Dynamic Analysis of a Long Run-Out Rockslide Considering Dynamic Fragmentation Behavior in Jichang Town: Insights from the Three-Dimensional Coupled Finite-Discrete Element Method

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper studied the dynamic process and rock deposit area of Jichang rockslide using remote sensing data and FDEM modelling. Several new findings are obtained from numerical simulation, which bring some input to the scientific debate. The manuscript is interesting. Some comments which can help researchers further improve the manuscript are listed below:

*Abstract.

1. Lines 28~29: Sentences are gramatically incomplete or wrong.

*Introduction.

2. Lines 44~45: In the sentence meaning, the word ‘and therefore’ mean repetition.

3. Lines 72~82: This paper provides a review of the classic literature in this field. Some recent published papers are missing in the literature review of numerical methods on rockslide inversion events.

* Study area.

4. The date of remote sensing images are suggested to be added in Fig.1.

5. Line 87~88: Sentences are poorly expressed and difficult to understand.

6. Line 93: The rock is in the Yangtze paraplatform. ===>>> The rockslide is in the Yangtze paraplatform.

7. Figure 3: The Fig does not indicate what year the rainfall data is for.

* Numerical simulation results and discussions

8. Line 222: There is no mention in the manuscript of how the stronger localized compressive stresses are generated, and it is suggested that additional clarification be provided.

9. Line 226-238: It is suggested that the authors discuss in comparison between analysis and actual data, it should be clearly stated what matches and what doesn't.

10. Figure9-12: The timing of the inflection points of the curves in Figures 9 and 10 do not coincide, and it is suggested that the reasons for this result be analyzed in the manuscript.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I have carefully read the manuscript and found this manuscript is interesting in general. The method is novel and shows new characteristics especially fracturing characteristics of the rockslide. Some comments are listed as follows which might benefit further improving the manuscript.

 1. Some errors appear in the manuscript, and the authors should carefully check the language.

2. In Fig.1, the date of pre-failure and post-failure images should be added.

3. The ordinate in Fig.3 lacks of unit.

4. Time in Fig.7 is unclear and the authors should mark it.

5. The format of the Figs. 3, 8-11 need to be revised.

6. In line 137, the format of the reference is not consistent with others.

7. The FDEM model can calculate fracturing energy, but I don’t think it is accurate, because the finite element is too large compared to the real rock fragmentation. This means more fragmentation processes will exist and the real fracturing energy should be much greater than numerical simulation.

 

8. Comparison between FDEM and SPH is simple in this version and it should be further discussed.

Comments on the Quality of English Language

The author need to check the language carefully, there some typo errors.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Review of the manuscript ‘Dynamic analysis of a long run-out rockslide considering dynamic fragmentation behavior in Jichang town: Insights from the three-dimension coupled finite-discrete element method’ by Zhu et al.

 

 

 

General comments:

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The topic is suitable for the Remote sensing journal. However, there are several points which should be addressed:

 

The topic is very interesting, however the presentation is not sufficiently presented. I am also missing come critical comment at the end of the manuscript. What are the advantages and disadvantages of your approach? What could be improved?

 

Also, the software description is completely missing.

 

You should add and/or discuss the modeling of the fractures/cracks, which you mention in some parts.

 

Consider adding the references of Anja Dufresne and especially Alexander Strom, which both published the mobility of rock avalanches and rockslides, along with Davies and McSaveney (you have one of their references cited).

 

The manuscript should be proofread for English, because many sentences are grammatically not OK, for example line 177: '...with a contact might forming', 'ration was adopted' (line 1999), 'time was as 75s' (line 215) etc.

 

Figures 8 to 11 should be merged, because they all have the same units on x- and y-axes. Also, the interpretation would be much easier on merged energy curves.

 

Is it possible that the process is also a rock avalanche, not only a rockslide?

 

 

Specific comments:

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Line 61: Regarding the fragmentation, you should include the works about fragmentation models of J. Corominas in the journal Landslides.

90: Figure 1: Outlines are very poorly visible. Also, add the date of the images.

93: 'The rock'? There is not only one rock.

93: Describe the paraplatform.

97: What do you mean by 'chaolite'?

102: Figure 2 is missing the legend.

111: Figure 3: Add the units on y-axis. Mark the date of the landslide event on the graph.

115: What is the inclination of the slope?

116: Usually the Quaternary deposits lie on horizontal surfaces, so please explain how do they appear on the slope.

123: What is the H/L ratio? Also, what is the maximum depth?

150: Equation 1 and also all other equations: Add the units.

156: Describe the 'damage period', this is not clear.

159: Equation 2: Provide the reference for this equation, if it is not your own work.

163: The first sentence of the paragraph (The CIE...) is not clear, please explain or rewrite.

189: Was the DTM data obtained by lidar scanning, photogrammetry, in any other way? Consequently, was vegetation considered in the DEM or not?

195: What do you mean by 'its (?) number is 15765'?

199: Poisson ratio were 'adopted' for the simulation – first, correct the grammar (was, not were!), second, what do you mean by 'adopted', and third, did you perform the Poisson values by yourself or was this value taken from some reference (if yes, include it).

205: 'Fracture energy' is not really a suitable term and should be renamed and/or explained in more detail.

221: Please explain how are the cracks included in the model.

226: What is terrain bugle?

228: Explain the 'groups of slides'.

232: 'Met once again' is a bit oversimplified term and not quite suitable for the landslides.

236: Landslide almost completely deposited (grammar!) at 75 s. If it was *almost* deposited, why did the simulation time stop at 75 s and not later?

237: Landslide should be outlined in the figures.

240: Figure 7: In the caption please add the numbers/letters for each image with corresponding explanations.

240: Figure 7: Text in all of the figures is not visible at all.

268: Figure 9: The curve is very smooth, how is it possible that the effects of separation and merging of two landslide bodies is not visible on the curve?

318: You are mentioning the heat energy, however this was not discussed before or modeled at all.

328: The process is not 75 s.

330: Velocities of 45 m/s are not visible on the graph (Figure 5).

335: ‘Violent’ is not a suitable term for the fragmentation.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf