Evaluating the Performance and Stability of the Highway Subgrades in Seismic Events, a Case Study of the Changning Earthquake, Sichuan

Round 1

Reviewer 1 Report

1)    Please put a subpanel on Fig. 1 to show the study area on a larger map showing china and its close vicinity.

2)    Please explain how the microseismical levels shown in Fig. 1 has been measured.

3)  Please try to better characterize the source parameters of the Changning earthquake. Please describe better the seismogenic zone of Changning earthquake, namely its responsible fault, the type of faulting (focal mechanism). There is no indication of which fault was responsible for the Changning earthquake and if the fault had a surface rupture. Authors only show active faults of the region. Also please mention how accurate is the location of the epicenter of the event by describing the distances of the recording stations and their azimuthal coverage.

4)    Please describe the geology of the cut-and-fill affected area and tell if possible site effect due to geology is the same along the most damaged area.

5)    Please bring an extra column in Table 1 for the closest distance between the responsible active fault and the affected site.

6)    Axes of Fig. 5 are not clearly readable. Please make them more clear.

7)    On line 281 authors state that to make the modelling closer to reality, they used a Gaussian distribution of the defined parameters around the used mean values. Please describe standard deviation of the Gaussian distribution for each parameter.

8)  Please show the location of accelerometer station used in your modeling. It is not clear to me where is the location of the recording accelerometer station shown in Fig. 9. I am wondering if it is close enough to the damaged area. Please show the location of the recording station on Fig. 1 and also describe if site geology and possible site amplification and its effect on the recorded acceleration.

9)    Please succinctly state the governing equations solved in the numerical methods and the used boundary conditions.

10) Plot the horizontal axis of Fig. 9 below the waveform plot not on its middle.

11) Labels of legends of Figs. 10 , 11 and 12 are not clearly readable. Please try to improve quality of Figures 10,11, 12.

12) Quality of Figs. 11 and 12 is not good. Please zoon into region with large deformation to show the details.

13) It is not clear to readers if the damaged structures did have any geogrid reinforcements. Please mention clearly this in the manuscript.

Author Response

The attached file is the list of responses

Author Response File: Author Response.pdf

Reviewer 2 Report

This article makes an interesting study on seismic damage of highway subgrades. Based on investigation of seismic damage, combined with detailed analysis and numerical simulation follow-up, a very comprehensive study was conducted. Some constructive conclusions have been put forward. 

To further improve the quality and readability of the paper, following suggestions are proposed for the author's reference.

1. The local site's soil/layer information should be addressed. Maybe in Table1 or in word form in adjacent sections.

2. Please define or explain in detail, what are "severe", "mild" or "minor" in terms of seismic damage in Table1.

3. When analyzing the earthquake damage of different sites, the detailed structral design and construction information of the location should be addressed.

4. Most pictures in the paper are not clear enough, especially some key pictures which show local earthquake damage are very important for the article. Suggest to improve these figures' quality.

5. Wrong layout for fig4.

6. Typo or print error for fig5.

7, In section 4.1, the authors are suggested to add more modeling information, including how to consider the nonlinear parameters of soil, and how to set the boundary relationship between the lower soil layer and the upper bearing layer (i.e. fill and subgrade in Figure 7), including connection, friction, separation, etc. These settings are very important for the paper, as which may directly affect the results of numerical simulation subsequently.

Author Response

The attached file is the list of responses

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

1- In the Introduction, some examples from the world should be given and the analysis of the damages encountered in large earthquakes should be expanded. For example, Işık et al. (2020), Bilgin et al. (2022), etc.

2-The representation of the faults in Figure 1 is not correct. In this state, it gives the appearance of a thrust fault. The fault representation usually also reflects the fault type. Therefore, its display should be corrected. On the other hand, the epicenter is usually represented with an asterisk. The magnitude of the earthquake should also be written at the earthquake focal point. It is not clear whether there is a fault in the place where the earthquake occurred. However, although it is stated in the following statements that the earthquake is a fault relationship, this situation cannot be understood in Figure 1.

3- Instead of conclusions, there should be a results and discussion section first, and the concrete inferences obtained from this should be given in the conclusions.

Author Response

The attached file is the list of responses

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Dear authors,

Thank you for the article and your corrections on it.