Modeling the Optimal Maintenance Strategy for Bridge Elements Based on Agent Sequential Decision Making
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn my opinion, the article is a very valuable proposal to solve the problem of cost optimization regarding the exploitation policy for bridges. It is important and interesting that the authors focus on searching and assessing comprehensive solutions regarding maintenance strategies.
The article contains all the components of a readable scientific work, including: description of the problem being solved, review of existing solutions, own proposal for evaluation and optimization, case study and conclusions.
To improve the readability of the article, I suggest considering supplementing the article with a short paragraph showing the general technical form of the bridge structure that was taken into account in the analyses.
To improve the readability of the article, I suggest considering supplementing the article with a short paragraph showing the general technical form of the bridge structure that was taken into account in the analyses. In the article, the authors refer to specific technical components that may be understood ambiguously.
- The main problem resulting from the described research is: How to optimally shape the maintenance strategy in relation to specific objects, such as bridges?
- In my opinion, the problem of choosing an exploitation strategy is very relevant, both in the scientific and modeling aspect, but above all, in the practical and industrial aspect. The value of this topic has direct consequences in decision-making, as well as the effects of these decisions, not only in relation to the current moment, but above all to the exploitation future. Due to the decision-making uncertainty occurring in this context, searching for and verifying more accurate methods for estimating this uncertainty is a very valuable and highly desirable task.
- The article addresses practical exploitation problems, that are the subject of many research works. The authors propose the use of existing methods, that have been used so far. But in this context, the solution proposed by the authors has practical aspect and is valuable due to the area of application (bridge exploitation).
- The conclusions are consistent, clear and understandable. They have been numbered and arranged in the correct order. They refer directly to the problems discussed in the article and explain the authors' intentions and achievements.
- The list of references is adequate to the research problem. References to literature in the text are correct.
- The tables and figures included in the text are legible and transparent. All figures and tables have been commented in the text of the article.
Author Response
Comments 1-2:
To improve the readability of the article, I suggest considering supplementing the article with a short paragraph showing the general technical form of the bridge structure that was taken into account in the analyses. To improve the readability of the article, I suggest considering supplementing the article with a short paragraph showing the general technical form of the bridge structure that was taken into account in the analyses. In the article, the authors refer to specific technical components that may be understood ambiguously. |
Response 1-2: Thank you for pointing this out. I/We agree with this comment. The specific technical components that may be understood ambiguously refers to prestressed reinforced concrete box girder and the superstructure of the bridge selected in this case is prestressed reinforced concrete box girder. The purpose of this case is to find the optimal defect maintenance strategy for the pre-stressed reinforced concrete box girder of the bridge. |
Comments 3: The main problem resulting from the described research is: How to optimally shape the maintenance strategy in relation to specific objects, such as bridges? |
Response 3: Yes, we optimize defect maintenance strategies for specific bridge elements.
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Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn the study, the authors have developed a strategy based on sequential decision making for optimization of bridge project level maintenance. Though the study is of importance for the audience, however, there are some minor modifications that need to be addressed before final approval of the manuscript.
- The authors are suggested to revise the title and select a more appropriate title as the current title does not reflect the actual scope of the study.
- Abstract is written poorly. It is written in small sentences that are discontinuous. It is suggested to get proofreading of the manuscript from a native English speaker before resubmission.
- What do authors mean by the word “disease”? It is suggested to replace with some appropriate word in the manuscript.
- Line 110: Limitations should be written under the separate heading “Limitations of the study”
- Leave a space between the text and the heading.
- The authors are suggested to add bridge description in the manuscript.
- Correct the Figure Numbers.
- Line 424. Figure 2. Bridge location with surrounding data and keymap should be shown.
- Line 460. Write the converted rate in USD as well.
- What does “Gamma” in Figure 4 & 5 stands for?
- Some more relevant references to be added in the manuscript.
- Correct references no. 5 ,28 and 29.
- DOI of most references are missing, please add as per the Journal’s format.
- It seems like the topic is research based topic and a deep understanding is required to implement it practically. Can the author suggest how to implement it easily in the design offices?
Comments on the Quality of English Language· Abstract is written poorly. It is written in small sentences that are discontinuous. It is suggested to get proofreading of the manuscript from a native English speaker before resubmission.
Author Response
Comments 1: The authors are suggested to revise the title and select a more appropriate title as the current title does not reflect the actual scope of the study.
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Response 1: Thank you for pointing this out. I/We agree with this comment. The original title is “Optimization of Bridge Project-level Maintenance Strategy based on Agent Sequential Decision Making”. With the consent of all the authors, we change the title to “Modeling the Optimal Maintenance Strategy for Bridge Elements based on Agent Sequential Decision Making”. It’s a more appropriate title as the current title reflect the actual scope of the study. |
Comments 2: Abstract is written poorly. It is written in small sentences that are discontinuous. It is suggested to get proofreading of the manuscript from a native English speaker before resubmission. Abstract is written poorly. It is written in small sentences that are discontinuous. It is suggested to get proofreading of the manuscript from a native English speaker before resubmission. |
Response 2: Abstract: Addressing the issues of low efficiency in bridge maintenance decision-making, inaccurate estimation of maintenance costs, and lack of specificity in decision-making regarding maintenance measures for specific defects, this study utilizes data from regular bridge inspections. It employs a two-parameter Weibull distribution to model the duration variables of the states of bridge elements, enabling the prediction of the duration time of bridge elements in various states. Referring to existing bridge maintenance and repair regulations, the estimation process of maintenance costs is streamlined. Taking into account the specific types and development state of bridge defects, as well as considering the adequacy of maintenance and the restorative effects of maintenance measures, an intelligent agent sequential decision-making model for bridge maintenance decisions is established. The model utilizes dynamic programming algorithms to determine the optimal maintenance and repair measures for elements in various states. The decision results are precise, down to the specific bridge elements and maintenance measures for individual defects. Using the case of the regular inspection data of 222 bridges along a highway loop, this study further validates the effectiveness of the proposed research methods. By constructing an intelligent agent sequential decision-making model for bridge elements maintenance, optimal maintenance measures for 21 bridge elements in different states are obtained, significantly enhancing the efficiency of actual bridge maintenance and the practicality of decision results.
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Comments 3: What do authors mean by the word “disease”? It is suggested to replace with some appropriate word in the manuscript. |
Response 3: As you mentioned, we've replaced the word “disease” with the word “defect”, please see the manuscript for details.
Comments 4: Line 110: Limitations should be written under the separate heading “Limitations of the study” Response 4: As you mentioned, we've written two separate heading in the introduction section, “Literature Review” and “Limitations of existing studies”, please see the manuscript for details.
Comments 5: Leave a space between the text and the heading. Response 5: As you mentioned, we've left a space between the text and the heading, please see the manuscript for details.
Comments 6: The authors are suggested to add bridge description in the manuscript. Response 6: As you mentioned, we've added our data sources and bridge description to the chapter, Data preparation, please see the manuscript for details.
Comments 7-8: Correct the Figure Numbers. Line 424. Figure 2. Bridge location with surrounding data and keymap should be shown. Response 7-8: We have modified the Figure Numbers, and have added bridge location with surrounding data and keymap to Figure 2, please see the manuscript for details.
Comments 9: Line 460. Write the converted rate in USD as well. Response 9: We have converted the article's unit yuan to USD, please see the manuscript for details.
Comments 10: What does “Gamma” in Figure 4 - 5 stands for? Response 10: The Gamma is the coefficient γ of formula (15)-(18). We have modified the Figure 5-6. γ is the discount factor that controls the importance of future rewards. The value is equal to the ratio of existing maintenance funds to the estimated cost of re-pairing all diseases and represents the adequacy of current maintenance funds.
Comments 11-13: Some more relevant references to be added in the manuscript. Correct references no. 5 ,28 and 29. DOI of most references are missing, please add as per the Journal’s format. Response 11-13: Reviewer 1 thinks that the content and number of references are sufficient for the research problem, so we do not add references in this Revision. We have modified the reference number 5, 28, 29, and we have supplemented and improved the missing DOI of references.
Comments 14: It seems like the topic is research based topic and a deep understanding is required to implement it practically. Can the author suggest how to implement it easily in the design offices? Response 14: This article is not a research-based topic, and perhaps the model algorithm needs a deeper understanding because it is complex, which does not mean that it cannot be implemented in practice. With reference to our bridge maintenance decision-making process, as shown in Figure 1, the author can easily reproduce this research result in the design office if bridge data and algorithms are available. In case study, we have constructed an intelligent agent sequential decision-making model for bridge elements maintenance, optimal maintenance measures for 21 bridge elements in different states are obtained, significantly enhancing the efficiency of actual bridge maintenance and the practicality of decision results. |
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe topic is interesting, still authors need to address the following comments.
In the introdution section there are some citations that the author report like review of literature. For examples, citation 7-9 and also many more in the introduction section. Authors are suggested to re-write those affected citation as report for citation 1-6. Also, in the introduction section, several definitions are made, author may create another subsection to define those terms or restructure the approach of definition in a concise manner. In lines 60 - 65, author discuss on the methodology. These may be restructured or move to Bridge Element Maintenance Decision Optimization Model.
Authors need to move the main objective of their study as their last sentence in paragraph 1 or as beginning sentence in paragraph 2. Authors should move their objective of their study from lines 149-151 to appropriate paragaph mentioned. Author should add a section to discuss their structure of the remaing study at as the closure paragraph for the introduction section.
The section Bridge Element Maintenance Decision Optimization Model. is too lengthy, it covers about 7 pages. Authors may reduce the discussion.
The authors need to specify the source of their data for transparency purpose and the countries which their data covered. Depite that authors reported that their data is historical data neither the duration of the data nor frequency of the data reported. Those missing information should be reported.
Furthermore, limitation of the study, practical implication and future research are required to be included in the conclusion section.
Author Response
Comments 1: In the introduction section there are some citations that the author report like review of literature. For examples, citation 7-9 and also many more in the introduction section. Authors are suggested to re-write those affected citation as report for citation 1-6. Also, in the introduction section, several definitions are made, author may create another subsection to define those terms or restructure the approach of definition in a concise manner. In lines 60-65, author discuss on the methodology. These may be restructured or move to Bridge Element Maintenance Decision Optimization Model.
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Response 1: As you mentioned in citations 7-9, there are too many details of the citation 7-9, so we briefly described this part, please see the manuscript for details. As you mentioned lines 60-65, so we have moved to “Bridge Element Maintenance Decision Optimization Model”, as a starting point, introduce the Sequential Decision Model.
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Comments 2: Authors need to move the main objective of their study as their last sentence in paragraph 1 or as beginning sentence in paragraph 2. Authors should move their objective of their study from lines 149-151 to appropriate paragraph mentioned. Author should add a section to discuss their structure of the remaining study at as the closure paragraph for the introduction section. |
Response 2: the main objective of our study is “This study aims to analyze the actual condition of bridge elements' defects, establish a quantified and clear model for maintenance strategies, develop a cost estimation model for maintenance activities, and conduct a benefit analysis of element maintenance. Based on these analyses, an intelligent agent-based sequential decision-making model for bridge element maintenance is established. Finally, the optimal maintenance strategy for bridge elements is solved using dynamic programming algorithms”. We moved the main objective of our study as our last sentence in paragraph 1.
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Comments 3: The section Bridge Element Maintenance Decision Optimization Model is too lengthy, it covers about 7 pages. Authors may reduce the discussion. |
Response 3: As you mentioned, we reduced the discussion, please see the manuscript for details.
Comments 4: The authors need to specify the source of their data for transparency purpose and the countries which their data covered. Despite that authors reported that their data is historical data neither the duration of the data nor frequency of the data reported. Those missing information should be reported. Response 4: As you mentioned, the lack of indication of the source of the data and the countries covered by the data is unreasonable. We've added our data sources and regions to the chapter, Data preparation, please see the manuscript for details.
Comments 5: Furthermore, limitation of the study, practical implication and future research are required to be included in the conclusion section. Response 5: As you mentioned, this part is actually covered in Conclusion (4), but we have added it accordingly. The specific contents are as follows: “In addition, the use case of this research is prestressed concrete box girder. The adaptability of other parts and other bridge types such as arch bridge、cable-stayed bridge and suspension bridge remains to be proved.” |
Author Response File: Author Response.pdf