Study on the Effect of Pile Foundation Reinforcement of Embankment on Slope of Soft Soil
Round 1
Reviewer 1 Report
The paper presents a numerical study and investigates the length, response, stability, and reinforcement positions of the pile foundations on a soft soil slope. It is an interesting topic to discuss the problem from a geotechnical point of view. However, it is believed, that the paper needs to detail various sections of the article body in terms of the research discussion and concept clarity. The Review comments are included in the manuscript as an uploaded, annotated, PDF copy of this paper.
Comments for author File: 
Comments.pdf
Author Response
Detailed Point-by-Point Replies to Reviewers’ comments on
“Study on the effect of pile foundation reinforcement of Embankment on slope of soft soil”
We would like to present our great thanks to the reviewers for giving the important and effective comments in the review that provide a significant improve of the manuscript for publication. All points have been corrected seriously according to reviewers’ comments and the details of corrections are listed in Authors’ reply as bellow.
The revised expressions according to the comments are marked in red in the revised manuscript.
Besides, the final revision has been carefully proofread by a native English speaker and many grammatical errors have been corrected.
Reply to Reviewer 1’ Comments
(Letters C & R denote comment and reply respectively)
We would like to thank the Editor and the reviewers for providing the useful comments, which certainly help us to improve the quality of this paper. We have considered them carefully and have revised the manuscript accordingly.
C1: Vague title, please update it. it should be short and clear and related.
R1: Thank you for the suggestion, the title has been changed as “Study on the effect of pile foundation reinforcement of Embankment on slope of soft soil”. Your suggestion will be helpful for the improvement of the paper.
C2：The structure of the abstract should be re-written. the objective and findings of the study are not clearly mentioned
R2：Thank you for the suggestions. The abstract of this paper have been reorganized and rewritten, and the rewritten part has been marked in red. The detail is as follow:
Abstract:
In order to study the working mechanism of pile structure applied in embankment engineering on weak slope foundation, a finite element model of embankment on weak slope foundation reinforced by pile foundation is established. The influence of the position of pile foundation reinforcement and the length of pile foundation on the deformation, stability, and pile foundation response of embankment on soft soil slope is studied by using finite element analysis method. The results show that the different reinforcement positions of pile foundation have great influence on the safety factor and deformation of embankment on the soft soil slope. The safety factor of the left side (point F) of the pile foundation is 50% higher than that of the right side. The maximum settlement of the embankment on soft soil slope reinforced by 3m pile is 27 times that of the 5m and 7m. With different pile lengths, the displacement of pile foundation can be significantly reduced, the maximum displacement of a pile foundation can be reduced by about 83.3%, and with different pile lengths, the distribution of shear stress of pile foundation can be largely influenced. The research results can provide more scientific help for the design of embankment on the soft soil slope reinforced by pile foundation. The introduction should answer the question 'Why:' why I choose that topic for research; why it is important; why I adopted a particular method.
（1）why I choose that topic for research;
With the development of social economy, highways and railways as links will be built in many mountainous areas, and problems of inclined soft soil foundation in mountainous areas will inevitably be encountered. This area will encounter many embankments works filled with soft clay slopes, which can’t be regarded as a simple combination of slope foundation and soft soil subgrade. The characteristics of the slope soft ground are that the foundation surface or the bottom of the soft layer is inclined, the foundation soil is loose, and has low strength and high compressibility [1-3], which cause certain difficulties for slope stability, embankment filling and construction, cutting excavation, etc. What’s worse, under the influence of slope, soft soil layer, self-weight of embankment and vehicle load, engineering problems such as uneven settlement, excessive lateral deformation and slope instability are easy to occur when the high-speed railway is built on the slope soft soil foundation. Therefore, reinforcement measures are required for such slopes. Engineering practices at home and abroad show that the pile foundation has wide application range and can be flexibly used with other prevention measures. It has obvious technical advantages in slope reinforcement engineering. Therefore, pile foundation is often used in engineering to reinforce weak soil to meet the requirements of embankment stability.
（2）why it is important;
For a long time, there have been many researches on the application of pile foundation, such as: scouring on pile groups embedded in soft clay is studied when piles are laterally loaded and affected by the formation of scour holes according to Wang……
However, there is little research on the stability of slope soft soil embankment reinforced by pile foundation. In order to ensure the stability, settlement and horizontal sliding of slope soft soil embankment slope meet the technical requirements, it is necessary to study the stability of slope soft soil embankment and the effect of pile foundation reinforcement, which has important practical significance for the construction and development of high-speed railway and highway
（3）why I adopted a particular method.
Finite element analysis method has the advantages of simple calculation and wide application range, and strength reduction method is widely used to calculate the safety factor of slope. Therefore, this paper uses finite element analysis method combined with strength reduction method to study the reinforcement of slope soft embankment by pile foundation. In this study, a Pile-Slope model is established by using finite element analysis method. The influence of the length and the reinforcement position of the pile foundation on the stability of the soft soil embankment on the slope is studied. The influence of different reinforcement schemes on stability of slope soft soil embankment and the mechanical response of pile foundation are studied, and the optimum reinforcement scheme for slope soft soil embankment is put forward. The results of this study are of guiding significance to the design of slope engineering for pile foundation reinforcement.
It has been revised in the revised version.
C3：The following literature should be added-FEM analysis
-embankment slope soft soil-highway slope soft soil
-reinforcement effect definition
Thank you for the suggestion. The embankment slope soft soil-highway slope soft soil is analyzed by FEM and the safety factor of it is 1.46. Because this paper is mainly about the influence of embankment pile foundation reinforcement on soft soil slope, the finite element analysis results will be attached here.
Fig 1 FEM analysis of embankment slope soft soil-highway slope soft soil
Thank the reviewers for their careful reading. I regret that the reinforcement effect hasn’t been well explained and the relevant parts of the paper have been revised and marked red. The detail is as follow:
The reinforcement effect is defined as Influence of reinforced slope on safety factor of embankment.
C4：the following items are missed-reference site
-site geotechnical soil data
-why did you select this site
-what is the problem of the site
Thank you for the suggestion. The reason why I choose the site is because it is typical[1] and adopted by many researchers[2]. The embankment is on the soft soil slope. The characteristics of the slope soft ground are that the foundation surface or the bottom of the soft layer is inclined, the foundation soil is loose, and has low strength and high compressibility [3-5] which will put the embankment in unstable condition and the geotechnical soil data is shown in the table 1. Obviously, Something important information is missed in the paper and the information is added in the manuscript marked in red.
C5: Soil input data and pile structural input data for modeling should be mentioned that how did you get them for modeling, soil model, pile model, soil interaction, soil interfaces model development, soil layers, boundary conditions, impact of meshing, what method, what soil model, what constitutive model for the structure part, and water table are missing.
The Soil input data and the numerical model is from the results of other researchers[2]. Thank you very much for the careful reading. These missed message will definitely confusing the readers. The message has been added in the manuscript. The detail is as follow:
Select typical slope soft soil embankment works. Based on the engineering situation, the finite element model of the embankment on slope of soft soil is established by Abaqus as shown in Fig. 1.The In order to reduce the boundary effect on the calculation, the transverse direction of the model is 100m, the slope of the embankment slope is 1:1.75, the thickness of the soft soil layer is 2m, and the slope gradient is θ1= θ2=7°. This embankment is composed of embankment filler, soft soil layer and underlying rigid and hard layer. The left and right sides of the model is constrained in horizontal direction, the bottom is constrained in horizontal and vertical directions, and the embankment and slope surface are free. The Mohr-Coulomb model is used for the soil part of the model, the elastic constitutive model for the pile foundation. The contact between the soil and the pile is hard contact. Finite element meshing using CPE4 4 planar strain quadrilateral element, regardless of the influence of groundwater level. Calculation of safety factor of numerical model by finite element analysis combined with strength reduction method.
C6: what is the definition of reinforcement effect? what do you mean?
Thank the reviewers for their careful reading. I regret that the reinforcement effect hasn’t been well explained and the relevant parts of the paper have been revised and marked red. The detail is as follow:
The reinforcement effect is defined as Influence of reinforced slope on safety factor of embankment.
C7: the following items should be clearly be mentioned-how did you get the FOS locally?
-what is the Fos globally?
-what is the loading challenges in this area? rain, snow, earthquake, and etc
Thank you for the question. In this paper, finite element analysis combined with strength reduction method is adopted to calculate the safety factor of numerical model. In this paper, only the influence of soil self-weight is considered, and other factors such as earthquake, rainfall and snow aren’t considered.
C8: You should define illustratively the embankment deformation and vertical deformation
R8:Thank you for your comments. The concepts in this regard are not clearly explained and tend to confuse the reader. An explanation has been added to the text. The detail is as follow:
The embankment deformation refers to the deformation value without considering the direction, while the vertical deformation refers to the displacement of the numerical model in the vertical direction.
C9: How about bending moments differentially and locally?!
R9: The purpose of this chapter is to discuss the influence of different reinforcement positions on the slope. As shown in the figure, the shear stress borne by piles at different reinforcement locations is different and presents certain variation rules. It is not the main purpose of this paper to study the shear stress of piles, but it is a good inspiration. In the future, this issue will be our research.
C10: What is the difference between vertical deformation and settlement?
R10: Thank you for your careful reading. I'm sorry to make you confused. These two expressions are really easy to make readers misunderstand, so I have made corresponding modifications to the full text. Your suggestions are of great help to the improvement of this paper.
C11:How did you come up with the geometry of the piles?
R11: Thank you for the question. The reason why I choose the geometry of the piles is because This model has been adopted in relevant research [2].
C12: The following is missing-discussion
-who can be benefitted from this study-comparison with other studies
-how did you calibrate your model-how do you want to validate the results-is it possible to do a large scale testing?
R12:Thank you for the suggestion. At present, there are few researches on slope soft soil embankment. The research results can provide more scientific help for the design of embankment on the soft soil slope reinforced by pile foundation which has been added in the manuscript. In this paper, the influence of embankment pile foundation reinforcement on soft soil slope is studied through finite element numerical simulation using actual process parameters and theoretical calculation, so as to provide theoretical guidance for engineering construction. At present, no large-scale experiments have been conducted, but large-scale experiments will be conducted in future studies
References
[1] X. Zhang, S. Rajesh, J.F. Chen, Z. Zhang, L.Y. Li, 3D coupled mechanical and hydraulic modeling of geosynthetic encased stone column-supported embankment over soft clay, Mar. Georesour. Geotec. 39 (11) (2021) 1285-1295, 10.1080/1064119X.2020.1825571.
[2] D. Liang, THE NUMERCIAL SIMULATION OFEMBANKMENT OVER SLOPE WEAKGROUND REINFORCED BY GRAVEL PILESJOINT WITH SLIDE-RESISTANT PILES ANDNON-EMBEDED PILE-PLANK STRUCTURE, in: Southwest Jiaotong University, 2013, p.
[3] S. Feng, H. Lei, A settlement prediction model considering tidal loading and traffic loading of soft soil subgrade, Comput. Geotech. 144 (2022) 104639, https://doi.org/10.1016/j.compgeo.2022.104639.
[4] F. Zhang, A. Yashima, H. Osaki, T. Adachi, F. Oka, Numerical Simulation of Progressive Failure in Cut Slope of Soft Rock Using a Soil-Water Coupled Finite Element Analysis, Soils Found. 43 (5) (2003) 119-131, https://doi.org/10.3208/sandf.43.5_119.
[5] Y. Wang, H. Fu, Y. Cai, X. Yu, J. Zhao, Seismic Subsidence of Soft Subgrade with Considering Principal Stress Rotation, INTERNATIONAL JOURNAL OF CIVIL ENGINEERING. 20 (7) (2022) 827-837, 10.1007/s40999-022-00709-0.
Author Response File: 
Author Response.docx
Reviewer 2 Report
sustainability-1939321: Research on Reinforcement Effect and Pile Foundation Response of Pile Foundation for Embankment on slope of soft soil.
The reviewer report is as follows:
I. The language of the paper is too poor to read. It is difficult to read and needs to be reformatted.
II. The abstract and introduction should be rewritten and focusses the contribution of the paper. First, the scope of the literature review should be extended. Second, the motivation in this paper should be clarified. The reviewer suggests the authors revise the introduction section to be more streamlined and more focused on the problem. Some critical/important references on the topic are missing.
III. What is the main purpose of the paper? How is it different from previous studies/papers? What is the main contribution of the paper to the literature? All these questions should have been fully explained without leaving any ambiguity in the introduction.
IV. I did not find any novelty in the paper in terms of the proposed method. Neither benchmarking nor case problems were not presented in the paper. In this case, how do we evaluate the superiority of the study?
V. The results obtained were not sufficiently discussed.
This reviewer is sorry to state that the submitted paper should be rejected.
Author Response
Reply to Reviewer 1’ Comments
(Letters C & R denote comment and reply respectively)
We would like to thank the Editor and the reviewers for providing the useful comments, which certainly help us to improve the quality of this paper. We have considered them carefully and have revised the manuscript accordingly.
C1: The language of the paper is too poor to read. It is difficult to read and needs to be reformatted.
R1：Thank you for your comments. Thank the reviewers for reading this paper carefully. At the same time, I'm sorry to let the reviewers find so many problems. Some grammatical errors and inappropriate sentences have been improved. For example, “When reinforcing B, C, D, E, and F respectively, the shear stress of the pile foundation decreases with the backward movement of the reinforcement position, which is consistent with the previous analysis. Since point A is located at the foot of the embankment, it bears less shear stress, but the reinforcement effect of the soft soil embankment on the slope is still good.” is modified as “When the positions (B, C, D, E, and F) are reinforced respectively, the shear stress of the pile foundation decreases from position B to position F, which is consistent with the previous analysis.”, “It can be seen from the figure that the shear stress of the pile foundation changes slightly with the increase of the pile length. Compared with the case where the length of pile group is 3m and 5m, the shear stress of each pile in this area varies greatly from - 5m to - 7m of the pile shaft. This shows that the length of pile group has a great influence on the distribution of pile shear stress. During the construction of the project, reasonable measures should be taken to adjust the pile foundation according to the changes of shear stress and displacement.” is modified as “The shear stress of the pile foundation changes slightly with the increase of the pile length. The shear stress of each pile in this area varies greatly from -5m to -7m compared with the pile group lengths of 3m and 5m respectively. This indicates that the length of pile groups has a great influence on the distribution of shear stress of pile foundation. During the construction of the project, reasonable measures should be taken to adjust the construction scheme of the pile foundation according to the changes of shear stress and displacement.”. Besides, the abstract, introduction and analysis of this paper have been reorganized and rewritten, and the rewritten part has been marked in red.
C2: The abstract and introduction should be rewritten and focusses the contribution of the paper. First, the scope of the literature review should be extended. Second, the motivation in this paper should be clarified. The reviewer suggests the authors revise the introduction section to be more streamlined and more focused on the problem. Some critical/important references on the topic are missing.
R2：Thank you for the suggestions. The abstract, introduction and analysis of this paper have been reorganized and rewritten, and the rewritten part has been marked in red. The detail is as follow:
Abstract:
In order to study the working mechanism of pile structure applied in embankment engineering on weak slope foundation, a finite element model of embankment on weak slope foundation reinforced by pile foundation is established. The influence of the position of pile foundation reinforcement and the length of pile foundation on the deformation, stability, and pile foundation response of embankment on soft soil slope is studied by using finite element analysis method. The results show that the different reinforcement positions of pile foundation have great influence on the safety factor and deformation of embankment on the soft soil slope. The safety factor of the left side (point F) of the pile foundation is 50% higher than that of the right side. The maximum settlement of the embankment on soft soil slope reinforced by 3m pile is 27 times that of the 5m and 7m. With different pile lengths, the displacement of pile foundation can be significantly reduced, the maximum displacement of a pile foundation can be reduced by about 83.3%, and with different pile lengths, the distribution of shear stress of pile foundation can be largely influenced. The research results can provide more scientific help for the design of embankment on the soft soil slope reinforced by pile foundation. The introduction should answer the question 'Why:' why I choose that topic for research; why it is important; why I adopted a particular method.
（1）why I choose that topic for research;
With the development of social economy, highways and railways as links will be built in many mountainous areas, and problems of inclined soft soil foundation in mountainous areas will inevitably be encountered. This area will encounter many embankments works filled with soft clay slopes, which can’t be regarded as a simple combination of slope foundation and soft soil subgrade. The characteristics of the slope soft ground are that the foundation surface or the bottom of the soft layer is inclined, the foundation soil is loose, and has low strength and high compressibility [1-3], which cause certain difficulties for slope stability, embankment filling and construction, cutting excavation, etc. What’s worse, under the influence of slope, soft soil layer, self-weight of embankment and vehicle load, engineering problems such as uneven settlement, excessive lateral deformation and slope instability are easy to occur when the high-speed railway is built on the slope soft soil foundation. Therefore, reinforcement measures are required for such slopes. Engineering practices at home and abroad show that the pile foundation has wide application range and can be flexibly used with other prevention measures. It has obvious technical advantages in slope reinforcement engineering. Therefore, pile foundation is often used in engineering to reinforce weak soil to meet the requirements of embankment stability.
（2）why it is important;
For a long time, there have been many researches on the application of pile foundation, such as: scouring on pile groups embedded in soft clay is studied when piles are laterally loaded and affected by the formation of scour holes according to Wang……
However, there is little research on the stability of slope soft soil embankment reinforced by pile foundation. In order to ensure the stability, settlement and horizontal sliding of slope soft soil embankment slope meet the technical requirements, it is necessary to study the stability of slope soft soil embankment and the effect of pile foundation reinforcement, which has important practical significance for the construction and development of high-speed railway and highway
（3）why I adopted a particular method.
Finite element analysis method has the advantages of simple calculation and wide application range, and strength reduction method is widely used to calculate the safety factor of slope. Therefore, this paper uses finite element analysis method combined with strength reduction method to study the reinforcement of slope soft embankment by pile foundation. In this study, a Pile-Slope model is established by using finite element analysis method. The influence of the length and the reinforcement position of the pile foundation on the stability of the soft soil embankment on the slope is studied. The influence of different reinforcement schemes on stability of slope soft soil embankment and the mechanical response of pile foundation are studied, and the optimum reinforcement scheme for slope soft soil embankment is put forward. The results of this study are of guiding significance to the design of slope engineering for pile foundation reinforcement.
It has been revised in the revised version.
C3： What is the main purpose of the paper? How is it different from previous studies/papers? What is the main contribution of the paper to the literature? All these questions should have been fully explained without leaving any ambiguity in the introduction.
R3：I’m sorry for the poor introduction. The introduction had been fully rewritten as your suggestion and you question will be answered in here.There is little research on the stability of slope soft soil embankment reinforced by pile foundation. In order to ensure the stability, settlement and horizontal sliding of slope soft soil embankment slope meet the technical requirements, it is necessary to study the stability of slope soft soil embankment and the effect of pile foundation reinforcement, which has important practical significance for the construction and development of high-speed railway and highway
C4: I did not find any novelty in the paper in terms of the proposed method. Neither benchmarking nor case problems were not presented in the paper. In this case, how do we evaluate the superiority of the study?
R4: In this paper, finite element analysis method combined with strength reduction method is mainly used to evaluate the stability of slope soft soil embankment. The main innovation is not in method, but to provide theoretical research for case problem. With the development of social economy, highways and railways as links will be built in many mountainous areas, and problems of inclined soft soil foundation in mountainous areas will inevitably be encountered. This area will encounter many embankments work filled with soft clay slopes, which can’t be regarded as a simple combination of slope foundation and soft soil subgrade. At present, there is little research on this problem. The research on this problem can provide theoretical guidance for future engineering construction.
C5: The results obtained were not sufficiently discussed.
R5：Thank you for the comment. Your comment do great help for the improvement of the paper. Conclusions have been rewritten. The detail is as follow:
4.Conclusions
Based on the practically embankment reinforcement construction, the finite element analysis method is adopted to study the influence of different reinforcement positions and pile lengths on the stability of the slope soft soil embankment, and explores the displacement and shear stress of the pile foundation in the slope soft soil embankment in this paper. The conclusions are as follow:
The stability and settlement of embankment are greatly influenced by pile foundation reinforcement at different locations of slope soft soil embankment. When the reinforcement position is A or B, the safety factor is 50% higher than the position F; The deformation of the slope soft soil embankment is mainly concentrated at the left toe of the embankment;
When the slope soft soil embankment is reinforced by group piles, not only the requirements of the safety factor can be met, but also the settlement of the embankment surface can be well controlled. The maximum deformation of 3m pile foundation reinforced embankment is 27 times that of 5m and 7m pile foundation reinforced embankment.
When the slope soft soil embankment is reinforced by group piles, the maximum horizontal displacement of a single pile foundation can be reduced by about 83.3%. Different pile lengths affect the distribution of shear stress on the pile foundation.
Author Response File: Author Response.docx
Reviewer 3 Report
This paper studied the influences of reinforcement position and length of pile foundation on deformation and stability of embankment on soft soil slope and the response of pile foundation. This research is logical and is of significance for slope engineering, but it is thin on content. The comments that should be addressed are listed as follows.
1. The title of this paper is wordy and the collocation is not proper, it should be revised to reflect the research highlight appropriately and clearly.
2. What does the abbreviation “IESP” mean in Line 79? The author should explain the meanings of abbreviations when first using them.
3. Which software did the author choose to carry out the finite element analysis method? The author should introduce it in section 2.
4. The author should add a figure of the meshed finite element model used for numerical simulation to make the paper more detailed and authentic.
5. In Line 117, the left and right sides of the model are constrained in horizontal direction, and the bottom is constrained in horizontal and vertical directions. Since the actual condition of soil mass is infinite, it is not reasonable to set the boundaries as fixed boundaries. The boundaries of the numerical model should be modified.
6. In Line 145, what does the “K” mean? Besides, the phrase “safety system” in Line 19 should be changed to “safety factor” according to the sentence in Line 155.
7. How did the author define and derive the safety factor in section 3.1? Since it reflects the stability degree of the embankment, the author should clarify its derivation process.
8. The author should explain the meaning of “x” in Figure 3 (a). Besides, the deformation values at reinforcement position A in Figure 3 (a) cannot be identified.
9. Why did the author consider the pile length as 3 m, 5 m, and 7 m rather than other values? Why did not the author consider the more detailed values for the pile length?
10. Figure 6 exhibits the horizontal displacement of pile foundation with different reinforcement depths, whereas the axis title is deformation. The author should check and reconfirm the wording of “deformation”, since “displacement” and “deformation” are two different concepts.
11. The title of x-axis of Figure 7 (c) is not consistent with those of Figure 7 (a) and (b).
12. The English quality is not up to the standard for publication, the wording and expression of this paper needs to be refined. There are many phrasal and grammatical errors in the main body. Please ask someone whose first language is English to correct the whole manuscript.
Author Response
Reply to Reviewer 2’ Comments
(Letters C & R denote comment and reply respectively)
We would like to thank the Editor and the reviewers for providing the useful comments, which certainly help us to improve the quality of this paper. We have considered them carefully and have revised the manuscript accordingly.
This paper studied the influences of reinforcement position and length of pile foundation on deformation and stability of embankment on soft soil slope and the response of pile foundation. This research is logical and is of significance for slope engineering, but it is thin on content. The comments that should be addressed are listed as follows.
C1: The title of this paper is wordy and the collocation is not proper, it should be revised to reflect the research highlight appropriately and clearly.
R1:Thank you for the suggestion, the title has been changed as “Study on the effect of pile foundation reinforcement of Embankment on slope of soft soil”. Your suggestion will be helpful for the improvement of the paper.
C2: What does the abbreviation “IESP” mean in Line 79? The author should explain the meanings of abbreviations when first using them.
R2: I’m very sorry for such mistake I made, the IESP belong to the paper I refer to. After consideration, for the less connection with the paper, so I delete the reference and add others in clear way.
C3: Which software did the author choose to carry out the finite element analysis method? The author should introduce it in section 2.
R3: I am sorry that the software used in this paper hasn’t been shown. The Abaqus has been adopted in this paper. This part has been added to the paper and marked in red.
C4: The author should add a figure of the meshed finite element model used for numerical simulation to make the paper more detailed and authentic.
R4: Thank you for the suggestion. The figure of the meshed finite element model used for numerical simulation has been added in the paper. The figure is as follow:
Figure 1. Pile-Slope model
C5: In Line 117, the left and right sides of the model are constrained in horizontal direction, and the bottom is constrained in horizontal and vertical directions. Since the actual condition of soil mass is infinite, it is not reasonable to set the boundaries as fixed boundaries. The boundaries of the numerical model should be modified.
R5: Thank you very much for your careful reading. First, the model has large horizontal and vertical values in order to avoid boundary effects. This model is a part of intercepting actual project. If horizontal restraint is cancelled on both sides, the slope model will deform under the action of self-weight, which is inconsistent with the actual situation. Therefore, this model chooses both ends of restraint, which is consistent with some papers. The calculation results are shown in the figure，and the deformation is mainly at the embankment.
C6: In Line 145, what does the “K” mean? Besides, the phrase “safety system” in Line 19 should be changed to “safety factor” according to the sentence in Line 155.
R6: Thank you for the carefully reading the paper. The K is defined as the horizontal distance between adjacent piles, and the phrase “safety system” in Line 19 has been changed to “safety factor”. The detail is as follow：
In order to study the influence of the pile foundation reinforcement position on the embankment on slope of soft soil, the distance between the adjacent piles defined as K among A, B, C, D, E and F is 4m.
C7: How did the author define and derive the safety factor in section 3.1? Since it reflects the stability degree of the embankment, the author should clarify its derivation process.
R7: Thank you for the suggestion. The derivation process has been added in the manuscript which can be helpful for the audience. The detail is as follow:
3.1 Limit equilibrium method
At present, the limit equilibrium theory is widely adopted to evaluate the reinforced slope. Bishop method has the advantages of being suitable for multi-layer filling, complex geometry, water level and other complex conditions. Therefore, Bishop method is also adopted in this paper.
The simplified Bishop method is a limit equilibrium analysis method satisfying moment equilibrium. In order to simplify the calculation, the method assumes that the forces (including normal force and tangential force) between the slices occur in pairs, with the same position, equal size and opposite direction in space. Therefore, the moments of the forces between the slices on the center of the circle can offset each other, thus reducing the location, size and other unknown quantities of the forces between the slices. At the same time, the method assumes that the shape of the sliding surface is a strict circular arc, so that all the positive pressures at the bottom of different strips pass through the center of the circle, and the torque generated by the positive pressure at the bottom of the strip is 0, thus reducing the unknown amount of the positive pressure at the bottom of the strip. Based on the above idealized assumption, in the simplified Bishop method, only the gravity of the slice and the tangential force at the bottom of the slice produce torque on the center of the circle. The simplified Bishop method meets the overall moment balance, but does not meet the overall force balance. Its safety factor is expressed by the bending moment of each slice to the rotation center, as shown in Figure 2.
Figure2. Simplified Bishop Calculation Model
By formula derivation, the safety factor of slope is as follows:
where F is the factor of safety, ci is the cohesion of the soil, φi is the internal friction angle of the soil, bi is the width of the soil strip i, Wi is the gravity borne by the soil block, tangential force is 0 and the αi is the angle between the sliding block and the horizontal.
C8: The author should explain the meaning of “x” in Figure 3 (a). Besides, the deformation values at reinforcement position A in Figure 3 (a) cannot be identified.
R8: I’m sorry for the unclear figure. The explanation has been added in the manuscript. The detail is as follow:
In the Fig.3, x is represented as the surface of the embankment from left to right.
C9: Why did the author consider the pile length as 3 m, 5 m, and 7 m rather than other values? Why did not the author consider the more detailed values for the pile length?
R9: As the table shown, the safety factor is 4 when the model reinforced with piles with 3m, 5m and 7m. Therefore, 3m, 5m and 7m pile lengths are enough to maintain the stability of the slope. If a longer pile foundation model is used, it will cause waste.
Table 2. Embankment safety factors under different pile lengths.
|
Pile length/m |
pile diameter/m |
Pile spacing /m |
Safety factor |
|
3 |
0.8 |
4 |
4 |
|
5 |
0.8 |
4 |
4 |
|
7 |
0.8 |
4 |
4 |
C10: Figure 6 exhibits the horizontal displacement of pile foundation with different reinforcement depths, whereas the axis title is deformation. The author should check and reconfirm the wording of “deformation”, since “displacement” and “deformation” are two different concepts.
R10: Thank you for the carefully reading the manuscript. The “deformation” indeed is a mistake. The axis title of the figure is changed to horizontal displacement. I'm very sorry for such the error.
C11: The title of x-axis of Figure 7 (c) is not consistent with those of Figure 7 (a) and (b).
R11:Thank you for the suggestion, and thank you very much for reading this manuscript carefully. I'm very sorry for such the error. The detail is as follow:
C12: The English quality is not up to the standard for publication, the wording and expression of this paper needs to be refined. There are many phrasal and grammatical errors in the main body. Please ask someone whose first language is English to correct the whole manuscript.
R12: Thank you for your comments. Thank the reviewers for reading this paper carefully. At the same time, I'm sorry to let the reviewers find so many problems. Some grammatical errors and inappropriate sentences have been improved. The abstract, introduction and analysis parts of the manuscript has been rewritten, and the rewritten part has been marked in red.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
sustainability-1939321-peer-review-v3: “Research on Reinforcement Effect and Pile Foundation Response of Pile Foundation for Embankment on slope of soft soil”
The authors eliminated the deficiencies in the previous versions of their paper. The replies to the reviewer’s comments were found satisfactory. The reviewer appreciates the authors' ability to improve the paper. As a result, the paper can be accepted as it is.
Author Response
Thank you very much for your approval. The author's revised article is more precise and reliable after following your suggestions.
Reviewer 3 Report
The present manuscript has been improved after major revision, however, there are still some problems exhibited through the manuscript. The specific recommendations are listed as follows:
1. In line 60-75, the citation format should be revised. For example, in line 60, change "Zhang" into "Zhang et al" since there are three authors listed in the reference, in line 63, change "Wang" into "Wang and Han" since there are only two authors listed in the reference.
2. In line 106, delete "The" in the sentence "The In order to...", the author should carefully check the whole manuscript to avoid this kind of mistake.
3. In line 206, change "fig. 3" into "fig. 4", the figure mentioned here should be figure 4 combined with the context.
4. In line 249, this expression is incorrect, since there are no geometric parameters of the numerical model presented in Table 1.
5. In line 265-267, repeating the same sentences.
Author Response
Detailed Point-by-Point Replies to Reviewers’ comments on
“Study on the effect of pile foundation reinforcement of Embankment on slope of soft soil”
We would like to present our great thanks to the reviewers for giving the important and effective comments in the review that provide a significant improve of the manuscript for publication. All points have been corrected seriously according to reviewers’ comments and the details of corrections are listed in Authors’ reply as bellow.The revised expressions according to the comments are marked in red in the revised manuscript.
Besides, the final revision has been carefully proofread by a native English speaker and many grammatical errors have been corrected.
Reply to Reviewer’s Comments
(Letters C & R denote comment and reply respectively)
The present manuscript has been improved after major revision, however, there are still some problems exhibited through the manuscript. The specific recommendations are listed as follows:
C1:In line 60-75, the citation format should be revised. For example, in line 60, change "Zhang" into "Zhang et al" since there are three authors listed in the reference, in line 63, change "Wang" into "Wang and Han" since there are only two authors listed in the reference.
R1:Thank you for your carefully reading. The problem has been solved and the revised parts is marked in red. The detail is as follow:
A series of centrifuge model tests were conducted on the pile-reinforced slopes and corresponding unreinforced slopes under self-weight and vertical loading conditions according to Zhang et al[17]. A three-dimensional multi-row polyurethane polymer micro anti-slide piles model for slope reinforcement considering different embedded depth and pile location is established according to Wang and Han[18]. Many researchers have done lots of achievement in this field. However, for a long time, there have been many researches on the application of pile foundation, such as: scouring on pile groups embedded in soft clay is studied when piles are laterally loaded and affected by the formation of scour holes according to Wang and Zhou[19]. Tang and Yang focuses on investigating the lateral behavior of a particular type of two-pile group foundations embedded in steep and weathered rock slopes[20]. The effect of soil slope, undrained cohesion, pile-soil interface adhesion, pile diameter and pile cap on the lateral load carrying capacity of pile located at the crest of clay slope is studied using PLAXIS-3D according to the Chandaluri and Sawant [21]. In this paper, the problem of the optimal location of piles used to stabilize slopes is analyzed according to Li et al[22].
C2: In line 106, delete "The" in the sentence "The In order to...", the author should carefully check the whole manuscript to avoid this kind of mistake.
R2: Thank you for the suggestion. I feel sorry about the mistake I made. The problem has been corrected and the whole manuscript has been check carefully.
C3: In line 206, change "fig. 3" into "fig. 4", the figure mentioned here should be figure 4 combined with the context.
R3: Thank you for the suggestion. The mistake has been corrected. Thank you a lot for careful reading which will be helpful to the improvement of the manuscript.
C4: In line 249, this expression is incorrect, since there are no geometric parameters of the numerical model presented in Table 1.
R4: The incorrect expression is revised which will definitely made the author confused too. The geometric parameters has been changed to physical parameters and marked in red in the manuscript.
C5: In line 265-267, repeating the same sentences.
R5: Thank you for the suggestion. The repeated part " The influence of different pile foundation lengths on embankment surface deformation is shown in Fig. 6. It can be seen from Fig. 6 " in the text has been deleted. Thank you for your careful reading. I really appreciate it.
