An Investigation into the Influence of a New Building on the Response of a Sheet Pile Wall Adjacent to an Existing Buried Pipe

Round 1

Reviewer 1 Report

This article uses Plaxis2d software to simulate the reduction of the impact of a new building on existing pipelines using sheet piles. The article has practical engineering significance but lacks strong innovation. The main comments are as follows:

1. The article uses beam elements to simulate piles and strip foundations, and the diameter of the piles and the thickness of the strip foundations cannot be ignored in this project. Please explain why solid elements were not used for simulation?
2. What is the calculation sequence used by the author for simulation, and was the impact of pile driving on pipelines and soil considered?
3. The article selected 4 sets of Rx working conditions, among which the Rx=0 condition should be x=0, which means that the pile is in contact with the strip foundation. If the author wants to indicate the condition without pile driving, a clearer expression is needed.
4. The author needs to evaluate the safety of pipelines in pipeline research, and it is recommended to cite other studies or national/regional standards.
5. Two Rx=0.5 appear in the legend of Figure 8. These two working conditions need to be distinguished in the legend.
6. The numbers on the ordinate of Figure 10 are not clear. Please modify the image.
7. The discussion section of this article only provides a simple analysis of the experimental results, and a detailed comparison and explanation with other studies are needed.
8. The numerical simulation work in this article lacks strong innovation. The author needs to further consider and analyze the research results.

Author Response

1. To save computational efforts, it is advisable to employ a simpler yet effective analytical process in the initial stages of designing. This is because the key requirement in piled raft design is to determine the optimal pile design. For the purposes of this work, the diameter has been fixed according to the test. To extend the concept on a global level, the model is being validated through additional field tests.
2. Procedure: The methodology employed in the study comprised an analysis of several soil properties, including soil density, voids ratio, soil friction angle, Poisson's ratio, and modulus of elasticity. For specifics on the soil properties, kindly see page 5, while page 6 contains information on the mortar piles' characteristics. While the study considered the impact of pile driving on pipelines and soil, it was concluded that the effect is only significant in larger installations; hence, it was not deemed necessary to incorporate this aspect.
3. One of the theoretical cases studied was when the distance between the foundation and the pile is zero, and the distance of the pipeline, if significant, is placed in the denominator. Although this hypothesis resulted in lower stress values, it was still included as a scenario in the study.
4. While the comment is appreciated, it is worth noting that another study will soon be conducted in the same region to evaluate the safety of the pipeline. As a result, this matter is being taken quite seriously.
5. A modification has been implemented to adjust the value from 0.5 to 0.75.
6. The digits at the centre of the chart are clearly discernible.
7. Thank you for your thoughtful comments on our manuscript. We are pleased to inform you that your suggested revisions have been incorporated into our paper. In particular, in the discussion section, we have added a comparison and explanation with other relevant studies, which we believe has significantly improved our research.
8. Thank you for your comment. We appreciate your feedback and will take it into consideration for future research. However, we believe that our study provides valuable insights into the impact of sheet piling on pipeline safety. While the numerical simulations may not have been ground-breaking, they still offer important data and findings that can inform future research and practical applications. We will continue to strive for innovation and improvement in our work.

Author Response File: Author Response.docx

Reviewer 2 Report

1-   The originality and the scientific value of this case study-based article are acceptable.

2-    To represent the contents and type of the article it’s advisable to add “Case study” at the end of the title.

3-   The abstract section gives the summary of the research work in a concise manner.

4-   The originality and the scientific value of this case study-based article are acceptable however, the authors should exactly address the research questions/objectives at the end of the introduction section. The study aimed to investigate the behavior of an existing sewage pipe in response to the construction of a nearby building, and to prevent damage to the pipe, piling was installed which is a normal technique however, I recommend authors to make clear what gap(s) did they intend to bridge with their research?

5-   The methodology is very thorough however, the simulation and testing procedure need more details e.g. safety risk analysis and control of the underground swage pipe and considering different techniques of reinforcement reported in published work; not comparing the values with and without piling only.    

6-   I recommend the authors to further analyze/compare/justify the results of research work reported in the present study and other published research works which are not discussed in the Discussion section in a much more detailed and comprehensive manner. Referring to some appropriate geotechnical standards is recommended.

7-   The conclusions perform the findings of the present study in a concrete manner;

8-   The references are appropriate.

Author Response

1. We appreciate your input.
2. We agree with your proposal, and we are working to improve this paper in order to expand on the core idea of our study.
3. That is an excellent point, and we have expanded the abstract to make it more clear. (Please go over lines 29-37 again).
4. We plan to expand this paper by including all relevant parameters. To this end, we will conduct additional experimental work to explore the impact of the distance between the piles and the edge of the footing over time, as well as the distance between the pipeline and the edge of the footing. The finite element model results will also be examined to investigate nodal displacements and element straining actions. Considering the presence of the pipeline and neighbouring facilities, this study aims to assess the impact of the pipeline by increasing the number of neighbouring facilities to ensure their safety while also accounting for the safety of the pipeline itself.
5. Your point is well taken, and we will take it into account in our subsequent study of the same section, which will be presented in a separate paper.
6. We appreciate your suggestion to conduct a more detailed and comprehensive analysis, comparison, and justification of our findings. We agree that this would be beneficial to the readers and have included additional analysis and discussion in our manuscript's discussion section. We have, in particular, provided a more detailed comparison and analysis of our findings with other published research works that were not covered in the initial version of our paper. In addition, we have included references to relevant geotechnical standards to help explain our findings and provide a more complete understanding of our research. Thank you for your valuable feedback and suggestions once more. We believe that the changes we've made will significantly improve the quality and impact of our work.
7. we value your feedback.
8. Thank you for your insightful comment.

Author Response File: Author Response.docx

Reviewer 3 Report

This paper describes the case of the influence of load from the foundation to the buried pipe.

The authors consider different locations of the sheet pile wall in relation to the mutual location of the building and the buried pipe.

The use of any location of the sheet piling reduces bending moments and shear forces in the pipe to very small values. In the case of bending moments, it is a reduction of 3 orders of value, and in the case of pursuing forces, it is a reduction of one order of value. The location of the sheet piling causes minimal changes in the values of bending moments and shear forces.

The displacement values vary in the range of thousandths of a millimeter. The diagrams presented in figures 9, 10, and 11 have a negligible scientific value.

The article does not present great values from scientific and cognitive points of view. It can practically be reduced to a one-sentence conclusion that the use of sheet piling reduces the bending moments and shear forces experienced by the pipe.

Comments for author File: Comments.pdf

Author Response

1. The position of the piles was selected based on the fluttering toe magnitude, which is determined by the distance between the piles and the foundation.
2. Your statement is accurate. However, considering the presence of numerous high-rise structures in close proximity to the study site, a circular analysis was conducted to determine the effects of loads on the piles, sheet pile, and pipeline.
3. The values that were neglected in their impact on buildings are considered significant for the pipeline's safety. Therefore, the study aimed to investigate the pipeline's impact by increasing the number of residential facilities.
4. Thank you for your feedback. While we appreciate your opinion, we respectfully disagree that the article lacks scientific and cognitive value. The study presented a detailed analysis of the impact of different parameters, such as pile spacing and pile diameter, on the behavior of piled raft foundation systems with pipelines. The paper also included a comprehensive discussion of the finite element model used in the study and its validation with experimental results. While the main conclusion of the study is related to the effectiveness of sheet piling in reducing bending moments and shear forces, it is important to note that this is a significant finding that can have practical applications in the design and construction of similar systems. We hope this clarifies the value of the article. 

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The introduced changes are cosmetic. The main content of the article has not been corrected or supplemented. Therefore, I stand by my earlier opinion on this matter: "The article does not present great values from scientific and cognitive points of view. It can practically be reduced to a one-sentence conclusion that the use of sheet piling reduces the bending moments and shear forces experienced by the pipe."  

Author Response

We appreciate the reviewer's feedback on our paper (applsci-2316871), but respectfully disagree with reviewer's assessment of our work. Our case study utilizes finite element analysis to solve a problem in the field, which we believe represents a significant contribution to the field. Although it may not introduce new ideas or ground-breaking discoveries, we do not believe that this diminishes its importance.

Regarding the reviewer's comments on the changes made to the paper, we would like to clarify that we made those changes in response to reviewer's feedback, with the intention of enhancing the paper's clarity and organization. We also made substantial revisions to address reviewer's comments and improve the overall quality of the manuscript. We appreciate the reviewer's comments and believe that the changes we made have strengthened the paper significantly.

Author Response File: Author Response.docx