Finite Element Modeling of the Soil-Nailing Process in Nailed-Soil Slopes

Round 1

Reviewer 1 Report (New Reviewer)

1. The legends in Figures 6 and 7 are missing and they are compulsory to better delineate the results.

2. The data in Tables 1 to 5 are referred to the previous paper of the authors and how are they determined should be briefly described.

3. How to determine the interface element parameters and do they yield significant effect on the numerical simulation?

4. Does different mesh size influence the numerical results?

5. Too many conclusions are drawn. Some of them are general and are not exclusive in this study.

Author Response

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Author Response File: Author Response.doc

Reviewer 2 Report (New Reviewer)

Authors report the finite element modeling of soil-nailing process in nailed-soil slope. The paper should be interesting and provide useful information, the result may provide the basis for increasing the understanding of the behavior of nailed-soil slope. The whole manuscript needs minor revisions before publication.
The manuscript is recommended publication after the following revisions are made.
(1) The title of the manuscript should be “Finite Element Modeling of Soil-Nailing Process in Nailed-Soil Slope”.
(2) More relative references should be cited and reviewed, and the contribution and engineering background of the manuscript should be explicitly pointed out. 
(3) If possible, at least one real engineering application of forecasting the safety of a real nailed-soil slope based on the method in this paper should be added and verified.

(4) Although the reviewer is not English native, I recommend the whole manuscript language improvement.

 

Author Response

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Author Response File: Author Response.doc

Reviewer 3 Report (New Reviewer)

1- What is the novelty of your work? Finite Element Modeling of Soil-Nailing Process has been performed previously by different researchers.

2- Table 1, why both Coefficient of uniformity and Coefficient of gradation were shown by Cu?

3- Table 2, what is the unit of Young's modulus?

4- Table 2, why stiffness unit is kN?

5- Table 3, what is με? Strain has unit?

6- Show the depths in Figure 1 as mentioned in lines 174-189.

7- Show the “q” in line 188 in Figure 1.

8- You used both PLAXIS-2D and PLAXIS-3D? Mention them clearly in last paragraph of introduction.

9- Line 198: there is no need to use Reference [33].

10-Use references for the Equations.

11-Figure4, show the mesh at stage 8.

12- Line 311, why m=0.5 for sand?

13-Define parameters in Table 5 and use the units for them. For example, why φ has no unit?

14- What is Comp. in Table 5?

15- Line 320 and 321: Why you used only the medium dense sand with relative density of 48% for modeling and not other relative densities (34 and 68%)?

16- Summarize the conclusions

17- Check the order of Figures and Tables. For example, there are three Figure 25 in Page 24.

18- Insert the legend for Figure 25, i.e., the legend for showing the values of horizontal and vertical displacements.

Author Response

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Author Response File: Author Response.doc

Round 2

Reviewer 1 Report (New Reviewer)

To the best knowledge of the current reviewer,the comments have been properly addressed in the revised version and it can be considered for pulication.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

See my comments given in separate file. Hope the comments are useful for the authors to improve the quality of their paper.

Comments for author File: Comments.pdf

Reviewer 2 Report

This paper is concerned with the influence of soil-nailing reinforcement on the response of a slope itself and when there is a shallow foundation at the surface. The finite element software Plaxis 2D is adopted using the hardening soil model for sand. 

Although this is an interesting topic, the results in the paper are poorly presented and the logic of the whole paper does not make sense. Firstly, the paper analyzed only a specific slope with fixed geometric dimensions. It is the slope from a 1g laboratory model test, which I believed was used for model validation. However, it is hard to accept that the analysis based on such a specific model slope can be applied to other cases, in particular, that it is a 1g small-scale model test. Both the stress level and dilatancy of the sand can not be well represented. Since the paper studies the topic through numerical modeling using the finite element model. It is natural to model the real slope instead of a model slope. In addition, the paper first presented a lot of results and discussion on the analysis of the model slope and then in the end presented the validation results. It is not logically making sense. The model should be first validated to prove the reliability of both the finite element model and the soil model. In addition, the figures presented in the paper are difficult to read. For example, in Fig. 9-11, the paper presents a lot of contour plots of the stress to elaborate the change of stress condition at different excavation stages and with/without the reinforcement. However, all the color legends of the figures are different and it is impossible to correlate the figures with the discussion in the main text. More importantly, all the discussions in the paper are very superficial without an in-depth analysis of the mechanism behind them. The reviewer found the results are fragmented and it is difficult to find the logic behind the discussion. In summary, the reviewer thinks the paper should be thoroughly reorganized and re-written. Some detailed comments are listed below:

1. The introduction part is quite long with a lot of discussions on the existing studies. However, the relationship of these studies with the work in the paper is not clear. The reviewer would suggest the authors shorten the introduction part by only presents the work that is most related to this study and clearly speak out what is the objective of this paper.
2. The description of the finite element model part can be significantly improved. The description of the details of the elements used, the interface model, and the constitutive model can be simplified since those are standard information in the software. Instead, the paper should present a figure of the model with clear labels on each component in the figure. For example, what is the meaning of “A”, “B” … in Table 4, where and how the nails are installed in the slope, and the corresponding reference for choosing these values.
3. Please add the reference for all the values defined in the paper, like the properties of the reinforcement element, the facing, the footing, the sand model parameters for the slope.
4. The reasonability of the model mesh should be validated by mesh sensitivity simulations.
5. There is no legend in Fig. 7 and it is difficult to read.
6. The definition of the axis in Fig. 12 is not clear, what D/H and z/H represent.
7. In Fig. 12a, the reviewer thinks the shape of slope movement at q=20 kPa is not realistic. Please explain why it looks like this.
8. The label of the x-axis of Fig.15 is missing and the same is for Fig. 19, 21.
9. The dark black lines in Fig. 17 are misleading. Where the vertical stress in the figure was extracted?
10. In the validation section, the details of the model tests and the corresponding finite element model should be presented. In addition, this part should be presented at the very beginning of the paper.
11. The conclusions should be shortened into more summative sentences.
12. The number of figures in the paper should significantly decrease.