Numerical Parametric Study of Countermeasures to Alleviate the Tunnel Excavation Effects on an Existing Tunnel in a Shallow-Buried Environment near a Slope

Round 1

Reviewer 1 Report

This paper addresses the numerical parametric study of countermeasures on interacting new and existing tunnel at a specific condition (shallow buried near a steep slope). Overall, the background and approaches to address the issue is sound. However, the contents of this paper requires significant modification fit to MDPI journal reqirements.

First of all, when I review this paper, it was relatively difficult for me to follow and concentrate the contents. I do understand the purpose of authors to address a very detailed introductory exploration on this issue, but it leads me to distract as well. Please check the requirement of the number of pages of MDPI. The current of version of paper is more likely a research summary report. I strongly suggest to make this paper be concisely reformatted to deliver more clear feature of this study. In line 274, there is no description on Figure 6 (b). From line 279, 280, is this analysis only considerting lining for the reinforcement? What about rock bolt? If there is  a specific reason only to employ lining reinforcement, please elaborate this. From Table 5, it is necessary to explain "rebar" application in the context. In line 328, I think "Figure 12" as a typo. Please check. The findings of this paper would be  a specific to this field condition. To be an academic paper, the results needs to be  be more general  that can be applicable to other condition. I strongly suggest to modifiy the results and concluding parts  based on the numerical and field observations.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript is well presented and presents a well-structured 3D model research: conceptual model, geomechanical model results and its discussion and finally the validation with monitoring data from the construction stage. Some small aspects can be improved:
- burial depth or cover layer should be replaced by overburden;

- the term "Model a" (or other references to models from Fig. 5 along with the text) is sometimes misleading; suggestion: add "(Fig. 5)" after "Model X", especially in the captions of Figs. 8 to 22;

- line 58: "tunnel foundation excavation" is it "tunnel floor/invert excavation"?

- line 118: "tunnel construction" = "tunneling";

- section 2.2: no reference is made to the rock strata strike and dip and its relation to the tunnel axis;

- line 157: "in the entrance section" should be "at the portal";

- line 168: remove "inside the slope" (a tunnel must be underground);

- line 185: the tunnel is located in a rock mass and not in a soil: suggestion: "Rock engineering characteristics and rock mass classification";

- please review: the units of the limestone unit weight - International Systems of units use Mg.m^3, but Table 1 units are incorrect for the values presented and in Table 4 a different unit system is used; also Poisson ratio is represented by an unusual symbol in Table 4 (usually is the Greek letter nu); there should always be a space between the values and the units;

- page 7: variables mentioned along with the text must be in italic letters;

- Table 3/5th line above the end of the table: is it "fractured blocks"? (it is the description of the rock mass behavior)

- sentence 236-7: unclear;

- line 283: "overload" should be the term used when describing the additional "loads" at the surface (before and after this line);

- Table 4: the caption is incomplete; it includes symbols not previously defined;

- line 328: Figure 8;

- line 330: review "a represents Model a"

- line 626: just "tunnel face";

- line 632: review reference format;

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

This paper has been extensively modified to be published in MDPI.