Seismic Response Analyses of a Large-Span Powerhouse Cavern Considering Rock–Structure Interaction
Round 1
Reviewer 1 Report
The paper carries out numerical modeling of powerplant cavern under seismic conditions using a software set Midas-GTS. The explanation of the original hydraulic fracture test for stress of in situ state is suggested. Also the demonstration of the principal stresses in 3D surrounding the cavern needs to be provided to better understand the stress contours shown in the current version.
Author Response
Response: Thanks for sparing time to review the manuscript. We completely agree with the Reviewer that the in situ stress state is a key factor determining the seismic response characteristics of the large span powerhouse cavern of concern, which constitutes the initial condition of the time matching dynamic analyses using FEM. However, A complete description of the determination on the in situ stress state is beyond the scope of this paper. References are thereby given (ISRM, 2003; Barla et al., 2008). For details the reader is referred to the given reference.
Reviewer 2 Report
The manuscript is overall interesting. However, some issues are found throughout the paper. Therefore, according to this Reviewer, a major revision would be necessary before the paper can be further considered for possible publication in Applied Sciences. All details are summed up in the following.
Required changes:
- Originality/novelty of the study proposed. This issue is very important and should be better clarified and well highlighted in the text.
- Despite understandable, English needs some improvements.
- Introduction is too short and should be extended. As performance analyses have been performed in the manuscript, a discussion about the performance-based approach should also be included. To help the authors in this aspect, some helpful references are suggested at the end of this report [1, 2].
- Details about the location of the considered hydroelectric plant should be provided.
- Section 4: details about the constitutive model employed to perform the analysis should be provided.
- The application is interesting. However, the authors should clearly point out how this application could be useful for the reader.
- Quality of figures is quite poor and should be enhanced.
- The number of references is not suitable for a scientific paper. More references are required, especially in the introduction.
REFERENCES
[1] Tiwari, R., Lam, N. Displacement based seismic assessment of base restrained retaining walls. Acta Geotech. (2022). https://doi.org/10.1007/s11440-022-01467-y
[2] Conte, E.; Pugliese, L.; Troncone, A. Earthquake-induced permanent displacements of embedded cantilever retaining walls. Géotechnique (2022). https://doi.org/10.1680/jgeot.21.00221
Author Response
Response: Thanks for sparing time to review the manuscript. We appreciate the positive comments. We have carefully addressed all the comments in this response as well as in the revised manuscript. Our responses are summarized as follows.
- Originality/novelty of the study proposed. This issue is very important and should be better clarified and well highlighted in the text.
Response: The novelty of the study proposed has been highlighted in the Lines 51-66.
- Despite understandable, English needs some improvements.
Response: As suggested, a detailed editing has been done through the manuscript by the authors, in order to correct grammatical errors and improve the readability of the manuscript.
- Introduction is too short and should be extended. As performance analyses have been performed in the manuscript, a discussion about the performance-based approach should also be included. To help the authors in this aspect, some helpful references are suggested at the end of this report [1, 2].
Response: We appreciate the instructive comment. The Introduction has been extended by including the performance-based approach, where the two important papers have been cited to offer a complete view of the state of the art.
- Details about the location of the considered hydroelectric plant should be provided.
Response: The location of the considered hydroelectric plant has been given in the Lines 68-69.
- Section 4: details about the constitutive model employed to perform the analysis should be provided.
Response: The Hoek-Brown model is employed to simulate the behavior of rock mass. The HB model is very general for rock mechanics and rock engineering, just like Mohr-Coulome model for soil mechanics. A complete description of the HB model is beyond the scope of this paper. A reference is thereby given. For details the reader is referred to the given reference (Hoek & Brown, 1997).
- The application is interesting. However, the authors should clearly point out how this application could be useful for the reader.
Response: As suggested, the practical relevance is highlighted in the Conclusions (Please see Lines 323-332).
- Quality of figures is quite poor and should be enhanced.
Response: The quality of figures has been enhanced.
- The number of references is not suitable for a scientific paper. More references are required, especially in the introduction.
Response: As suggested by the Reviewer, the Introduction has been extended and more references have been included.
Reviewer 3 Report
This manuscript tends to investigate the seismic response of a large span powerhouse cavern considering rock-structure interaction. By going through the whole manuscript, it is not suitable for publication in “Applied Sciences” due to the following major issues.
1) This manuscript is more like a report than a research article.
2) The novelty of the findings is very limited.
3) The introduction is too simple.
4) The description of rock-structure interaction in the FEM model is not clear.
5) The nonlinearity of the complete model is not considered
6) The rule for determining the design response spectrum is not clear.
Author Response
Response: Thanks for sparing time to review the manuscript. We appreciate the comments. We have carefully addressed all the comments in this response as well as in the revised manuscript. Our responses are summarized as follows.
- This manuscript is more like a report than a research article.
Response: Major revision has been made to enhance the quality of the manuscript.
- The novelty of the findings is very limited.
Response: The novelty of the findings has been highlighted in Line.
- The introduction is too simple.
Response: The Introduction has been extended, where more recent papers have been cited to offer a complete view of the state of the art.
- The description of rock-structure interaction in the FEM model is not clear.
Response: Detailed description of rock-structure interaction in the FEM model has been added in Lines 226-229, as well as the reference (Day & Potts, 1994).
- The nonlinearity of the complete model is not considered.
Response: The implicit modified Newton-Raphson method in Midas/GTS code is used to capture the nonlinearity of the complex rock-structure system, in which the tangent stiffness is updated in each time step based on deformation (Midas-GTS, 2010).
We give the statement in the Lines 218-222.
- The rule for determining the design response spectrum is not clear.
Response: The design response spectrum is determined according to EUROCODE 8. We give the statement in the Lines 205-208, as well as the reference.
Round 2
Reviewer 2 Report
The replies provided by the Authors are sufficient to address the comments previously raised by this Reviewer. Accordingly, this Reviewer believes that the manuscript can be now considered for pubblication.
Reviewer 3 Report
The authors have successfully addressed the comments and the manuscript can be recommended for publication.
