Physical Modeling and Intelligent Prediction for Instability of High Backfill Slope Moisturized under the Influence of Rainfall Disasters
Round 1
Reviewer 1 Report
· Line 1: Abstract: I do not think the statement in the abstract (first line) “ Natural disasters such as rainfall…….”. The rainfall only cannot be considered a natural disaster. Please rewrite the statement.
· Line 23: In the abstract, the author used the acronym term “BP”. Please for the first time, use the full form, and then the acronym.
· Please briefly mention the method of displacement and moisture monitoring method in the abstract.
· I will suggest the authors rethink the term “Model test”.
· Line 34: “Due to shortage of…..”. Rewriting is suggested.
· Line 41: “Under rainfall conditions, …..”. I will suggest “ Under the influence of rainfall,…
· Line 49: “14” is typed as part of the sentence, I think the author meant it to be the citation number. Please check.
· The overall introduction is informative and provides background information. However, I will highly recommend rewriting the introduction for the well-reasoned argument of the research.
· Line 78: Can the author explain on what basis the slope angle was considered 41o in the model?
· The backfill slope was 35o, it is important to explain the reason for preparing the model backfill slope with the angle mentioned above.
· Line 110: Spelling mistake. “Protype”
· Line 123: The relative density of the backfill was considered 80%. Typically, 90 to 95% relative density is desired in the field condition. In the model test using the relative density of typically required values would have provided realistic scenarios. The reviewer is a bit skeptical about the results obtained based on the relative density assumed here to prepare the model. I would highly recommend the author explain this 80% consideration.
· Line 129: The author mentioned that the study mainly considered the influence of rain on the stability of the high backfill slope. Table 2 shows the rainfall intensity considered. It is highly recommended that the authors include the rationale for the intensity considered. Did they have any intensity duration frequency (IDF) curve developed?
· Line 147 through 150: Sentence restructuring required.
· Line 154: “The loading device……” Please rewrite the sentence to avoid grammatical errors.
· Line 185: “The earth pressure cells were kept almost constant during the loading test…...”. This statement is incomplete and difficult to appreciate. They were kept constant concerning what? How the authors are sure that there was no influence from the surcharge? Also, the authors should clarify: the earth pressure cells of S1 and S5 were kept constant…. Or it should be earth pressure of S1 to S5?
· Line 193: ‘Indication’ instead of signal.
· Line 210: The authors mention the moisture content in tests T2 and T3. Is it at the end of the rainfall? Please clarify. Also, As the author mentioned the soil gets saturated because of heavy rain, and the associated soil suction would have provided more insight into the content.
· I think Figure 7 requires more discussion (or explanation) in the paper.
· Line 257 and Line 42: Please be consistent in using the term “Matric”. If you use “matrix”, use it everywhere. The reviewer suggests using “matric”.
· Line 257: “The rest model test…..”. Not clear by the statement, or grammatical error.
· A discussion is required why the T-2 was used to calibrate the model.
· The authors need to explain how the suction was calibrated. The authors used moisture sensors, not the tensiometers in the model. Do they have any laboratory-characterized SWCC? Without proper explanation, it is hard to comprehend the reliability of the calibration of the software.
· Line 308: Clearly define the “SN.”
· Line 310: The author used the sigmoid function as the transmission function and traingdx as the training function. It is highly recommended that the author clearly explain the justification for using this. The readers need to know it.
· Line 314: Why is an additional momentum factor applied? Need explanation.
· The predicted results in Tables 6 and 7 are appreciable. That’s why it needs all the details of the model calibration process, factors considered, and why specific models or factors were considered in the prediction are extremely important for readers to know and implicate.
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Author Response
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Reviewer 2 Report
This paper carried out a series of tests under plane strain conditions to investigate the stability of a high backfill slope moisturized by rainfalls, considering the influences of rainfall duration and intensity. The test results show that increasing the rainfall intensity and duration caused the slope near the surface to be saturated, resulting in significant influences on the lateral displacement of the slope and reduction of stability, as well as the sizes of the sliding mass. The authors use experiments and numerical simulations to reach conclusions. The problem is interesting, and the paper is well-written. Below I write some suggestions and questions.
In line 49, there is a “14” which is not a reference. Might be a typo.
In section 4, the method could be better described. Do you use only neural networks or also solve differential equations (if yes, please write them)? Do you use different samples with a heterogeneous random distribution of porosities? What changes in these 112 cases which were studied and how were they produced?
Can your numerical model treat the erosion of the soil and, consequently, the formation of channels. Besides that, could this approach be used to describe fluid displacement in porous media as in doi.org/10.1016/j.jocs.2021.101360?
In Fig. 8, what do the colours mean? And what are the units? The numbers on the axis are also small, it would be good to increase the fonts.
In Fig. 10, It is also difficult to read the numbers. Please increase the fonts.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
The study uses physical modeling and intelligent prediction to investigate the stability of a high backfill slope moisturized by rainfall. A series of physical tests were carried out under a plane strain condition considering the influences of rainfall duration and intensity. The slope displacements, earth pressures, and water content in the backfill mass were monitored during the test. Results indicate that the increase in rainfall intensity and duration might induce the slope near the surface to be saturated. It significantly impacts the lateral displacement of the slope, reduction of stability, and sliding mass volume. The trained BP model shows an average relative error of 1.02% and goodness of fitness of 0.999, indicating a good prediction effect.
Here is the list of my comments and questions for the manuscript:
1. Line 97-100: Why do you select the grain size of each material?
2. Line 115: why do you choose 5% water content to be the initial condition of backfill soil?
3. Line 151 and 156: After each test and leaving to rest for 24hr, what is the water content of backfill soil? Is the excavated layer 50mm vertical or horizontal excavation?
4. Line 164: please give detail on how rainfall significantly impact the stability of the slope
5. Line 167: What’s part of figure 2 that illustrates: “instability 166 critical surcharges of 149 kPa, 125 kPa, 117 kPa, and 136 kPa in the tests T-1 to T-4, respectively”?
6. Line 169: you might compare the details between model tests T-2 + T-3, and T-2 + T-4 to show rainfall intensity and duration that could have a strong influence on the stability of the slope. For example, the T-2 and T-3 have the same intensity but they have different rainfall duration, and they have different slope displacement responses.
7. Line 175: Could you explain why the lateral remained stable after reaching a certain value? What could the certain value indicate for the behavior?
8. Line 190: how could you explain the significance of the peak value?
9. Line 198: figure 4: how do rainfall duration and intensity impact the increment of earth pressure?
10. Line 240: figure 8: the value scale bar should be the same range and color for all cases.
11. Line 256: why do you use test T-2 to calibrate the numerical model? Will the results of the numerical model be the same when you use other tests to calibrate the numerical model?
12. Line 270: do you mean Table.4?
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thank you for addressing all the comments. I will recommend the authors proofread before the final submission to the journal. Thank you for contributing to the scientific society.
Reviewer 2 Report
The authors addressed my comments. I can now support the publication of the manuscript.
