Seismic Performance Evaluation of Highway Bridges under Scour and Chloride Ion Corrosion
Round 1
Reviewer 1 Report
It's interesting that this manuscript focuses on Seismic Performance Evaluation of Highway Bridges under Scour and Chloride Ion Corrosion, and it presents an interesting approach for structural failure probability and reliability index of pile foundations under different scour depth.Howerer,there are some major problems with this manuscript,that is,
1). On page 2, the authors point out that "Earthquake and scour are two common natural disasters that easily lead to bridge damage and destruction", here can refer to the following content,https://doi.org/10.1016/j.istruc.2020.12.089 and https://doi.org/10.3311/PPci.15276.
2). In the introduction of this manuscript,the authors point out that "the failure probability of bridges crossing rivers in seismic zones may increase further as the depth of scour at the foundation changes, at which point the seismic damage pattern of bridge needs to be re-evaluated",here should refer to the following content,
https://doi.org/10.1016/j.conbuildmat.2011.11.002 and https://doi.org/10.1080/13632469.2021.1927905.
3). There are too many conclusions in this manuscript, which should be concise.
Once the above concerns are fully addressed, I would be very glad to re-review the manuscript in greater depth because the subject is interesting.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper presents an interesting study on the seismic performance of highway bridges under the action of scour and chloride ion corrosion. The authors conducted concise, extensive, and valuable study, investigating many parameters. The paper is well-written and structured, the results are presented widely.
Before accepting final decision on relevance of the manuscript for publication in Applied Sciences the following issues need to be addressed:
1. Abstract: Current abstract is quite long and maybe the information given is too detailed. It should be shortened and condensed.
2. Literature review: Concise and clear summary of the selected existing literature in the field is presented. However, almost all of the cited references are older than 5 years. Authors are encouraged to conduct state-of-the-art literature review with some fresh references included.
3. Presentation & Description:
a) The last paragraph (lines 122-134) of Introduction summarizes the content of the presented study, what it is actually not explicitly stated in this paragraph. It is suggested to add “In this study…” somewhere at the beginning of the paragraph.
b) The extent of the current paper is quite long and should be reduced. In parallel, the number of figures included in the manuscript exceeds common extent in scientific paper. In this context, for instance, the results presented in Figs. 17-18 actually duplicate the results shown in Tab. 3. On the contrary, the selected obtained results are poorly commented and discussed (they are just shown in Figs. or Tabs.).
c) Besides the schemes shown in Fig. 22 adding some actual photos from the performed test specimens would be appreciated.
d) Table 5 should be revised or (for the sake of brevity, better) excluded from the paper. In its current form it does not provide any new information – it duplicates the data quoted yet in Tab. 4!?
4. Research material & methodology:
a) The investigated highway bridge is not described/presented enough (section 2.2.1). Some essential data are missing: the geometry of the structure (cross sections, plate thickness, pile lengths); material characteristics; arrangement, location and characteristics of the friction pendulum bearings; the level of vertical load (dead, live etc.) considered in the analysis; dynamic characteristics of the structure (period of vibration, mode shapes etc.), etc.
Similar comment is given also for presentation of the considered seismic load (which time-histories, how many accelerograms, scale factors, etc.) – line 244.
b) The “resistance values” quoted in Tab. 2 need explanation (definitions, units (are the quoted units kNm correct?), comment on the level of the quoted values, etc.)
c) Please, check (lines 340-341) Eqn. (17) – the use of semicolon within the equation? Similar comment also for line 609.
d) The data on used Rebar Type quoted in Table 4 (HRB335 & 400) does not correspond to statement in line 359 (only HRB400). Explain, please.
5. Results and Discussion
a) One of the main paper shortcomings observed by this reviewer is the unusual presentation of the applied methodology and the obtained results in the 1st part of the paper i.e. the methodology (background, calculation etc.) and the obtained results are presented simultaneously, at the same time.
b) Please, check Figure 29: energy dissipation is expressed in “Load (kN)”?
6. Conclusions: The current section Conclusions should be a little bit shortened – particularly the last part (concl. remarks 5-7). Besides, the assumptions and limitations of the presented study need to be mentioned and discussed and directions for further work given.
7. The current manuscript requires a revision of language, style, etc.:
a) Line 107: correct the surname of the 1st author of the cited study (Ghosh instead of “Gho”).
b) Line 232: delete the last (unnecessary) sign at the end of the sentence.
c) Fig. 8 – label of X axis: correct spelling (“Hight”).
d) The use of space between words:
o delete space after word “ideas” (line 359) and insert space before parentheses (line 359);
o insert space before/after parentheses in caption of Fig. 22 (lines 434-435).
e) Correct a mistake in line 428: number of cited Figure (22 instead of 20)!
f) Fig. 22 – a, b, d, f: correct a mistake (Spalling instead of “Scaling”).
g) Revise diction “plastic development in plastic hinge region” in “plasticity development in plastic hinge region” (lines 506, 619).
h) List of References:
o Use the same citation style (according to the journal’s rules) consistently throughout the list: use or not a comma after the authors’ surnames (check lines 647-659, 723)
o Line 649: delete “ after “Approaches”
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
1. The title of the manuscript mentions the seismic, scour, and corrosion issues to investigate the performance of the bridge. It might give readers an image to consider all three factors simultaneously. However, the authors divided the content into two parts, the combination of seismic and scouring effect, as we ll as seismic and corrosion as the second part. So, it is hard to expect the actual performance of a corroded bridge with different scouring depths on the pile when it suffers different seismic intensities based on the findings and conclusions in the manuscript.
2. In section 3.3.2, it is hard to understand the minor reduction in the yielding and ultimate strength of the reinforcement (Figure 21) causes a dramatic decrease in the peak point in specimens LLE, MME, and MHE (Figures 23-28). However, the observed smaller displacement capacity is reasonable.
3. In section 3.3.6, the finite element analysis of the corroded columns is oversimplified. Therefore, the authors should give modeling details, not only the element type but the process of dealing with the corrosion. Since the simulation by OpenSees is affected by many factors, primarily due to failure mode identification.
4. In section 3.4, the M-Park Model underestimates the damage index until 1.0, compared to the index from the Park-Ang model. But, then, the M-Park Model trend rapidly increases when the index exceeds 1.0. So, using M-Park Model shows an unconservative result and needs more explanations.
5. A new section before the conclusion is suggested to quantify the seismic performance of a corroded bridge with different scouring depths.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
It is believed that the article is well structured and of good scientific relevance. To improve it, it is believed that the initial introductory part should be slightly deepened by adding other references relating to different approaches to the evaluation of seismic problems in viaducts. Among the references to be introduced, for example, the following is recommended: Seismic Assessment of Six Typologies of Existing RC Bridges (Crespi, Zucca, Longarini, Giordano), Comparison between non-linear dynamic and static seismic analysis of structures according to European and US provisions. (Causevic, M .; Mitrovic, S.) and Alternative retrofitting strategies to prevent the failure of an under-designed RC frame (Valente, Milani).
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have addressed most of the comments raised by the reviewers satisfactorily. Now, the manuscript is well written and the topic interesting and worth of investigation.I think it can be accepted as it is.
Reviewer 3 Report
The authors clearly explain all questions. Therefore, there are no further questions.
