Influence of Initial Conditions on Wind Characteristics at a Bridge Middle Span in a U-Shaped Valley by CFD and AHP

Round 1

Reviewer 1 Report

This is an overall good paper to be shared with the scientific community. The paper looks at the combination of CFD with AHP, which will be useful for complicated studies such as this described in the paper. A few questions for the authors here:

1. Is there any validation done to the CFD methodology? It will be good to put some thoughts into this. If not, some discussion on why validation is not necessary will be good. 
2. Why did the authors think that URANS is necessary for this work, and also, the choice of the turbulence model.
3. Can the authors also share some details on the meshing methodology, ie. the y+ value? 
4. In Table 1, what is the wind speed factor relative to? Is it relative to a measured wind value, or is it retrieved solely from the CFD data?
5. From the analysis done through AHP, is the results compared to the CFD? Is there some coupling between the both?

Author Response

Response to Reviewer 1 Comments

 

This is an overall good paper to be shared with the scientific community. The paper looks at the combination of CFD with AHP, which will be useful for complicated studies such as this described in the paper. A few questions for the authors here:

 

Point 1: Is there any validation done to the CFD methodology? It will be good to put some thoughts into this. If not, some discussion on why validation is not necessary will be good.

Response 1: Thanks for the reviewer’s suggestions. As for the validation done to the CFD methodology, we conducted and discussed 6 groups of mesh division in the section 2.3.

 

Point 2: Why did the authors think that URANS is necessary for this work, and also, the choice of the turbulence model.

Response 2: Thanks for the reviewer’s suggestions. In order to study the wind characteristics in mountainous areas by CFD, references were made to literatures, such as [25-30], we utilized the methodology also and cited those papers. And therefore, the URANS and the k-w turbulence model was chosen and used in this paper.

25. Huang, G., et al., Aerodynamic shape of transition curve for truncated mountainous terrain model in wind field simulation. Journal of Wind Engineering and Industrial Aerodynamics, 2018. 178: p. 80-90.
26. Bitsuamlak, G.T., T. Stathopoulos, and C. Bédard, Numerical evaluation of wind flow over complex terrain: Review. Journal of Aerospace Engineering, 2004. 17(4): p. 135-145.
27. Hu, P., et al., Numerical simulation of wind fields at the bridge site in mountain-gorge terrain considering an updated curved boundary transition section. Journal of Aerospace Engineering, 2018. 31(3): p. 04018008.
28. Hu, P., et al., Effects of Inhomogeneous Wind Fields on the Aerostatic Stability of a Long-Span Cable-Stayed Bridge Located in a Mountain-Gorge Terrain. Journal of Aerospace Engineering, 2020. 33(3).
29. ANSYS, Ansys Fluent User Guide 2019R2. 2019, U.S.A: ANSYS. Inc.
30. Pattanapol, W., et al. Modeling of Surface Roughness for Flow Over a Complex Vegetated Surface. in Conference of the World-Academy-of-Science-Engineering-and-Technology. 2007. Bangkok, THAILAND.

 

Point 3: Can the authors also share some details on the meshing methodology, ie. the y+ value?

Response 3: Thanks for the reviewer’s suggestions, we apologized for our inadequate representation. As for the y+ value, due to the boundary layer grid was created by Blocken’s suggestions[24], and the main areas of concern in this paper was not near wall. So the y+ value is not presented.

24. Blocken, B., Computational Fluid Dynamics for urban physics: Importance, scales, possibilities, limitations and ten tips and tricks towards accurate and reliable simulations. Building and Environment, 2015. 91: p. 219-245.

 

Point 4: In Table 1, what is the wind speed factor relative to? Is it relative to a measured wind value, or is it retrieved solely from the CFD data?

Response 4: Thanks for the reviewer’s suggestions, we apologized for our incorrect writing. We have made the following revisions and corrections. And wind speed factor was replied by nondimensional velocity ratio according to the figure 4. And the wind value is retrieved from the CFD data.

 

Point 5: From the analysis done through AHP, is the results compared to the CFD? Is there some coupling between the both?

Response 5: Thanks for the reviewer’s suggestions. The analysis results of AHP was based on the CFD data, so there is not any comparison between the two methods. However, the coupling relationship of the two methods was presented and discussed in section 4.2 mainly. And the coupling between the both is one of the novel and significant point of the paper.

 

The numbers of the figures and tables were changed in this manuscript, the correction in the text also be done.

 

Thanks for the reviewer’s valuable comments.

 

Reviewer 2 Report

Please further elaborate on the novelty of your work in abstract.

The presented introduction is pretty modest. Please include a brief but critical review regarding the conducted research studies in the introduction.  It is recommended to add a section “research significance” and highlight the main contribution of your findings.

Please include the latest research studies related to your work preferably between 2019 and 2022

Please include a brief summary of improving the long-term response of bridge structures. Accordingly, please mention the advantages of using the article titled “Physical modelling of the long-term behavior of integral abutment bridge backfill reinforced with tire-rubber” in your research.

Please include statistic characteristics of the presented graphs in Figure 4.

Please relocate the subsection 4.1 Initial condition from Results and Discussion to another section such as methodology.

Please further discuss on the limitation of the presented equation (10) page 7.

Please include a comparative analysis based on the presented graphs in Figure 5.

It is recommended to add more discussion on the effect of azimuth angle and wind speed following the presented results.

Please revise some figures (i.e. Figure 10, Figure 11 and etc with better quality).

Further elaborations are required on the outcomes of Table 4 and Table 5.

Please further explain the main outcomes of your work in conclusion.

 

 

Author Response

Response to Reviewer 2 Comments

 

 

 

 

 

Point 1: Please further elaborate on the novelty of your work in abstract.

Response 1: Thanks for the reviewer’s suggestions, the abstract has modified as followed.

(1) “The wind parameter distribution law at a bridge middle span in a U-shaped valley was researched by CFD” was changed to “The wind parameter distribution law at a bridge middle span in a U-shaped valley has important inluence on wind-resistant of the bridges and was researched by CFD”

(2) “The effect of four initial (surface roughness, inlet wind speed, wind speed profile, and oncoming wind direction) conditions on wind speed, wind attack angle, and wind azimuth angle were analyzed.” was modified to “The effect of four initial (surface roughness, inlet wind speed, wind speed profile, and oncoming wind direction) conditions on wind speed, wind attack angle, and wind azimuth angle were comprehensively analyzed.”

(3) “A quantification model” was revised to “An innovative quantification model”.

 

Point 2: The presented introduction is pretty modest. Please include a brief but critical review regarding the conducted research studies in the introduction.  It is recommended to add a section “research significance” and highlight the main contribution of your findings.

Response 2: Thanks for the reviewer’s suggestions. We did some revision as followed”

(1) In order to introduce the paper’s study aim and AHP, based on the research state presented as before, we added “In summary, scholars have done many numerical studies on wind parameters at mountainous bridge sites, but only one or two of the factors, such as oncoming wind direction, inlet wind speed, wind speed profile, or surface roughness, are considered. However, the simultaneous influence of these initial conditions on wind parameters is not considered, and their influence degree of initial conditions is not explained.”

(2) We added “Therefore, the AHP was introduced as followed.”, “Whereas,” ,“and promote understanding of the initial conditions’ influence on wind parameters distribution” and so on.

 

Point 3: Please include the latest research studies related to your work preferably between 2019 and 2022。

Response 3: Thanks for the reviewer’s suggestions. We apologized for our inadequate work.

We added “Huang et al. [16] analyzed the wind directions’ effect on wind characteristics over complex terrain by CFD. Song et al. [17]discussed the influence of wind direction on wind speed along the bridge axis also.”

16. Huang, W. and X. Zhang, Wind field simulation over complex terrain under different inflow wind directions. Wind and Structures, 2019. 28(4): p. 239-253.
17. Song, J.-L., et al., Field measurements and CFD simulations of wind characteristics at the Yellow River bridge site in a converging-channel terrain. Engineering Applications of Computational Fluid Mechanics, 2022. 16(1): p. 58-72.

 

Point 4: Please include a brief summary of improving the long-term response of bridge structures. Accordingly, please mention the advantages of using the article titled “Physical modelling of the long-term behavior of integral abutment bridge backfill reinforced with tire-rubber” in your research.

Response 4: Thanks for the reviewer’s suggestions. The integral abutment bridge backfill reinforced with tire-rubber is very useful for improved the long-span bridge’s wind-resistant performance.

We added the reference in this paper.

23. Zadehmohamad, M., et al., Physical modeling of the long-term behavior of integral abutment bridge backfill reinforced with tire-rubber. International Journal of Geo-Engineering, 2021. 12(1): p. 36.

 

Point 5: Please include statistic characteristics of the presented graphs in Figure 4.

Response 5: Thanks for the reviewer’s suggestions, please forgive our incomplete description.

We added “At the same time, the nondimensional velocity ratio was defined by the velocity of the Middle2 divide the other cases at the same height. Due to the maximum of the nondimensional velocity ratio, ranged from 1.01 to 1.20, and the 1.01 - 1.02 represent the relationship between the Middle2 and Fine1, Fine2. Further,”

 

Point 6: Please relocate the subsection 4.1 Initial condition from Results and Discussion to another section such as methodology.

Response 6: Thanks for the reviewer’s suggestions, we changed the paper’s structure according to your advice. As showed in the revised manuscript.

 

Point 7: Please further discuss on the limitation of the presented equation (10) page 7.

Response 7: Thanks for the reviewer’s suggestions. As for the Equation (10), it is suitable for using for CFD based on ANSYS. Due to the  ranges from 0.5-1, so the required cell height is limited to some extent by maximum of , especially for the lowest boundary layer cell [32].

                                  (10)

32. Blocken, B., T. Stathopoulos, and J. Carmeliet, CFD simulation of the atmospheric boundary layer: wall function problems. Atmospheric Environment, 2007. 41(2): p. 238-252.

 

Point 8: Please include a comparative analysis based on the presented graphs in Figure 5.

Response 8: Thanks for the reviewer’s suggestions. We are sorry for our inadequate description.

We added “And the surface roughness has a greater influence on the wind attack angle and wind azimuth angle than on wind speed profile.”.

 

Point 9: It is recommended to add more discussion on the effect of azimuth angle and wind speed following the presented results.

Response 9: Thanks for the reviewer’s suggestions, we added some discussion on the effect of azimuth angle and wind speed, as shown in the revised paper. Such as:

“And the surface roughness has a greater influence on the wind attack angle and wind azimuth angle than on wind speed profile.”

“It could be found that the oncoming wind direction has obvious influence on the wind characteristics, especially, when the oncoming wind direction is 270°, that is blocked by the mountains as shown in Figure 1(a) and Figure 10(b). Therefore, the wind speed、wind attack angle and wind azimuth angle fluctuate strongly in the low height region, such as the height is lower than 2200 m.”

 

Point 10: Please revise some figures (i.e. Figure 10, Figure 11 and etc with better quality).

Response 10: Thanks for the reviewer’s suggestions, we changed the all figures with better quality, as shown in the revised paper.

 

Point 11: Further elaborations are required on the outcomes of Table 4 and Table 5.

Response 11: Thanks for the reviewer’s suggestions, we are sorry for our incomplete discussion.

We added “It could be found that the relationship between the coefficient of factor sensitivity and the scale value represents a logarithmic base 2. The scale value increases with the coefficient of factor sensitivity, but the increase velocity decreases gradually. In other words, as the scale value rises, the corresponding interval of the coefficient of factor sensitivity augments sharply.” and “The first 5 columns of Table five consist an antisymmetric matrix, and the scale value ranges from 1/6 to 6. It could be found that the initial conditions have a huge influence on wind parameters distribution.”.

 

Point 12: Please further explain the main outcomes of your work in conclusion.

Response 12: Thanks for the reviewer’s suggestions, we added some comment in conclusions.

We added “ As for study the wind-resistant of bridges in the U-shaped valley, oncoming wind direction is the first initial condition and need most and comprehensive consideration. The second is the wind speed profile. The surface roughness and inlet wind speed are the least important factor. ”.

The numbers of the figures and tables were changed in this manuscript, the correction in the text also be done.

 

Thanks for the reviewer’s valuable comments.

 

Author Response File: Author Response.docx

Reviewer 3 Report

The presented paper analyzes parametrically the influence of wind general conditions on the wind acting on a bridge located in U-shaped valley. That influence has been assessed with a CFD, whose results were evaluated with an analytical hierarchy process. The analysis procedure has some reference value, but there are still major flaws in the paper that leads to the recommendation to reject this manuscript for publication:

1. The results presented in Table 6 show that wind speed on the construction location is very sensitive to wind speed profile. This is true for any location even in flat terrains. Please verify your analysis method, so that it would mainly consider the effects of the valley orography. Please consider the use the wind conditions before entering to the valley as reference.

 

2. The paper present interest theoretical results but lacks of experimental or onsite date measurements discussion. It would be helpful to discuss briefly the results of the paper with those of this article: “Wang, J., et al., Research on wind field characteristics measured by Lidar in a U-shaped valley at a bridge site. Applied Sciences- 449 Basel, 2021. 11(20): p. 9645. “. Other references might be employed to discuss the results.

 

3. Please propose or discuss possible methods to consider terrain influence in the wind for structural project use. CFD sometimes might be costly for some construction projects.

 

4. Please discuss briefly the results shown in Figure 10.

 

In addition, there are minor issues that also must be addressed by the authors:

5. For a better understanding of the paper acronyms use must be more self-explanatory:
   1. Avoid using acronyms not defined previously in the abstract.
   2. Please check that every acronym employed in the paper are defined, some as the one shown in line 130, “CFL”, have not been defined.

 

6. Some Figures and Tables are missing or need to be corrected:
   1. Figure 3 was not found in the paper.
   2. Figure 11: Wind speed is present in two boxes, please distinguish between both by using adjectives such as “inlet”, for example.
   3. Table 5: title missing.
   4. Table 6: wind direction influence not described and inlet wind speed is present in two columns, please check.

 

7. The present paper has some typos and some expressions need English improvement, the reviewer lists some of them in the following lines:
   1. Lines 59 to 61: names “flared mountain pass crane” and “the junction of the canyon bridge and tunnel” are not clearly understood by the reviewer. The authors might use the same names as the ones employed by the cited reference authors.
   2. Line 85: change “analysis” with “analyze”.
   3. Line 88: please clarify what are you referring to in “19 working conditions”.
   4. Line 103: check “down loaded”, besides the typo might be its batter to change it with “created” or “defined”.
   5. Line 230: check “sur face”.
   6. Line 282: the following expression “wind speed profile adopts the method” might be improved as follows “wind speed profile adopted follows the shape”.
   7. Line 296: “, and the wind speed is taken as 47.87 m/s.” it is repetitive; it has already been mentioned in line 292.
   8. Line 343: “wake area” is not understandable, please check.

Author Response

Response to Reviewer 3 Comments

 

 

 

The presented paper analyzes parametrically the influence of wind general conditions on the wind acting on a bridge located in U-shaped valley. That influence has been assessed with a CFD, whose results were evaluated with an analytical hierarchy process. The analysis procedure has some reference value, but there are still major flaws in the paper that leads to the recommendation to reject this manuscript for publication:

Thanks for the reviewer’s suggestions.

 

Point 1: The results presented in Table 6 show that wind speed on the construction location is very sensitive to wind speed profile. This is true for any location even in flat terrains. Please verify your analysis method, so that it would mainly consider the effects of the valley orography. Please consider the use the wind conditions before entering to the valley as reference.

Response 1: Thanks for the reviewer’s suggestions.

(1) The surface roughness at the valley is ununiform and difficult to measure, so refer to Wieringa’ s paper, 0, 0.03, 0.06, 0.09, and 0.12 m, five cases are analyzed.

Wieringa, J., Updating the Davenport roughness classification. Journal of Wind Engineering and Industrial Aerodynamics, 1992. 41(1): p. 357-368.

(2) Due to the 102° oncoming flow is less blocked by mountains and may be the most dangerous oncoming wind direction at the valley, so, taking 102° oncoming flow as an example, in order to analyze the influence of inlet wind speed on wind parameters, the uniform oncoming flow is also set; the wind speed is 10–70 m/s, the interval is 15 m/s,

(3) Taking 102° oncoming flow as an example, too, the wind speed profile adopts the method recommended by Zhang et al. [35]. As shown in the following figure.

35. Zhang, J., et al., Comparison of wind characteristics in different directions of deep-cut gorges based on field measurements. Journal of Wind Engineering and Industrial Aerodynamics, 2021. 212.

 

(4) Due to the U-shaped valley is the research object in this paper. And the valley is located in Southwest of China, so the wind direction at the bridge site may be related to the valley extension direction and the dominant wind directions, So the five directions were designed, 102°, 211°, 326°, 90°, and 270°, as shown in Figure 1(a).

Wang, J., et al., Research on wind field characteristics measured by Lidar in a U-shaped valley at a bridge site. Applied Sciences-Basel, 2021. 11(20): p. 9645.

Wang, F., et al., Wind characteristics in mountainous valleys obtained through field measurement. Applied Sciences-Basel, 2021. 11(16).

Song, J.-L., et al., Field measurements and CFD simulations of wind characteristics at the Yellow River bridge site in a converging-channel terrain. Engineering Applications of Computational Fluid Mechanics, 2022. 16(1): p. 58-72.

Because the surface roughness, inlet wind speed, wind speed profile, and oncoming wind direction in valley terrain are complex, therefore, as for each initial condition, we considered at least five cases.

 

Point 2: The paper present interest theoretical results but lacks of experimental or onsite date measurements discussion. It would be helpful to discuss briefly the results of the paper with those of this article: “Wang, J., et al., Research on wind field characteristics measured by Lidar in a U-shaped valley at a bridge site. Applied Sciences- 449 Basel, 2021. 11(20): p. 9645. “. Other references might be employed to discuss the results.

Response 2: Thanks for the reviewer’s suggestions. We apologized for our analysis was based on the CFD data, and didn’t compare with experimental or onsite data measurements. As for the article: “Wang, J., et al., Research on wind field characteristics measured by Lidar in a U-shaped valley at a bridge site. Applied Sciences- 449 Basel, 2021. 11(20): p. 9645. ”, that paper was one of our team’s findings. We discussed the wind speed profile type and found the wind direction deflection phenomenon in the U-shaped valley. Due to the field measurement data was recorded about a half year, so the data was limited. Although, there was no comparison analysis, the validation works were done about CFD methodology, so we think the analysis in this paper is reliable.

 

Point 3: Please propose or discuss possible methods to consider terrain influence in the wind for structural project use. CFD sometimes might be costly for some construction projects.

Response 3: Thanks for the reviewer’s suggestions. We had briefly discussed the advantages and disadvantages of those methods in the section 1: introduction.

That is “Research on the wind characteristics of valley is mainly based on field measurements[1, 2], wind tunnel tests[3], and numerical simulations. Although field measurement can directly obtain the wind parameter data at the measured position, it is time-consuming, labor-intensive, and requires huge investment, and the obtained wind parameters are limited in quantity, time, and space. The wind tunnel test is widely used, but there are some problems with the accuracy of feature flow simulation and scale model production. With the development of computer technology and computational fluid dynamics (CFD), numerical simulation is more widely used, and the reliability has been verified [4, 5].”. In the domain of wind field study, especially for the mountainous area, the CFD maybe more convenient and cheaper than others. 

Sometimes, CFD might be costly for some construction projects. We are sorry and we don’t know much about it.

 

 

Point 4: Please discuss briefly the results shown in Figure 10.

Response 4: Thanks for the reviewer’s suggestions. We sincerely apologize for pur careless work.

We added “It could be found that the oncoming wind direction has obvious influence on the wind characteristics, especially, when the oncoming wind direction is 270°, that is blocked by the mountains as shown in Figure 1(a) and Figure 10(b). Therefore, the wind speed、wind attack angle and wind azimuth angle fluctuate strongly in the low height region, such as the height is lower than 2200 m.”

 

In addition, there are minor issues that also must be addressed by the authors:

Point 5: For a better understanding of the paper acronyms use must be more self-explanatory:

1. Avoid using acronyms not defined previously in the abstract.
2. Please check that every acronym employed in the paper are defined, some as the one shown in line 130, “CFL”, have not been defined.

 

Response 5: Thanks for the reviewer’s suggestions. We did some revised in the new manuscript, such as:

1. In abstract, the “CFD” replaced by “computational fluid dynamics (CFD)”, the “AHP” changed to “analytic hierarchy process (AHP)”.
2. As for the CFL, we added its definition in the paper. The Courant-Friedrichs-Levy (CFL) is computed by the solver and used to ensure the success of the simulation.

 

Point 6: Some Figures and Tables are missing or need to be corrected:

1. Figure 3 was not found in the paper.
2. Figure 11: Wind speed is present in two boxes, please distinguish between both by using adjectives such as “inlet”, for example.
3. Table 5: title missing.
4. Table 6: wind direction influence not described and inlet wind speed is present in two columns, please check.

 

Response 6: Thanks for the reviewer’s suggestions.

1. We are sorry for our mistaking write, Figure 3 is located in Lines 128-129.

Figure 3. Schematic diagram of grid and boundary

2. We are sorry for our mistaking write, and we changed the second wrong “wind speed” to “inlet wind speed” the Figure 11, as shown in following.
3. We are sorry for our mistaking write, we added the subtitle of the Table 5(a)-(c).
4. We are sorry for our mistaking write, we modified the last wrong “inlet wind speed” into “oncoming wind direction”.

 

Point 7: The present paper has some typos and some expressions need English improvement, the reviewer lists some of them in the following lines:

1. Lines 59 to 61: names “flared mountain pass crane” and “the junction of the canyon bridge and tunnel” are not clearly understood by the reviewer. The authors might use the same names as the ones employed by the cited reference authors.
2. Line 85: change “analysis” with “analyze”.
3. Line 88: please clarify what are you referring to in “19 working conditions”.
4. Line 103: check “down loaded”, besides the typo might be its batter to change it with “created” or “defined”.
5. Line 230: check “sur face”.
6. Line 282: the following expression “wind speed profile adopts the method” might be improved as follows “wind speed profile adopted follows the shape”.
7. Line 296: “, and the wind speed is taken as 47.87 m/s.” it is repetitive; it has already been mentioned in line 292.
8. Line 343: “wake area” is not understandable, please check.

Response 7: Thanks for the reviewer’s suggestions.

1. We are sorry for our mistaking write, and we modified the description.

As for “flared mountain pass crane” in the reference [14].We changed the “flared mountain pass crane” to “trumpet-shaped mountain pass”.

As for “the junction of the canyon bridge and tunnel” in the reference [15].We changed the “the junction of the canyon bridge and tunnel” to “the canyon bridge-tunnel junction”.

14. Li, J., et al., Buffeting response of a free-standing bridge pylon in a trumpet-shaped mountain pass. Wind and Structures, 2020. 30(1): p. 85-97.
15. Wang, L., X. Chen, and H. Chen, Research on wind barrier of canyon bridge-tunnel junction based on wind characteristics. Advances in Structural Engineering, 2021. 24(5): p. 870-883.
16. We are sorry for our mistaking write, and we modified the “analysis” to “analyze”.
17. We are sorry for our mistaking write, and we explained the “19 working conditions” in detail. the four initial conditions (surface roughness (five working conditions), inlet wind speed (five working conditions), wind speed profile (five working conditions), and oncoming wind direction (five working conditions, but one of it is same as the before)) are considered in turn, and 19 working conditions. That is 5+5+5+4=19.
18. We are sorry for our mistaking write, and we modified the “down loaded” to “created”.
19. We are sorry for our mistaking write, and we replaced “sur face” with “surface”.
20. We are sorry for our mistaking write, and we revised expression “wind speed profile adopts the method” to “wind speed profile adopted follows the shape”.
21. We are sorry for our mistaking write, and we deleted “, and the wind speed is taken as 47.87 m/s.” in Line 296:
22. We are sorry for our mistaking write, the “wake area” is the region with low wind speed and high turbulence characteristics, the region is usually located at the rear of the mountains or buildings.

 

The numbers of the figures and tables were changed in this manuscript, the correction in the text also be done.

 

Thanks for the reviewer’s valuable comments.

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The quality of the manuscript is improved

Author Response

Response to Reviewer 2 Comments

 

 

The quality of the manuscript is improved.

 

 

Response：

Thanks for the reviewer’s valuable comments.

Author Response File: Author Response.docx

Reviewer 3 Report

The present reviewer appreciates author’s responses and updates of the manuscript. However, there are some points that the authors must change before the paper is accepted for publication:

1. The aim of Point 1 of the previous review was to understand why a certain condition in the bridge location was taken as a reference in Figures 5, 6, 8 and 9 (b), (d) and (f), instead of taking as a reference the value of that same parameter before entering the valley. Please justify your decision in few lines.

 

2. There are still some room for use of English improvement. The present reviewer suggests that the authors should review thoroughly the text, and as a guidance gives the following points as examples:

 

1. First abstract sentence (lines 9-11) is too long. Might be better to divide it two shorter sentences for an easier reading.
2. Line 9: check if “midspan” is more appropriate the “middle span”.
3. Line 10: check the expression “wind-resistant of the bridges”. It might be better to employ “wind strength of this structure”.
4. Second abstract sentence (lines 11-13) is not easy to read, please rephrase, the abstract should be clear and easy to read.
5. Sentence between lines 39-41 has no connectors; please rephrase this sentence to make it easier to read.
6. Line 77: “as follows” seems to fit better than “as followed”.
7. Sentence between lines 87-89, please check commas.
8. Line 99: please avoid using double parenthesis.

 

Author Response

Response to Reviewer 3 Comments

 

 

 

The present reviewer appreciates author’s responses and updates of the manuscript. However, there are some points that the authors must change before the paper is accepted for publication:

 

Thanks for the reviewer’s suggestions.

 

Point 1: The aim of Point 1 of the previous review was to understand why a certain condition in the bridge location was taken as a reference in Figures 5, 6, 8 and 9 (b), (d) and (f), instead of taking as a reference the value of that same parameter before entering the valley. Please justify your decision in few lines.

Response 1: Thanks for the reviewer’s suggestions. We are sorry for our unclear description. And we added some sentences in the paper as followed.

As for Figure 5(b), (d) and (f), we took “the condition with the surface roughness of 0 m as the reference condition, and according to Equations (7) – (9), the nondimensional factors were shown in Figure 5(b), (d) and (f).”

As for Figure 6(b), (d) and (f), we took “the condition with the inlet wind speed of 10 m as the reference condition, and according to Equations (7) – (9), the nondimensional factors were shown in Figure 5(b), (d) and (f).”

As for Figure 8(b), (d) and (f), we took “the condition with the wind speed profile of U as the reference condition, and according to Equations (7) – (9), the nondimensional factors were shown in Figure 5(b), (d) and (f).”

As for Figure 9(b), (d) and (f), we took “the condition with the oncoming wind direction of 90° as the reference condition, and according to Equations (7) – (9), the nondimensional factors were shown in Figure 5(b), (d) and (f).”

 

Point 2: There are still some room for use of English improvement. The present reviewer suggests that the authors should review thoroughly the text, and as a guidance gives the following points as examples:

1. First abstract sentence (lines 9-11) is too long. Might be better to divide it two shorter sentences for an easier reading.
2. Line 9: check if “midspan” is more appropriate the “middle span”.
3. Line 10: check the expression “wind-resistant of the bridges”. It might be better to employ “wind strength of this structure”.
4. Second abstract sentence (lines 11-13) is not easy to read, please rephrase, the abstract should be clear and easy to read.
5. Sentence between lines 39-41 has no connectors; please rephrase this sentence to make it easier to read.
6. Line 77: “as follows” seems to fit better than “as followed”.
7. Sentence between lines 87-89, please check commas.
8. Line 99: please avoid using double parenthesis.

 

Response 2: Thanks for the reviewer’s suggestions.

1. We are sorry for our mistaking write, we revised the sentence as followed.

The wind parameter distribution law at a bridge midspan in a U-shaped valley has important influence on the wind strength of this bridges. And the wind characteristics were researched by computational fluid dynamics (CFD).

2. We are sorry for our mistaking write, and we replaced “middle span” with “midspan”.
3. We are sorry for our mistaking write, we replaced “wind-resistant of the bridges” with “wind strength of this bridges”.
4. We are sorry for our mistaking write, we modified the sentence as followed.

“The surface roughness, the inlet wind speed, the wind speed profile, and the oncoming wind direction were selected as the initial conditions, the wind speed, the wind attack angle, and the wind azimuth angle were set as wind parameters, and the effect of the four initial conditions on the wind parameters was comprehensively analyzed.”

5. We are sorry for our mistaking write, we revised those sentence as followed.

“In the other hand, the wind tunnel test is widely used, but there are some problems with the accuracy of feature flow simulation and scale model production. Lastly, with the development of computer technology, computational fluid dynamics (CFD), the convenient operation and lower cost, numerical simulation is more widely used, and the reliability has been verified [4, 5].”

6. We are sorry for our mistaking write, we replaced “as followed” with “as follows”.
7. We are sorry for our mistaking write, we revised the commas again.
8. We are sorry for our mistaking write, we deleted a parenthesis.

 

 

The numbers of the figures and tables were changed in this manuscript, the correction in the text also be done.

 

Thanks for the reviewer’s valuable comments.

 

Author Response File: Author Response.docx