Improved Surrounding Rock Classification Method for the Middle Rock Pillar of a Small Clear-Distance Tunnel
, Ansheng Cao 1, Zhao Wu 1, Xuezeng Liu 1,2,*, Zonghai Li 3, Lihua Lin 3, Xiaotian Liu 1, Huboqiang Li 1 and Yuanwei Sun 1
Round 1
Reviewer 1 Report
1- In Equation 1, definition of Vpm and Vpr should be revised.
2- The following sentence should be revised and rewritten:
"Kv was determined by the square of the ratio of the acoustic longitudinal wave of the same rock mass to that of the rock, as shown in Equation (1):"
3- Concerning numerical simulation,
a) the model should be explained clearly.
b) The fine mesh region of the model should be indicated.
c) The validity of the model should be investigated thoroughly.
d) Loading of the model and analysis type (static or dynamic) should be stated.
e) What material model was used for soil? I think Mohr-Coulomb model was used for soil and elastic behavior was used for lining according to Table 9.
3- In Page 17, it was stated that "The total score of the middle rock pillar, T, is the sum of T1-T6."
Why was not weight factor used for obtaining the total score (T)?
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Author,
Thanks for submitting your manuscript to the Applied Sciences.
Please find the notes and minor points for improvement in the attached pdf file. It is suggested to use foxit reader.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper presents a real time case study of the classification standard for middle rock pillar associated with Xiamen Haicang Evacuate Channel project.
Six indices from geometric, physical and mechanical factors that included integrity, hardness, combination of the main structural planes of the middle rock pillar and tunnel axis, permeability, initial stress state and geometric state were evaluated.
A classification index was established from basic and auxiliary indices.
The vertical and horizontal deformation, stress, and plastic zone of the central area of the intermediate rock mass obtained by numerical simulation were used as the quantitative and grading basis of the width-span ratio index of the middle rock pillar.
A quantitative and qualitative evaluation method along with specific scoring method(with 5 grades) was proposed to grade the middle rock pillar.
The classification has solved the uncertainty problem caused by discrete mass parameters and subjective human errors.
Following are the suggestions are to be incorporated in the manuscript
1.Figure 5 a & b are not clear. Separate high clarity graphs can be aligned one after the other.
2.Figure 6 can be scaled up and can be presented with higher clarity.
3.In section 3.3.2 Width-Span Ratio, the numerical simulation is described. A separate section for the numerical simulation will provide better understanding.
4.It is better to express boundary conditions and compatibility equations involved in numerical modeling in detail.
5.Explanation and comparison of stress analysis using stress contours will improve the quality of the paper.
Overall, the quality of the paper is good and much required realistic case study with respect tunnel engineering. It is helpful in providing enhanced details about classification of tunnel strata for any new design concept.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Your proposed new rating system is specialized in the application of a small little pillar in twin tunnels, does your rating system has applicability in mining? A new proposed rating system must be linked with the well considered systems such as RMR and Q (and QTBM) systems.
· Add MRMR mining rock mass rating classification system
LAUBSCHER, D.H, 1990. A geomechanics classification system for the rating of rock mass in mine design. J. S. Atr. Inst. Min. Metal/., vol. 90, no. 10. pp 257-273.
Jakubec, J., & Laubscher, D. H. (2000). The MRMR rock mass rating classification system in mining practice. Australasian Institute of Mining and Metallurgy Publication Series, 7.
· You need to emphasise the advantages over other systems that have been used for years and therefore have been implemented and verified in many cases.
· I would recommend that the calibration be done for scores 0-100.
· Missing a proposed correlation with an existing system (such as RMR or Q) that would make it easier to implement and accept.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The responses made by the authors are satisfactory. No more revisions are needed.
