An Improved Model for Design Fatigue Load of Highway Bridges Considering Damage Equivalence

Round 1

Reviewer 1 Report

The authors investigate the fatigue load of highway bridges in China. It is of great research significance. The following comments are given to the authors to improve the manuscript.

1. The title is not appropriate. It does not describe the objective, innovation, and method of this study well.
2. Table 7, there are eight typical locations used to determine the finial standard. Please explain the reason why the eight locations are selected as the typical cases.
3. In Figure 4, the flow diagram must be improved.
4. Line 298, the description does not match with the Figure 9.
5. In Figure 14, the significant figures of coefficients of determination must be uniform.
6. Please discuss the difference between the proposed standards and the existing standards.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

I believe the research topic is not within the scope of this journal. It is recommended to be submitted to other journals with scope of structures and bridge design. However, I can highlight few suggestions for further improvements:

 

1. Paper title is general. It should be more specific.
2. Abstract should include a brief of the research methodology.
3. Last paragraph of the introduction should clearly highlight the research gap.
4. Section 2 should be research methodology. A part of the research method is Traffic data collection. Research method must be clearly presented after the introduction.
5. There are no reference(s) to support the justification of the results. This is a major weakness of this paper.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,
Thank you very much for the article evaluating the adequate fatigue life of highway bridges. 
First of all, I would like to point out that I agree with your hypotheses and I find that in general the article is very interesting. 
I have the following comments on particular parts of the article:

The title and abstract are fine. 
The first sentence of the abstract and the introduction should not be the same - it looks strange. 

The introduction is quite short and I would recommend expanding it to provide a broader context towards fatigue damage per se. Your introduction focuses a lot on the reasons and modelling of traffic loads, but lacks broader information about the dangers of fatigue, the need for it, why we address it, etc. 
I would recommend expanding in terms of, for example, other fatigue loads, but especially their effect on the structure:
10.3390/ma14247726
10.1016/j.ijfatigue.2019.105190
10.1007/s13369-021-06318-8

You present a very interesting procedure related to sorting and omitting vehicles by weight. Even the follow-up statistics are logical and supported. 

I support the fatigue load spectrum and the subsequent evaluation of influecen lines. 

Have you considered (outside of the paper) combining it with a probabilistic approach or fuzzi logic? (I am not referring to chapter 6.2 now, but to traffic simulation using probabilistic or fuzzi approaches).

A very interesting approach that is supported by logical steps. 

After the conclusions, the mandatory fields of the article are missing according to the template.
References are not according to the template. 
Some figures have too small font - cannot be read at normal size. 
Figure 11 very small. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

All the comments are addressed.

Author Response

We are glad to receive the positive comments. We would like to extend our appreciation to you for carefully reviewing our manuscript.

Reviewer 2 Report

The authors addressed my comments. However, I still believe that the research topic is not directly in the scope of the journal and the journal special issue.  

Author Response

Thanks for the comments, and previous suggestions are very useful for the improvement of the manuscript. As for whether the research is in the scope of the journal special issue, we do have different views and are willing to make further explanations.

Firstly, Building is an international, scientific, peer-reviewed on building science, building engineering and architecture published monthly online by MDPI. Bridge engineering is a type of building science and engineering which deals with building and repairing of massive bridge buildings. In addition, many studies on bridge engineering have been published in this journal, such as F.S. Ademir, S.B. Mauricio, S.S. Helder et al. Improvement of the Inspection Interval of Highway Bridges through Predictive Models of Deterioration. Building 2022, 12(2), 124.

Secondly, based on fatigue damage theory, the method to improve the design fatigue load model for fatigue analysis of bridge structures is mainly studied. In engineering practice, the fatigue problem is particularly prominent for highway steel bridges. Take the orthotropic steel deck systems, for example, fatigue cracks can often be found in a matter of years or decades of service as a result of all the passing vehicles. Fatigue damage can affect the function and safety of structures, and the durability will also be directly affected thereby. Reasonable fatigue design or analysis can be considered to be an important (not the only) step to achieve the goal of structural durability. Therefore, the research is helping to improve the rationality of fatigue durability design and analysis. It can be seen that the two words are used together in the titles of many research articles (Ya S, Yamada K. Fatigue durability evaluation of trough to deck plate welded joint of orthotropic steel deck[J]. Doboku Gakkai Ronbunshuu A, 2008, 64(3): 603-616.; Dzionk S, Przybylski W, Ścibiorski B. The Possibilities of Improving the Fatigue Durability of the Ship Propeller Shaft by Burnishing Process[J]. Machines, 2020, 8(4): 63; Dalaei K, Karlsson B. Influence of overloading on fatigue durability and stability of residual stresses in shot peened normalized steel[J]. Materials Science and Engineering: A, 2011, 528(24): 7323-7330; Yoshitake I, Hasegawa H. Moving-wheel fatigue durability of cantilever bridge deck slab strengthened with high-modulus CFRP rods[C]//Structures. 2021, 34: 2406-2414; Dalaei K, Karlsson B. Influence of overloading on fatigue durability and stability of residual stresses in shot peened normalized steel[J]. Materials Science and Engineering: A, 2011, 528(24): 7323-7330.).

  That's why we think that research topic can be intrinsically connected to the journal special issue and is within the scope of the journal.

  In addition, we reviewed the manuscript again and all changes involved are marked up in the revised manuscript.

At last, the author also noticing the opinion of the reviewer to the English and style used in our work. Thanks for the kind reviewing work by the reviewer, and we are quite sorry for the unqualified English level showed in the original manuscript. For the revised version of our paper, major revision and improvement including the grammar, vocabulary and structure were conducted by several colleagues who are skilled authors of native speakers.

We believe that the present language can fulfill the requirement of the journal.

 

Please accept my sincere thankfulness for your utmost effort and full support. Thank you for reviewing our manuscript!

Best regards