Search results for " clay"
showing 10 items of 106 documents
A Landslide in Overconsolidated Clays that Has Involved an Important Road of Access to an Internal Mountain Town
2019
The paper presents a case study on the interference of a landslide in overcosolidated clays, triggered in autumn 2004 - winter 2005 by high pore water pressures, on the usability of an important provincial road of an internal town. In the period of 2004–2019 the landslide suffered several mobilisations that led to temporary closures of the road and continuous interventions on the roadway for its use, that caused significant inconvenience for the population and damage to the commercial, sanitary, touristic, agricultural and other activities. In 2018 a study has allowed to identify the kinematic characters of the landslide and the depth of the sliding surface. The study has confirmed that the…
Burial and thermal evolution of the Sicilian fold-and-thrust belt: preliminary results from the Scillato wedge top basin (central-northern Sicily, It…
2016
Wedge top basins are key elements for unravelling the tectonic evolution of fold-and-thrust belts. In detail, their thermal signature and sedimentary fill records modes and time of exhumation of their edges. The Scillato basin is a wedge-top basin located in the central-northern sector of the Sicilian fold-and-thrust belt (western sector of the Madonie Mts). Upper Serravallian-upper Tortonian succession composed by up to 1,200 m thick delta-river to open marine siliciclastic sediments, fills the basin. This succession lies on a deformed substrate made up of thrust sheets composed of Numidian Flysch, Sicilidi and Imerese units stacked with a SW tectonic transport. The basin fill records a po…
Portulacaceae
2017
Trattamento tassonomico delle Portulacaceae della Flora d'Italia, seconda edizione, a cura di Sandro Pignatti
Crustacean dynamics in two argillotrophic, temporary ponds (North-Western Sicily, Italy)
2004
Modelling of protonation constants of halloysite clay nanotubes in various aqueous media, at different ionic strengths
2015
In the last decade nanoparticles have assumed more and more importance because of their particular properties mainly due to the nanometer-scale dimensions that confer them a large surface/volume ratio. Among nanomaterials one of the most studied is the halloysite that, as well as the other natural clay minerals is safe for human and environmental friendly. Halloysite is abundant and cheap and is present in large deposits worldwide like those in New Zealand, France, Belgium and China [1,2]. It is similar to kaolin but has a hollow tubular structure that can be attributable to particular crystallization conditions. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20 aluminosilicate l…
Definizione composizionale delle "Argille Ceramiche" presenti nella Sicilia Nord-Occidentale: Inquadramento geologico e ricadute di carattere archeom…
2006
Effect of the mineralogical composition on the elastoplastic hydromechanical response of Opalinus Clay shale
2021
Abstract Opalinus Clay is the shale currently under investigation as the host formation for geological radioactive waste disposal in Switzerland. Its hydromechanical response has been widely studied, and the experimental results show a range of values whose dispersion needs to be clarified. This work aims to explain the dispersion in the literature results by correlating the hydro-mechanical response to the mineralogical variability of the tested specimens . Based on published microstructural studies, the Opalinus Clay shale is herein schematised as a sequence of two kinds of layers: the shaly (high in clay-mineral content) and the sandy (low in clay-mineral content) layers. The mineralogic…
1D Compression Behaviour of Opalinus Clay
2017
One of the main concerns related to tunnel excavations, drilling operations and wellbore stability in shales is the generation of excess pore water pressure due to changes in mechanical stress; therefore the consolidation of shales is a fundamental process that must be considered. This paper presents a compre- hensive methodology for analysing the compression and consolidation behaviour of shales. An apparatus to perform high-pressure oedometric tests is presented and an analytical method is introduced to analyse the shale consolidation behaviour, which allows information to be gathered on the coeffi cient of consolidation, stiffness, poroelastic properties, and permeability of the tested m…
Il ruolo della facies sulla resistenza a taglio di argille estremamente consistenti
2022
L’Opalinus Clay Shale è la formazione che ospiterà il deposito profondo di scorie radioattive di alta attività in Svizzera. A causa della sua composizione fortemente eterogenea, tale materiale è stato classificato in diverse facies. Inoltre, esso è caratterizzato da una struttura fissile e da un comportamento idro-meccanico anisotropo. Queste particolari complessità rendono particolarmente difficile la scelta di parametri geomeccanici unici per l’intera formazione. In questa memoria viene presentato uno studio sperimentale mirato alla caratterizzazione del limite inferiore dei parametri di resistenza al taglio, attraverso l’esecuzione di prove di compressione trias siale e prove di taglio a…
Role of Stress History on the Swelling-Shrinkage Behavior of Compacted Scaly Clay
2022
Compacted scaly clays are complex geomaterials widely used for the realization of dam cores and waste dump liners. This research aims to investigate the swelling/shrinkage behavior of these geomaterials subjected in an oedometric cell to complex hydromechanical stress paths, including different sequences of cyclic variations of suction and stress. Microstructure investigations, based on scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) techniques, highlighted the microstructural characteristics of the material, which are the distinctive microfabric features (particles assemblages and scales) and the double-porosity networks, where micro- and macropores coexist. More…