Research on the Seismic Isolation Effect of the Ring Spring–Friction Pendulum Bearing in the Dakai Underground Subway Station
Round 1
Reviewer 1 Report
This article describes seismic soil structure impact and methods to understand in columns (vertical and horizontal) in underground subway stations. This study is very important for cities operating in a earthquake frequent zones and trying to expand its public transportation in order to curb global emissions caused by automobiles. The article is timely and well written, I would recommend its publication with some minor comments.
Some previous works need to be cited in this manuscript such as the patent for the seisemic control pendulum Application CN201510440267 , paper regarding the similar topic Ou et al Appl. Sci. 2020, 10(22), 8235, Jia et al etc. and seminal paper by P.M. Calvi et al. Soil Dynam Earthq Eng (2018) should be cited in introduction.
The methods are adequately described, however the assumption behind the modeling is not stated properly. Authors are suggested to make a separate paragraph regarding the assumptions made in the modeling regarding the pendulum method.
This method is already patented and used in some constructions; authors should be very specific about the novelty of these studies.
Figure 18 is very important and carried out nicely, good job on that. However, figures are not chronologically set, please rearrange that
Table 3 is not clearly explained in the manuscript, suggesting expanding more on the condition and the data correlation
Author Response
The responses to the reviewers are in the uploaded file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article entitled "Research on Seismic Isolation Effect of Ring Spring–Friction Pendulum Bearing in the Underground Subway Station" proposed to analyse the effect of combined devices (ring spring and friction pendulum). The topic is interesting, but the proposed study needs to be further investigated to gain general perspectives on the use of this device.
- The references in the introduction should be replaced by the original works (for instance, for the friction pendulum and the ring spring system).
- The analyse of a damped single degree of freedom system seems to be classical and can be found in textbooks on vibration of structures. It may not be necessary to discussed in detail this point. In contrary, the complexity and the specificity of the proposed device needs to be addressed. It seems this complexity is very roughly approximated by the authors by considering a equivalent spring. Why do the authors not consider or at least compare the stiffness evaluated with the finite element model of Figure 6 with the simplified formula?
- Numerically, how the contact and friction are managed? The numerical part (integration scheme, numerical tools to tackle contact problems, ...) should be detailed.
- The references associated with the material model should be given. The parameters used for the study as well.
- Do the authors have performed a convergence analysis concerning the mesh? The mesh in Figure 5 seems to be very rough.
- How have the authors take into account the soil and the soil-structure interaction?
- What kind of regularization technic has been considered by the authors to manage the softening response of the damage model?
- Is the damage variable used in Figure 14? If it is the case, how to explain in the color bar negative values and values higher than one?
Author Response
The responses to the reviewers are in the uploaded file
Author Response File: Author Response.pdf
Reviewer 3 Report
Please refer to the attached review report.
Comments for author File: Comments.pdf
Author Response
The responses to the reviewers are in the uploaded file
Author Response File: Author Response.pdf
Reviewer 4 Report
I have reviewed the manuscript entitled “Research on Seismic Isolation Effect of Ring Spring–Friction Pendulum Bearing in the Underground Subway Station” submitted to Applied Science journal. This paper compares the performance of Dakai subway equipped with ring spring–friction pendulum bearing with other available base-isolation techniques. On the plus side, the importance of this subject is clear to the target community, while there are some bottlenecks mostly related to FE modeling, ground motion selection as well as some other minor issues. Hence, this manuscript needs a major revision and the authors are recommended to address the following comments:
1. Can you concise abstract? It’s a little bit long!
2. In literature review, there are a wide range of studies which are not indexed in WoS. For example, the parameters of Table 1 are derived from Ref 21 published in “Journal of Disaster Prevention and Mitigation Engineering” journal. It is of prime importance to enrich this study by papers from WoS-indexed English language journals. Hence, the authors are recommended to so something in this regard.
3. A major concern: I would like to express my concern regarding the seismic excitations. More specifically, please explicitly mentioned that “how strong” are the applied motions as follows?
i) What are their return period.?
ii) Did you scale the ground motions to match a target spectrum? Please provide a detailed explanation.
iii) According to Figure 7, given that the PGAs are about 0.25 and 0.35 g, it seems they are not strong enough for the entire simulations. So, there is a BIG question regarding the reliability and trustworthiness of the whole manuscript.
4. Since record-to-record variability is not addressed here, there exists another problem, which can be neglected due to the high computational cost of simulations. To mention this issue and provide a context for future studies you can add https://doi.org/10.1016/j.ress.2022.108402. This study proposed a novel artificial intensifying accelerator for seismic analysis/design of infrastructures in an efficient way.
5. In line 162: “The concrete in the station uses the plastic damage model in Abaqus”. Which damage plasticity model, i.e., constitutive model, is used? The authors are asked to provide a full representation of their FE model.
6. The applied demand parameters are limited to displacement, force and pressure. Given that Abaqus can provide interesting damage metrics such as Plastic strain equivalent (PEEQ), it is highly recommended to add this metric and other advanced ones (NOT mandatory).
7. The findings in the conclusion part should be limited to this study. Please add the scope and limitation of this study.
8. The respected authors are asked to address the following typos and minor issues (Please double-check the whole manuscript for other potential problems):
Use space after the period and before references. There are a long list of typos:
-Line 19: “30%.In addition by”
-Line 51: “underground structures[6].”
-Line 75: “have better anti-overturning effect.[11]”
-Line 200: “Figure.9(b).In order to simulate the”
-Line 361: “(2)By comparing the seismic isolation”
- …
Author Response
The responses to the reviewers are in the uploaded file
Author Response File: Author Response.pdf
Round 2
Reviewer 4 Report
In this round, the manuscript is proper to publish in this journal.
