Scientific-Practical Enhancement Principles for the Long-Term Stability of Cultural Heritage Objects through a Multi-Component Underground Space Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please review the images extracted from other sources and if possible edit them to improve the quality of the text, in many cases the text is blurry.

Please consider adding a subheading to mark clearly the beginning of the recommendations for field and laboratory work.

Also consider:

 

Line 111: Please use the extended form the first time and abbreviation is used.

Line 257: Could you please explain briefly some of the mechanisms these bacteria use to damage the concrete matrix?

Line 266: Here too, kindly add a few lines to provide info of the processes which result in groundwater contamination.

Line 267: Could you please add a fourth column describing the normal range of these elements? it would help for a faster comparison. Same for table 3.

Line 346: the "special research" here needs a reference.

 

Author Response

Comment 1: Please review the images extracted from other sources and if possible edit them to improve the quality of the text, in many cases the text is blurry.

Response 1: Unfortunately, we were not able to fully improve the quality of the maps presented in our work. One of the figures ("A map of the area from 1698 indicating territories occupied by swamps (constructed on the basis of a Swedish map from the archives of the Cartographic Department of the Saint Petersburg Public Library)", Figure 2) was digitized to preserve the necessary information on the map (the presence of bogs, while another ("Topographical map of the city of New York showing original watercourses, marshes, and made land by engineer-topographer Egbert Viele in 1865", ex Figure 4) was removed and replaced with a reference, allowing anyone interested to view the map in more detail.

Comment 2: Please consider adding a subheading to mark clearly the beginning of the recommendations for field and laboratory work

Response 2: A subsection titled "Recommendations for conducting field and laboratory research in the foundation zone of cultural heritage objects" has been added (lines 437-438 in the new version of the article)

Comment 3: Line 111: Please use the extended form the first time and abbreviation is used.

Response 3: The abbreviation 16S rRNA has been expanded (line 130 in the new version of the article)

Comment 4: Line 257: Could you please explain briefly some of the mechanisms these bacteria use to damage the concrete matrix?

Response 4: The influence of microbial activity on the condition of concrete has been shown, as per your recommendation, through a brief explanation of the mechanism of material degradation and photographs of the corroded concrete surface obtained using a scanning electron microscope, clearly showing the impact of biocorrosion (Figure 6) (lines 292-303 in the new version of the article)

Comment 5: Line 266: Here too, kindly add a few lines to provide info of the processes which result in groundwater contamination.

Response 5: A brief explanation of the reasons for the influence of eliminated and active cemeteries on the condition of underground water has been provided. (lines 310-316 in the new version of the article)

Comment 6: Line 267: Could you please add a fourth column describing the normal range of these elements? it would help for a faster comparison. Same for table 3.

Response 6: As per your recommendation, a fourth column with the results of the chemical composition of underground water in the park zone of Saint Petersburg, where minimal technogenic contamination is noted, has been added to Tables 2 and 3 (lines 318-321, 335-338 in the new version of the article). It is important to note that such areas are extremely rare within the historical center of the city due to the long duration and intensity of contamination in Saint Petersburg before its foundation and during more than 300 years of the city's functioning.

Comment 7: Line 346: the "special research" here needs a reference.

Response 7: References to studies on the influence of radon on the number and activity of microorganisms have been provided (line 404 in the new version of the article)

We express our deep gratitude for the work you have done to improve our article.

Best regards,

The authors

Reviewer 2 Report

Comments and Suggestions for Authors

It would be great if you could think about adding some extra case studies from different places around the world. This would show how your method can be used in lots of different situations. We'd love to see more quantitative data and statistical analyses to really strengthen your findings! This will make your study even more reliable and convincing! It would be great if you could talk about how modern technologies like remote sensing, GIS and advanced computational models could be used to make your methodology more precise and efficient, which would help us preserve our heritage in a more effective way. We'd love to hear more about the policy implications of your findings! If you could provide recommendations for updating preservation regulations and guidelines based on your research, that would be amazing. Could you also improve the clarity and presentation of your figures and tables? High-resolution images and more detailed captions can significantly enhance the readability and impact of your paper.

By addressing these suggestions, your article can further contribute to the field of cultural heritage preservation and serve as a valuable resource for both researchers and practitioners.

Author Response

Comment 1: It would be great if you could think about adding some extra case studies from different places around the world. This would show how your method can be used in lots of different situations.

Response 1: 

In accordance with your suggestion, we have expanded our article by adding a section titled "Some examples of the methodology's application in Saint Petersburg and abroad." In this section, we have highlighted our scientific and practical experience in successfully applying the developed principles for conducting engineering-geological and geotechnical research in the foundation zone of architectural and historical monuments. The aim is to identify the causes of destruction of their underground bearing and enclosing structures, as well as to determine the factors contributing to the long-term development of deformations in the studied objects. This approach to conducting research has led to significant changes in the preparation of reconstruction and restoration projects for historical and cultural objects located in Saint Petersburg, such as the New Hermitage complex, Saint Isaac's Cathedral, the Yusupov Palace, the Old Saint Petersburg Stock Exchange, and the Alexander Column. Given the particularly complex engineering-geological, geotechnical, and geo-ecological conditions characteristic of the historical center of Saint Petersburg - including the development of soft Quaternary sandy-clayey soils, the aggressiveness of underground water towards construction materials, the presence of buried bogs, filled-in water bodies, and watercourses - great attention is paid to the comprehensive monitoring of the condition of cultural heritage objects. This monitoring is based on original and non-standard methods for studying the multi-component underground space. Specifically, programs and recommendations for conducting comprehensive monitoring have been provided for a number of restored, reconstructed, and recreated 19th-century churches in Saint Petersburg, as well as for the aforementioned objects - Saint Isaac's Cathedral and the Alexander Column.

In the section "Some examples of the methodology's application in Saint Petersburg and abroad," we have provided an example of the use of the described methodology for studying the multi-component underground space in assessing the condition of some monuments in Hanoi - the Hanoi Cathedral (second half of the 19th century), the Hanoi Flag Tower (first half of the 19th century), and the Doanmon Gate of the Imperial Citadel of Thang Long (15th century). The results of the studies and the concept of comprehensive monitoring of the condition of these objects are reflected in published works, as well as in the thesis for the degree of PhD titled "Engineering-Geological Monitoring of the Underground Space in the Historical Center of Hanoi (Socialist Republic of Vietnam)" by Vietnamese graduate student Nguyen Tien Chung, prepared under the supervision of one of the authors of the article - Professor Dashko R.E.

The concept of the multi-component nature of the underground space can be applied in historical megapolises where buried bogs, sandy-clay soils with organic matter, and long-term technogenic contamination of soils and underground water over centuries are observed. Such cities include London, Cologne, Venice, Mexico City, Santa Fe de Bogota, Washington, and others.

The general applicability of the approach to the underground space as a multi-component system has been successfully demonstrated in its use by one of the authors to enhance the safety of mining operations at mineral deposits in Russia.

Comment 2: We'd love to see more quantitative data and statistical analyses to really strengthen your findings! This will make your study even more reliable and convincing!

Response 2:

To ensure the reliability of the conclusions presented in the article, the section "Results of underground space research at the regional level" includes the results of experimental studies to identify patterns of the negative impact of microorganisms on the strength of clay soils and the permeability of sands (Figures 4 and 5). Additionally, the results of studies of concrete samples via scanning electron microscopy have been added. The obtained images clearly show the active occurrence of biocorrosion processes on the surface of the concrete and its irreversible transformation as a result of the activity of underground microorganisms (Figure 6).

Comment 3: It would be great if you could talk about how modern technologies like remote sensing, GIS and advanced computational models could be used to make your methodology more precise and efficient, which would help us preserve our heritage in a more effective way.

Response 3:

Modern technologies such as remote sensing, GIS, and computational models are very important and promising directions for increasing the effectiveness of preserving world heritage. These serious topics require separate and detailed consideration but they are beyond the scope of the authors' research, which reflects the methodological basis for studying the multi-component underground space. In working on individual cultural heritage objects, we recommended the use of foundation models composed of water-saturated clay soils, which are developed on a rheological basis, as well as the application of remote sensing.

Comment 4: If you could provide recommendations for updating preservation regulations and guidelines based on your research, that would be amazing.

Response 4:

During the work to ensure the long-term stability of architectural and historical monuments in Saint Petersburg and other cities in Russia, in collaboration with specialists in the field of design, as well as reconstruction, restoration, and recreation of historical and cultural heritage, the methodology presented in this article serves as the basis for the content and organisation of engineering-geological and geotechnical research. The integration of these principles into the regulatory documents of the Russian Federation in the field of preserving cultural heritage objects is an important task for the authors of the article. Research is actively progressing in this direction.

Comment 5: Could you also improve the clarity and presentation of your figures and tables? High-resolution images and more detailed captions can significantly enhance the readability and impact of your paper.

Response 5: 

Regarding the comment on the quality of some figures, one of the maps ("A map of the area from 1698 indicating territories occupied by swamps (constructed on the basis of a Swedish map from the archives of the Cartographic Department of the Saint Petersburg Public Library)", Figure 2) has been digitised to preserve the necessary information. Another map ("Topographical map of the city of New York showing original watercourses, marshes, and made land by engineer-topographer Egbert Viele in 1865", ex Figure 4) has been removed and replaced with a reference, allowing anyone interested to view the map in more detail.

The presentation of information in the tables has been improved by incorporating data on the condition of underground water in areas experiencing the least technogenic impact over time to Tables 2 and 3.

We express our deep gratitude for the valuable suggestions to improve our research and developments.

Best regards,

The authors of the article