Mechanics of Rainfall-Induced Landslides after a Prolonged Dry Period Based on Laboratory Tests and Numerical Models Incorporating Soil-Water Characteristic Curves

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study presents the effect of dry and heavy rainfall resulting in saturation degree of soils in slope stability. Experimental investigations and FEM numerical analyses were performed to evaluate the stability of the slopes. Following comments may improve the quality of the manuscript.

·        The literature review a poor in the introduction section.

·        The procedure for using the software should not be noted, while the background behind it should be explained and clarify the motivation of your study.

·        Some sections are more like technical reports and not research papers. For example: the testing procedures according to ASTM standards are common knowledge that there is no need to be explained in detail.

·       As you know Hyderabad is located in a seismic region and most failures associated with seismicity occur by variation of soil saturation degree, even in very low-level earthquake magnitudes. How do you explain this phenomenon?

·        Table 3: the dry density unit in SI should be gr/cm³

·        Table 5: replace “Dry density” with “different compactions”

·        Figure 20: The graph points are vague. What do points represent which are locations at mid-year?

·        Almost all conclusions are qualitative, please quantify the conclusions based on the numerical results.

·        Please compare your results with the results from previous studies. 

 

 

For the numerical simulations:

 

·        Which constitutive model is implemented and why?

·        There are critical assumptions that have to be made and proofed for the numerical analyses that are not mentioned in the context, such as mesh dimension and parameters associated with the considered constitutive model.

·        Present boundary conditions.

·        The saturation degree should vary by depth, how do you explain this simplification considered in the models?

·        Did you consider the water seepage in the models?

·        The models are created considering similar properties for the whole slope while the mechanical properties, especially the elastic modulus, cohesion, and friction angle as the stability controlling factors may vary with depth.

·        Generally, the graphs and numerical output images have low quality.

·        The coupled effect of hydro-mechanical is not stated clearly.

·        Figures 23 and 24: What do the numerical model legends represent?

·        The mechanical properties used for numerical simulations should be presented.

·        The suction condition resulting in saturation variation not simulated in the model?

·        Why did you assume only the 80 and 190 mm/day conditions, while the variation makes the slope susceptive to failure?

 

Comments on the Quality of English Language

·       L123: fix Error! Reference source not found

·       The spaces after camma and parentheses should be corrected for the entire context. The English is generally acceptable, however some corrections have to be made.

·       Fig 4. Due to heavy

·       L204: contribute instead of contributes

·       L256: employing soil sample

·       L280: shows the particle

·       L340: restricted to a minimum of 1.05 and a maximum of 20.0

·       L348: shows a simple

·       L349: the need to define

·       Table 4: average weight of specimens

·       L473: with an angle of 30

·       L486: other parts of the slope

·       L504: effort toward understanding

·       L598: the initial factor

·       L650: such as Attergberg limit

Author Response

"Please see the attachment."

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

- The study focuses on landslides triggered by post-dry period rainfall events in India's North-Eastern territories, highlighting the significant damage caused to life and infrastructure. Could the authors provide more context on the frequency and severity of such landslide incidents in the region, particularly in relation to historical data and trends?

-          The investigation emphasizes the importance of pre-emptive measures and slope stability analysis in landslide prevention. Considering the diverse geological and environmental conditions across the study area, how were the sites selected for soil sampling and slope failure analysis?

-          Did the selection criteria take into account factors such as terrain morphology, land use patterns, and historical landslide events to ensure a representative sample of different slope types and conditions?

-          Could the authors elaborate on the specific laboratory procedures and testing methodologies used to measure these parameters?

-          How were the soil samples collected and prepared, and what quality control measures were implemented to ensure the accuracy and reliability of the experimental results?

-          The study employs a combination of numerical modeling and empirical laboratory investigations to evaluate the integrity of slopes before and after rainfall events. It would be helpful to provide more details on the numerical modeling techniques used, including the specific software tools and algorithms employed for slope stability analysis. How were the laboratory data integrated into the numerical models, and what assumptions or simplifications were made to simulate real-world slope behavior?

-          The utilization of Soil-Water Characteristic Curve (SWCC) curves and Unconfined Compressive Strength (UCS) tests on partially saturated soil at different densities and saturation levels constitutes a crucial aspect of the research. Could the authors discuss any challenges or limitations encountered during the experimental testing phase, particularly in terms of sample preparation, data collection, and interpretation?

-          How were uncertainties and variability in soil properties accounted for in the analysis?

-          The study underscores the importance of real-time rainfall data in driving numerical analysis and understanding the role of precipitation in inducing slope failure. What methods were used to collect and analyze rainfall data from the Mizoram Meteorological Department?

-          Were any statistical or predictive models employed to forecast rainfall-induced landslide events, and if so, what were the key findings or insights derived from these analyses?

-          The implications of the study's findings for the development of an advanced landslide early warning system are significant. Could the authors elaborate on the specific components or features envisioned for such a system, and how it would integrate the research outcomes into practical applications for disaster preparedness and mitigation?

-          Additionally, what institutional or stakeholder partnerships are necessary to facilitate the implementation and operation of an early warning system in the study area?

-          I would like to suggest following article that will helps authors to improve their manuscript quality and increase level of the work:

https://doi.org/10.1038/s41598-022-19246-w

https://doi.org/10.1016/j.gr.2024.02.011

https://doi.org/10.3390/rs16030455

 

 

Author Response

"Please see the attachment."

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have adequately addressed my comments. I recommend the publication of the revised manuscript. 

Author Response

We have courteously attached the responses for your review in a PDF document.

Author Response File: Author Response.pdf