Numerical Analysis and Experimental Study of the Mechanical Response of Pavement Slab Supported on an Inhomogeneous Settlement
Round 1
Reviewer 1 Report
In the manuscript, the effect of the uneven subgrade was studied. Twofold approach was used - a set of numerical tests was carried out and also a set of laboratory experiments was performed. In my opinion, the research problem itself is interesting. However, there is no substantial novelty in the paper. The main conclusions are not unexpected. Moreover, there is no discussion on the possible accounting for the uneven subgrade in the design procedure. The numerical part is very limited. Only the static load is considered and the description of the applied constitutive model is missing. There is no discussion on the quality of the obtained numerical results. In my opinion, the FE meshes are too dense. Thus, the numerical results are not reliable.
Below, the list of additional remarks is presented:
Line 17 and other lines in the abstract: "Should experience"?
Lines 20-21: "Increasing the thickness of the pavement slab and reducing the uneven subgrade support can effectively improve the mechanical performance of the pavement structure." These conclusions are not unexpected rather...
Keywords: The phrases are too long.
Equation 1: Describe the formula (its background and asssumptions) and the reasons for the particular values used.
Paragraph starting at line 72: Discuss the reasons of the uneven subgrade support in a more detailed way.
Line 95: Format "fr" properly.
Line 101: Explain the methodology in detail and clarify how the specific values were adopted.
Line 108: What kind of "connection"?
The concrete slab is not modelled as the rigid. Only the elasticity modulus exhibits a high value.
Line 112: What do you mean by "both ends of the pavement slab"?
Line 116: What was the justification of these specific values?
Line 124: Why this position was used?
Line 174: "In addition, increasing the thickness of the pavement slab can effectively improve" - it is nothing unexpected, in fact.
Lines 182 and 197: "the effect of uneven subgrade support on pavement slab thickness should be considered." - how to account for it in the design procedure? The subgrade is assumed to be compacted properly. One cannot estimate the possible zones of the failure in the subgrade.
Line 222: Describe the applied model.
Figure 7: The mesh density seems to be insufficient. Refine the mesh and study the results convergence. Show the remaining part of the model (Figure 1).
Lines 254-257: Remove these lines (they are from the template file).
Line 289: Explain how the difference of the slab thickness can simulate the time varyinf-effect of the uneven subgrade.
Line 292 - Where is Formula (2)?
Lines 309-310: Once again - such a conclusion was clear from the very beginning...
Line 325: How the time effects were accounted for?
In my opinion, the quality of English is sufficient.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The present research (submitted by the authors/applsci-2414374) is mainly focused; on the numerical and experimental analysis of mechanical response of pavement slab supported on uneven subgrade. The article is well organized and the work is very interesting. Therefore, I suggest that the manuscript must be accepted after major revision.
1. The Abstract is too short and does not contain any results. The entire abstract section must be revised to give a brief explanation of the importance, investigations and outcomes with the advantages/significance of this research study. Also, the novelty of the study should be reflected in the abstract.
2. Please add recent author references in the introduction section, and it is necessary to mention clearly the originality and novelty of this. What is the novelty of the work, explain that at the end of the introduction.
3. The introduction seems too short, as the objective of the present work.
4. Please, it is necessary that the authors present and more discussed the results and compare with other work in the literature.
5. The authors are not showing any other data as a comparison or reference value, to be compared with their generated data.
6. In the conclusions, the authors should clearly indicate the novelty of their contribution and the important results.
7. A complete revision of the document is necessary. Improved bibliography, as there are more recent references not cited.
8. The manuscript should be revised for more concise.
Minor editing of English language required.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper mainly studies the influence of different aircraft wheel load types and rigid pavement thickness on the uneven subgrade of airport roads. In this paper, a three-dimensional numerical analysis model of aircraft load pavement structure with uneven horizontal subgrade support is established. The factors such as different aircraft wheel load types, rigid pavement thickness, spatial and time effects of uneven subgrade support are considered. The influence of uneven horizontal subgrade support on the bending tensile stress and thickness of pavement and the time-varying influence of pavement mechanical response under aircraft load are analyzed. At the same time, the proportional model test of the airport pavement structure supported on the uneven subgrade was carried out, and the strain generated by the pavement slab was analyzed. The time-varying effect of horizontal uneven distribution of pavement subgrade is studied in this paper, which provides an appropriate reference for the design method of long-life pavement structure of airport.
The structure of the article is reasonable. The numerical analysis method and the simulation test scheme are reasonable. However, this paper needs very significant improvement before acceptance for publication. My detailed comments are as follows:
Abstract needs to be streamlined. There should not have detailed enumeration, and the final data should be used to support the conclusion.
The introduction part lacks the subject in the summary of previous studies. It is necessary to select the research status related to the research content of this paper. And the unrelated research status is not repeated.
What is the basis of using rubber plates and silica gel plates to simulate uneven subgrade support in pavement scale model test ? why is the thickness of the pavement slab set to 0.07 m and 0.08 m when analyzing the time-varying effect ? It can be supported by appropriate references.
Figure 1 and Figure 9 have different text proportions. The numbers in Figure 1 should be on the same side. And the notes are not clear.
The Table 2 and Table 3 format needs to be adjusted. There are some problems with the numerical format of scientific notation in Table 2 and lines 243-244.
Whether the sentence in lines 158-159 should be modified to‘ The highest flexural tensile stress is taken as the flexural tensile stress of each condition in Group I and Group II’？
The content in line 254-257 is irrelevant to this article.
The title format of line 288 is not uniform.
The format of the 11th reference is wrong.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
In my opinion, the corrections made by the Authors increased the readability of the manuscript and its general quality. My suggestion is to present in the next paper the study of the numerical results convergence in terms of the finite element mesh. I would expect much reliable results than the current ones presented for a coarse mesh.
I found several textual mistakes in the manuscript. Please, reread it carefully and correct them.
Author Response
Thanks very much for your warm work earnestly. This work is an ongoing study and we will be working on it. According to your suggestion, we will conduct more rigorous and detailed numerical simulation work in next phase. Besides, we have corrected the textual mistakes.
Reviewer 2 Report
Accept in present form.
Minor editing of English language required.
Author Response
We feel really appreciate the careful reading of the paper. According to your suggestion, English writing has been polished by some native speakers. We have corrected the minor and major writing mistakes in the paper.
