0000000000409871
AUTHOR
Ercoli Laura
A risk assessment proposal for underground cavities in Hard Soils-Soft Rocks
Abstract Underground calcarenite quarries in Marsala (Sicily) have been involved in a number of collapses that have, seriously damaged numerous buildings. The stability conditions were therefore examined in order to assess risk conditions within the historical centre of the town and the surrounding areas, which are subject to urban expansion. Starting with an extensive collection of historical information, the research was carried out through surveys of the cavities, systematic sampling of material, petrographic analysis and geotechnical testing. The results of laboratory tests and in situ investigations provided a geotechnical characterization of both the intact material and the rock mass.…
Resistenza e collasso strutturale di una sabbia parzialmente satura
Studi recenti hanno evidenziato il ruolo del comportamento meccanico dello strato di sabbie collassabili interposte tra le calcareniti e le sottostanti argille plioceniche nell’evoluzione dei crolli dei costoni su cui sorgono i monumenti storici della Valle dei Templi. Tali sabbie, caratterizzate da una struttura aperta e da ridotti valori del contenuto naturale d'acqua, sembrerebbero soggette ad elevati valori di suzione così come evidenziato dalla curva di ritenzione idrica, ricavata combinando i risultati provenienti da due tecniche differenti basate su evaporazione (Hyprop) e misura di pressione di vapore. La sperimentazione, presentata dagli autori in questa nota, ha consentito di anal…
Evaluation of accelerated weathering effects on the surface of two coloured sicilian building stones
The dark grey Breccia di Billiemi and the Ammonitico Rosso of Piana degli Albanesi, widely employed outdoor and indoor in monuments in Sicily, undergo significant alteration processes, affecting not only the chromatic aspect but also the state of aggregation. In a previous paper [1] the effects of accelerated weathering in laboratory was compared with natural ageing in the urban environment. The study included the description of lithofacies, the characterisation by means of petrographic and physical-chemical techniques and accelerated weathering experiments on both lithotypes.
The Latomiae of Syracuse: A Geotechnical Mapping Through Rock Reflectivity
The archeological site of the Latomia del Paradiso (Syracuse) is endangered by severe instability phenomena due to the shape of walls and underground excava-tion related with the poor mechanical characteristics of the weathered and wet rock. The failure of huge blocks from the ceiling of the underground areas and the detaching of rock "flakes" from the walls surface make the geotechnical zon-ing particularly complex. the zoning is based on the characteristics of the rock wall surface that, in first approximation, can be distinguished in regularized sur-faces because of mining , and in irregular surfaces characterized by fracture prop-agation. The elaboration of reflectivity values obtained …
Collapsibility of metastable sand by non-conventional oedometer tests
The stability of foundations soils could represent a clear and present threat for the conservation of even well preserved buildings, particularly for Architectural heritage conservation and land art heritage. A dramatic case is the presence of collapsible metastable sands as foundation soils, as it occurs in the sacral complex Valle dei Templi in Agrigento. This site listed by UNESCO, stands on a crest of a calcarenite cuesta, overlaying a layer of these sands. When the collapsible sand is dry, the structure is strong enough to bond the sand particles together. When the sand becomes wet, a de-structuration mechanism occurs and the soil’s strength is compromised. This paper has a twofold aim…
un antico sistema di drenaggio sotterraneo. i "cunicoli borbonici di Petralia Sottana (Sicilia)
Lo studio riguarda un intervento geotecnico in sotterraneo realizzato diversi secoli fa la cui esecuzione ha influenzato positivamente le condizioni di stabilità dei versanti contigui a una linea di impluvio che, attraversando il centro storico del comune di Petralia Sottana, ne minacciava la sicurezza.