Analysis of Excavation Parameters on Face Stability in Small Curvature Shield Tunnels

Round 1

Reviewer 1 Report

I have gone through a technical note entitled "Analysis of Excavation Parameters on Face Stability in Small Curvature Shield Tunnels" where authors tried to check tunnel settlements with two different types of tunnel, ie. straight and curvature types. Shield tunneling is a highly mechanized tunnel construction method. Compared with traditional construction methods, the shield tunneling method is relatively safe and fast. However, the tunneling efficiency of a shield machine greatly depends on the stratum, hydrology, environment, and other conditions.

The article's english is fine and the citing references are also well. The flow of paper presentation is well written but results are quite confusing, only tunnel settelements have discussed with different shield pressure on surrounding tunnel walls. Also not show any figures of Plaxis model results where it can be seen the developed stresses. Authors should includes and mentioned how much stresses developed during excavation? Please check the

3.1 section, line 129- authors mentioned small radius of 180m, please the radius of tunnel, how it is small or it is the length of length? It’s so confusing statement, please see it again

Also please check the table 1 data shield shell Youngs modulus, 200×10^6 KPa? it's mean 200 GPa, is it right value?

 

Author Response

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Reviewer 2 Report

Specific comment:

1. Please use the full name when it appears first time in the paper, such as ‘3D’ in line 91.

2. Why authors only utilize numerical method to analyze face stability? what are disadvantages of LEM and experimental methods? Please add the corresponding statement in the Section 2.

3. There is almost no difference between Fig. 5 and Fig. 6. It is suggested to use one of them to illustrate the influence of supporting pressures and curvature on tunnel settlement.

4. In this paper, the influence of supporting pressures and curvature on the settlement was simply studied, and no other parameters (such as soil parameters) were involved. The research content is too simple.

5. This paper does not use quantification indices to present the difference between straight tunnel and small curvature tunnel. It is recommended that latter's modeling details be strongly highlighted.

6. The content of the paper is seriously insufficient and the readability is not strong. It is suggested to add more parameter analysis and further improve the syntax structure of the paper.

Author Response

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Reviewer 3 Report

I reviewed "Analysis of Excavation Parameters on Face Stability in Small 2 Curvature Shield Tunnels".

This paper investigates the face stability of small curvature shield tunnels during excavation and its relationship with excavation parameters. This paper examines research from the results of numerical simulations in analyzing the effect of different excavation parameters, such as jacking force, cutting speed, and soil conditioning on face stability. Conclusion of the study show that the excavation parameters significantly affect face stability.

This paper is useful for tunneling papers. Aim of the study is different and interesting. But, I have some advices for a few problems.

* Literature can be development. Especially other different journals. for example this paper can be cited.Numerical analysis of underground space and pillar design in metalliferous mine, Journal African earth sciences.  Thus, paper can be made visibility in other journals.

* Numerical model boundary conditions should be given as picture.

* Vertical and horizontal stress numerical models should be shown in Figure for all cases (Case I, Case I-II, ....... etc.).

Best regards,

Author Response

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Round 2

Reviewer 1 Report

The authors have incorporated the suggestions in the MS, still, minor check should require before acceptance which are-

Authors should recheck the abstract and conclusion.

Authors should recheck the MS English spelling.

Authors should consider numerical modeling articles to strengthen the MS, which may be 1) Stability Analysis of Shallow Depth Tunnel in Weak Rock Mass: 3D Numerical Modeling Approach

2) A Numerical Simulation of Influence of Rock Class on Blast Performance

Author Response

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Reviewer 2 Report

The author explains the review comments very well

Author Response

Thank Reviewer 2 for the positive comments.