Comparative Tests on Failure Characteristics and Mechanisms of Mine Waste Dumps with Different Material Layouts
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper entitled "Comparative tests on failure characteristics and mechanisms of mine waste dumps with different material layouts" mainly studies the deformation characteristics and mechanism of mine dump materials under different layout conditions. Four models with different material arrangements were studied by base friction experiment. The topic of the article is novel, innovative, logical, and compact. The establishment of the experimental model is introduced in detail, and the experimental results are demonstrated by combining the experimental methods. The logic of derivation of the experimental results and conclusions is rigorous. The research results of this paper have good guidance and reference significance for the stacking of materials in the future dump, thereby minimizing the risk of landslides and promoting the sustainability of the mining industry. In conclusion, I strongly recommend accepting this article.
Some suggestions for paper revision are given below:
1. Section 2.1: The linear speed of the frictional belt, rather than the motor speed, is crucial to the test results. Please provide the linear speed of the frictional belt in Section 2.1.
2. Figures: In Figure 1, there is a certain angle between the test platform and the ground. Is the angle set in the experiment?
3. Section 3.2: Please unify the data format in section 3.2. For example, is it more appropriate to change "At 196s, the maximum horizontal displacements of the third-grade and second-grade stages increased to 26 mm and 23.5 mm…" to " At 196s, the maximum horizontal displacements of the third-grade and second-grade stages increased to 26.0 mm and 23.5 mm…".
4. References: It is suggested that some references on geological layer property and natural fracture should be added in appropriate places.
Comments on the Quality of English LanguageIt is good.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIt is an interesting experimental study, and the problems studied in this article are very meaningful. In this manuscript, the deformation and failure behavior of waste dumps with different material layouts are studied by means of the base friction test, and the displacement histories of points over waste dumps were measured by an updated image-capture and displacement-measurement system, which has strong novelty and practicability. The manuscript is well written and organized, the methodology of the experiments is simply and properly explained, and the results are reliable and interesting. If the author can make changes to address the following issues, we will be happy to accept this manuscript. Some suggestions for improvement are as follows:
(1) In Introduction section, most of citations are from China. Some of them should be deleted from this section and instead, new citations from other countries should be added.
(2) It is suggested that the notation of formula might be used in more common symbol and the limitations and assumptions of formula should also be mentioned in the article. 1) Section 2.3: In table 1, the unit of density should be changed from “kN/m3” to “kN/m3”. 2) Section 3.1: The word “f1” in “As the test proceeded to 244 s, the third-grade and second-grade stage sliding bodies slid along the crack f1 and crack f2, respectively (Figure 5(e)).” should be in italics and subscripted. 3) Section 3.3: Is the citation format of the reference changed from “[20,21]” to “[20-21]”? It is more appropriate to unify with the previous format.
(3) Keywords need to be modified. In this paper, the failure characteristics and mechanism of mine waste dumps with different materials layouts are compared and tested, whether it is more appropriate to add "failure characteristics" in the keyword.
(4) Page 6, lines 206 to 210: The sentence “Due to the constraints of the size of the modeling, the gravels with diameters in the ranges of 3-5 mm were represented to simulate the boulders greater than 150 mm, which weakened the strength of the boulders to a certain extent, whereas this study mainly focused on the comparative study of the dumping methods and different material layouts, and the effect of this treatment on the test results was negligible.” is too long. Consider breaking it up into several shorter sentences.
(5) Page 14, lines 452 to 456: The sentence “It is noted that the maximum horizontal displacements in Models B1 and B2 had a slight difference, although the moments of initial crack formation were significantly different, demonstrating that the failure mechanisms were totally different for Models B1 and B2, which is consistent with the results of image-based analyses.” Consider rewriting this sentence.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article contains original modeling studies on determining failure models for waste dumps. The obtained characteristics of displacements and strains over time are interesting both scientifically and technologically and indicate the validity of the research. Below are a few minor comments and suggestions:
1. In the introduction, please expand on the information on the impact of dynamic loading on the stability of the waste dump and what technological procedures are undertaken in such a situation;
2. In the subsection 2.1, please write how many research tests were performed;
3. In Figure 2, the letters overlap and should be corrected;
4. In the subsection 2.2, please write more clearly why different inclinations of layers were modeled - whether there are areas with large differences in inclination on the waste dump;
5. In the subsection 3.1, please add a few sentences explaining to what extent the test times corresponded to real conditions;
6. In the subsection 3.2 for Figure 13, please write what caused the local failures;
7. In the subsection 3.4, please add two/three sentences explaining what criterion was chosen to define Phase III in Figure 16;
8. For Figure 19, correct the letters so that they do not overlap;
9. In the discussion section, please refer to the standard values ​​or the failure index (factor of safety) so that the results constitute an extended discussion;
10. The conclusions cover the scope of the analyses and are sufficient.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe manuscript entitled “Comparative tests on failure characteristics and mechanisms of mine waste dumps with different material layouts” was reviewed with interest. The authors present the deformation and failure behavior of waste dumps with varying material layouts. The topic of the manuscript is quite interesting and novel, and the manuscript structure is well organized. In particular, the authors measured the displacement histories of points over waste dumps by an updated image-capture and displacement- measurement system. In this manuscript, the stability of the waste dump was illustrated and comparatively analyzed based on a simplified approach, in which the moments of initial cracking and local failure were used as a failure index for the model tests. The research results provide a scientific basis for the stacking of waste materials in open-pit mine dumping sites, effectively ensuring the safety of open-pit coal mine dumping projects, which are very meaningful and practical. Therefore, I highly recommend the manuscript for acceptance.
1. I would suggest slight changes to the "keywords": consider replacing "waste dump" with "mine waste dump", “material layout” with “waste material layout”, and “slope stability" with two terms, e.g. "slope stability analysis; potential slip surface".
2. While base friction tests have demonstrated themselves as a potent method for investigating failure patterns and deformation mechanisms of slopes under various conditions, they do have limitations. Authors should list the limitations of the lab experiments.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
