Application and Practice of Variable Axial Force Cable in Powerhouse Truss Reinforcement System
Round 1
Reviewer 1 Report
Please, see attachment
Comments for author File: 
Comments.pdf
Author Response
Thank you for your hard review, I will carefully check and modify each item, thank you again!
Best wishes!
Mary
30Mar-2023
Author Response File: Author Response.pdf
Reviewer 2 Report
The manuscript concerns retrofitting of long-span trusses via the variable axial force cable method. The method is applied for two case-studies. Modelling and analysis outputs are discussed to evaluate the influence of such a retrofit approach. This reviewer suggests strong improvements of the manuscript are required before a revision process can be carried out.
The introduction requires substantial revisions. Explanation on the variable axial load cable method for retrofitting trusses is required. Without a presentation is impossible for the reader to understanding the methodology and results within the manuscript. Additionally, Section 1 is not well written and unclear. This reviewer is unable to assess the appropriateness of the state of the art.
It is not clear, what is the novelty of this study. It seems the authors apply conventional approaches for modelling and analysis for the design of a retrofit strategy based on the use of cables.
Understanding the manuscript is difficult for reviewers and readers. It needs for substantial language and grammar checks. Several sentences need for substantial language improvements. For example, L114 “Due to the addition of roof photovoltaic panels in the two plant buildings, the existing plant buildings cannot meet the requirements of the new code according to the requirements of the new code.” Or L123 “Due to the large span of the trusses in the workshop of Zhejiang Hong Cheng Company, if the conventional increase or increase the force surface of the column is arranged 123 between the rigid trusses”. Several sentences are very vague “The span is large, the cross-sectional area of the main beam is small, the overall dead weight is light, and the controlling force is flexible”.
Figures should be added to section 3 to show the layout of the retrofit strategy.
Author Response
Thank you for your hard review, I will carefully check and modify each item, thank you again!
Best wishes!
Mary Shen
30-Mar/2023
Author Response File: 
Author Response.docx
Reviewer 3 Report
This research combines the large-span powerhouse trusses of Hongcheng Powerhouse 1 and No.2 located in Tonglu, Zhejiang Province. The structure is reinforced by applying prestressed cables to the trusses of two different spans, the changes of stress and deflection before and after reinforcement are studied. A reinforcement method of large span plant truss is introduced. However, there are some deficiencies. Here are the specific modification suggestions:
1. Figure 3, Figure 4 The expression is not clear, and the data is relatively complex, giving people a chaotic feeling. It is suggested to only keep the relevant content of this article;
2. The English expression is not professional enough, and many details need to be modified.
3.The prestress of 22m span is 400 kN and 24m cable is 600 kN. Only calculate a set of data, the data is slightly insufficient.
4. The single-span continuous beam is divided into multi-span continuous beam with the boom, and how to determine whether it is divided into 4 spans. If the boom is used, whether it is divided into 3 spans or 5 spans, and whether the stress deflection and other parameters of each component have changed？
5. Chapter 4 only calculates the stress distribution of reinforcement bolts with a span of 24m and a prestress of 600 kN. The span is 22m and the prestress is 400 kN. Can the bolt stress also be reduced?
6.Whether the prestress value of 22m and 24m is the optimal scheme, and whether there is a prestress value, the calculation results are better than the calculation results of all parameters in the paper.
7. In the finite element simulation, only a single truss is calculated for the practical application？It is suggested to analyze the overall structure and whether this method can meet the reinforcement requirements？
Author Response
Thank you for your hard review, I will carefully check and modify each item, thank you again!
Best wishes!
Mary Shen
30-Mar/2023
Author Response File: Author Response.docx
Reviewer 4 Report
1. In general, the citation is not presented in the abstract section. The abstract is too long and did not give a clear presentation.
2. In introduction, the background is much lack of description. The present introduction did not show sufficiently academic.
3. In figure 13, why the red line and green line are not symmetrical?
4. Some figures show not clear, and the words are too diffcult to read.
5. What is the difference between Fig.20(a) and Fig.20(b)? Please complement it.
Author Response
Thank you for your hard review, I will carefully check and modify each item, thank you again!
Best wishes!
Mary Shen
30-Mar/2023
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Still wrong:
Wrong signature of figure 3, applies to building 2. (Should be: Cross-section view of Powerhouse 2).
Wrong signature of drawing 4, applies to building 1. (Should be: Cross-section view of Powerhouse 1).
Critical length is not for displacement but about determining the length of the bar, e.g. 2 x height or 0,5 x height. Please specify how it was designated.
Author Response
Response Letter
Reviewer #1：Still wrong:
Comment 1: Wrong signature of figure 3, applies to building 2. (Should be: Cross-section view of Powerhouse 2).
Wrong signature of drawing 4, applies to building 1. (Should be: Cross-section view of Powerhouse 1).
Response: Thanks. We have changed it.
Comment 2: Critical length is not for displacement but about determining the length of the bar, e.g. 2 x height or 0,5 x height. Please specify how it was designated.
Response: Thanks. We understood. The critical length is determined according to the different bearing conditions of the pressure rod. When one end of the pressure bar is fixed and the other is free, the critical length is equal to 2X; When the two ends are fixed, the critical length is 0.5X; When one end is fixed and the other end is hinged, the critical length is 0.7l; When the two ends are hinged, the critical length is =2X.
Thank you very much again!
Mary Shen
April-27/2023
Reviewer 2 Report
This reviewer considers this study as a case-study work, since it reports details on the design and the effect of the application of variable axial force cable on steel trusses.
The authors did not address some questions of the first review reports.
1. Explanation on the variable axial load cable method for retrofitting trusses is required. Without a presentation is impossible for the reader to understanding the methodology and results within the manuscript.
2. Some vague sentences are still present in the manuscript e.g. “The span is large, the cross-sectional area of the main beam is small, the overall dead weight is light, and the controlling force is flexible”.
3. Figures explaining the constructive layout of the retrofit system are needed. Figures 11 and 12 are not clear on this issue.
4. The authors mention that the proposed retrofit approach is used as seismic reinforcements (L86). However, seismic analyses are not carried out and the seismic response of the case studies is not considered.
5. L174 Clarify G axis.
Author Response
Response Letter
Reviewer #2：This reviewer considers this study as a case-study work, since it reports details on the design and the effect of the application of variable axial force cable on steel trusses.
The authors did not address some questions of the first review reports.
Comment 1: Explanation on the variable axial load cable method for retrofitting trusses is required.Without a presentation is impossible for the reader to understanding the methodology and results within the manuscript.
Response: Thanks,The Variable Axial Load Cable Method is a structural retrofitting technique used to strengthen trusses. This method involves the installation of steel cables with appropriate tension to transfer the loads from weak or damaged members of the truss to stronger ones.
The process of retrofitting through this method starts with the identification of the damaged or weak member(s) and an assessment of the truss system's overall strength. Once identified, steel cables are installed in place of the damaged or weakened member(s) so that the original load-bearing function is restored.
The cables are then pre-tensioned to a specified load and attached to the adjacent members of the truss. The tension in the cables is adjusted to ensure the load is evenly distributed among all members of the truss. This ensures that the strength of the entire truss system is improved without overloading any one member.
In summary, the Variable Axial Load Cable Method is a reliable and cost-effective way to retrofit trusses and restore their structural integrity. It is commonly used in structures such as bridges, roofs, and other large-scale constructions where trusses form a significant part of the load-bearing structure.
We have added an explanation of this approach to the introduction.
Comment 2: Some vague sentences are still present in the manuscript e.g. “The span is large, the cross-sectional area of the main beam is small, the overall dead weight is light, and the controlling force is flexible”.
Response: Thanks,This paragraph is to explain an explanation used by the previous researchers in the steel bridge structure, and we deleted it after consideration. Thank you for your suggestion.
Comment 3: Figures explaining the constructive layout of the retrofit system are needed. Figures 11 and 12 are not clear on this issue.
Response: Figure 11 and Figure 12 are a structure calculation software independently developed by Tongji University in China. If the structure calculation can be passed, the model can be established; if the calculation fails, the model cannot be established. If the figures are cited for explanation(As illustrated in following figure), there will be many and readers will not understand them. Thank you for your advice.
Comment 4: The authors mention that the proposed retrofit approach is used as seismic reinforcements (L86). However, seismic analyses are not carried out and the seismic response of the case studies is not considered.
Response: Your suggestion is very good. We have incorporated seismic calculation into the modeling and calculation process of 3D3S software by multiplying some basic data (such as bending load and tensile load) by the corresponding seismic coefficients (such as 1.1, etc.).
Comment 5: L174 Clarify G axis.
Response: Sorry, this is an editing error, this axis should be 3/A axis
Thank you very much again! Best wishes!
Mary Shen
April-27/2023
Reviewer 3 Report
The authors answered all the questions. It can be accepted now.
Author Response
Thank you very much!Best wishes!
Mary Shen
April-27/2023
Reviewer 4 Report
It could be accepted.
Author Response
Thank you very much!Best wishes!
Mary Shen
April-27/2023
