A Conceptual Design Approach for Archaeological Structures, a Challenging Issue between Innovation and Conservation: A Studied Case in Ancient Pompeii

Round 1

Reviewer 1 Report

GENERAL COMMENTS

The paper presents a methodology for the assessment of archaeological structures to design conservation interventions focused on a case study in Pompeii. The subject is interesting and the work performed seems valuable. However, there are major issues that must be addressed following (hopefully not too harsh) remarks below.

The introductory section can be shortened and better organized. Both the literature review and the goals of the study are presented without a logic order.

The study is focused on the structural assessment of the masonry walls, but this is not clearly stated when defining the goals of the study. The reader only becomes aware of this when reaching section 2.

I suggest the authors highlight the main goal of the work following by listing the objectives.

The structure of the manuscript and the text also need to be better organized. Section 3 contains too many subsections (the numbering is incorrect – section 3.9. is missing and section 3.10 is repeated) that do not follow a logic order:

3. A studied case: the house aggregates of Championnet

3.1 The subsoil stratigraphy and foundation analysis

3.2 The ancient masonry walls

3.3 Innovative aspects of structural design

3.4 Experimental Campaigns

3.5 The Basalt fibre use

3.6 The Rubber Bearing Devices

3.7 The steel roof skeleton

3.8 Roofing made with Corian slabs

3.10 Structural analysis results

3.10 Efficiency analysis

Moreover, some subsections address the topic very generally, while others are focused on very specific aspects of the case study:

I suggest dividing section 3. in 3 subsections: 3.1. dedicated to the experimental campaign and modelling, 3.2. dedicated to the design of the intervention based on the results of the analysis obtained, 3.3. dedicated to the intervention performed.

The authors seem to have performed a vast experimental campaign to evaluate the materials of the case study’s masonry. However, the description of the methods used as well as the presentation of the results lacks scientific correctness.

For instance, the authors mention they have collected 7 types of stone from the masonry, but they do not identify from where the samples were collected nor how they were prepared for the compressive test performed, which is also not described. Following, the authors state they have tested the mortars with a penetrometer while referring to Figure 7 that shows an image obtained under the microscope and an elemental analysis spectrum. Neither the penetrometer test nor the microscopic and elemental analysis is described and the results are not discussed, thus becoming superfluous.

I suggest the authors focus on the actual methodology design and the reasoning of each step leaving out details of analysis performed that do not support the choices for the intervention.

In general, the figures presented are not supported by the text. I give some examples below.

The article is difficult to read due to the use of very long sentences and poor choice of terms. I suggest the authors make a revision focusing on shortening the text and improving clarity. For instance, the sentence 48-50 can read better if changed to the following version: “This paper presents a design rehabilitation approach considering conservation principles, materials, and structural performance and safety.”

There are also several typos, e.g. line 257 “lytic clasts”, line 262 “desegregation”, and poor choice of terms, e.g. line 280: “stones picked up from the walls” instead of “stone samples collected from the walls”, line 323: “fluid mortar” instead of “grout”.

These major issues and others specified below should be taken into account in a major revision before the manuscript can be considered for publication.

SPECIFIC COMMENTS

Line 159 - The design proposed applies only to masonry structures. This should be stated in the text when referring to Figure 2, as well as in the figure caption.

The methodology proposed in the flowchart of Figure 2 does not include the evaluation of the possible presence of protective and/or decorative plasters. This aspect should also be highlighted in the text when considering the structural design, because special measures must be undertaken to preserve non-structural elements that can be affected during the structural intervention.

In the flowchart of Figure 2, the steps that are included during the execution works cannot be clearly identified. I suggest using a different colour.

Figure 3 presents interesting pictures per se, but there is no relation with the work, apart that they made part of the archival research performed.

Figure 4 – If the intention is to give a picture of the aspect before and after the intervention, the authors should select comparable pictures.

Figures must be mentioned in the text before they are presented - Figures 5 and 6 appear before being mentioned in the text.

3.2 The ancient masonry walls

The description of the masonry walls and its state of conservation is vague, though it focuses on some details (e.g. the type of mortar and its degradation process) based on assumptions rather than on scientific proof. At this stage, I suggest the authors identify the main types of masonry, the main anomalies associated with each type, and possible active sources of damage.

3.3 Innovative aspects of structural design

This subsection consists of a paragraph that does not reflect its title as it merely states that the design of the intervention was based on tests performed.

3.5 The Basalt fibre use

The authors begin this section by stating that the damage state of the masonry is characterized by deteriorated mortars, and presence of holes and alveolization. Next, the authors mention that the ancient walls have been consolidated by injection of fluid mortar and the insertion of basalt fiber nets and ropes without explaining the choice of the materials, which should be based on the tests performed as mentioned earlier.

Idem for the following sections.

The conclusions’ section is vague and should be rewritten after addressing the highlighted issues.

Author Response

please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper proposes a conceptual design for archeological structure. To validate the proposed methodology the conservation of the ancient Pompeii is studied. The following changes are required to make it suitable for publication in the journal Buildings:

• Abstract: The novelty of the paper is not clearly presented. It is advised to focus on the differences of the proposed methodology with the general steps of the traditional design procedures of the historical constructions.
• Introduction: (Page 2) provide more details about the proposed interactive design approach.
• Introduction (Page 2): State clearly the novelty of the paper. The paper seems just a description of the conservation works of a particular project. No significant novelty is clearly presented.
• Introduction: It should be reordered the information. Right now many paragraphs are presented to illustrate what the paper “presents”. At the end of those paragraphs the literature is reviewed. It should be the other way around. (see eg pages 2 and 3).
• Introduction: Include a final paragraph detailing the structure of the paper.
• Section 2: Are the contents of Figures 1 and 2 original? If not please include the proper references.
• Section 2: More details about the novelties of the proposed conceptual design methodology are needed.
• Section 3: Include references of Figure 3.
• Section 3.3: Definition of the innovative aspects of structural design are not explained with enough detail. Please extend the information presented in Page 9.
• Section 3.4: Provide more information about the devices used for the experimental campaigns and the location of the tests on site.
• Table 2 and 3: Introduce the superindices in the table for the volumic mass and the mean square strength.
• Section 3.10: Efficiency analysis. Explain in detail the analyses performed and the results presented in Figures 18 and 19.
• Conclusions: Improve the presentation of the novelty of the proposed work.
• References: The list of references should be extended and include more current works (be aware that the newest referenced paper dates back to 2018).

Author Response

Please see attachement

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript aims to present a specific design approach for ancient constructions' rehabilitation works in archaeological sites. The reviewer believes that the subject fits with the scope of the Journal. However, some aspects described below must be better clarified and discussed along with the manuscript. The English language shall also be improved. I recommend major revisions of this paper according to the observations/suggestions listed below:

Abstract

• A brief sentence of the major conclusions found in this study must be included

Section 1

• Several references are presented without a proper introduction, for example line 59. The authors are invited to revise it.
• Please revise the language and gramme between lines 71-87
• The motivation for this study is quite clear. However, the novelty needs to be revised.

Section 2

• Please include a small discussion of the possible integration of a holistic approach, including Energy and sustainability retrofitting and structural performance improvement.

Section 3

• Details about the design criteria for the retrofitting of the structural elements are missing. It would provide a good perspective for the reader.
• Do the authors have images from the evolution of retrofitting?
• Sub-section 3.3 is too poor. Innovation is not well explained.
• Figure 7b: The units and scales' dimension is too small and the quality of the image is not adequate. Please improve it.

Section 4

• Please include future works

Author Response

Please see attachment

Author Response File: Author Response.pdf

Reviewer 4 Report

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General Review:

The paper entitled ”A conceptual design approach for archeological structures, a challenging issue between innovation and conservation: a studied case in the ancient Pompeii” proposes a conceptual design approach to define and plan rehabilitation works of ancient constructions in archaeological sites.

The proposed methodology aims at an oriented and optimised design process that can account for increasing levels of knowledge on existing structures, particularly considering the following steps: the collection of data, the structural identification, hazard, and vulnerability analysis, damage and risk analysis, a cost-benefit analysis. 

The methodology's efficiency is presented and applied on a real case study in the archaeological site of Pompeii: the Domus of Championnet.

The paper is well-written, is interesting and fits the Journal’s scope. Nonetheless, to improve the impact of the manuscript, the Reviewer recommends a major revision, which should take into account the following aspects. 

Specific Comments

The Authors state: “The optimum design should be found considering and weighting all different aspects, by using a cost-benefit analysis that is oriented to the preservation of the material fabric with a reduce invasiveness of the intervention works.” (lines: 35-38)

Has a cost-benefit analysis been performed for the case study involving the Domus of Championnet? If so, I would encourage the Authors to briefly describe it.

The main aim of the paper is to propose a holistic, interactive design process that should be oriented and changed accordingly even during the execution work. In the Reviewer’s opinion, the paper, particularly Section 3, lacks an accurate presentation and discussion of the main changes, re-directions of the design during the execution work. This aspect is key, particularly to illustrate how the proposed methodology affected the final design.

The Authors state that: “On the other side, most designers are often oriented to use compatible and natural materials, such as wood, stone etc. [5, 6, 7, 8]. For these reasons, during the design process, the decision on the type of intervention and material yields to a different level of safety.” lines(44-46). Can the Authors discuss which criteria were used to select a Corian slab?

The sentence in between lines 92-94 needs a reference.

Line 106: why citation [18] is specifically used on that point/context?

The paper illustrates the use of new technology, i.e. an application of rubber bearing installed between masonry walls and steel roof. The author frames this technology (as used in the present work) as a Base Isolation System (BIS). In the reviewer’s opinion, it is a BIS for the steel roof that was added over the old structure. But referring to the original masonry wall structure, that system cannot be framed as a BIS. Indeed, the potential shear actions acting on the top of the ancient walls, once the steel roof has been added, is greater than the original one (zero).

In agreement with the Authors when they state that: “the need for reversibility and no-invasiveness of the interventions require great attention”. The Authors selected a solution with a steel roof directly installed either on the top of the original walls or over additional “new walls” and using steel plates anchored in the masonry with 2 m long bolted steel bars. This solution does seem invasive.  Why did the Authors select this solution instead of having a standing alone roof with its own structure? I would suggest to introduce and illustrate the reasons behind this decision in the paper.

“The additional loads due to the new roof is transferred indirectly, using an additional masonry built on the top of the ancient walls of the houses.” Looking at Figure 6, it does not seem the load are transmitted indirectly, at least not everywhere. 

What is missing is a preliminary study of the horizontal resistance capacity of the walls without a roof. This is key to prove either the need for a connection with a roof or to demonstrate that the roof (directly installed on the walls) does not reduce significantly the horizontal capacity of the ancient original walls.

It seems that the Rubber bearing tensile load is 15 kN, while the pull-out test for the bars gives as results 26 kN. It seems that the rubber is the bootle neck for tensile actions: did the connection bar-wall designed for that purpose? If so, why?

It would be advisable to report the compressive forces due to the roof.

The Authors should discuss better the assessment of the ancient masonry walls (lines 394-396). 

Line 413: why the reduction (as from Figure 19 and Table 5) is 424%?

The Introduction or Section 3 would benefit from a discussion/reference to the following works:

• Pagano, M. (1992). Metodologia dei restauri borbonici a Pompei ed Ercolano. Metodologia dei restauri borbonici a Pompei ed Ercolano, 169-191.
• Salassa, C. M. (1999). Le coperture di restauro a Pompei. Rivista di Studi Pompeiani, 10, 91-115.
• Flamini, M. G., Prisco, G., Capanna, F., Guglielmi, A., Caligaris, M. O., & Salerno, C. S. (2000). L'Istituto Centrale per il Restauro a Pompei: interventi nella Casa dei Vettii e nella casa VI 15, 2. Rivista di Studi Pompeiani, 11, 252-262.
• Bergamasco, I., Gesualdo, A., Iannuzzo, A., & Monaco, M. (2018). An integrated approach to the conservation of the roofing structures in the Pompeian Domus. Journal of Cultural Heritage, 31, 141-151.

Minor Comments

Fig.1 - The Authors are encouraged to work on the Figure in order to make it more compact.

Fig.2 - The Authors are encouraged to work on the Figure in order to make it more compact.

Fig.4 - To improve the readability of image 4a, would be opportune to define the area subjected to restoration works.

Fig.8 - Would be advisable to format figures a and b with the same height

Fig.12 - Please, improve the quality of the image.

Fig.13a - Please, improve the quality of the image.

Line 214: picture -> watercolour

Line 215: “Felix 214 Duban on 1987” -> I think is wrong. Please check it.

Line 214: Please, introduce and add a reference for Fig. 3b

Line 288: to trace - >tracing

Line 296: Please, be consistent using the same unit of measurement.

Table 2: Please, improve the quality of the table, formatting it better (rows can and should be equally spaced)

Table 2: Please, check if the word “square” is a typo

Line 309-314: Please, break the sentence and rephrase it.

Line 388: Please, add a reference([4]) to NTC2008.

Line 394: NCT2008 -> NTC2008

Author Response

please see attechment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The suggested comments have been properly address and publication is advised

Reviewer 3 Report

The authors considered all the reviewers suggestions and the manuscript quality was improved. The current version of the manuscript is suitable for publication.

Reviewer 4 Report

The authors addressed all comments in a satisfactory way. I suggest the paper for publication once the following sentence has been rephrased:

"The result comparison shows a 424% reduction..."

which is not scientifically correct. Indeed, the reduction is 81% as it comes from (v_final-v_initial/v_initial

0,81