Seismic Vulnerability Assessment and Strengthening Interventions of Structural Units of a Typical Clustered Masonry Building in the Campania Region of Italy

Round 1

Reviewer 1 Report

Dear authors:

Your paper is well presented, easy to read, clear and well organized. Figures and graphs are of good quality. The chosen case study is very interesting and useful, since it is a typical construction of the area and the conclusions could extrapolated to other cities.

I have some comments for you:

-In the introduction section, as well in the Conclusion section or in the rest of the text, I cannot see clearly what innovation you present in this paper. Could you please provide this information?

-The reference #17 ( Chieffo, N.; Formisano, A,. 2019) is a research of yours which present several similarities with the paper at hands. Could you provide more details about their relationship, please? Is this new research a continuation? Is this new research a study in another city to test the methodology presented in the previous one? Are both papers part of the same research project with different study areas? Please, provide the context in which both works have been done to help the readers understand the differences and similarities between both papers. 

-References to other authors and other Mediterranean countries with similar constructions are missing. The national context is well presented (similar studies in Italy); however, the study is not compared to other international cases.

-What are the implications of the results (lines 209-213; 225-229; 246-250, 279-284)? Are they what you were expecting, or they are surprising in any way? Are there other studies with which you can compare? Please, comment on this.

-Results in figure 13: Could you compare the fragility curves of c) with those of e); and the curves of d) with f)? It would be interesting to explain how the intermediate and head SUs perform similarly in aggregated condition (c and e); but the head SU is expected to suffer higher damage than the intermediate SU when analyzed in isolated condition (d and f).

-In figure 10 caption, you refer to the curves with letters a, b, c. This might be confusing since these letters do not appear in the graphs. Same for figure 11.

-The reference #22, mentioned in line 292, is not included in the References list.

-Any reference to the fragility curve concept is missing in section 4.3.

-Some typos probably in lines 68, 127, 176 (SUs), 219 (reaching?).

Author Response

Replies can be found in the attached file.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript deals with the seismic vulnerability assessment and retrofitting of masonry buildings, with application to a clustered building in the Campania Region. The study on the seismic behaviour of adjacent masonry buildings is pertinent and well introduced, and the case study is suitably presented. In any case, the novel contributions of the work should be further highlighted, when compared with similar works. The manuscript is in general well structured and written. The results are interesting, but there are some aspects that should be clarified and further discussed. Specific comments are provided below. The conclusions should include some quantitative indicators related to the aggregate effect.

1. The writing has room for improvement, e.g. in line 65 ‘SUs that can estimate’, and in line 68 ‘buildings that must be consider studying’. Please revise it carefully.
2. Line 119: ‘γM used for the structural analysis has been assumed equal to 2.5’. This applies also to pushover analysis since, in that case, γM is normally taken equal to 1? Are the reported values of mechanical parameters the ones before or after the application of FC and γM?
3. When reference is made to Figs. 4-7, the difference between a structural unit in aggregate and isolated conditions is not so clear. It is explained later but should be clear from the start.
4. Section 3: The modelling approach in 3Muri and the developed numerical models can be further explained and illustrated. Not so clear what the rotational period, T3, is?
5. Figs. 10-11: The worst analysis scenarios are not identified either in the text or in captions. Why reason the curves for the whole-aggregate and isolated configurations are different among the two figures? Maybe it is related to the corresponding analysis scenarios.
6. Caption of Table 2: Explain the definition of ‘Safety risk index’. Maybe risk is not a suitable term.
7. Fig. 11: It is strange that the stiffening of floors has no influence on the stiffness of the buildings. Rigid floors may be an issue/factor when considering the dynamic effects; please discuss. Improve the layout of Figs. 11-12.
8. Caption of Fig. 12: ‘Masonry retrofitting solutions’ is not a fit terminology. The influence of the masonry type on the values of ductility can be further explained.
9. The fragility analysis should be better framed in the manuscript. Reference [22] is missing.
10. Revise [21] to the 3Muri software. There are a couple of references which can be added, e.g. ‘Seismic Vulnerability of Historical Masonry Aggregate Buildings in Oriental Sicily’.

Author Response

Replies can be found in the attached file.

Author Response File: Author Response.docx

Reviewer 3 Report

Thank you for this interesting work, but some more details and explanations are requested by the reviewer, as highlighted by the pointed comments in the attached paper, to clarify issues and unclear aspects of the paper. A summary of the major points can be found below:

• The intro needs to be strongly supported by an adequate literature review endorsing the choices made in the proposed work.
• It is not clear if the proposed interventions on floors and materials should be considered as a possible retrofit solution for an existing building or as a recommendation to be taken into consideration in the design of a new building of the same type, as the one discussed in the paper.
• Mechanical properties should also be provided with reference to recent literature review on experiments yellow tuff stones (and referring to Eurocode).
• The approach used to derive fragility curves requires to be discussed to clarify how damage state distribution has been derived. The fragility curves are cumulative functions therefore should be provided for building type and not for the single push-over direction, otherwise the provided fragility curves are impossible to be used.
• Please provide values of Φ and β and describe the type of building to which these fragility curves are applicable.
• Please check the reference list and figure numbers

Author Response

Replies can be found in the attached file.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I would suggest to present the fragility functions for the  building type, not for x/y direction

the values of Φ and β for the single fragility curves are not provided 

Author Response

Replies can be found in the attached file

Author Response File: Author Response.docx