Study on Load Transfer Mechanism of Pile-Supported Embankment Based on Response Surface Method
Round 1
Reviewer 1 Report
Point 1：Mentioned in 3.1.1 “When the cohesion is greater than 15kPa, the pile-soil stress ratio tends to be stable……” and “the cohesion is greater than 20 kPa, the soil arching effect tends to be stable……”The description of deformation law of pile-soil stress ratio is inconsistent. Please check the pattern law and modify the description of pile-soil stress.
Point 2：Mentioned in 3.1.1 “The difference between the earth pressure on the upper part of the geogrid and the filling earth pressure is the load transfer caused by the soil arch effect, and the upper part is the load transfer caused by the membrane effect .……” The representation is inaccurate.
Point 3：Mentioned in 3.1.4 “when the geogrid strength reaches 120kN/m, the increase of pile-soil stress ratio is small.……” The strength analysis range of geogrid in this paper is 6-150kN/m. It is recommended to supplement the load transfer rule for high-strength grids to accurately describe the load transfer rule when the grid strength is greater than 120kN/m.
Point 4: Significance analysis of interaction effects in 3.2.2. It is recommended to supplement the P value of each interaction item to further illustrate the significance of each factor.
Author Response
Dear Editor and Reviewer:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Study on Load Transfer Mechanism of Pile-Supported Embankment Based on Response Surface Method”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in yellow in the paper. The main corrections in the paper and the responds to the reviewers’ comments are as flowing:
Point 1：Mentioned in 3.1.1 “When the cohesion is greater than 15kpa, the pile-soil stress ratio tends to be stable……” and “the cohesion is greater than 20 kPa, the soil arching effect tends to be stable……”The description of deformation law of pile-soil stress ratio is inconsistent. Please check the pattern law and modify the description of pile-soil stress.
Response: According to the opinions of reviewers, the graphic rules have been checked and the content of this manuscript has been corrected.
Line 209: the statements of “When the cohesion is greater than 15kpa, the pile-soil stress ratio tends to be stable……” were corrected as “When the cohesion is greater than 20 kpa, the pile–soil stress ratio tends to be stable……”
Point 2：Mentioned in 3.1.1 “The difference between the earth pressure on the upper part of the geogrid and the filling earth pressure is the load transfer caused by the soil arch effect, and the upper part is the load transfer caused by the membrane effect .……” The representation is inaccurate.
Response: The content of the manuscript has been revised according to the comments of the reviewers.
Line 219-222: the statements were corrected as “The difference between the earth pressure on the upper part of the geogrid and the filling earth pressure is the load transfer caused by the soil arching effect, and the pressure difference between the lower part and the upper part of the geogrid is the load transfer caused by the membrane effect.”
Point 3：Mentioned in 3.1.4 “when the geogrid strength reaches 120kN/m, the increase of pile-soil stress ratio is small.……” The strength analysis range of geogrid in this paper is 6-150kN/m. It is recommended to supplement the load transfer rule for high-strength grids to accurately describe the load transfer rule when the grid strength is greater than 120kN/m.
Response: According to the reviewer's comments, the load deformation law when the grid strength is 180 kN / m has been supplemented. As shown in Figure 9, it can be seen from the comparison that: “when the geogrid strength reaches 120 kN/m, the increase in the pile–soil stress ratio is small.”
Point 4: Significance analysis of interaction effects in 3.2.2. It is recommended to supplement the P value of each interaction item to further illustrate the significance of each factor.
Response: The variance information for the interaction term has been supplemented in Table 6 according to the reviewer's comments, and the interaction has been reanalyzed in Section 3.2.2.
Line 440-449: “It can be seen from Table 6 that the Prob(P) value of AB is 0.0118, indicating that the difference of AB is significant. The Prob(P) value of AC is less than 0.0001, indicating that the difference of AC is extremely significant. In addition, the contour line presents an ellipse with large curvature, indicating that the interaction is significant. As shown in Figures 10(b)(d), the slope of the response surface of the cohesion and embankment elastic modulus is relatively slow, and the contour line presents an ellipse with small curvature. However, the response surfaces of the cohesion and internal friction angle are saddle-shaped with large slopes. Therefore, from the perspective of interaction, the combination of the cohesion and internal friction angle has a great influence on the test results.” was added.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: 
Author Response.doc
Reviewer 2 Report
- The Introduction and literature review parts are merged, which should not be the case, and these two parts should be explained separately.
- the introduction part needs more information about this sector and should be upgraded.
- In the literature review part, the previous research in this field should be explained more completely and the gap that led to this research should be explained.
- in the 2.1 part, how the written parameters are obtained, it should be explained where and how these parameters were obtained and explained.
- It is better to show all the processes performed in this research as a figure or diagram for better understanding.
- In the conclusion section, more explanations of the process and the results of this research are needed.
Author Response
Dear Editor and Reviewer:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Study on Load Transfer Mechanism of Pile-Supported Embankment Based on Response Surface Method”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in yellow in the paper. The main corrections in the paper and the responds to the reviewers’ comments are as flowing:
Point 1：The Introduction and literature review parts are merged, which should not be the case, and these two parts should be explained separately. the introduction part needs more information about this sector and should be upgraded.
Response: Thanks to the reviewers for their comments, we have revised Section 1 according to the reviewers' comments. In this section, the current research results and existing problems are mainly introduced. And introduced the research content and innovation points of this paper.
Point 2：In the literature review part, the previous research in this field should be explained more completely and the gap that led to this research should be explained.
Response: Thanks to the reviewers for their comments, which have been supplemented in Section 1 based on the reviewers' comments.
Line 65-67: “Because of the different assumptions about the shape of soil arches and the deformation of reinforcements in pile-supported reinforced embankments, there are differences between the calculation methods.” was added.
Line 86-90: “The above research on the load transfer law mainly analyzes its influence on the load transfer by changing a single variable. Due to the single evaluation index, it is impossible to clarify the embankment load transfer law under the influence of various factors, as is also the case for the contribution of the soil arching effect and membrane effect to the load transfer.” was added.
Line 91-112: “Through the above analysis, it can be seen that the research on the load transfer mechanism of pile-supported embankments still has the following problems: At present, the commonly used load transfer calculation method is to first use the relevant theory of the soil arching effect to calculate the load acting on the horizontal reinforcement. Then, take the reinforced body as the research object and carry out the force analysis and deformation calculation; however, the soil arching effect and membrane effect are interactive. The deformation of the reinforced material depends on the size of the load, that is, the degree of soil arching effect; however, the existence of reinforced materials will affect the magnitude of differential settlement, and then affect the soil arching effect. Therefore, it is of great significance to clarify the contribution of the soil arching effect and membrane effect to the load transfer mechanism. In the study of the load transfer law, the main research method at present is single-factor analysis of each influencing factor, without considering the interaction between various factors. Response surface optimization design can determine the optimal design from a range of design variables under given constraints. Therefore, based on the single-factor test, this paper firstly clarifies the contribution of the soil arching effect and membrane effect to the load transfer, in addition to the degree of the load transfer under the combined action of the soil arching effect and membrane effect. The sensitivity of each influencing factor is evaluated. Additionally, based on the response surface optimization test, the multiple regression equation of the influencing factors and the evaluation index was established, the interaction relationship between the embankment filling properties and the grid strength was analyzed, and the optimal parameter combination was solved.” was corrected.
Point 3：in the 2.1 part, how the written parameters are obtained, it should be explained where and how these parameters were obtained and explained.
Response: Thanks to the reviewers for their comments, the source of the parameters has been explained in Section 2.1 based on the reviewers' comments.
Line 134-138: “the parameters are shown in Table 1. The material parameters of piles, reinforcements, cushions, and embankment fillers are from laboratory tests. The material parameters of the soft soil foundation are inversely deduced by the finite element software according to the deformation of the subgrade in the field test.” was added.
Point 4：It is better to show all the processes performed in this research as a figure or diagram for better understanding.
Response: Thanks to the reviewers for their comments, the research ideas of this paper have been supplemented in Section 3 based on the reviewers' comments.
Please see the attachment.
Point 5：In the conclusion section, more explanations of the process and the results of this research are needed.
Response: Thanks to the reviewers for their comments, the research content of this paper has been explained in the conclusion section according to the reviewers' comments, And the main reasons for these conclusions are explained.
Line 472-479: “Based on the improved three-dimensional finite element model, this paper analyzed and compared the influence of the embankment filler properties and geogrid strength on the load transfer. Firstly, based on the single-factor test, the contribution of the soil arching effect and membrane effect to the load transfer, as well as the variation law of the pile–soil stress ratio under embankment load, was clarified. Then, based on the response surface optimization test, the interactive relationship between the embankment filler properties and the geogrid strength was analyzed, and the original design was optimized. The results show that.” was corrected.
Line 508-516: “In summary: In this paper, a load transfer analysis method of embankments, considering the combined action of multiple factors, was proposed, which could accurately calculate the pile–soil stress ratio under the embankment load. The change of embankment filling properties and geogrid strength will affect the degree of the soil arching effect and membrane effect, and the transfer efficiency of the soil arching effect and membrane effect on load is different. Therefore, in the design of pile-supported embankments, the reinforcement form of embankments should be determined first, and then, the nature of embankment fillers should be determined to ensure that the design has a high load transfer efficiency.” was added.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.doc
