section.

2. The type of loading condition can be explained for deformation data (Figure 11)

3. The analysis of structure (Figure 8) and reality of the loading case (figure 16), the nature of applied loading seems to be different. This should be made clear.

4. The FE analysis results are not properly discussed.

5. Figure 15 shows the deformation of key points with respect to days of observations. The displacement is also significant. It is a suggestion that considering the displacement vs time, the strain rate can be considered properly for FE analysis (refer to 5 mm/min loading rate)

 

Author Response

Thanks for the reviewers' careful review and valuable recommendations. Details of the changes are in the word document.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In this paper, the authors designed a tunel support based on energy dissipation theory. Below is my major concerns:

1. In the introduciton/literature review part, the authors cited a lot of references in early to late 20th century, only a few papers are after 2000. The authors should clearly state the current reseach background in this topic, the gap/limitation in current research. The energy and dissipation method and its optimization is not something new, many research has been conducted in this area before. So what are the innovations in this study? 

2. In section 2.2, the titles says "Testing of steel plate composite structure". It seems all the structure members are made by Q235B steel plates, so what does "composite" mean here? 

3. In the same section as above, the authors mentioned:  "The steel plate composite structure was set on the steel frame so that the original rigid structure was transformed into a yielding structure so that the steel frame showed no signs of buckling or other damage in the deformation process." However, I really cannot tell if it is failed due to buckling or yielding. According to the figures, it looks more like buckling. The authors should show more testing resutls/data to support their statement or conclusion. Besides, I am just wondering if the vertical steel plate is still under elastic stage or not since it will dramatically affect the perforamnce of the tunel support. 

3. in Table 1, double check all the data. it seems there is a typo. The elastic modulus for vertical and horizontal plates should have the same elastic modulus, and why the poission's ratios are different? Also check plastick parameter. 

4. in FE analysis, please show the image of the FE model with laterial deformation/strain/stress. Also show more details about modeling. The laterial displacement as what happened in the experimental testing is unlikely to occur in the FE static analysis based on the information provided by the authors. 

5.  The authors should clearly state: (1) the purpose of the testing, and (2) how this test related to the other part of study . Based on the statement in the article, I was really confused about the purpose of testing specimen, although the answer can be found in the following chapter.

6. Based on my understanding, the "design of energy-dissipation support" is simply add the steel structure at some locations in the orginal tunel support. How are the section of the steel enery absorting structure determined? And how the installation locations are determined? Simply put an energy absoring device cannot be considered as "design". 

7. In section 3.3.3, the authors measure the strain using the embedded strain gauges. Please show some details about the measurement, such as sensor type, data collection methods. I cannot see the installed sensors and their locations based on images/contents in the paper. 

8. Check cross-reference for the figures, it shows error.

 

Author Response

Thanks for the reviewers' careful review and valuable recommendations. Details of the changes are in the word document.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

In this article the authors present a practical case of wall stabilization in a tunnel in its construction phase.

The introduction is appropriate, as is the case presented. The aspects to improve are:

- The tests on steel elements and the Abaqus model, what do they contribute new?

- Explain the measurement system used in the tunnel? (deformations, tensions,...)

- In pag. 2 there is a problem with the references. In all the paper there are problems with the references.

 

Author Response

Thanks for the reviewers' careful review and valuable recommendations. Details of the changes are in the word document.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

This is the review manuscript entitled “Energy-dissipation Support Technology for Large Deformation Tunnels based on the Post-peak Behavior of Steel Plate Buckling: A Case Study”. The topic is interesting; however, some major modifications must be addressed as follows:

1-      The abstract must be rewritten based on the detailed results.

2-      The figure names are missing in the text.

3-      In Figure 6, all you need is to present your compression device. Why you brought the MTS machine which is being used in the pull-out test.

4-      How did you find plastic and elastic modules, such as Poisson’s ratio or plastic strain, in Table 1?

5-      What kind of boundary conditions have you used in your simulation? Detailed answer is required.

6-      How did you calibrate your model?

7-      For the case study, you must bring a geographical map showing the location of your case and the geological settings of the area.

8-      I have not found anything about your damage model, presented in Fig. 10, in the text.

9-      I was expecting to consider the energy absorption model in your paper. Why did you not describe that in the paper?

 

 

Author Response

Thanks for the reviewers' careful review and valuable recommendations. Details of the changes are in the word document.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed all the issues, and I recommend it for publication.

Reviewer 4 Report

Comments and Suggestions for Authors

I thank the authors for the improvements made according to the indications received by the reviewers.

Reviewer 5 Report

Comments and Suggestions for Authors

Please consider the decision letter.