Influence of Longitudinal Joint Setting and Synchronous Cooling Zone on High Altitude Region’s Dam Construction
Round 1
Reviewer 1 Report
The work has an interesting technical-structural and technological aspect. The article, although narrowed to hydropower dam structures, deals with the basic problems of massive concrete structures. Scientific and technical issues are related to concrete, its composition, forming and care, shrinkage, creep, cracking, etc. are the essence of the work of any civil engineer or scientist. While only numerical analyses have been carried out in the article, they apply to structures that have already been built and can be of great value in the design of new concrete dams.
One important point needs clarification by the authors. Tables 1 and 2 and Figures 1, 2, 10 and 11 are identical or very similar to the tables and figures presented in the article: Temperature Control Measures and Temperature Stress of Mass Concrete during Construction Period in High-Altitude Regions (Advances in Civil Engineering, 2018). There is no citation of this article in the currently reviewed work. It seems necessary that, in this article, it is better to indicate what has been borrowed from other research, what is some common part of past and present research, what, if any, are the differences. It may simply be difficult for the reader to discern what part of the results are related to the JX dam, for example, and what is related to the ZM dam.
Nevertheless, I think that after explaining the analyzed problem more fully, presenting more extensive results of performed numerical experiments, the article could be reviewed again and probably accepted.
I attach the detailed comments below:
- line 41-43: Liao - what item of literature? The last sentence (42-43) of the paragraph is unclear
- Formula (1): the member of the left side of the equation is the derivative of the temperature after time, so it should be ¶T/¶t
- line 61 and 95: the coefficient a has two different meanings (formula 1 and 8)
- line 74: what exactly are the meanings of the symbols Ri and Ki
- in formula (4), the fourth component is incorrectly described DPSi
- in formula (6), no description of symbols D and B
- line 97: should be T0
- Section 2.5: Specify in which finite element method program the numerical analyses were performed: author's or commercial. Lack of information about the parameters of the boundary conditions assumed in the numerical model.
- Figure 1 and 3: please add a sketch of the coordinate system with description
- line 164: instead of 2.5.2 it should be 2.5.3
- line 171: explain the meaning of the dimension 3263 m
- Figure 4: please indicate on the drawing the location of joints in the structure
- line 186: a better term for "construction unit" would be, for example, section component or structural component
- line 194-197: no spaces or unnecessary spaces (e.g. 26.3°C)
- Figure 6: unreadable descriptions
- Section 3.3: This chapter clearly lacks an analysis that would confirm the final solution adopted. It might have been possible to make modifications to the model and, for example, propose 2 or 3 other joint locations and show their effect on temperature and stress distribution.
- line 229-230, suggestion of better phrase: Therefore, the proposed position of the longitudinal joints system is reasonable and can meet the safety needs of the project.
- Figure 9 and 10: unreadable descriptions
- Section 3.4: It is not explained how the temperature measurement (point, linear, area?) of a given layer of concrete is carried out and how the cooling of the concrete is taken into account in the numerical model - the description given is incomprehensible.
How do the heights of the synchronous cooling zones presented in the article (scheme 1-3) relate to realistic concreting conditions? What would be observed if layer thicknesses were reduced to, say, 3-4 meters?
Author Response
Reviewer :
- Comment: One important point needs clarification by the authors. Tables 1 and 2 and Figures 1, 2, 10 and 11 are identical or very similar to the tables and figures presented in the article: Temperature Control Measures and Temperature Stress of Mass Concrete during Construction Period in High-Altitude Regions (Advances in Civil Engineering, 2018). There is no citation of this article in the currently reviewed work. It seems necessary that, in this article, it is better to indicate what has been borrowed from other research, what is some common part of past and present research, what, if any, are the differences. It may simply be difficult for the reader to discern what part of the results are related to the JX dam, for example, and what is related to the ZM dam.
Response: thank you .Both articles have studied the same hydropower station, so the concrete parameters mentioned in the table are the same. However, this paper studies the overflow dam section of the hydropower station, and another article studies the bank slope dam section.Figure 10 introduces the formation process of temperature gradient zone in the foundation constraint zone. Since the two articles analyze the same hydropower station, the process flow is basically the same. According to your opinion, we have quoted this article.The results of this paper are all about JX dam, but it is mentioned in a paragraph that the dam body of JX dam is similar to that of ZM dam. According to the experience of ZM dam, longitudinal joints are added.
- Comment:- line 41-43: Liao - what item of literature? The last sentence (42-43) of the paragraph is unclear
Response: Thank you very much The literature of Liao cited in the article is numbered in line 43.
（However, the cooling water pipe was not used in this project [15]）
3.Comment:- Formula (1): the member of the left side of the equation is the derivative of the temperature after time, so it should be ¶T/¶t
Response: Thank you ,you are right.We have corrected this mistake.
4.Comment:- line 61 and 95: the coefficient a has two different meanings (formula 1 and 8)
Response: Thank you very much, a in both places should have the same meaning, but we made a mistake in expression, and we have corrected it.
5.Comment:- line 74: what exactly are the meanings of the symbols Ri and Ki.
Response:You are right.There are some deficiencies in this article, and we have corrected this mistake.
6.Comment:- in formula (4), the fourth component is incorrectly described DPSi
- in formula (6), no description of symbols D and B
- line 97: should be T0
Response: Thank you ,we have correcter these mistakes.
7.Comment:-- Section 2.5: Specify in which finite element method program the numerical analyses were performed: author's or commercial. Lack of information about the parameters of the boundary conditions assumed in the numerical model.
Response: Thank you very much. We have added paragraphs introducing the software package.
8.Comment:- Figure 1 and 3: please add a sketch of the coordinate system with description
- line 164: instead of 2.5.2 it should be 2.5.3
- line 171: explain the meaning of the dimension 3263 m
- Figure 4: please indicate on the drawing the location of joints in the structure
- line 186: a better term for "construction unit" would be, for example, section component or structural component
- line 194-197: no spaces or unnecessary spaces (e.g. 26.3°C)
- Figure 6: unreadable descriptions
- Figure 9 and 10: unreadable descriptions
- line 229-230, suggestion of better phrase: Therefore, the proposed position of the longitudinal joints system is reasonable and can meet the safety needs of the project.
Response: Thank you for your suggestions. We have noticed these problems.We have modified the picture and some content problems according to your opinions. We have added the required spaces, but some journals require adding spaces before the unit in the format.
9.Comment:- Section 3.3: This chapter clearly lacks an analysis that would confirm the final solution adopted. It might have been possible to make modifications to the model and, for example, propose 2 or 3 other joint locations and show their effect on temperature and stress distribution.
Response:Thank you very much .We have added paragraphs confirm the final solution adopted in 3.3.The location of longitudinal joints shall be determined according to the structural characteristics and functions of all dam sections of the whole project, taking into account the retaining dam section, powerhouse dam section and overflow dam section. The position selection should be reasonable, so the longitudinal joint position cannot be selected at will.
10.Comment:- Section 3.4: It is not explained how the temperature measurement (point, linear, area?) of a given layer of concrete is carried out and how the cooling of the concrete is taken into account in the numerical model - the description given is incomprehensible.
Response:Generally, the average value of the temperature in the middle of each bin in the same cold zone. It is mainly to determine the temperature of a certain position by points Concrete cooling is to bury water pipes when pouring concrete, and take away the hydration heat through the flow of cooling water in the water pipes, so as to reduce the concrete temperature. The cooling effect is controlled by the water temperature, flow and water duration, so as to achieve the effect of reducing temperature stress; The timely and reasonable water supply mode needs to be determined through simulation calculation.
11.Comment:How do the heights of the synchronous cooling zones presented in the article (scheme 1-3) relate to realistic concreting conditions? What would be observed if layer thicknesses were reduced to, say, 3-4 meters?
Response:When pouring concrete, it is poured in layers, generally 3M a layer, and the synchronous cold zone generally includes 3 layers of concrete, and the pouring interval is considered at the same time; If the thickness of the cold zone is reduced to 3-4m, the deformation coordination between the cooling zones is weakened, which is not conducive to crack prevention.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The work entitled Influence of Longitudinal Joint Setting and Synchronous Cooling Zone on High Altitude Region's Dam Construction presents a series of deficiencies that do not allow its acceptance in its current state.
-Eq. 1, the equations are described in terms of time "t" and the equation uses (tau).
-Eq. 3 does not describe the term Ki, and the other factors are listed out of order.
-Matrices D and B, and terms epsilon^c, epsilon^t, epsilon^s are not described.
-The expression: negative heat source, is not considered correct.
-In line 95 "a" was written but (alpha) was described,
-∇T temperature increase? in Eq. 8... this description is not correct.
-the units in several equations are not compatible... (day is used and other quantities are expressed in hours, check also units shown for heat transfer coefficients...)
-The definitions shown from line 253 cannot be included in the results of the job.
-A complete revision of the work is recommended
Author Response
Reviewer :
- Comment: 1, the equations are described in terms of time "t" and the equation uses (tau).
Response: Thank you,We have changed back to 't'.
- Comment: 3 does not describe the term Ki, and the other factors are listed out of order.
Response: Thank you very much,We have added a few descriptions.
- Comment:-Matrices D and B, and terms epsilon^c, epsilon^t, epsilon^s are not described.
Response:Your help was very much appreciated.We have corrected this mistake.
- Comment:The expression: negative heat source, is not considered correct.
Response:Thank you,We have changed it to 'heat absorbing medium'. Do you think it is appropriate.
5.Comment:-In line 95 "a" was written but (alpha) was described
Response:Thank you very much,we have corrected this mistake.
6.Comment:∇T temperature increase? in Eq. 8... this description is not correct.
Response:Thank you for your suggestion, here ∇T refers to the added value of temperature.
7.Comment:the units in several equations are not compatible... (day is used and other quantities are expressed in hours, check also units shown for heat transfer coefficients...)
Response:Your help was very much appreciated.We have corrected this mistake.
8.Comment:The definitions shown from line 253 cannot be included in the results of the job.
Response:Thank you,we have placed the segment in a more suitable position.
Author Response File: Author Response.docx
Reviewer 3 Report
This topic is quite good, discussing one solution to prevent temperature cracking in the High Altitude Regions Dam Construction. However, the publication still needs some improvements, including:
Line 181-182, In the sentence “Stress will be decreased; moreover, the scheme of …… ” is this sign (;) correct
Line 183-184, you wrote “The concrete material parameters of JX dam are unfavorable to the temperature control and crack prevention of the dam, and the safety degree is lower than that of ZM dam.” I don't agree with this sentence. How the parameters of concrete materials are considered unfavorable, even though this paper discusses solutions to prevent concrete cracking and considering that the majority of concrete materials are used in DAM construction. Please correct this sentence according to the context
Line 204, Figure 6. If seen in Figures 6 (a) and (b) shows that when the temperature decreases, the stress increases and the risk of cracking occurs. And the logic beyond this problem, when the concrete is exposed to hot temperatures usually cracks occur, and the surface tension of the concrete increases. Please explain with a more in-depth explanation of this problem.
Line 303. Conclusion no 2, I agree with the sentence “Setting the longitudinal joint in the middle of length direction at the bottom of the dam can significantly reduce the temperature stress along the river, lower the possibility of cracking, and increase the mass concrete structure's crack resistance". Please explain the problem of temperature, stress, and cracking in more detail and depth in the discussion of section 3.1 or 3.1
Figure 2, The drawing lines are not clear
Figure 5, The drawing lines are not clear
Figure 9, The drawing lines are not clear
Figure 10, The drawing lines are not clear
Lines 310-311. “Meanwhile, the larger the synchronous cooling zone's height, the more favorable it is to reduce the temperature stress,”. If we look at Figure 11 (b), with increasing time the Height of synchronous cooling zone (Scheme 1) has a tendency for the voltage to decrease when compared to schemes 2 and 3. Why is that? Which scheme is the best?
Comments for author File: 
Comments.pdf
Author Response
Reviewer :
- Comment:Line 181-182, In the sentence “Stress will be decreased; moreover, the scheme of …… ” is this sign (;) correct
Response: Thank you very much.We have changed to (;)
- Comment:Line 183-184, you wrote “The concrete material parameters of JX dam are unfavorable to the temperature control and crack prevention of the dam, and the safety degree is lower than that of ZM dam.” I don't agree with this sentence. How the parameters of concrete materials are considered unfavorable, even though this paper discusses solutions to prevent concrete cracking and considering that the majority of concrete materials are used in DAM construction. Please correct this sentence according to the context
Response:Thank you very much for your advice, and we have provided a supplementary description of this issue,he data shows that the material properties of JX dam body are very different from those of ZM. For example, the adiabatic temperature rise of JX concrete is more than 3 ℃ higher than that of ZM, and the linear expansion coefficient is about 1.22 times that of ZM, but the elastic modulus and tensile strength are equivalent to that of ZM. These parameters are closely related to temperature control, so the material parameters of JX are relatively unfavorable to crack prevention, and the difficulty of temperature control is greater than that of ZM.
- Comment:Line 204, Figure 6. If seen in Figures 6 (a) and (b) shows that when the temperature decreases, the stress increases and the risk of cracking occurs. And the logic beyond this problem, when the concrete is exposed to hot temperatures usually cracks occur, and the surface tension of the concrete increases. Please explain with a more in-depth explanation of this problem.
Response:Your question is very valuable.Generally, objects have the characteristics of thermal expansion and cold contraction. When the object is exposed to high temperature, it will expand. If the expansion is restrained or resisted by surrounding objects, it will cause structural damage, but not temperature stress. When it reaches high temperature and then decreases, the object begins to shrink. Constrained by the surrounding objects, it is easy to produce tensile stress, so it cracks. This is temperature stress.
- Comment:Line 303. Conclusion no 2, I agree with the sentence “Setting the longitudinal joint in the middle of length direction at the bottom of the dam can significantly reduce the temperature stress along the river, lower the possibility of cracking, and increase the mass concrete structure's crack resistance". Please explain the problem of temperature, stress, and cracking in more detail and depth in the discussion of section 3.1 or 3.1
Response:Thank you very much for your suggestion.The greater the cooling range, the greater the shrinkage of concrete, the greater the temperature stress, and the easier it is to crack; The longer the structure size is, the stronger the constraint of the foundation is. Under the same shrinkage, the greater the temperature stress is, and the easier it is to crack. Therefore, in engineering, the temperature stress is generally reduced by reducing the cooling range and reducing the constraints to prevent cracking.
- Comment:Figure 2, The drawing lines are not clear;Figure 5, The drawing lines are not clear;Figure 9, The drawing lines are not clear;Figure 10, The drawing lines are not clear
Response:Your help was very much appreciated.We have replaced the pictures
- Comment:Lines 310-311. “Meanwhile, the larger the synchronous cooling zone's height, the more favorable it is to reduce the temperature stress,”. If we look at Figure 11 (b), with increasing time the Height of synchronous cooling zone (Scheme 1) has a tendency for the voltage to decrease when compared to schemes 2 and 3. Why is that? Which scheme is the best?
Response:Thank you very much.The overall trend of the three schemes is the same, and schemes 2 and 3 also have a downward trend, but the date in the figure is only March 26th, 2019, and the overall alignment is not fully displayed. Therefore, scheme 3 is the smallest σmax with the highest safety factor, which is the optimal scheme.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
I thank the Authors of the article for their detailed response to all my comments. I am fully satisfied with the answers provided and the corrections made to the content and figures of the reviewed article. I approve its revised form, under the small condition that the Authors correct the description of the authors of articles 13-17 and provide the name and journal number of article 23 (References).
I wish You interesting ideas and more successful scientific research.
Reviewer 2 Report
Once the suggested modifications have been implemented, I give my favorable opinion to the publication of the article entitled Influence of Longitudinal Joint Setting and Synchronous Cooling Zone on High Altitude Region’s Dam Construction in Applied Sciences
