Seismic Vulnerability Assessment and Sustainable Retrofit of Masonry Factories: A Case Study of Industrial Archeology in Naples

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper "Seismic Vulnerability Assessment and Sustainable Retrofit of Masonry Factories: A Case Study of Industrial Archaeology in Naples" describes the results of some nonlinear static analyses (Pushover) performed on a historic industrial facility close to Naples. 

Although the scientific soundness of the paper is questionable (use of commercial code and simplified procedures with no particularly novel result), the paper could be of some interest for the readers of this journal as it provides a comprehensive, albeit a bit superficial, overview of the methodology adopted to tackle such a complex task, that is assessing the seismic vulnerability of a large industrial facility with an historic/cultural value. 

This reviewer believes that the paper should undergo some revisions in order to improve clarity and reproducibility of the analyses. When revising the paper, these comments should be accounted for:

• Some additional details are needed in order to understand how the numerical model was built. The structure studied – from photos reported in Figure 2 – seems to be in  rather deteriorated conditions, and its integrity is almost lost (no roof, some unconnected walls are there). This reviewer believes that it would be beneficial to position the pics in Figure 2 in the plan, where the analysed portion is highlighted. Moreover, it would be useful to understand which hypotheses were made in terms of roofing, vertical loads etc. At present, reproducibility is prevented because of a very poor description of how the model was set up. Please try to improve as a reader should always be able, in principle, to reproduce your analyses on his own!
• The discussion on the strengthening solutions appears weak in its present form. A description of possible strengthening techniques is useful but does not provide any novel insight by itself. The Authors mention "After designing the metal ties to be installed along the structure short direction to prevent the overturning phenomena involving, among others, Wall 1 and Wall 2, the local collapse mechanism checks were repeated." but it is indeed not possible to understand anything about the process that led to the final results and, thus, the numeric values in table 5 and 6 are not very useful as the characteristic of the strengthening system designed can't be deduced anywhere from the text. Please, try to provide a more detailed and targeted description of which remedial solutions you designed, how you did it (if necessary supporting this discussion with quantitative data). It is not clear if at present the only "designed" solution is the one preventing the out of plane mechanisms for the walls 1 and 2. In that case it would be helpful to the reader to understand how you determined the number and the characteristics of the ties, what is their spacing, how are they modelled in the commercial code, rather than having a numeric result from an analysis which is run by a code as if it was a black box. 
• note: always make sure that sources for images are cited in the text or captions as copyright issues might prevent the use of images if they are not property of the Authors. 

Comments on the Quality of English Language

• English language needs some polishing; plural/singular in verbs need to be checked throughout the paper;
• The use of specific jargon should always be accompanied by quotes or italic font (e.g. Scuci e cuci at page 2, line 87. This is later on in the paper marked appropriately, but should be since the beginning of the paper);

Author Response

Please see attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents a numerical investigation on the seismic behavior of masonry buildings retrofitted with steel tie rods, using the 3Muri software. The effects of the intervention on structural performance are analyzed, and a comparison of different modeling approaches is provided. The topic is of clear relevance and potential interest for the scientific community working on the seismic assessment and retrofitting of existing buildings.

However, a major revision is recommended, as the following critical issues need to be addressed:

1. The novelty of the paper must be clearly emphasized, both in the abstract and in the introduction. At present, the contribution of the study with respect to the existing literature is not sufficiently highlighted, which reduces the clarity and impact of the work.

2. The literature review is incomplete. In particular, it is necessary to consider the methodologies proposed in the following studies, which are directly relevant to the assessment of local collapse mechanisms in masonry structures:

   https://doi.org/10.1007/s11012-020-01161-x
   https://doi.org/10.1080/15583058.2022.2139207

3. The paper https://doi.org/10.1016/j.aej.2024.08.043, which also uses the 3Muri software adopted in the present study, should be critically discussed. That study provides a benchmark against a block-based model, showing that 3Muri does not accurately capture the effects of retrofitting masonry structures with steel tie rods, mostly in the in-plane analysis. This issue is particularly relevant and must be addressed in the discussion and interpretation of the results.

4. The case study includes reinforced concrete (RC) elements (beams and columns), but no information is provided regarding the mechanical properties assigned to these components. Moreover, the interaction between RC and masonry elements is not described, particularly in terms of structural continuity and boundary conditions. The following clarifications are requested:

   • what mechanical properties were assigned to the RC elements, and on what basis these values were determined (e.g., in-situ testing, literature references, conservative assumptions);

   • how the RC components were represented within the structural model, and what role they played in both global and local (kinematic) analyses;

   • what type of interaction was assumed between the RC and masonry structures, specifically regarding the boundary conditions and connectivity at the interface between different materials.

5. Table 2 reports the values of the α coefficient for the two main directions. However, the position of the control node used in the analyses is not specified, nor is it stated whether multiple pushover simulations were conducted by varying its location. It is requested to:

   • indicate the position of the control node used in the analyses reported in Table 2, and whether this location was used to identify the combinations that yielded the most critical results;

   • clarify whether multiple pushover analyses were performed using different control node positions.

   Furthermore, the results show a significant discrepancy between the two directions: the α value in the X direction is 2.276, while in the Y direction it is 0.149. A technical discussion of this difference is required. It should be explained what geometric, structural, or connection-related aspects might justify such unbalanced behavior. Additionally, given the high α value in the X direction, it should be clarified whether retrofit interventions in that direction can actually be excluded.

6. In Section 3.3, the overturning verification results are presented for two walls, which do not satisfy the safety condition. It should be specified whether this outcome applies exclusively to these two walls, or if similar analyses were carried out on other walls of the complex. If additional analyses were performed, a summary overview should be provided indicating which walls exhibited activation of the overturning mechanism.

7. Figure 9 is not referenced in the text. In addition, Figure 9(c) shows the dimensions of an opening, but the location of this detail within the building is not specified. It is suggested to clarify both the placement and the relevance of this figure in relation to the structure of the case study.

8. In Section 4.3, the replacement of damaged RC lintels with full steel frames around the openings is described. The technical choice of using full frames instead of simpler solutions (e.g., a steel lintel) should be justified. It is requested to clarify the expected structural benefits (e.g., improved in-plane stiffness of the wall), as well as any architectural or construction-related considerations that may have influenced this decision.

9. Minor comment: Tables 3 and 4, as well as Tables 5 and 6, could be merged into single tables to improve the readability and compactness of the presentation.

Author Response

Please see attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all the issues raised in the previous review round in a minimal - albeit formally consistent - way. This reviewer believes that the paper is ready to be passed on to production, given that no further meaningful improvements can be envisaged. 

Reviewer 2 Report

Comments and Suggestions for Authors

The paper can be accepted in its current form.