Comparative Study on Shaking Table Tests for a Pile–Nuclear Island Structure under Different Soil Conditions
Round 1
Reviewer 1 Report
In this research article, the authors have performed the shaking table tests in medium soft and hard base soil to find out seismic-soil-pile-superstructure-interaction. The article is interesting and may be useful for the readers of the scientific society. Please find my review comments below;
1. The introduction part is not properly written. The authors should study more research papers related to the study.
2. Line no. 124-125, the bearing capacity of the shaking table system is defined as 3 x 104 kg. Please re-check.
3. Line no. 173-174, the size of the model baseplate is consistent with those of the pile cap, and four high-strength bolts are used in the four corners of the base plate to connect with the pile cap. Incorporate this by adding a picture of the setup at the test site.
4. Line no. 187-189, is the dynamic response of pile #4 under horizontal load monitored using the sensors?
5. In Figure 8, the authors discussed the fourth layer. Are layers being defined?
6. The authors have performed the experimental tests and presented them appropriately in the research article. However, the validation of the results with the numerical three-dimensional analysis or with the results previously published in the literature has not been done. Suggest validating.
7. References are to be re-checked thoroughly.
It may be improved.
Author Response
Dear Reviewer,
Thank you very much for reviewing the manuscript. Below are individual responses to your suggestions and comments:
Q1: The introduction part is not properly written. The authors should study more research papers related to the study.
A: There are indeed few references in the original manuscript. The author has made corresponding supplements.
Q2: Line no. 124-125, the bearing capacity of the shaking table system is defined as 3 x 104 kg. Please re-check.
A: Thank you for your reminder. The bearing capacity is 3 x 104 kg (30 t). The author has made modifications in the manuscript.
Q3: Line no. 173-174, the size of the model baseplate is consistent with those of the pile cap, and four high-strength bolts are used in the four corners of the base plate to connect with the pile cap. Incorporate this by adding a picture of the setup at the test site.
A: The author has added photos of the shaking table test to the manuscript.
Q4: Line no. 187-189, is the dynamic response of pile #4 under horizontal load monitored using the sensors?
A: Due to the fact that pile #4 and #2 are located in symmetrical positions regarding the direction of seismic motion input, and the test model is also symmetrical about the direction of seismic motion input, It can be considered that the seismic response of Pile #4 is similar to that of #2. In the test, part of sensors were installed on pile #2 to obtain its seismic response.
Q5: In Figure 8, the authors discussed the fourth layer. Are layers being defined?
A: The author has added description of the positions of each layer to the manuscript.
Q6: The authors have performed the experimental tests and presented them appropriately in the research article. However, the validation of the results with the numerical three-dimensional analysis or with the results previously published in the literature has not been done. Suggest validating.
A: The author has added relevant numerical simulation analysis to the manuscript and verified the experimental results.
Q7: References are to be re-checked thoroughly.
A: The author has checked the references in the manuscript carefully.
The manuscript has been revised to be more reasonable and rigorous according to your helpful suggestions and comments. The author expresses his gratitude to you once again.
Sincerely,
Author
Reviewer 2 Report
The manuscript presents “Comparative Study on Shaking Table Tests for Pile-Nuclear Is- 2 land Structure under Different Soil Conditions”. The topic is good, the paper is well organized and presented an interesting study. This reviewer would like to suggest the following for further possible improvement of the paper.
1. Why the “comparative analysis” of the behavior under medium soft and hard soil site conditions are need? Important of this, and use of the comparative analysis to the advancement of knowledge in this field of study, needs more explanation
2. Figure 2, Figure 3: what are the units of dimensions
3. Shear wave velocities of the medium soft and hard soil are 175 m/s and 300 m/s , However, the shaking table is having a capacity of a maximum velocity of 1.5 m/s. Better to explain how possible wave velocity can be simulated in the shaking table.
4. What are the characteristics of selected wave form? Are they real earthquake recordings?. It is suggested to include them in a Table.
5. This is the Shaking Table Tests for Pile-Nuclear Island Structure under Different Soil Conditions. Why this study is specifically for Pile-Nuclear Island Structure is not clear from the methodology. Can the current study be a general pile, which would have been driven in ground?
6. Current laboratory study is for scaled down pile. Can the findings be directly utilize for real structure, which would be larger, in dimensions. Any care needs to take, when applying the findings? needs explanation and justifications
Author Response
Dear Reviewer,
Thank you very much for reviewing the manuscript. Below are individual responses to your suggestions and comments:
Q1: Why the “comparative analysis” of the behavior under medium soft and hard soil site conditions are need? Important of this, and use of the comparative analysis to the advancement of knowledge in this field of study, needs more explanation.
A: The stiffness ratio between soil and pile is a very important influence factor of the seismic soil-pile-superstructure interaction, so a comparative study was conducted. The description has been added to the manuscript.
Q2: Figure 2, Figure 3: what are the units of dimensions.
A: The units of numbers in Figure 2 and Figure 3 are millimeter. The description has been added to the manuscript.
Q3: Shear wave velocities of the medium soft and hard soil are 175 m/s and 300 m/s , However, the shaking table is having a capacity of a maximum velocity of 1.5 m/s. Better to explain how possible wave velocity can be simulated in the shaking table.
A: The wave velocity of a soil layer represents its hardness. In the shaking table test, the wavelength can be reduced by increasing the frequency of the input seismic motion, which means shortening the time of the seismic motion according to the relation between wavelength, wave velocity, and frequency. However, due to the inability to satisfy the similarity relation strictly, there is only a qualitative discussion in the manuscript, and no time compression was performed on the input seismic motion.
Q4: What are the characteristics of selected wave form? Are they real earthquake recordings?. It is suggested to include them in a Table.
A: The selected RG1.60 wave is not a real seismic record, but an artificial seismic motion fitted according to the design response spectrum. This seismic motion has more high-frequency components (10-20 Hz) compared to general natural seismic motions. The description has been added to the manuscript.
Q5: This is the Shaking Table Tests for Pile-Nuclear Island Structure under Different Soil Conditions. Why this study is specifically for Pile-Nuclear Island Structure is not clear from the methodology. Can the current study be a general pile, which would have been driven in ground?
A: Compared to general building structures, nuclear islands have greater mass and stiffness. Therefore, the impact of nuclear islands on the seismic response of their pile foundations may be different from that of general building structures. Considering the importance of nuclear islands and the potential significant harm after damage, it is necessary to conduct research on their seismic performance. When making the superstructure model, the mass and stiffness of the model were increased, which can represent the nuclear island. The description has been added to the manuscript.
Q6: Current laboratory study is for scaled down pile. Can the findings be directly utilize for real structure, which would be larger, in dimensions. Any care needs to take, when applying the findings? needs explanation and justifications.
A: Due to limitations in the size of the shaking table, reduced piles were used in the test. Since the dynamic similarity relation of all variables cannot be satisfied strictly in the shaking table test of soil-structure dynamic interaction, the nuclear island and its pile foundation are only designed based on geometric similarity. The conclusions obtained from the test can provide qualitative references for the practical engineering.
The manuscript has been revised to be more reasonable and rigorous according to your helpful suggestions and comments. The author expresses his gratitude to you once again.
Sincerely,
Author
Round 2
Reviewer 1 Report
The authors have incorporated all the review comments. The article may be accepted for publication.
It can be improved.
