0000000000448821
AUTHOR
N. Nocilla
Destructuration of typical Sicilian calcarenites
The paper discusses some interesting features of Sicilian fine grain calcarenites. Uniaxial, triaxial, oedometer and isotropic compression tests were undertaken on intact specimens of two types of calcarenite in order to investigate their mechanical characteristics. It was found that the strength and deformability is significantly influenced by the structure (fabric and bonding) and by the destructuration processes. A better understanding of fracture development behavior is gained through a combination of acoustic emission and photographic monitoring on non-homogeneous samples with natural pre-existing heterogeneities due to cementation or to density. The results show that the destructurati…
Evaluation of cliff recession in the Valle dei Templi in Agrigento (Sicily)
Abstract The sacral complex of the Valle dei Templi in Agrigento, added in the UNESCO Heritage Site List, stands over the crest of a rigid calcarenite cuesta, which overlies a layer of partially saturated (S = 6–12%) carbonate sand. In turn, the sand stratum lies on a thick stratum of clays. The environment is highly prone to landslides as highlighted by several previous studies that identify the undermining of slopes and the discontinuity pattern, occurred in the late Neotectonic phase, as causes of cliff failure. For wider and less exposed areas, where the undermining local instabilities can be present because of the specific morphology of the site, a recent research has proposed a new in…
Fragmentation during Rock Falls: Two Italian Case Studies of Hard and Soft Rocks
In recent years, rock fall phenomena in Italy have received considerable attention for risk mitigation through in situ observations and experimental data. This paper reports the study conducted at Camaldoli Hill, in the urban area of Naples, and at Monte Pellegrino, Palermo, Italy. The rocks involved are volcanic Neapolitan yellow tuff (NYT) in the former area and dolomitic limestone in the latter. Both rocks, even though with different strength characteristics, have shown a significant tendency towards rock fragmentation during run out. This behavior was first investigated by comparing the volumes of removable blocks on the cliff faces (V 0) and fallen blocks on the slopes (V f). It was as…
Influence of the behaviour of soft rocks on cliff evolution
Two cases, of evolution of mor phostructure of cliffs in soft rocks like tuff and calcarenite, respectively outcropping in the Cape of Posillipo in Campania and in the Agrigento town and Valley of Tem- ples in Sicily, are analyzed on the basis of mor phologic characteristics of the sites, mesostructural survey and mechanical characterisation of the lithotypes. The cultural and environmental heritage of these sites is heavily hastened by instability processes, due to the super position of different lithotypes, the presence of dis- continuities and differential erosion and deformation of bedrock. Both the rock masses are characterized by variability of the cohesion and the cementation, and we…