Hypogea2023 Proceedings of IV International Congress of Speleology in Artificial Cavities Italy, Genoa, September 29th / October 1st Editors Stefano Saj, Carla Galeazzi Michele Betti, Francesco Faccini, Paolo Madonia
PROCEEDINGS OF IV INTERNATIONAL CONGRESS OF SPELEOLOGY IN ARTIFICIAL CAVITIES HYPOGEA2023 SEPTEMBER 29th / OCTOBER 1st GENOA, ITALY PALAZZO DUCALE, SALA MINOR CONSIGLIO Piazza Matteotti 9, Genova Opera Ipogea Journal of Speleology in Artificial Cavities Union Internationale de Spéléologie Società Speleologica Italiana ETS Regione Liguria Comune di Genova Università di Genova UNESCO Chair Istituto Nazionale di Geofisica e Vulcanologia Istituto di Ricerca per la Protezione Idrogeologica Ordine degli Architetti Pianificatori Paesaggisti e Conservatori Genova Ordine Ingegneri Genova Ordine Regionale dei Geologi della Liguria Federazione delle associazioni dell’Antico Acquedotto Storico Genova Opera Ipogea Organized by
Proceedings of IV International Congress of Speleology in Artificial Cavities HYPOGEA2023 PALAZZO DUCALE, SALA MINOR CONSIGLIO Piazza Matteotti 9, Genova Edited by CENTRO STUDI SOTTERRANEI Supplement to issue 1-2 / 2023 Opera Ipogea - Journal of Speleology in Artificial Cavities Memorie della Commissione Nazionale Cavità Artificiali www.operaipogea.it Semestrale della Società Speleologica Italiana ETS Autorizzazione del Tribunale di Bologna n. 7702 dell’11 Ottobre 2006 Editors Stefano Saj, Carla Galeazzi Michele Betti, Francesco Faccini, Paolo Madonia Scientific Commitee Michele Betti, Roberto Bixio, Francesco Faccini, Carla Galeazzi, Paolo Madonia, Roberto Maggi, Alessandro Maifredi, Massimo Mancini, Mario Parise, Mark Pearce, Luigi Perasso, Stefano Saj, Martino Terrone, Marco Vattano, Ali Yamac, Boaz Zissu Organizational Secretariat Marina Barbieri [email protected] Organizing Committee Guglielmo Barranco, Marina Barbieri, Michele Betti, Roberto Bixio, Timothy Bonassi, Beatrice Cella, Andrea Ferrando, Rita Foglia, Carla Galeazzi, Martina Gogioso, Ivan Greco, Matteo Mammi, Luigi Perasso, Pietro Piana, Danilo Repetto, Gabrio Taccani, Mauro Traverso, Stefania Traverso Composition and layout Luca Paternoster, Stefano Saj Graphic project Carla Galeazzi, Stefano Saj Cover photo Martina Gogioso Back cover photos Ivan Greco, Fernando Naldoni, Danilo Repetto, Stefano Saj, Luca Torti, Mauro Traverso Typography Corigraf Srl – Viserba, Rimini, Italy With the financial support of Società Speleologica Italiana ETS € 200,00 ISBN 978-88-32241-32-7
3 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa CONTENTS FOREWARD: Mario Parise ................................................................................................................................. 7 CONGRESS PRESENTATION: Stefano Saj, Carla Galeazzi ............................................................................ 9 SPECIAL CONTRIBUTION ABOUT GENOA HISTORY The plague (1656-1657) in the history of the Maritime Republic of Genoa (Italy): an important testimony of efficacious measures of safety and prevention in the field of hygiene and public health and a wonderful discovery of a precious historical heritage to protect. A “blend” of speleology and history of medicine Mariano Martini, Stefano Saj, Danilo Repetto, Martino Terrone, Simon Luca Trigona, Nico Radi, Giancarlo Icardi, Francesca Ferrando ....................................................................................................................... 13 UNDERGROUND ARCHITECTURE AND URBAN PLANNING The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi Roberto Grammatico, Roberto Mazzeo ............................................................................................................... 21 Genoa Municipality GeoPortal as tool for underground and overground analysis (Italy) Martino Terrone, Elena Ausonio, Flavio Marovic, Cristina Olivieri, Andrea Rimassa, Federico Rottura, Emilio Vertamy, Luca Volpin, Stefania Traverso .............................................................................................. 29 ARTIFICIAL CAVITIES AS A POSSIBLE GEOLOGICAL RISK FACTOR Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) Francesco Faccini, Roberto Bixio, Andrea Mandarino, Pietro Piana, Stefano Saj, Martino Terrone, Mauro Traverso, Stefania Traverso ............................................................................................................................... 37 Artificial cavities and geo-risk assessment: the case of “The Strade Nuove and the system of the Palazzi dei Rolli” Unesco World Heritage site in Genoa (Italy) Francesco Faccini, Andrea Ferrando, Giacomo Montanari, Pietro Piana, Stefano Saj, Martino Terrone, Stefania Traverso ................................................................................................................................................ 47 A chronology of sinkholes related to artificial cavities in the hydrographic district of the Southern Apennines of Italy Isabella Serena Liso, Carmela Vennari, Maria Assunta Fabozzi, Daniela Ruberti, Marco Vigliotti, Gennaro Capasso, Vera Corbelli, Mario Parise ................................................................................................................ 57 The hidden world of artificial cavities in the hydrographic district of the Southern Apennines of Italy: findings, architectural variability and risk assessment Maria Assunta Fabozzi, Isabella Serena Liso, Mario Parise, Carmela Vennari, Piernicola Lollino, Marco Vigliotti, Gennaro Capasso, Vera Corbelli, Daniela Ruberti ............................................................................ 65 On the role of geo-structural features in the development of failure mechanisms affecting man-made underground cavities Piernicola Lollino, Mario Parise ........................................................................................................................ 75
4 Contents ANCIENT UNDERGROUND HYDRAULIC WORKS Ahmet Çelebi Qastel of Gaziantep (Turkey) Ali Yamaç ............................................................................................................................................................ 85 Water monuments in Hittite and Neo-Hittite periods: structure, functions, and connection with the “other world” Maria Elena Balza, Marco Capardoni, Clelia Mora ......................................................................................... 91 The ancient aqueducts of Asolo (Italy): new investigations and acquisitions Massimiliano Zago, Daniele Davolio M., Marcello Pellegrini, Roberto Sordi, Marco Sordi ........................... 99 The Civil Forum cisterns in Pompeii (Italy) Graziano Ferrari, Daniele De Simone, Alberta Martellone, Bruno De Nigris, Massimo Osanna ................... 107 Aqua Augusta in Campania. New section under the Posillipo ridge (Naples, Italy) Graziano Ferrari, Daniele De Simone ................................................................................................................ 111 The water storage system of Marcigliana (Rome, Italy): an unusual representative of a Roman cistern Andreas Schatzmann, Mara Abbate, Andrea Peresso ....................................................................................... 119 An Archaeological Survey in the Jerusalem Hills and Water Facilities for Pilgrims during the Early Roman Period Boaz Zissu, Danny Bickson, Dvir Raviv ............................................................................................................ 127 ROCK-CUT SETTLEMENT WORKS Quarried underground hiding complexes in the Galilee, Israel: new evidence for their use in the SecondCentury CE Revolt against the Romans Yinon Shivtiel ...................................................................................................................................................... 137 Castle of Gaziantep (Turkey). Tunnels, Dwellings, Excavations and Earthquakes Ali Yamaç ............................................................................................................................................................ 147 Underground Shelters in Cappadocia (Turkey) Roberto Bixio, Ali Yamaç .................................................................................................................................... 153 From Xenophon houses to Armenian rock-cut dwellings and sacristies Samvel M. Shahinyan, Ashkhen Shahinyan, Nerses Varderesyan, Gayane Erkoyan, Ani Badasyan ........... 161 Intended use and dating of rock-cut dovecotes in Cappadocia (Turkey) Andrea Bixio, Roberto Bixio, Andrea De Pascale, Ali Yamaç ........................................................................... 171 Underground living spaces in the Chinese loess Constantin Canavas ............................................................................................................................................ 177 A cave settlement in Ardahan (Turkey): Harosman Göknil Arda ......................................................................................................................................................... 183 Discovery and documentation of the underground structures of Hagia Sophia (Istanbul, Turkey) Ali Hakan Eğilmez, Özlem Kaya, Barkın İren, İrem Kapucuoğlu, Eylül Horoz, İrem Güzel, Tuğçe Nur İlbaş, Burcu Cavdar, Kadir Gürses .............................................................................................................................. 189 UNDERGROUND RELIGIOUS AND CULT STRUCTURES St. Euphemia’s cave inscriptions: ancient navigation, beliefs and devotion (Vieste, Italy) Giuliano De Felice, Danilo Leone, Mario Mazzoli, Maria Turchiano, Giuliano Volpe .................................... 197
5 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa Use of natural caves for ritual purposes as a forerunner of the formation of architecture Samvel M. Shahinyan, Armen Davtyan, Smbat Davtyan, Boris Gasparyan .................................................. 205 Physical evidence of dedication rites in rock churches of Basilicata and Apulia (Italy). Some case studies Sabrina Centonze ................................................................................................................................................ 213 New considerations on the Uplistsikhe rock-cut ensemble (Georgia) Nodar Bakhtadze ................................................................................................................................................ 227 Artificial cavities under worship places: case studies from the province of Caserta (Italy) Emilia Damiano, Francesco Fabozzi, Maria Assunta Fabozzi, Paolo Maria Guarino, Ivana Guidone, Erika Molitierno, Lucio Olivares, Arcangelo Pellegrino, Marco Vigliotti, Daniela Ruberti ...................................... 233 The hypogeum of San Gavino a mare in Porto Torres (Sassari, Sardinia, Italy): preliminary epigraphic, glyptographic and speleological investigations Giuseppe Piras, Pier Paolo Dore ......................................................................................................................... 243 The rupestrian churches in the monastery of Geghard, Armenia Marco Carpiceci, Fabio Colonnese, Antonio Schiavo, Rachele Zanone ............................................................ 251 Làjos Bethlen’s crypt (Chiraleş, Romania): a geological viewpoint Tudor Tămaş, Codruţa Valea, Szabolcs Attila Kövecsi, Eusebiu Szekely ........................................................ 261 MINING AND EXTRACTION WORKS Exploration of the Quarries of Moldavanka District in Odesa City (Ukraine) Igor Grek, Yevheniia Pechenehova, Nataliya Moldavska, Yuliia Pelovina, Mike Shyrokov ........................... 271 Quarrying Methods in the Cave of Zedekiah in Jerusalem at the Ancient time (Israel) Avraham (Avi) Sasson ........................................................................................................................................ 277 Antrona Valley’s Gold Mines: from ore deposits to cultural opportunity for mining heritage (Piedmont, Italy) Luca Palazzolo, Alex Briatico, Enrico Zanoletti, Andrea Basciu, Flavio Caffoni, Andrea Martinelli, Luca Miglierina, Elena Mileto, Antonio Moroni, Luca Nardin, Giulio Oliva, Renato Oliva, Roberto Piatti, Edoardo Rota, Marco Ulivi, Marco Venegoni, Daniele Piazza .................................................................................... 285 Ancient mines in Valsesia (northeastern Piedmont, Italy): 25 years of historical research and speleological exploration Paolo Testa, Riccardo Cerri ................................................................................................................................ 293 Multidisciplinary research on two ancient mining sites in Western Liguria (Italy) Alberto Assi, Simone Baglietto, Marco Marchesini, Simona Mordeglia, Andrea Roccatagliata, Antonio Travi, Daniele Vinai .................................................................................................................................................. 303 NEW TECHNOLOGIES FOR ANALYZING AND DOCUMENTING THE ARTIFICIAL CAVITIES Re-defining the relationships between the tangible and intangible heritage: the rock-cut village of Vitozza, Sorano (Tuscany, Italy) Carmela Crescenzi, Alessandro Baldacci ........................................................................................................... 309 The Pozzuoli (Naples, Italy) Flavian Amphitheatre cisterns: a basic experience in 3D modelling with LIDAR Graziano Ferrari ................................................................................................................................................. 319
6 Contents Notes on the survey of the Catacomb of San Senatore at Albano Laziale (Rome, Italy) Marco Carpiceci, Fabio Colonnese, Roberto Libera ........................................................................................... 325 CADASTRE, CATEGORIES AND TYPOLOGIES OF ARTIFICIAL CAVITIES: UPDATES The Modern-era technique of the semi-rupestrian architecture in the Matera area (Italy) Franco Dell’Aquila, Francesco Foschino, Raffaele Paolicelli ............................................................................ 335 20 Years of the project “The map of ancient underground aqueducts in Italy”, and future perspectives Paolo Madonia, Carla Galeazzi, Carlo Germani, Mario Parise ....................................................................... 343 Rock-cut dovecotes in Cappadocia (Turkey): elements in comparison Andrea Bixio, Roberto Bixio, Andrea De Pascale, Ali Yamaç ........................................................................... 349 Underground structures inventory project of Kayseri (Turkey): a short summary Ali Yamaç ............................................................................................................................................................ 359 Cadastre of artificial cavities of Piedmont and Valle d’Aosta (Italy): new perspectives for the use and updating of data Arianna Paschetto, Massimo Taronna, Davide Barberis, Enrico Lana, Michelangelo Chesta, Giandomenico Cella, Michele Gallina ........................................................................................................................................ 365 MILITARY AND WAR WORKS Artificial caves shelters in vertical tuff escarpments in Cappadocia (Turkey) and Upper Mustang (Nepal) Igor Grek, Nataliya Moldavska, Mike Shyrokov ............................................................................................... 373 The place of no return in ancient Ani (Kars, Turkey): report of the explorations Vedat Akçayöz ...................................................................................................................................................... 383 Some aspects of the wartime work underground in the Southeastern Alps (Italy) during World War I and carried out mainly on the Marmolada and Adamello mountain ranges and on the Trentino highlands (Lavarone, Pasubio, Asiago), but also on the so-called backward front such as the Cadorna Line Lamberto Laureti ................................................................................................................................................ 391 SPECIALIZED UNDERGROUND FAUNA Hypogeal fauna of the military subterranean fortification Forte di Vernante Opera 11 “Tetto Ruinas” (Piedmont, Italy) Enrico Lana, Valentina Balestra, Michelangelo Chesta, Dario Olivero ........................................................... 401 The caves of Finalese karstic area (Finale Ligure, Liguria, North-Western Italy): a project for the coexistence between the touristic activity and the Chiroptera conservation Anastasia Cella, Roberto Toffoli, Federico Mantovani ...................................................................................... 409 AUTHORS INDEX Authors index ..................................................................................................................................................... 415 APPENDIX GUIDED TOURS “HYPOGEA2023” ................................................................................................................... 417 CENTRO STUDI SOTTERRANEI FORM ............................................................................................................ 421
7 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa FOREWARD Mario Parise1,2 It is with huge pleasure that I am writing these lines, in order to present the congress Hypogea2023, and to introduce this piece of work, the 2023 proceedings that represent the new-born member of the Hypogea family, adding to those produced at the previous meetings in Rome (Italy), Cappadocia (Turkey) and Dobrich (Bulgaria). As President of the Commission on Artificial Cavities of the International Union of Speleology (UIS), I am very proud of this work, that continues the road started 8 years ago when we realized the need of organizing an international congress dedicated to artificial cavities. The idea, unanimously approved by the Commission, resulted in a success well above our initial expectations, and as such has been in the following years. After the first edition of Hypogea, held in 2015 in Rome, we are back in Italy, this time being hosted in Genoa, a beautiful town in the north-western Italian coasts of Liguria, characterized by a long history and a wide use of the underground: as many other towns in Italy, the underground of Genoa presents a great variety of sites of interest, but have been many times, 1 Earth and Environmental Sciences Department, University Aldo Moro, Bari, Italy 2 International Union of Speleology, President of the Commission on Artificial Cavities
8 Foreward during the last decades, also places that in some ways played a role on the occasion of the main flood events affecting the town. As elsewhere, the human actions in the underground environment have resulted in locally exacerbating the negative effects of natural hazards, and their impacts on society. In the attempt to put together cavers and scientists from very different disciplines, the issue of artificial cavities is particularly suitable for merging different expertise: within artificial cavities many professionals and scholars actually work and make research activities, from geologists, to archaeologists, historians, architects, engineers, hydrologists, biologists, just to mention some disciplines. Artificial cavities are the perfect place for multi-disciplinary works, and this is widely documented in these proceedings, where many contributions put together scholars coming from quite diverse experience and background. 50 articles included in the proceedings (out of the 52 presented at the congress), counting 150 authors from 8 countries worldwide, and dealing with case studies from artificial cavities in 10 countries, is a great result! Of course, countries as Italy (the hosting nation) and Turkey are the most represented, and in particular the Italian contributions cover not less than 15 regions in the country, thus testifying the variety of underground sites, and of their typologies as well, in Italy. Beside the geographical distribution, the works are also extremely varied in terms of topics, ranging from archaeology and history, to geology, hydrogeology and geotechnics, to survey techniques, geotourism, and mitigation of natural hazards. At the same time, practically all the categories of artificial cavities in the UIS classification (Parise et al., 2013) are dealt with, with great emphasis on worship sites, hydraulic works, civilian settlements, military works, but also with regard to quarries and mines and dovecots as well. Worth to be mentioned are also the several works about inventory of caves or deriving from projects that had artificial cavities as the main object of their study. This testifies, once again, the growing interest for the underground world created by man, and the importance to know as much as we can of what is present beneath our inhabited areas. In the case of artificial cavities, knowledge goes necessarily through the collection of data, possibly organized by means of inventories or catalogues, a very difficult work that, once started, can really make the difference for the complete knowledge of any territory. When preparing these lines of preface to the Hypogea2023 proceedings, I went back to the preface authored by Carla Galeazzi and myself in Rome, in 2015: there, we presented our auspice that this congress “might have in the future a cyclic nature, in order to allow a constant discussion on the issues regarding artificial cavities” (Galeazzi and Parise, 2015, p. 7). Today, I am extremely happy to confirm that Hypogea, at its fourth edition, has become a fundamental occasion of meeting for all scholars dealing with artificial cavities, notwithstanding the great difficulties posed in the last years by the pandemic. Thus, I am sure that the congress will keep going, and look forward to visiting other countries in the next future, on the occasion of the Hypogea to come. Bibliography Galeazzi C. & Parise M., 2015, Preface. Proceedings of the International Congress in Artificial Cavities “Hypogea 2015”, Rome, March 11-17, 2015, ISBN 978-88-89731-79-6, p. 7-8. Parise M., Galeazzi C., Bixio R., Dixon M., 2013, Classification of artificial cavities: a first contribution by the UIS Commission. In: Filippi M. & Bosak P. (Editors), Proceedings 16th International Congress of Speleology, Brno, 21-28 July 2013, vol. 2, p. 230-235.
9 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa CONGRESS PRESENTATION Stefano Saj1,2,3, Carla Galeazzi1,4,5 This publication gathers the contributions presented during the IV International Congress of Speleology in Artificial Cavities, Hypogea2023, organized in Genoa by Centro Studi Sotterranei (Underground Studies Center) with the support of the SSI - Società Speleologica Italiana (Italian Speleological Society), in partnership with the UIS - Union International de Spéléologie (International Union of Speleology) and in collaboration with the Hypogean Federation, the SSI Artificial Cavities Commission, the Ligurian Speleological Delegation and the Opera Ipogea - Journal of Speleology in Artificial Cavities. The Genoa Congress is the first one organized in presence after the restrictions and great difficulties faced by all communities due to the Covid-19 pandemic, following the previous ones held in Italy - Rome (Hypogea2015), Turkey - Cappadocia (Hypogea2017) and Bulgaria - Dobrich (Hypogea2019). In the prestigious historical venue of the Palazzo Ducale in Genoa, the 52 congress contributions (oral and poster) confirm the synergistic commitment that has characterized research over these last few difficult years in which the pandemic has never stopped. The Congress, distinguished by the same scientific rigor as the previous editions, constitutes a strategic moment for the exchange of experiences in various highlevel scientific, technical, and design fields thanks to the participation of Italian and international experts. Different methodologies, issues and achieved results are shared. The research lines are organized divided into 11 ses1 General chair of the Congress 2 Centro Studi Sotterranei, Genoa, Italy 3 Opera Ipogea - Journal of Speleology in Artificial Cavities 4 Società Speleologia Italiana, Bologna, Italy 5 Hypogea Federation for research and enhancement artificial cavities, Rome, Italy
10 Congress presentation sions, each addressing a significant topic related to the central focus of the conference. It emerged from the speeches that cooperation between academic and non-academic entities and that the cooperation between these entities and the institutions has strengthened in recent years. Even in the more strictly scientific field, decisive steps forward have been taken. The complex picture emerging from the congress provides theoretical and practical insights, bibliographical and documentary references related to the multitude of areas of intervention, which are useful for the best continuation of our studies and researches. Talking about the state-of-the-art means drawing lines between what has been done, what is currently being done, and what will be done taking advantage of new knowledge, renewed skills, and technological progress. Multidisciplinarity is essential in the path of study, research, and efficient management of results, and it is worth highlighting how the commitment of each entity and the recognition of expertises can make a difference. Based on the work carried out in the years which preceded to the congress and based on the organization of Hypogea2023, the need for constant experimentation in speleology has emerged, requiring a flexible attitude. The transformation process that has characterized our work at the Centro Studi Sotterranei has led us to redefine our project year after year, and continuous connections have emerged among the different levels of research of those involved. The congress represents an essential point of reference for the knowledge, protection, and enhancement of underground heritage of historical and archaeological interest at international level. In fact, it provides a reading of a wide-ranging researches and monitoring of completed and ongoing initiatives, offering an updated, innovative, yet realistic picture of a field which is constantly evolving and therefore increasingly complex. In this journey, it is fundamental the commitment of administrative leaders at various levels and, also, the need to share the importance of the topic with the society. Local government represents a key role to coordinate and influence what can be implemented in the territory, and its cooperation with higher institutions represents the possibility of developing more effective policies. The growing interest in topics covered by the scientific literature sector, of which the journal Opera Ipogea is a significant example, has not yet significantly reflected in local policy, where the issue is still largely experimental. Fortunately, there are representative cases in the management and urban planning of the underground, with adequate regulatory support from the urban resilience perspective, as it is the case of Helsinki has demonstrated for many years (Helsinki Underground Master Plan). The Hypogea2023 Congress also aims to provide a contribution and stimulus in this direction, focusing on the active role of those within Public Administrations who are tasked with making decisions or systematic evaluations at the local level. The result of this IV Congress represents valuable support for the fruitful future work of a relatively recent discipline such as Speleology in Artificial Cavities.
Special contribution about Genoa history
Roberto Bixio, 1997 Invisible Genoa Representation of Genoa (Italy) from a 1564 painting, inserted in a “mezzaro” (printed cloth, typical of the Genoese tradition). Icon of the full original painting. (Ink drawing, coloured with markers 17.5×17.5 cm)
13 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa 1 Department of Health Sciences, University of Genoa, Italy 2 UNESCO Chair “Anthropology of Health - Biosphere and Healing System”, University of Genoa, Italy 3 Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy 4 Centro Studi Sotterranei, Genoa, Italy 5 Opera Ipogea – Journal of Speleology in Artificial Cavities 6 National Commission of Artificial Cavities of the Italian Speleological Society 7 National Alpine and Speleological Rescue Corps, Italy 8 SIT Office, Technology Office Management - Information Services, Municipality of Genoa, Italy 9 Ministry of Culture, Soprintendenza Archeologia Belle Arti e Paesaggio per la città metropolitana di Genova e la provincia della Spezia, Italy 10 Department of Antiquities, Philosophy and History, University of Genoa, Italy * Reference author: [email protected] - phone +39 010 3538502 - [email protected] The plague (1656-1657) in the history of the Maritime Republic of Genoa (Italy): an important testimony of efficacious measures of safety and prevention in the field of hygiene and public health and a wonderful discovery of a precious historical heritage to protect. A “blend” of speleology and history of medicine Mariano Martini1,2,3,*, Stefano Saj4,5,6, Danilo Repetto4,7, Martino Terrone8 , Simon Luca Trigona9 , Nico Radi9 , Giancarlo Icardi1,3 and Francesca Ferrando10 Abstract The epidemic of bubonic plague that hit Genoa and its domain between May 1656 and August 1657 has gone down in history as the most fierce and devastating calamity to strike the territory of the Republic of Genoa during the modern age. Its severity is revealed by a remarkable historiography, which, right from the beginning of the epidemic, dealt with the features of the disease and the means utilized to control its spread. This study comes also from the discovery of skeletal remains (that are probably attributable to the plague of 1656/57) which first came to light in 1989, by the Centro Studi Sotterranei (Centre for Underground Studies) of Genoa which, this year, has resumed research in collaboration with the local Superintendency, the University of Genoa and the University of Urbino. For hundreds of years, these have remained buried under Acquasola Park, in a central area of Genoa. The authors analyze the institutional response of the Republic of Genoa to this calamity that devastated the city. This contribution initially focuses on the public health measures implemented, as demonstrated by original, unpublished and archival documents found in local archival sources, furthermore studies and research with the best specialist centers in the sector could soon allow us to shed new light on this destructive event and to clarify what it meant for the entire Genoese population and beyond. Genoa, at that time, was divided into 20 zones, each of which was placed under the authority of a commissioner endowed with criminal jurisdiction. The Commissioners’ duties concerned the spheres of public health, public order, and other preventive measures. The measures implemented by the Health Magistrate roughly retraced the model that had already been tried and tested during the plague of 1579: public health officers were deployed to guard the coasts; the city gates were garrisoned, and a network of secondary hospitals was created to relieve the pressure on the Lazaretto at the Foce. This structure, built in the early 16th century, was the city’s main outpost for the treatment of plague victims. The Commissioners of the zones were called upon to enforce the regulations of the Health Magistrate and to maintain public order. The experience of the plague in Genoa in the 17th century once again testifies to the importance of adopting measures of safety and prevention in the field of hygiene and public health. Genoa was well organized from the public health standpoint; its planning was innovative, and its set of dedicated norms and system of sanctions proved to be fairly efficacious. From the historical-social, standpoint and public health perspectives, this crucial experience clearly shows the organization of a large and powerful port city, which was at the time one of the most flourishing commercial and financial hub. Keywords: history of hygiene and public health; history of pandemics; plague; Maritime Republic of Genoa; speleology; history of medicine.
14 The plague (1656-1657) in the history of the Maritime Republic of Genoa (Italy) Introduction In October 1989, during a speleological expedition to explore some underground tunnels in the “Sestiere della Maddalena” – one of the six ancient districts of Genoa – a remarkable discovery was made by the Genoese team of explorers from the National Commission for Artificial Cavities of the Italian Speleological Society. The team was composed by Luca Canepa, Roberto Guagliardi, Marcella Marcenaro, Laura Marchesi, and Stefano Saj. Descending through a manhole, the group entered an underground passageway located 12 meters beneath the Spianata dell’Acquasola. After a very narrow and difficult path, the researchers found the walls structures of the 16th-century Bastione dell’Acquasola, which had been buried and forgotten under the homonymous public park. Inside the galleries of the military fortification, the speleologists made an important and astonishing discovery. In the darkness, under the light of their torches, they found piles of skulls and bones, a vast osteological deposit of thousands of skeletal remains not in anatomical connection (Bixio-Saj, 1991) (Fig. 1). The press emphasized the extraordinary discovery and called the site: the “città dei morti (city of the dead)” (Fig. 2). The plague that reached Genoa by sea The epidemic broke out in 1647 on the African coast, from where it spread first to Andalusia and then to Catalonia. It was subsequently carried by an infected ship from the port of Barcelona, reaching Sardinia in 1652. In Sardinia, the disease struck in two waves: - the first wave (1652-1653) involved the northern part of the island and carried a mortality rate of over 55%; - the second wave (1654-1657) involved the central and southern parts, from where it spread to mainland Italy. Between April and May 1656, the plague reached Naples, followed by Rome and finally Genoa. The pattern of its spread was always the same; the disease first appeared in the vicinity of a port (in Rome, the cities of Civitavecchia and Nettuno) and then spread like wildfire throughout the rest of the territory, following trade routes and the pathways of flight from the cities to the countryside (Topi, 2017). Although commerce with the port of Civitavecchia was banned by cities such as Rome, Florence, Livorno and Lucca, Genoa continued to receive traffic up to the month of June. The Republic of Genoa, however, was well organized, and as early as the 16th century had been endowed with an effective system to safeguard public health. Hence, the plague did not catch the city off its guard; the public health system, which had already been tested by the 1648-1650 epidemic of exanthematous typhus, was activated as soon as the plague manifested itself in Sardinia. In the city of Genoa, there was much talk of the plague, and, on the proposal of the Magistrate for Health, particular measures were adopted in order to reduce the probability of contagion. Nevertheless, these measures were initially ignored by most of the population (ASGe, Magistrato della Sanità, ms. 498, 1656). Paradoxically, this non-cooperation was greatest in the poorest and most populous neighbourhoods, precisely those that were at greatest risk, and which should have been the first to comply with the new measures and restrictions. Thus, the attempt to cordon off the city, to impose quarantine and to ban the importation of goods coming from infected areas did not meet with success, and in May 1656, the disease reached Genoa’s neighbouring villages in the Bisagno Captaincy (Assereto, 2011). At the time when the plague hit Genoa, about 90% of the city’s population lived within the “old walls”, in cramped houses with little sunlight and in an unhealthy environment without adequate sanitation. As a result, the spread of the plague was rapid and devastating. Fig. 1 – Cover of the six-monthly Speleologia magazine published by the Italian Speleological Society, depicting the last impressive unloading of bones inside the sixteenth-century bastion of Acquasola, belonging to the VI city walls (XVI century) of Genoa (photo C. Leoni).
15 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa The “Magistrate for Health” and the public health measures implemented Each day, the Magistrate for Health of the Republic of Genoa recorded the number of new cases of plague and of deaths. For this purpose, the city was divided into numerous districts; these were supervised by officials, who took a census of the inhabitants and their homes (ASGe Magistrato della Sanità, ms. 265, 1656). In general, the numbers of deaths and infections recorded by the neighbourhood commissioners were sent to the Magistrate for Health. In accordance with agreements made with neighbouring states, the Magistrate forwarded these data to the other health administrations at the end of each week. Often, however, states did not trust the reports provided by their neighbours and sent their own officials to check the truth of the information. If the presence of the plague was confirmed, the infected state was declared off-limits, and transit and trade were strictly forbidden. The measures implemented by the Magistrate for Health roughly retraced the model that had already been tried and tested during the plague of 1579: public health officers were deployed to guard the coasts; the city gates were garrisoned, and a network of secondary hospitals was created to relieve the pressure on the Lazaretto at the Foce (Assereto, 2011). In September 1656, the city authorities identified four areas (Fig. 3) inside the ancient walls; named after the patron saints of the city (St Laurence, St George, St John the Baptist and St Bernard), each of these areas was subdivided into five zones, denominated by the letters A to E (ASge, Sanità, 1656). Administration of these zones was entrusted to “Commissioners”, who were randomly selected from among all the patricians aged between 25 and 70 years, excluding those already engaged as health officers in the coastal areas. The Commissioners of the zones were called upon to enforce the regulations of the Magistrate for Health and to maintain public order. However, they also had duties in the sphere of public health and assistance (Campasso, 1669: 61v-67v). Indeed, they had to coordinate the work of the health personnel, close and seal warehouses containing precious goods, ensure that the streets were kept clean, supervise the controlled burning of any type of conFig. 2 – Article in the newspaper “Il Secolo XIX” of Genoa with the news of the discovery of the ossuary found by speleologists in the subsoil of the Acquasola city park.
16 The plague (1656-1657) in the history of the Maritime Republic of Genoa (Italy) taminated material, etc… They were also responsible for ensuring that a doctor and surgeon were on duty in the various zones, even during the night, that quarantine procedures were properly respected, and that infected individuals were correctly transferred to the plague hospitals assigned. Any transgression or noncompliance with the orders of the Commissioners resulted in sanctions being directly imposed by the Commissioners themselves. The Commissioners were assisted by chancellor and foremen (Campasso, 1669: 68r-75r), who verified the proper functioning of “sewers and wash-houses”, visited people in quarantine, and distributed bread and alms to the poorest. Their principal task, however, was to carry out a census of the population living in the streets under their jurisdiction and to record family data, for each house. During the 1656 plague, the Magistrate for the Poor suspended the Sunday distribution of “charity” bread in order to avoid dangerous gatherings of paupers. Silk, velvet and leather, but not only, were particularly dangerous and risky, as the particles of contagion could easily adhere to these materials and remain active for years and this was really a huge threat to everyone. For this reason, it was decided that clothes and any other material that could have come into contact with contaminated individuals should be immediately burnt. Furthermore, in the various areas and neighbourhoods, a diffuse information network was set up; this was coordinated by the foremen and by some citizens, who were terrified by the effects of the plague and also worried about the consequences it was having on the city’s economy. The Genoese plague hospitals and the management of the plague One of the main tasks of the Commissioners was to manage the sick and to organise their transfer to the Lazzaretto della Foce. This plague hospital had been built at the mouth of the Bisagno river at the beginning of the 16th century as a result of the intervention of the Compagnia del Divino Amore, a lay brotherhood founded by the followers of Saint Catherine Fieschi Adorno and by the Genoese notary Ettore Vernazza (Solfaroli Camillocci, 1994). This latter, as can be read on a plaque in the Albergo dei Poveri in Genoa, had been the most prominent welfare activist of his time. In Genoa alone, he had contributed to the foundation of the Ospedale degli Incurabili, of a “convent for penitents”, of a charitable organisation for homeless children and, above all, of Fig. 3 – Division of the city of Genoa into areas (graphics F. Ferrando and M. Gogioso).
17 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa the “Lazaretum ad ora Bisanii pro peste infectis” (Ferrando, 2023). Indeed, in 1512, the “Protectors of the Incurably Sick” had obtained authorization from the Senate to build “a refuge capable of housing the sick [...] detained on account of epidemics”. A further function was immediately added - that of the “purging” of goods, i.e. the quarantine of people and the fumigation of goods arriving from places suspected of being infected by the plague; this activity was directed by the Magistrate for Health. The refuge (Fig. 4) had a rectangular plan, with a perimeter courtyard divided into two others of equal size by a central arm, which was in turn divided longitudinally by an open-air corridor. Its location, at a safe distance outside the city walls, meant that it was isolated from the city, which was why it had been chosen at the end of the 16th century as the first place of internment for beggars. During the first phase of the 1656 epidemic of the plague, the Lazzaretto della Foce served as a shelter for all infected persons. However, from October 1656 onwards, some were transferred to the Convento della Consolazione, directed by Father Antero da San Bonaventura (Antero da San Bonaventura, 1658). Inside the plague hospitals, victims were assisted by a physician and a surgeon. - The physicians ordered blood-letting, established the patients’ diet and chose which “refreshments”, i.e. syrups, to administer. According to Father Antero of San Bonaventura, the most effective potions were those composed of inexpensive elements, such as those based on “cedar fruit juice [...], and rose petal sugar [...] with distilled water, black salsify, or scabiosa e or chicory”, while alchermes and potions containing crushed pearls and were to be avoided. - The surgeons were responsible for incising and cauterizing buboes, scarifying carbuncles and applying ointments to the lesions to help purge them of their fluid and to prevent wound infection and gangrene. As the months passed, however, it became increasingly difficult to find good quality ointments in the city, and each plague hospital produced its own by boiling black pitch and Greek pitch, white wax, pork fat and turpentine (Antero da San Bonaventura, 1658). The wealthier classes objected to being assigned to the Lazzareto della Foce, since it meant sharing cramped accommodation with members of the lowest social order. Furthermore, many claimed that the care provided was not beneficial and that theft and violence were commonplace. The end of the plague did not mark the end of the city’s subdivision into districts; on the contrary, this scheme was adopted several times during the 17th century, in order to carry out censuses of the population and other operations, such as the assignment of street numbers to buildings and the maintenance of public lighting (ASGe, Senato Senarega, n. 1092). Conclusions The experience of the 17th century plague in Genoa illustrates the fundamental importance of the prevention and safety measures that were adopted in the field of public health. The same can be said of our recent experience of the Covid-19 pandemic. The plague that hit Genoa in the 1600s was certainly a tough challenge for the city. As a subject of study, it is of interest to us from several points of view: - hygiene; - public health; - epidemiology; - patterns of spread of infectious diseases; - legislation; - health care organisation, etc… In those days, although legislation and healthcare organisation were not particularly advanced, the situation was handled well. Moreover, efficient communication with the population was able to yield good results in terms of the diffusion of information and people’s perception of the devastating event in progress. Obviously, however, it must be borne in mind that people’s behaviours and habits, especially with regard to hygiene, were far from optimal. In addition, at that time Genoa was a large city, a thriving commercial centre and, Fig. 4 – J. Howard, An account of the principal lazarettos in Europe: with various papers relative to the plague: together with further observations on some foreign prisons and hospitals, and additional remarks on the present state of those in Great Britain and Ireland, Printed by William Eyres, Warringhton, 1789.
18 The plague (1656-1657) in the history of the Maritime Republic of Genoa (Italy) above all, one of Europe’s main ports; it was densely populated and many of its neighbourhoods were hemmed in by very narrow streets (the famous Genoese “carrugi”). All these circumstances facilitated the spread of the plague. And yet, albeit with due caution and considering the standards of large cities in the middle of the 17th century, we can claim that Genoa was well organised from the public health standpoint; its planning was innovative, and its set of dedicated norms and system of sanctions proved to be fairly efficacious. Moreover, the strategy of dividing the city into zones in order to curb the spread of the plague proved to be effective, and the deployment of “neighbourhood commissioners” was able to yield greater control over daily activities. This approach gained the approval of the citizenry, so much so that, once the emergency was over, the subdivision of the city into districts was maintained, being adopted for various purposes on other occasions during the 17th century (ASGe, Senato Senarega, 1092). The study of this devastating historic event has prompted us to begin examining some skeletal remains that are probably attributable to the plague of 1656/57. For hundreds of years, these have remained buried under Acquasola Park, in a central area of Genoa. The remains first came to light in 1989, and this year research has been resumed by the Centro di Studi Sotteranei (Centre for Underground Studies) in collaboration with the University and the Genoese superintendence. Study and research with the best specialist centres in the sector could soon enable us to shed new light on this destructive event and to clarify what it meant for the entire population of Genoa and beyond. Bibliography Antero da San Bonaventura P., 1658, Li lazaretti della città e riviere di Genova del MDCLVII [...] descritti dal R. P. Antero Maria da S. Bonaventura scalzo agostiniano, Genova, Pietro Giovanni Calenzani e Francesco Meschini, ristampa anastatica 1974, Genova. Assereto G., 2011, Per la comune salvezza dal morbo contagioso, I controlli di sanità nella Repubblica di Genova, Città del Silenzio, Genova, pp. 15-20. Bixio R., Saj S., 1991, La peste ed il basione dell’Acquasola, in rivista Speleologia, n. 24, Società Speleologica Italiana Bologna, pp. 5-7. Campasso G.B, 1669, cc. 61v-67v, Istruzioni dei commissari di quartiere. Biblioteca Medica Mario Segale, Compendio de’ decreti de Ser.mi Colleggi et Ill.mo Mag.to di Sanità con insertione di leggi de Consegli della Ser.ma Rep.ca per preservare, e liberare la città e dominio dalla peste negl’anni 1656 e 1657 raccolti da Gio. Bartolomeo. Campasso G.B., 1669, cc. 68r-75r, Istruzioni dei capistrada. Ferrando F., 2023, Assistere, correggere, rieducare. I ricoveri per mendicanti di Genova, Bologna e Venezia (XVII-XVIII), Viella Ed., Roma, pp. 47-52. Solfaroli Camillocci D., 1994, La “carità segreta”. Ricerche su Ettore Vernazza e i notai genovesi confratelli del Divino Amore in Tra Siviglia e Genova: notaio, documento e commercio nell’età colombiana, a cura di Vito Piergiovanni, Giuffré, Milano, pp. 393-434. Topi L., 2017, Forme di controllo in una città “appestata”: Roma 1656-1657, «Eurostudium», 2017, pp. 25-26. Archival sources ASGe, Magistrato della Sanità, 1656, ms.498, Manuale delle deliberazioni. ASGe, Magistrato della Sanità, 1656, ms. 265, cc.74-76, Relazione (12 settembre). ASGe, Sanità, n. 1881, 1656, (13 settembre). ASGe, Senato Senarega, n. 1092.
Underground architecture and urban plannig
Roberto Bixio, 2002 Cappadocia Rendering of a hypothetical Arab attack on a Byzantine underground settlement. Icon of the full original painting. (Ink and watercolour, 45.5×34.5 cm)
21 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa 1 Speleo Team Trapani ETS, Via Case di Grazia 22, 91019 Valderice, Trapani, Italy * Reference author: Roberto Grammatico - [email protected] The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi Roberto Grammatico1,*, Roberto Mazzeo1 Abstract The city of Trapani during the Second World War was, due to its geographical position, an important outpost for supplies to the troops engaged on the African front, as well as a submarine base and warships and equally important for the two military airports of Milo and Chinisia and for the hangars of Marsala and Pantelleria. The strategic importance of Trapani was in the storage of naphtha for torpedo boats to defend the naval traffic of the Regia Marina together with the deposits of Cagliari, Palermo and Syracuse. An important aspect that conditioned the construction of these tanks for the storage of liquid fuels, in the years immediately preceding the Second World War, was the difficulty of finding ferrous materials already heavily used for the construction of armaments as well as the autarkic choice of the regime which prevented any importation, for which an alternative construction system had to be sought that would guarantee the stability of structures with large spans therefore, while in the rest of Europe structures with metal frames and roofs continued to be built, in Italy thanks to the scientific and technological research conducted between 1936 and 1940 by the engineer Pier Luigi Nervi on the potential of reinforced concrete was tested and subsequently patented the construction technique of tanks with containing cavities due to the difference in density of the liquids. The discovery in the area of Monte Erice (TP) of a system of tanks based on the Nervi project and the related underground tunnels that connect them to the liquid transfer systems up to the underground distribution point confirm the strategic importance of this area during the second world war. Key words: royal navy, fuel tanks, reinforced concrete, interspaces, speleothems. Geographical location and geological outlines The study area where the Nervi tanks for liquid fuels are located falls within the locality of “Casa la Porta” in the territory of the Municipality of Erice, in the sud-ovest sector of the mountain, within an area of 2,38 hectares at an altitude of 75 m a.s.l. (fig. 1). The outcropping lithotype (fig. 2a) in the easternmost portions of the site consists of stratifications Fig. 1 – Geographical location of Erice tanks (graphics R. Grammatico).
22 The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi with decimetre banks of white - gray marly calcilutites and calcisiltites with lists and nodules of flint with paleofaunistic content consisting of Foraminifera, Belemnites, Radiolarians, Brahciopods and fragments of crinoids of the Lias sup.- Dogger (Wendt, 1971); this lithotype is mainly covered in discordance by a detrital accumulation (fig. 2b) arranged on surfaces of non-deposition and sub-aerial erosion belonging to the Capo Plaia synthem of upper Pleistocene-Holocene and consisting of debris Fig. 2 – a) Geological section W-E; b) Excavation for the construction of the Nervi tanks in contrada Argenteria, north Erice (photo and graphics R. Grammatico).
23 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa layer of conglomerate size immersed in a matrix of moderately cemented ruditic size whose upper limit is the current topographic surface (Di Maggio et al., 2009) . Design methods of the Pier Luigi Nervi tanks In 1935 the engineer Pier Luigi Nervi elaborated, for the Royal Navy, the prototype project for an underground tank in reinforced concrete intended for the storage of fuel called «type Ingg. Nervi and Bartoli». It is a cylindrical structure in reinforced concrete (fig. 3), built using the excavation as a base formwork. On the circular plan, with a diameter of 32 or 36 meters, the columns are set, in number of twelve or twenty-one depending on the size of the cistern, for a height, also variable, of 10 or 16.5 meters. From the prototype project, different solutions were elaborated that responded to the characteristics of the place of construction and to the specific military needs. In addition to the dimensional variants, the typology for “rocky terrain” and that for “no-rocky terrain” are distinguished. Then there is the «simple masking type», which provides only for covering with vegetal soil, and the «armored covering type», designed to resist the direct impact of two 500 kg bombs. The commitment and genius of the engineer Pier Luigi Nervi demonstrated in the search for increasingly performing solutions on the hydrostatic and structural seal of the tanks are highlighted by the succession of patents registered between 1936 and 1940, listed below (Ribera et al., 2014): • year 1936 - patent n° 338800 - “Tank for liquids lighter than water and not miscible with it, especially naphtha, oils, petrol and the like”. The typology is a reinforced concrete tank with a diaphragm separating water from oil, with tanks having a circular section. This first version of tanks exploits the greater specific weight of the water to reduce the loss of naphtha through probable damage to the shell: a layer of water was interposed, in fact, between the liquid to be conserved and the internal surface of the tank, a layer which, in case of imperfect sealing of the bottom or walls of the tank, it was constantly restored with pumps or other sources in order to avoid any loss of the lighter liquid stored in them. This typology could also be applied to already built water reservoirs which could have been transformed into tanks for naphtha, oil and petrol; • year 1937 - patent n°349384 - “Procedure for the construction of a composite cement wall, formed of alternating layers of cement conglomerate and thin layers of pure cement for sealing liquids or gases and the relative product”. It is the first case of a tank with a reinforced concrete shell against the ground. As is known, all conglomerates have a high penetrability to liquids such as oils or naphtha at high pressure. The cement wall in question was formed by a first layer of normal cement conglomerate, onto which, after setting but before hardening, a layer of pure cement mortar and water was projected with the cement gun technique, of a thickness equal to 5 or 10mm. A subsequent layer of normal cement conglomerate was then poured. The layer of pure cement (white and free from blast furnace slag) completed its seasoning in conditions of perfect humidity, being included between the other two layers. The wall thus formed, due to the perfect solidarity between the various layers, was characterized by excellent mechanical characteristics, thanks to the layers of normal cement conglomerate, and by a high impermeability, conferred by the layer of pure cement; • year 1937 - patent n. 348774 - “Double cement wall for sealing and control for large underground tanks”. The shell in this case consisted of a wall in direct contact with the liquid which was entrusted with the function of sealing and a wall against the ground which was entrusted the function of containing hydrostatic thrusts. Walls and bottom against the ground could be made of reinforced concrete, masonry or be obtained from a regularized rock surface. The innermost wall, in perforated concrete blocks, was to be built at a distance of 10 or 20 cm from the concrete wall, with the holes in the blocks arranged vertically in continuation of each other. As the wall in blocks was raised, a layer of conglomerate was poured between the two walls at a normal dosage and carefully compacted. Grooves were foreseen between a row of blocks and the upper one to accommodate a reinforcement formed by Ø 5 iron rods. These rods were drowned in the concrete casting, protruding from the sealing wall in blocks. A similar stratigraphy was foreseen for the bottom, in which the perforated blocks obviously followed a horizontal structure. All the channels that were formed by the succession of blocks converged in perimeter galleries at seabed level of the tank, entering via steel or asbestos pipes closed with a screw cap. Furthermore, the layer of conglomerate thrown into the cavity was kept in constant humidity, by circulating water in the vertical channels of the perforated blocks. While the concrete was acquiring its mechanical properties, a 20 cm wire mesh was joined to the bars protruding from the blocks, finished with a subsequent Fig. 3 – Project and plastic of Nervi tanks (adapted from Argiroffi, 2008).
24 The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi casting of a 7 cm layer of cement paste using the cement gun technique; • year 1937 - patent n° 355466 - “Improvement in underground tanks for liquid fuels and the like, in order to make them suitable for the attack of aerial bombs”. In this case the truncated-cone tank consists of two walls with an aerated cavity; the internal wall which contains the liquid is metal while, the external one, is in reinforced concrete and has a section that gradually decreases as one moves away from the roof, namely as the effects of a deflagration are reduced; • year 1938 - patent n°363646 - “Procedure and device for creating and maintaining a layer of pressure determined in value and direction between two bodies, for example between a building structure and the supporting ground”. Engineer Nervi experiments with the First method of preventive forcing. In many technical fields it is necessary to solicit two contiguous bodies or one in the presence of the other by means of a pre-established force. The state of stress is activated by means of special devices, which in turn need accessory elements and, once the desired state has been reached, it requires subsequent actions to be kept as such. The 1938 patent applied this principle to the walls of the tank, which, previously stressed, were prepared to resist the pressures of the liquid substances they were to contain, without the risk of uncontrolled deformation. To this end between the walls to be put in a reciprocal state of stress the introduction of bags was foreseen made of flexible and different material depending on the nature of the walls which were then filled with cement mortar or asphaltic substances. Thus, a well-defined pressure was created on the entire surface of the bags which, following the subsequent hardening of the injected substance, would keep the state of compression constant due to deformation; • year 1938 - “Improvement of concrete tanks for liquid fuels”. This patent introduced the typology of tanks with cavity in loose material. The impenetrability of the oils inside the conglomerate is given by the presence of small quantities of water inside the pores of the same; over time, the loss of water in the pores of the concrete makes the material more permeable to petroleum products. The patent solved the problem by keeping the concrete wall always moist, through the introduction of porous and rot-proof loose material (such as pozzolan, pumice, crushed stone, coke powder or diatomaceous earth) inside the cavity formed between two layers of cement conglomerate; the loose material tended, in fact, to retain large quantities of water between the pores, which kept the adjacent internal concrete wall at a constant humidity, making it impenetrable to the hydrocarbons present in the tank; • year 1938 - patent n° 364418. This patent made some improvements to the seal and was applicable to any tank with reinforced concrete shell. The patent, called “Improvement of tanks in reinforced concrete for liquid fuels”, aimed to reduce the drying out of the cement wall that made up the shell, using hygroscopic substances (such as calcium chloride) in the preparation of the plaster applied to the external surface of the tank, capable of absorbing atmospheric humidity; • year 1938 - patent n°375055 - “Procedure and device for creating and maintaining a state of pressure determined in value and direction, between two bodies, for example between a building structure and the supporting ground”. In this case, the Nervi & Bartoli firm achieved a high level of specialization in the induction of states of compulsion between the structure and the ground, developing what can be defined as the second method of preventive forcing. The inner wall of the tank was made with special lean concrete blocks composed of two parts, one C-shaped and one T-shaped, placed side by side and between which a jute tube was inserted. After installation, the jute pipes were filled with water, thus causing the two parts of the blocks to move away and the formation of cavities (in an alternating position with respect to those containing the pipes) which were, therefore, filled with cement mortar. After the mortar had set, the bags that contained water were emptied by unscrewing the cap present in the inspection tunnels and subsequently extracted from the interspace. The forcing blocks could be placed side by side with a load-bearing masonry structure or with a reinforced concrete mantle against the ground, allowing for the compaction and settlement of the soil-structure system; • year 1939 - patent n°377827 - “Improvement in the construction of masonry tanks with sheet metal lining, especially for liquid fuels”. Introduction of a system to solve some executive and operational drawbacks for masonry tanks with casing in thin metal sheets. In fact, a method was presented which allowed for checking the welds between the joints of the various sheets before being put into service, as well as checking the seal over time. The system envisaged arranging the metal jacket not in direct contact with the wall structure, constituting the walls and the bottom of the tank, but leaving a cavity of limited thickness between them. The plates were fixed with nails, whose heads would then be covered by welding, on wooden currents fixed in turn with clamps to the wall structure. This made it possible to test the tightness of the welds by introducing lightly pressured air into the cavity, at the same time passing a soapy solution over the surface of the sheet: the formation of bubbles would have highlighted even the slightest leak. Furthermore, by assigning a slope to the wall structure, any loss of liquid that would have occurred during the operation phase would have been immediately detected by inspecting the manhole positioned at the pre-established point of convergence; • year 1940 - patent n°384152 - “Improvement of tanks for liquids and particularly for hydrocarbons through the adoption of bottoms or walls in plastic clay”. The latest family of underground tanks de-
25 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa signed by Nervi belongs to the typology with plastic clay walls, exploiting the principle according to which clay, sufficiently pure and suitably treated and compacted, is perfectly impermeable to the passage of liquids, such as hydrocarbons. The clay was then placed on the bottom and in the cavities of the mantle and was constantly kept in a plastic state, as well as constipated; • year 1940 - patent n°388212 - “Improvement of tanks for liquids and particularly for hydrocarbons through the adoption of bottoms or walls in plastic clay”. It provided for the case in which the underground tank was built in clayey soil, very compact and therefore already impermeable in itself. Description of the Monte Erice tanks All the tanks projects were probably carried out by Nervi’s own firm, the «Nervi & Bartoli» but the locations of the locations are still covered by military secrecy even though some of them have been made state-free so that the discoveries are always random as in the case of the 12 cisterns of Monte Pellegrino in Palermo whose identification took place due to the collapse of the cover of a cistern and the consequent formation of a chasm. In the case of the cisterns of Monte Erice in Trapani, the discovery took place by young people who entered the shafts and who informed the writers of the presence of cisterns, wells and underground tunnels. The underground structure (fig. 4) has 4 entrances which lead to the various underground rooms. The first 2 entrances communicate via an 11 m long stairway and a short 5 m long tunnel with the two cisterns, accessible via a walled-in iron ladder (fig. 5a), with a diameter of 36 m and a depth of 19 m for a volume equal to 18,270 m3 , 28 load-bearing columns (fig. 5b) arranged in concentric circles with a diameter of 1.2 m with shape at the base flared outwards up to a diameter of 2.8 m Fig. 4 – Plan and section NNE-SSW of Monte Erice tanks (graphics R. Mazzeo). Fig. 5 – a) Access stairway to the Erice tanks (photo D. Clemente); b) System of columns bearing Erice tanks (photo D. Caparotta).
26 The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi Fig. 6 – Pipes for water injection: a) horizontal injection; b) vertical injection (photo G. Monteleone). Fig. 7 – Speleothems on water input pipes: a) cannulas; b) crusts; c) stalagmites (photo G. Monteleone).
27 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa while the internal perimeter of the tanks has a flared shape towards the center. The tanks can be traveled up through a tunnel along the entire circumnavigation and through a well with an iron staircase one enters the basal portion of the same, which can also be traveled through a tunnel throughout the circumnavigation. At the base there are the pipes for the transfer of liquids. All the pipe ducts, both horizontal (fig. 6a) at the base of the tanks and vertical (fig. 6b) on the wall of the tanks, which were used to introduce water into the containment interspace, are also visible. Of interest is the formation of speleothems along these pipes due to the percolation of infiltration water with very thin cannulas over a meter long (fig. 7a) and the formation of stalagmites at the base (fig. 7c) as well as very white calcium carbonate crusts (fig. 7b). Another entrance leads to the main descent 32 m long consisting of a staircase flanked by a slide useful for moving materials inside the tunnels. The shaft communicates with a maneuvering area where there is currently a system for the forced movement of fluids (figs. 8a, 8b) consisting of a pumping system with an internal combustion engine. Two tunnels branch Fig. 8 – Pumping system: a) side view; b) front view; c) maneuvering shutters (photo G. Monteleone).
28 The tanks of the Regia Marina of Monte Erice (Trapani, Italy) on a project by the engineer Pier Luigi Nervi off from this maneuvering area, one of which in the nord-nord-est direction 44 m long and another in the sud-sud-est direction 20 m long, which lead to 2 rooms connected to the base of the two cisterns where the maneuvering gate valves are located (fig. 8c ) and two 18 m high vertical shafts which are connected via a walled-in iron staircase with the upper part of the cisterns. Another 170 m long tunnel branches off from the maneuvering area which, at a distance of 61 m, has a vertical ventilation shaft 13 m high; said tunnel leads, on the bottom, to an environment where there are currently aspirators for forced ventilation and a tank for the collection of waste currently filled with oily substance; just before this room there is a staircase that leads to another entrance while before the staircase, on the left wall of the tunnel, there is the connection of the pipe which is buried in a northerly direction towards the discharge points of which an intermediate hut is known at the point with UTM coordinates 33S 284845.99 E 4211810.76 N and probably a final unloading point located on the beach of San Giuliano with UTM coordinates 33S 283559.50 E 4212506.44 N where there is a “shed of 30 square meters for docking of submarine cables” owned by the Ministry of the Defense of maritime state property. Acknowledgements For exploration activities, topographic surveys and photographic documentation: Rosario Bonventre, Luigi Fontana, Dario Caparotta, Giuseppe Monteleone, Gabriele Grammatico, Francesco La Grutta, Francesco Urso, Angelo Perniciaro. Bibliography Di Maggio C. et al., 2009, Unità a limiti inconformi utilizzate per la cartografia dei depositi quaternari nei fogli carg della sicilia nordoccidentale - Il Quaternario, Italian Journal of Quaternary Sciences 22(2), pp. 345-364. Paoletti C., 2016, La logistica dei combustibili della Marina durante la Grande Guerra, Bollettino Associazione Nazionale Marinai d’Italia 04/2016, pp. 4-9. Ribera F. et al., 2014, Sulle tracce delle opere di Pier Luigi Nervi in Campania: i serbatoi interrati a Pozzuoli (Napoli), III Congresso Internazionale Concrete 2014, Progetto e Tecnologia per il costruito tra XX e XXI secolo, pp. 285-296. Argiroffi G., 2008, Le cisterne sotterranee di Pier Luigi Nervi a Palermo, Lexicon n. 7/2008, Edizioni Caracol, pp. 75-77. Wendt J., 1971, Geologia del Monte Erice (provincia di Trapani, Sicilia occidentale), Geologica Romana, volume X, pp. 53-76.
29 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa 1 SIT Office, Technology Office, Municipality of Genoa, Italy * Reference author: [email protected] Genoa Municipality GeoPortal as tool for underground and overground analysis (Italy) Martino Terrone1,*, Elena Ausonio1 , Flavio Marovic1 , Cristina Olivieri1 , Andrea Rimassa1 , Federico Rottura1 , Emilio Vertamy1 , Luca Volpin1 , Stefania Traverso1 Abstract For nearly twenty years, the Municipality of Genoa has developed the GeoPortal which is used for the visualization and processing of spatial queries and geographical analysis of the various representative information layers of the City that our team. The SIT (Sistemi Informativi Territoriali, Technology Office, Municipality of Genoa), has published these layers in collaboration with all the technical offices. The GeoPortal is digital service of great importance for citizens, investee company and various municipality departments, as it allows spatial localization of information and different areas zoning in order to prepare urban planning regulations. In a growing interest in the search for spatial and temporal detail, the GeoPortal has been completely renewed and is now a powerful tool for 3D visualization aiming to build the digital twin and smart city. In this context the digitalization of the underground is particularly important because it allows an agile visualization of interference between the overground and underground utilities, underground cavities and deep geological strata. This paper proposes the very first prototypical results of the modeling of five cases of anthropic hypogean environments pertaining to the historic center of Genoa: all examples of a stratified and centuriesold city history whose precise spatial location not only adds historical, cultural and material knowledge, but also allows a precise definition for the geo-hydrological risk mitigation. Keywords: artificial cavities, inventory, typology, risk, GIS, GeoPortal, Urban Planning. Introduction Geographical data pay special attention to Urban Planning, which implicitly needs to be graphically supported by a computer environment for its visualization. The tool suited for this aim, and which allows geographical information to be shared via web is called GeoPortal. The first geoportal was realized by US National Spatial Data Infrastructure in the early 1990s in the United States with a government project (Maguire et al., 2005): digital features were catalogued and divided into individual information layers, by overlapping them, it is possible to compare different and heterogeneous objects in different fields and themes. After Thirty years, geoportals of public organization around the world not only allow simple visualization and querying, but work with advanced spatial analysis tools to query, filter, measure and edit both text and shapes. Over the past decade and, more frequently, in recent years, the development of computer technology has made possible to visualize and edit three-dimensional objects with photorealistic details on a centimeter to micrometer scale. In this context, the SIT (Sistemi Informativi Territoriali, Technology Office) of the Municipality of Genoa started to enhance its GeoPortal by integrating the Cesium platform (Woo et al., 2022) and having special algorithms developed and freely available on various software project hosting services (Di Pisa et al., 2022). Within the GeoPortal interface, by enabling the 3D mode, thanks to special measurement tools (length, elevation above sea level, angles, areas) it is possible to measure the aero-photogrammetric model of the Genova land area (precision of 5.5 cm) (Cau et al., 2022) and also create ‘Views’, i.e. limited portions of the City. In order to obtain an accurate knowledge of the Genoa’s underground, functional to the risks and urban management and resources use, the Municipality of Genoa began a project of prototype 3D rendering of some particularly significant anthropic hypogea to be visualized within the GeoPortal. This work is the evolution of a 2D mapping conducted in the early 2000s, which had led to the location and classification of 124 elements of the Historic Center, i.e., the buffer area of the UNESCO site (Giusso et al., 2021). The aim of this paper is to outline the methodologies and workflow for various formats of three-dimensional geographical data in municipal databases their visualization in the GeoPortal to get the digital copy of underground cavities for the construction of the Digital Twin of the City (Alva et al., 2023). Study area, Identification of the hypogea and peculiarities The five cases studied are in Historic Centre of the city (North-West Italy) (fig. 1). According to the Clas-
30 Genoa Municipality GeoPortal as tool for underground and overground analysis (Italy) sification of Artificial Cavities of the International Union of Speleology: In the category A - Hydraulic Underground Works 1) The Belimbau Cistern (17th century) classified as A4 – cisterns the building and its complex were placed in the first class of the Rolli genovesi (Bochicchio et al., 2010) e acquired in the 2007 by University of Genoa. 2) The medieval Fontane Marose Well gives its name to the 19th-century Piazza Fontane Marose square. Initially classified as A4, should correctly belongs to the subcategory A5- Wells; 3) Trace of the Old Aqueduct (from medieval to modern age) placed in Corso Paganini, A6 - Distribution; In the Category D – Military and war works: 4) Ruins of Acquasola Bulwark (16th century) occurring the ossuary dating back to the plague victims of the 17th century, D2 - Galleries 5) Shelter Prefecture of Villetta Di Negro (WWII epoch), D6 - Shelters for Soldiers The SIT Team commissioned both the survey and three-dimenasional processing of the five cases to the Centro Studi Sotterranei (later called CSS), an expert team in hypogea survey which records point clouds both in static mode with a Leica RTC 360 (Cyclone Core/3D) laser scanners of and in dynamic mode with iPHONE 14 Pro mobile phone (later called iPHONE) for detection of the most cramped underground cavities (Torkan et al., 2023). In addition, for all cases, BIM models were developed to integrate other information that cannot be deduced from the point cloud visualization, such as the thickness of the masonry in the extrados of the artefacts buried in the ground. For this reason, CSS, based both on scientific reference (Poleggi et al., 1966) and professional experience with similar coeval manufact, managed to estimate architectural parameters. For the case of the Fontane Marose Well, the BIM model allows to balance the information lack regarding to deeper parts of the hypogeum. This was due to the difficulties of pumping out the groundwater inside the well. Differently to the other cases, Fontane Marose Well is the only site where the original function (storing water in this example) is still present. Specifically, the survey operations consisted of a preliminary pumping of water (evacuated into the near Sant’Anna stream culvert) to lower the piezometric level, which was partially unsuccessful because the rate pumps failed to counteract the discharge (Zekai et al., 2007) with the result of point clouds recording failing. Fig. 1 – Location map: 1) Belimbau Cistern; 2) Fontane Marose Well; 3) Old Aqueduct (Corso Paganini); 4) Acquasola Bulkward; 5) Shelter Prefecture of Villetta Di Negro.
31 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa Material and Methods Materials The materials used to visualize 3D data within the GeoPortal, as mentioned above, pertain to the five cases covered by the surveys. The files were delivered by the client to the SIT Team in two different formats: the point clouds in .e57 and the BIM model in Autodesk in .rvt (Autodesk REVIT format). The reference system is the RDN2008 UTM fused 32N (EPSG 7791). In some cases, the point clouds have a size greater than 10 GB, because both hypogea and their overground environments were treated (fig. 3). Methods A workflow was design to convert input file delivered by the supplier to the correct format in Cesium Platform Engines (fig. 2). The point clouds were preliminarily manipulated through the PDAL library for: • clipping the strictly area zones of the hypogea for each case and applying Reference System transformation from RDN2008 UTM zone 32N (EPSG 7791) expressed in meters to pure WGS84 (EPSG 4326) expressed in angles, which is the SR compatible with Cesium; • optimizing format compression in relation to the desired resolution. Because of its high point clouds density (2 mm of resolution) when the reference system transformation is applied, it is necessary the seventh or the eighth decimal precision. Next, the CESIUM ION converter was used to transform the .LAS files into 3dTiles format (.pnts). For BIM environment, in order to be compliant as public administration and using OGC format, a preliminary model conversion was performed from .rvt to .IFC type (OGC format). For now, it is no possible to import IFC format directly in the GeoPortal and, for this reason, it must be accepted to lose georeferenced and material information. For this reason, a workaround was created: a WFS Fig. 2 – Workflow. Fig. 3 – One of the first outcome from underground survey (Cloud Points of Fontane Marose Well).
32 Genoa Municipality GeoPortal as tool for underground and overground analysis (Italy) Fig. 4 – The five cases on GeoPortal: a) Belimbau Cistern Point Cloud; b) Belimbau Cistern pseudo-BIM model; c) Fontane Marose Well Point Cloud; d) Fontane Marose Well pseudo-BIM model; e) Old Aqueduct Point Cloud; f) Old Aqueduct pseudo-BIM model; g) Acquasola Bulwark Point Cloud; h) Acquasola Bulwark pseudo-BIM model; i) Shelter Prefecture of Villetta di Negro Point Cloud; l) Shelter Prefecture of Villetta Di Negro pseudo-BIM model.
33 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa layer was set within the GeoPortal, containing a number of anchor points that act as barycenter to receive the .Gltf format which, appropriately rotated on the XY plane and shifted on the Z axis, allows a perfectly georeferenced pseudo-BIM model to be displayed. Results and Discussion The five cases were imported into the GeoPortal according to the workflow described above. For all of them, pseudo-BIM models were imported. The word ‘pseudo-BIM’ means a 3D feature, derived from a real BIM model, where only geometry is preserved and georeferenced and material information are lost. For the Old Aqueduct case only, iPHONE point cloud was imported; for the remaining cases, Laser Scanner point clouds were imported (fig. 4). Uploding 3D features, allows to assess the geometric dimensions of hypogea and their spatial relationships with the surrounding geographical environment. The Belimbau Cistern is made of two adjoining vaulted rooms in plastered limestone masonry of multi-decimeter size with an estimated thickness of 80 cm; with regard to the larger room, where the load-bearing column is located and in which the chimney connecting with the interior of the palace is inserted, the overall dimensions measure 8.35 m x 7.7 m x 7.1 m, while the smaller room is 3.76 m x 4.2 m x 6.96 m. The Fontane Marose Well consists of three vaulted rooms in exposed limestone, varying in size, longitudinally contiguous and symmetrical, with an overall size of 13.8 m x 8.5 m x 13.9 m. To access the main tripartite hypogeum, it is necessary to enter a flush drain into a 2.20 m high antechamber, then walk down a stone staircase that leads to a hypogenous chamber. This space divides the tombed bed of the Rio Sant’Anna from the well whose depth is around 15.95 m above ground level or 1.30 m slm. The trace of Old Aqueduct has a straight tunnel that measures 162 linear meters and is made of a vaulted channel in stone and masonry with an average thickness compared to the intrados of 0.5 m and a height of approximately 1 meter. Every 10 m, the vault is surmounted by a 0.84 m high chimney structure that connects it with the stone paving on the surface. Fig. 5 – 3D Rendering of “Views” of pseudo-BIM model of Fontane Marose Well and Shelter Prefecture of Villetta Di Negro overlapped on Hydrogeological Map of Genoa. In legend: 1) Landfill; 2) Sediments over impervious rocks; 3) Sediments over permeable and semipermeable rocks; 4) Permeable Rocks. In the map the red line is Sant’Anna culverted stream.
34 Genoa Municipality GeoPortal as tool for underground and overground analysis (Italy) The Acquasola Bulwark is a rhomboid limestone structure consisting of two parts. There is an external tunnel walkway characterized by a stone and masonry vault 2.5 m high and 0.8 m wide for a total linear length of approximately 375 m, which is divided into a SW trace 112 m long and a NE one 81 m long, and a cusped part with various tunnel walkways approximately 60 m long. The inner rhomboid part consists of a vaulted room 2.3 m high and 2 m wide with a total linear length of approximately 160 m. From Spianata of the Acquasola, a garden created at the beginning of the 19th century with elevation of 40 m above sea level, the hypogeum can be accessed through one of the three existing chimneys for a total height of 10 m. The Shelter Prefecture of Villetta di Negro is located at an elevation between 44 and 50 slm. It has a ‘T’ shape: the E-W tunnel is an oriented section measures approximately 115 linear meters, while the N-S one measures over 90 linear meters. It consists of galleries interspersed with halls, both made of reinforced concrete. The average width is 3.9 m, and the height is 3 m. A view was subsequently created on the GeoPortal, clipping the aero-photogrammetric mesh for each case to view the underground and overground at the same time without the encumbrance of the building out of the area of interest (fig. 5). Moreover, the GeoPortal allows to upload additional information layers from others project database such as the Hydrogeology layer, to understand the urban geological model, the circulation of groundwater, how the hypogeum interfered with by the underground, possible geo-hydrological risks (flooding, possible contamination of the water table) and groundwater exploitation. These evaluations are an integral part of land management, a necessary step for building Smart City as process for planning processes and simulation and, firstly, for Digital Twin Model to understand the great complexity of a stratified and vertical city like Genoa. In the case of the urban hypogea, what is the interference with the soon-to-be planned construction sites, with the existing underground utilities, with the surrounding buildings. Conclusive remarks This paper showed the methodology and workflow for transforming three-dimensional data collected in the field and processed in post-production for five artificial hypogea within the GeoPortal of the Municipality of Genoa. The result showed the perfect georeferencing of the two-point clouds obtained with the Laser Scanner and the iPHONE in GeoPortal. Regarding to the BIM model elaborated with the proprietary software REVIT, but now it is not possible to import a georeferenced file in opensource environment and therefore, through various format steps, five pseudo-BIM models without spatial information were imported, hooked to as many georeferenced anchor points. Further studies and future software development will be needed to be able to directly import BIM models for an even more effective visualization and management of the territory by realizing the topsoil with the anthropogenic underground cavities. Acknowledgments This work was carried out thanks to the ordinary fund (year 2021-2022) of the Technology Office of Municipality of Genoa. Bibliography Alva P., Mosteriro Romero M., Pei W., Bartolini A., Yuan C., Stouffs R., 2023, Bottom-up approach for creating an Uban Digital Twin: platform and use cases, in Proceedings of the 28th International Conference of the Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), 2023-1, 605-614. Bochicchio L, 2010, Between tradition and innovation: A preliminary survey on the artistic heritage of the University of Genoa, Italy, in Journal Opuscula Musealia 18-2010, pp. 23-24. Cau G., Rossi M., Rottura F., Traverso S., Ausonio E., Raso J., Torre S, 2022, Rilievo aerofotogrammetrico e visualizzazione 3D della città di Genova, in Proceedings of ASITA 2022. Di Pisa T., Rottura F., Bovio S., Olivieri C., Ausonio E., Giannecchini S., 2022, Il Geoportale del Comune di Genova: progettazione implementazione e lessons learned, in Proceedings of ASITA 2022. Maguire, D.J., Longley, P.A., 2005. The emergence of geoportals and their role in spatial data infrastructures, in Computers, Environment and Urban Systems 29-2010 pp. 3-14. Poleggi E., 1966, Il rinnovamento edilizio genovese e i magistri Antelami nel secolo XV, in Proceedings of Convegno Internazionale “Premesse per un repertorio sistematico delle opere e degli artisti della valle Intelvi”, pp. 53-68. Torkan M., Janiszewski M., Uotinen L., Rinne M., 2023, Method to obtain 3D point clouds of tunnels using smartphone LiDAR and comparison to photogrammetry, Rock and Fracture Mechanics in Rock Engineering and Mining, in Proceedings of IOP Conference Series: Earth and Enviromental Science, 2023. doi:10.1088/1755-1315/1124/1/012016. Woo K., Onsen A., Kim W., 2022, Georeferencing 3D Tiles Generated from Photogrammetry-Derived Mesh Using Ground Control Points, in Journal of Geographic Information System, 14-2022, 430-443. Zekai S., Altunkaynak A, 2007, Variable Discharge Type Curve Solutions for Confined Aquifers, in Journal of the American Water Resource Association, 40-2004, pp. 1189-1196.
Artificial cavities as a possible geological risk factor
Roberto Bixio, 1996 Meteors (Greece). Icon of the full original painting. (Watercolour and golden foil, 35×35 cm)
37 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa 1 Università degli Studi di Genova (Italia) 2 Centro Studi Sotterranei, Genova (Italia) 3 Opera Ipogea - Journal of Speleology in Artificial Cavities, Società Speleologica Italiana, Bologna (Italia) 4 Ufficio SIT, Servizi Informativi, Direzione Technolgy Office, Comune di Genova (Italia) * Reference author: [email protected] Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) Francesco Faccini1,2,*, Roberto Bixio2 , Andrea Mandarino1 , Pietro Piana1 , Stefano Saj2,3, Martino Terrone4 , Mauro Traverso2 , Stefania Traverso4 Abstract In recent years, artificial cavities have raised interest among the scientific community, both due to their relevance in terms of cultural and landscape heritage and because they are linked to potential hazards to surface structures. Underground voids in cities have been often established over time with a specific purpose or have resulted from the layering of different urban evolution phases, which in Mediterranean cities are often thousand years old, the case of culverts being particularly frequent. Generally, culverts have been associated with the need to expand urban areas due to space constraints. Underground voids have been established and modified (or even under-dimensioned) over time and their state of efficiency and preservation is hardly verified, leading to very hazardous conditions. This research presents the waterways in the historical centre of Genoa, the coverage of which, now almost complete, began in the Middle Ages. While the historical channelization of the streams of the old city can be considered as a structure of cultural value, it should be pointed out that the subsequent modifications and state of preservation of such artifacts have led to localized hazardous conditions and thus risk to buildings and infrastructure, some of which have been recognized as UNESCO World Heritage Sites (“Strade Nuove and Palazzi dei Rolli”). Therefore, there is need to acquire detailed surveys of the entire channelized and culverted hydrographical network in order to assess its hydraulic efficiency, hydrogeomorphic features, and structural suitability, and to activate a monitoring network. Such measurements are crucial for effective management of hydrogeomorphic risk in urban areas, also in light of Global Climate Change. Keywords: culvert, flood hazard, man-made landforms, artificial cavities, Genoa. Introduction The city of Genoa is internationally known for its recurrent floods, mainly related to the Bisagno River (Paliaga et al., 2019). The high level of river-related risk is linked on the one hand to meteo-hydrological hazard, associated with an atmospheric circulation prevailing over the Ligurian Sea, and on the other hand to the high level of urbanization in hazardous areas and the relevant exposure of vulnerable elements to floods (Acquaotta et al., 2019). Ongoing climate change, which is expressed by a growth in average air temperature and a change in the rainfall regime, increases the degree of hazard, while unregulated urban planning interventions and modifications to the hydraulic balances in the city increase the vulnerability component, worsening the overall risk for buildings and infrastructure. The present research concerns the hydrographical network that characterises the historical centre of Genoa, i.e. the natural amphitheatre located between the Polcevera valley to the W and the Bisagno valley to the E and which is bordered by the seventeenth-century historical walls (fig. 1). In this area of just 8.5 km2 there are seven small catchments and this hydrographical network flows into the old port of Genoa. The watercourses of the city have been subject to relevant anthropic modifications (diversions, rectifications, culverts, and in general channelization, Rovereto, 1938) since the Middle Ages; today the hydrographical network appears almost entirely artificial, flowing under the streets and buildings of the historical centre (Brandolini et al., 2020; Faccini et al., 2021). The name of some streets recalls the presence of underground streams and the original morphology of the city, which is otherwise not perceptible (Bixio et al., 2015). Only a couple of catchments have their main fluvial system characterised by natural riverbed
38 Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) in their upper stretch, but even in this case the landscape is significantly urbanised. These waterways represent artificial cavities referable to the type “Ahydraulic underground works”, category “A8-water ways” (Parise et al., 2013). The construction of these culverts over time and the modifications they have undergone over the centuries up to very recent times due to progressive urbanisation led to a reduction in the riverbed crosssection, which can lead to possible overflows of water under pressure and consequent floods. This makes a better knowledge of culverted streams in Genoa historical city crucial for hazard and risk assessments and for the planning of related hydraulic risk reduction activities. Since more than thirty years, the Centro Studi Sotterranei of Genoa has been carrying out underground inspections and surveys of the hydrographical network, using both traditional and innovative techniques, with highly detailed reconstructions of the geometry of the culverted riverbed. Among the watercourses in the historical centre of Genoa, recent surveys along the Carbonara and Sant’Anna streams have been carried out. The preliminary results have highlighted both localised flood-hazard conditions and great elements of cultural value. Physical geography of Genoa historical centre The natural morphological amphitheatre of the old historical town covers an area located between the two main catchments of Genoa, the Polcevera (W) and the Bisagno Streams (E) (fig. 1). It is a roughly triangularshaped area surrounded by the seventeenth-century walls which started from the Promontory of the Lighthouse up to M. Peralto (489 m asl), where Sperone Fort is located; the eastern walls were along the western bank of the Bisagno Stream in order to protect the hill of Carignano, which is the eastern ridge of the natural amphitheatre of the historical centre (Brandolini et al., 2018). This sort of morphological amphitheatre includes seven small and steep catchments that today are barely identifiable due to high urbanisation (fig. 2). They are effectively represented by the “Genova Zero” map (Barbieri, 1938) (fig. 3): from W to E we can identify Fig. 1 – Geographical location of study area [modified from Brandolini et al., 2018] (graphics M. Terrone).
39 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa the catchments of Dinegro (or S. Lazzaro), San Teodoro, Lagaccio, Sant’Ugo, Carbonara, Sant’Anna and Torbido. From a geological point of view the area is characterised by flysch formations belonging to the tectonic units of Antola and Ronco and by post-orogenic deposits (APAT, 2008; AA.VV., 2008). The Antola Unit is represented by the formation of Mt. Antola Flysch - mainly consisting of marly limestones, occasionally silty, with thin interlayers of shales, and by the formations of Montoggio shales, a basal complex represented by blackish or greenish shales, which crops out in some limited areas along the western ridge. The Ronco Unit and formation is featured by siltstone, marly limestone and shales and it crops out in the western sector along the watershed divide between the historical amphitheatre and the Polcevera valley. The post-orogenic deposits, represented by the formation of Ortovero Clays, crop outs in the area of the medieval historical centre and old harbour area, within a graben structure with WNW – ESE direction (Limoncelli e Marini, 1969). The climate of Genoa is Mediterranean, with dry and hot summers, relatively mild winters and rainfall mainly concentrated in spring and autumn. The mean annual temperature is 15.8 °C, the annual rainfall is 1268 mm and the rainy days (>1 mm) are 101. The historical weather station of Genoa University, located in the study area and in use since 1833 allowed the reconstruction of statistically significant climate trends: the mean annual temperature shows a positive trend, while the number of rainy days has a negative trend. The amount of annual rainfall does not show any significant trend and therefore the rainfall rate increased. Based on this data, it is possible to state that the rainfall is concentrated in fewer days, particularly between the second decade of October and the first decade of November and it is more intense. This is confirmed by the numerous flash flood events which affected Genoa in the last 50 years. The history of Genoa probably dates back to the preRoman period and the first fortified settlement was on the hill of Castello along the Eastern edge of the natFig. 2 – Stream network in old Genoa city morphological amphitheatre (base map: ortophoto 2018 by Genoa Municipality): A) poorly modified and/or natural riverbed; B) culverted stream; C) concrete channel; D) eaves channel; E) abandoned channel; F) “Strade Nuove and Sistema dei Palazzi dei Rolli” UNESCO World Heritage limits. Main Streams: 1) Torbido; 2) Sant’Anna; 3) San Gerolamo; 4) Carbonara; 5) Sant’Ugo; 6) Lagaccio; 7) San Teodoro; 8) Di Negro (graphics M. Terrone).
40 Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) ural amphitheatre (Grossi Bianchi & Poleggi, 1980; Melli et al., 2006). The castrum was located above the primitive harbour which was naturally protected by the peninsula of Il Mandraccio. In the Middle Ages the historical centre progressively expanded around the port and in the inland area where Strada Nuova (Via Garibaldi), built in 1550, and the late Via Nuovissima (Via Balbi, built in 1606) constituted for centuries the northern limit of the city (Bixio et al., 2015). The culverted watercourse network The morphological amphitheatre within which the historic city of Genoa has developed over centuries represents as a whole a composite catchment area presenting a series of small basins, described below from east to west (fig. 4). The catchment area of the Torbido Stream (so named for its erosive activity on the stiff fissured clays), which is entirely urbanized, covers about 1.17 km2 and consists of two branches: the first, to the W, flows along the axis of Via Palestro; the second originates just upstream Via Solferino and bends to the E until it reaches Via Assarotti. The two waterways join underneath piazza Corvetto in a decantation chamber; the watercourse continues following largo Eros Lanfranchi, cutting perpendicularly through via Vernazza and via XX Settembre reaching piazza Dante, then it descends via Madre di Fig. 3 – Geomorphological sketch map of the morphological amphitheatre of Genoa (base map: Genova Zero by Barbieri, 1938): A) marly limestone, marly siltstones with shales and calcarenites Interlayers; B) stiff fissured clays; C) v-shaped valley; D) sandy and gravelly beach; E) alluvial fan; F) edge of seacliff; G) catchment number: 1) Torbido; 2) Sant’Anna; 3) San Gerolamo; 4) Carbonara; 5) Sant’Ugo; 6) Lagaccio; 7) San Teodoro; 8) Di Negro (see Fig. 2 for comparison with man-made landforms) (graphics M. Terrone).
41 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa Dio, always having on its orographic left the hill of Carignano, and it flows at the docks. In 1519 the watercourse was still uncovered while today the riverbed is entirely culverted, with a rectangular cross-section and an estimated flood discharge for T=200 years of 55 m3 /s (Autorità di Bacino, 2019). The Sant’Anna stream catchment area, which is fully urbanized and covers 0.72 km2 , is also composite, as two main axes join approximately at Piazza Portello while the watershed has its edge along Salita Sant’Anna. The right tributary flows under Via Caffaro, the left one under the route of the Portello-Magenta funicular. The watercourse then follows Via Luccoli, it continues through Piazza Campetto and Piazza Banchi, and it flows to Piazza Caricamento. The lower part of the catchment, partly due to inadequate hydraulic section, is characterized by flood hazard (Lanza, 2003): the estimated maximum flow rate for T=200 years is 44 m3 /s (Autorità di Bacino, 2019. The Carbonara Stream basin is articulated, as it also includes the basin of the San Gerolamo Stream, once independent and later diverted into the Carbonara stream itself (Bixio et al. 2015). Overall, the basin is 1.10 km2 and only ¼ of the surface area is not or scarcely urbanised. The San Gerolamo Stream (also called Vallechiara) originates at the top of Via Pertinace, crosses Corso Carbonara, Via Lomellini and Piazza Fossatello to flow into Ponte Calvi. In the 13th century, the riverbed was diverted at Largo della Zecca toward via Bensa. This diversion made this creek a tributary of the Carbonara; their confluence is located in Via delle Fontane (Bixio et al. 2017). The Carbonara catchment (also known as Nunziata) presents two main valleys in its upper part. Their main channels join in a collector that, between Via Bellucci and Piazza F.lli Bandiera, crosses Piazza della Nunziata and continues along Via delle Fontane, flowing into the sea at Ponte Morosini. In the stretch between Albergo dei Poveri and Piazza della Nunziata, the riverbed shows several hydraulic works, such as weirs, waterfalls, settling chambers, spillways and anthropogenic secondary branches. In 1336 the Carbonara Stream was uncovered, while today the entire riverbed is culverted. Fig. 4 – Stream networks in old Genoa city morphological amphitheatre (Base map: shaded relief on Lidar by Genoa Municipality): A) poorly modified and/or natural riverbed; B) culverted stream; C) eaves channel; D) abandoned channel; E) “Strade Nuove and Sistema dei Palazzi dei Rolli” UNESCO World Heritage limits; F) historical building of Albergo dei Poveri (Hotel of the Poor) - Catchment number: 1) Torbido; 2) Sant’Anna; 3) San Gerolamo; 4) Carbonara; 5) Sant’Ugo; 6) Lagaccio; 7) San Teodoro; 8) Di Negro (see Fig. 3 for a comparison without man-made landforms) (graphics M. Terrone).
42 Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) The downstream-most stretch has a reduced hydraulic section due to foundation structures that partially obstruct the conduit; the flood discharge for T=200 yr is estimated to reach 68 m3 /s (Autorità di Bacino, 2019. The Sant’Ugo stream shows an almost entirely urbanized basin of only 0.80 km2 , and an estimated maximum flood discharge for T=200 years of 45 m3 /s. The watercourse flows at the S. Limbania inlet, originates in Oregina, crosses Acquaverde Square (the name suggesting the old presence of a pond made green by marsh grass), and at its mouth it flows under the Commenda di San Giovanni di Pre, which dates back to the twelfth century. The Lagaccio stream is the largest basin of the historical Genoese amphitheatre with 2.3 km2 . More than 50% of the area (at higher elevation) presents agricultural areas, woodlands, shrubs, and herbaceous vegetation, with maximum flood discharge for T=200 years of 103 m3 /s (Autorità di Bacino, 2019. This catchment is made up of 5 sub-basins whose main fluvial stems merge into the Lagaccio ditch (formerly San Tomaso) and flows near Ponte dei Mille, at Via Adua, alongside Palazzo del Principe. Two tributaries drain the upper basin: one is close to Via Bartolomeo Bianco; the other one originates at Via Vesuvio and it flows into the main collector at Via Ponza. The hydraulic situation is critical in the downstream-most section because the slope of the culvert, built in the 19th century, is moderate and some foundation structures obstruct the water flow. The San Teodoro stream has a catchment area of 0.54 km2 and a discharge of 44 m3 /s for T=200 yr (Autorità di Bacino, 2019); about 50 percent of the basin is urbanised. This fluvial stem has no tributary, and it flows into the sea in the middle of via Buozzi (next to Ponte Doria). The downstream-most section presents critical conditions with potential flood hazard due to the limited hydraulic section and the slope of the culvert. The San Lazzaro stream, formerly Di Negro ditch, has a catchment area of 1.33 km2 and a discharge for T=200 years of 74 m3 /s (Autorità di Bacino, 2019). Approximately 60 percent of the basin is urbanised and is characterised by a series of small, parallel-axis tributaries leading to a collector that flows into the sea at Ponte Colombo. Piazza Di Negro is located on the ancient alluvial fan shaped at the outlet (or mouth) of this stream, which was modified in the terminal section as early as 1150 (Limoncelli, Marini, 1969). The hydrogeomorphic hazard is related to the first culverted section after the confluence of the stream into the San Lazzaro channel. Natural hazard and final remarks Mediterranean cities have undergone significant anthropogenic changes in recent centuries, especially in riverine, slope, and coastal areas: although still debated by the scientific community, the term Anthropocene has become commonly used, at least to highlight the anthropogenic impact on the natural processes of the earth’s surface (Brown et al., 2017). A first analysis of the hydrographical network in the historical centre of Genoa revealed a very articulated situation, as anthropogenic modifications over the centuries have led to the almost complete transformation of the riverbeds into artificial cavities (sensu Parise et al., 2013) (figs. 5, 6) and a progressive urbanization of the catchments, which now reaches values around 75 percent. Hydraulic sections, sometimes under-dimensioned since their construction or designed in another geomorphological and climatic context, are now inadequate: sealed surface areas have changed over time, and experimental data useful for determining the relationship between surface water flowing to the urbanized catchment area and the actual flow rate flowing through the culvert are not updated. As mentioned in the introduction, Genoa is a Mediterranean city in which climate change is evidenced by an increase in average air temperature and a change in rainfall patterns (Acquaotta et al., 2018). Recent years have experienced an increase in flooding episodes in the metropolitan city of Genoa, concentrated mainly in the autumn period and often characterised by exceptional rainfall values with records even at the international level (Cat Berro, 2021): 181 mm/1h were recorded in November 2011, while in October 2021 378 mm/3h, 496 mm/6h, 741 mm/12h, and 884 mm/24h were measured (not far from the Italian historical record of 948 mm registered in October 1970 in Genoa). Flood hazard in the historical city is also associated with pluvial flood hazard, due to the inefficiency of the urban drainage system because of the intensity of rainfall, which has been particularly frequent in the past 30 years. In situations such as those of Genoa’s historical centre, with such a high anthropogenic impact on the natural morphogenetic system, it is particularly difficult to design risk mitigation actions: it is not possible to operate with structural interventions aimed at increasing the hydraulic section due to urbanization, nor is it possible to significantly reduce the impervious area. One possible solution could be to use cisterns connected to buildings as temporary floodwater storage basins in order to laminate the peak discharges, which is usually very rapid given the physical-geographical layout of Genoa’s historical centre. Based on preliminary research, it has been verified that there are 2 hectares of cisterns with an average height of 4 m and, thus, about 80 million litres of reservoir capacity in the historic centre. These structures could be also useful for sanitary and hygienic purposes during possible drought periods. To the light of the above considerations, it is crucial to carry out detailed surveys of all the culverted watercourses that characterise the historical centre of Genoa. The first relevant inventory began in 2000 within the frame of the Civis project supported by the Municipality of Genoa; this work allowed a first fundamental collection and overlap between urban fabric
43 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa Fig. 5 – A) Rio Torbido [see n. 1 in Fig. 2] (photo L. Perasso); B) Rio Torbido [see n. 1 in Fig. 2] (photo L. Perasso); C) Rio Sant’Anna [see n. 2 in Fig. 2] (photo S. Saj); D) Rio Sant’Anna [see n. 2 in Fig. 2] (photo S. Saj); E) Rio Carbonara [see n. 4 in Fig. 2] (photo F. Faccini).
44 Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) Fig. 6 – A) Rio Carbonara [see n. 4 in Fig. 2] (photo M. Traverso); B) Rio San Gerolamo [see n. 3 in Fig. 2] (photo M. Traverso); C) Rio San Barnaba, Carbonara catchment [see n. 4 in Fig. 2] (photo L. Perasso); D) Rio Sant’Ugo [see n. 5 in Fig. 2] (photo M. Traverso); E) Rio Lagaccio [see n. 6 in Fig. 2] (photo L. Rosselli).
45 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa Fig. 7 – Overlap between urban fabric and culverted hydrographical network (Civis project, 2000). Fig. 8 – Longitudinal section of Carbonara Stream below the historical building of Albergo dei Poveri (see point F in Fig. 4). Instrumental relief was carried out with Faro Laser Scanner Focus 3D and Leica ScanStation 2. Digital restitution was carried out with BIM Design Software of Autodesk and was graphically divided with three consecutive parts (A, B, C). The drawing shows the information of the relief point cloud (graphics T. Bonassi).
46 Culverted watercourses as an anthropogenic constraint of flood risk in the historical centre of Genoa (Italy) and underground development of watercourses and other artificial cavities (fig. 7). However, thanks to the intervention of the Municipality of Genoa, knowledge of the landscape and of geoenvironmental dynamics has assumed a relevant importance as a fundamental element for hydrogeomorphic risk management only over the last years. The systematic survey of underground cavities by means of traditional and innovative techniques has recently begun and is ongoing. Some preliminary results have been obtained along reaches of the Carbonara Stream (fig. 8), the Sant’Anna Stream and at the cistern below Piazza Fontane Marose. A second key activity is related to the implementation of a meteo-hydrological and structural monitoring system of culverted watercourses and related structures, both for cognitive and warning purposes. The involvement of experienced and scientifically qualified speleologists and professionals is crucial in order to collect data for both hazard assessment and consequent risk management, as well as for the analysis of artificial cavities under cultural and historical perspectives. Bibliography Acquaotta F., Faccini F., Fratianni S., Paliaga G., Sacchini A., 2018, Rainfall intensity in the Genoa Metropolitan Area: secular variations and consequences, Weather, 73(11), pp. 356-362. Acquaotta F., Faccini F., Fratianni S., Paliaga G., Sacchini A., Vilìmek V., 2019, Increased flash flooding in Genoa Metropolitan Area: a combination of climate changes and soil consumption?. Meteorol. Atmos. Phys., 131(4), pp. 1099-1110. APAT, Regione Liguria, 2008, Foglio 213230 “Genova” della Carta Geologica d’Italia alla scala 1:50.000, Selca Editore, Firenze. AA.VV., 2008, Note Illustrative del Foglio 213-230 “Genova” della Carta Geologica d’Italia alla scala 1:50.000, APAT-Regione Liguria, Selca Editore, Firenze. Autorità di Bacino Regionale, 2019, Piano di Bacino Stralcio per l’assetto Idrogeologico, Ambito 14, [Basin Master Plan for the Geo-hydrological risk reduction], Retrieved from http://www.pianidibacino.ambienteinliguria.it/GE/ambito14/ambito14.html Barbieri P., 1938, Forma Genuae, Ed. Municipio di Genova. Bixio R., Faccini F., Maifredi A., Perasso L., Saj S., Traverso M., 2017, The culverted streams in the historical amphitheatre of Genoa city (Italy): flood risk or geoheritage protection?, Hypogea2017, Proceedings of International Congress of Speleology in Artificial Cavities – Cappadocia, Turkey, March 06/10, pp. 165-176. Bixio R., Saj S., Traverso M., 2015, Urban hydrographic network of Genoa’s historic centre: the underground course of the Fossatello stream, in: Parise M., Galeazzi C., Bixio R. & Germani C. (Eds.) - Proceedings of the International Congress in Artificial Cavities “Hypogea 2015”, pp. 129-140, Rome, March 11-17. Brandolini P., Cappadonia C., Luberti G.M., Donadio C., Stamatopoulos L., Di Maggio C., Faccini F., Stanislao C., Vergari F., Paliaga G., Agnesi V., Alevizos G., Del Monte M., 2020, Geomorphology of the Anthropocene in Mediterranean urban areas, Progress in Physical Geography, 44(4), pp. 461-494. Brandolini P., Faccini F., Paliaga G., Piana P., 2018, Man-Made landforms survey and mapping of an urban historical centre in a coastal Mediterranean environment, Geogr. Fis. Din. Quat., 41, pp. 97-102. Brown A.G., Tooth S., Bullard J.E., Thomas D.S.G., Chiverrell R.C., Plater A.J., Murton J., Thorndycraft V.R.,Tarolli P., Rose J., Wainwright J., Downs P., Aalto R., 2017, The geomorphology of the Anthropocene: emergence, status and implications, Earth Surf. Process. Landforms 42, pp. 71–90. Cat Berro D., 2021, 4 Ottobre 2021: Nubifragi alluvionali e precipitazioni record sull’Appennino Ligure, SMI / Redazione Nimbus 5 ottobre 2021, http://www.nimbus.it/eventi/2021/211005PioggeRecord-AppenninoLigure.htm Faccini F., Giardino M., Paliaga G., Perotti L., Brandolini P., 2021, Urban geomorphology of Genoa Old City (Italy), Journal of Maps, 17(4), pp. 51-64. Grossi Bianchi L., Poleggi E., 1980, Una città portuale del medioevo. Genova nei secoli X-XVI, Sagep Ed., Genova. Lanza S.G., 2003, Flood hazard threat on cultural heritage in the town of Genoa (Italy). Journal of Cultural Heritage, 4(3), pp. 159-167. Limoncelli B., Marini M., 1969, Condizioni geologico-strutturali, idrografiche e geomorfologiche del territorio urbano della città di Genova e loro riflessi applicative, Tamburini ed., Milano. Melli P., Bixio R., Saj S., Traverso M. & Ferrando L., 2006, Genova sotterranea, Erga Editore, Genova. Paliaga G., Luino F., Turconi L., Faccini F., 2019, Inventory of geo-hydrological phenomena in Genova municipality (NW Italy), Journal of Maps, 15, pp. 28-37. Parise M., Galeazzi C., Bixio R., Dixon M., 2013, Classification of Artificial Cavities: A First Contribution by the UIS Commission, in Proceedings of the 16th International Congress of Speleology, edited by M. Filippi and P. Bosak, 2, pp. 230-235. Brno: Czech Speleological Society, July 21-28. Rovereto G., 1938, Genova e la geomorfologia urbanistica, Consiglio Nazionale delle Ricerche, Comitato per la geologia, estratto da “La ricerca scientifica”, vol. I, n. 11-12.
47 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa 1 Università degli Studi di Genova (Italia) 2 Centro Studi Sotterranei, Genova (Italia) 3 Opera Ipogea - Journal of Speleology in Artificial Cavities, Società Speleologica Italiana, Bologna (Italia) 4 Ufficio SIT, Servizi Informativi, Direzione Technolgy Office, Comune di Genova (Italia) * Reference author: [email protected] Artificial cavities and geo-risk assessment: the case of “The Strade Nuove and the system of the Palazzi dei Rolli” Unesco World Heritage site in Genoa (Italy) Francesco Faccini1,2, Andrea Ferrando1 , Giacomo Montanari1 , Pietro Piana1 , Stefano Saj2,3, Martino Terrone4,*, Stefania Traverso4 Abstract Artificial cavities are increasingly studied by the scientific community and several researches were carried out in recent years concerning their importance as elements of cultural heritage but also associated geo-risks. This is a highly interdisciplinary line of research, requiring not only the combination of science and social science approaches, but also technical knowledge for surveying activities in the underground environment, made easier in recent years by technological development. The research becomes even more complex and articulated in urban areas, not only due to a greater concentration of artificial cavities, but also for the complex historical evolution of buildings and the stratification of urban phases. This research introduces a first census of artificial cavities in the historical centre of Genoa, with particular reference to the area recognised as a UNESCO World Heritage Site since 2006. A preliminary database containing more than 150 artificial cavities referable to hydraulic underground works was developed, which includes hypogean civilian dwellings, religious work, military and war works, mines and transit. The overlay of underground development of man-made cavities and the built environment on the surface using GIS has highlighted numerous buildings of great historical-monumental value and connecting streets built on underground voids. This opens up many research perspectives, and it highlights the priority to complete the census and detailed survey of all artificial cavities in Genoa historical centre: in light of the effects of climate change, correct management of cultural heritage and landscape is crucial. Keywords: artificial cavities, sink-hole hazard, cultural heritage, risk assessment, Genoa. Introduction Mediterranean cities record the multi-layered nature of phases of urban expansion: historical centres, generally settled in ancient times, underwent significant expansion from the Middle Ages and progressively grew over time. Since the second half of the 19th century, and later after the Second World War, cities have undergone uncontrolled development and sometimes irrational urban sprawl: the Anthropocene epoch is now accepted in science (Brandolini et al., 2020). The morphological modifications of the natural ground have taken place over time, not only in terms of topographic surface (excavations, filling, sea embankments, hydrographic network modifications), but also with underground works (urban hypogea of hydraulic, civil, religious, war, mining and transport nature). The city of Genoa, and in particular its historical centre (fig. 1), features both significant morphological changes of the original morphology, and a dense network of underground environments covering a significant surface of the urban area hectares (Brandolini et al., 2020). Although the city of Genoa was probably founded in the early fifth century B.C. by the Ligurians in the oldest settlement of the oppidum known as “di Castello”, on the hill overlooking the ancient port (today Piazza Cavour), it was in the Middle Ages that the city became internationally powerful (Grossi Bianchi, Poleggi, 1971). Emancipated from imperial power in the course of the First Crusade, during the late Middle Ages it was a major trading power in the Mediterranean and Black Sea. After the political reform instituted by Andrea Doria in 1528 and until the early 18th century it represented one of the major financial centres of Europe. As a consequence, the city gradually developed within the morphological amphitheatre comprised between
48 Artificial cavities and geo-risk assessment: the case of “The Strade Nuove and the system of the Palazzi dei Rolli” the promontories of Lanterna to the west and Carignano to the east and limited to the north by Mt. Sperone: clear evidence of this is the progressive expansion of the city walls between the 10th and 17th centuries. The landscape has resulted in progressive and thorough modifications of the ground morphological profile, with frequent excavation, landfilling, covering of watercourses, and sea embankments (Faccini et al., 2021). Artificial cavities fit perfectly into these morphological changes as new structures were built underground or became hypogeal due to stratigraphic overlapping and subsequent urban reworking. These artificial cavities can be analysed either in terms of the potential impact of urban development at ground surface on underground spaces, and in terms of geological risk associated with the instability of artificial cavities and consequent propagation of deformations at ground level. In addition, climate change is leading to an intensification of meteo-hydrological events whose ground effects may trigger sink-hole phenomena (Argentieri et al., 2018). Based on archive research and original underground surveys, this research presents the first results of the artificial cavities inventory in the historical centre of Genoa, characterised by great hydro-geomorphological and urban complexity (Bixio et al., 2006; Terrone Fig. 1 – Geographical sketch map of old Genoa city. The yellow area is “The Strade Nuove and the system of the Palazzi dei Rolli” Unesco World Heritage Site (core and buffer zone) (graphics A. Ferrando).
49 Fourth IC of Speleology in Artificial Cavities Hypogea 2023 - Genoa et al., 2021). In particular, the area studied is “The Strade Nuove and the system of the Palazzi dei Rolli”, a UNESCO World Heritage Site. Artificial cavities assimilated to hydraulic underground works, hypogean civilian dwellings, religious work, military and war works, mines and transit were surveyed in the historic centre of Genoa. Punctual, areal, or linear data related to the underground void were subsequently overlaid on a map of the buildings subject to monumental protection in the UNESCO area, thus obtaining a first assessment of the related risk which is useful for the management of cultural and landscape heritage. General settings of Genoa historical centre and UNESCO WH area The historical centre of Genoa is the core of the old city structured in a dense network of alleys (“Caruggi”) of medieval origin that spreads from east to west from the Carignano Hill to the Genoa Piazza Principe railway station, close to what was once Palazzo del Principe, the residence of Admiral Andrea Doria. The elevation range varies between the landings of the Old Port, at 2 m above sea level, to 50-60 m asl between Piazza Corvetto, Spianata Castelletto and Albergo dei Poveri. Fig. 2 – Images of hypogea of the “Strade Nuove and system of the Palazzi dei Rolli World Heritage” area: A) helical tunnel for people on horseback in the back of Palazzo Giorgio Spinola [n. 3 of Fig. 3] (photo R. Bixio); B) air shelter in the underground of Palazzo Belimbau, formerly Palazzo di Antoniotto Cattaneo [n. 25 of Fig. 3] (photo S. Saj); C) entrance of the shelter of the garden of Palazzo Pallavicini, formerly Palazzo di Agostino Ayrolo [n. 6 of Fig. 3) (photo M. Traverso); D) Vault of a former branch of the Bank of America located in the basement of Palazzo Gio Vincenzo Imperiale [n. 69 in Fig. 3] (photo by G. Barranco).