Search results for " Geology"
showing 10 items of 533 documents
Safeguarding historic towns on hilltops threatened by land sliding: The case of San Fratello in Sicily
2015
The paper presents the case history of San Fratello, a small town in the Nebrodi Mountains in Sicily rich in history and having very peculiar environmental and cultural characteristics. Both slopes of the narrow ridge where San Fratello lies were affected in 1754, 1922, 1986 and 2010 by very large landslides. The landslide of February 2010 is largely the reactivation of that of 1754. It destroyed many infrastructures and seriously damaged more than 200 buildings and caused the evacuation of 25% of the population. Emergency actions to block regression of uphill movements and secure the buildings and their inhabitants as quickly as possible, were carried out. The sliding slope down to the tow…
Meccanismi di collasso nelle Latomie di Siracusa
2015
The aim of this work is to support, through geomechanical methods, the historical hypothesis proposed by the archaeologists according to which the Latomiae of Syracuse, ancient Greek quarries, were originally mainly developed underground. In order to reach this objective, the finite elements numerical modelling was applied. The input data were inferred from the geologic history, from different archaeological reports and from the geomechanical characterization both of the intact rock and of the rock mass. The study highlighted the geotechnical events which modified the shape and the safety conditions of these amazing ancient quarries over the centuries.
Terreni collassabili e processi di instabilità nella Valle dei Templi
2015
The sacral complex of the Valle dei Templi in Agrigento, included in the UNESCO Heritage Site List, stands over the crest of a rigid calcarenite cuesta, which overlies a layer of partially saturated carbonate sand. The environment is highly prone to landslides and the calcarenite stratum is often in limit equilibrium conditions. Toppling phenomena threaten some of the more relevant archaeological structures such as the Giunone's Temple, the Vulcano's Temple, the Santuario rupestre and the palaeochristian Necropolis. As highlighted by several previous studies, the instabilities and the recession of slopes have been caused by the undermining of slopes combined with the discontinuity pattern. …
Geophysical and geotechnical investigations to support the restoration project of the Roman ‘Villa del Casale’, Piazza Armerina, Sicily, Italy
2011
A multidisciplinary geophysical and geotechnical study, including some non-invasive geophysical applications, was carried out during the restoration of the ‘Villa del Casale’, a Roman villa discovered near Piazza Armerina (Sicily, Italy) in 1929, famous for its Roman floor mosaics. The project aims were to characterize the geology of the subsoil and provide information for solving the main building structural problems including the subsidence of some parts of the floor and the detachment of the tesserae (i.e., the tiles) of the mosaics. Another goal was the detailed study of the underground structures of the Corridor of the Great Hunt, a part of the villa strongly affected by subsidence and…
Geochronology of the mid-German crystalline rise west of the River Rhine
1996
The mid-German crystalline rise has its westernmost exposures at the western margin of the Rhine graben in the southern Pfalz and the northern Alsace. The outcrops are made up of granitoid rocks and minor volcano-sedimentary sequences. Radiometric ages obtained by U/Pb, Pb/Pb, Sm/Nd and Rb/Sr analyses of the igneous rocks from this area range from ∼433 to ∼325 Ma thus covering a time span from the Silurian to the end of the lower Carboniferous. Because the investigated rocks are — according to their chemical composition — largely related to subduction zone environments, the following three geodynamical scenarios are postulated, always taking subduction of oceanic crust beneath the mid-Germa…
Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests
2021
Rock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-De…
Effect of epicentral direction on seismic response of asymmetric buildings
1984
The paper deals with the influence of the epicentral direction on the displacement and stress response of multistorey asymmetric buildings to earthquake horizontal ground motion. A method is given for computing for each plane frame of the complex structure a particular direction of the bidirectional stationary random input for which the horizontal floor displacement of the given frame is maximized. It is shown that this direction can be considered conservative for the corresponding non-stationary process.
Detecting the chaotic nature of advection in complex river flows
2012
In order to detect signatures of chaotic advection in river surface motion, surface buoys equipped with GPS were deployed in a field experiment in River Danube, Hungary. The buoys were released in the vicinity of groynes where complex mixing processes occur. A detailed analysis of the trajectories was carried out, focusing on the time evolution of the distance between buoy pairs. The analysis included the determination and comparison of local Lyapunov exponents and prediction times of finite-time hyperbolic behaviour, which is related to strong mixing. Despite of the small number of applied buoys we found evidence on Lagrangian chaos in the wake of a groyne field. In order to supplement the…
Estándar del inversor prudente y confianza legítima
2019
El trabajo analiza el conflicto planteado por las reformas del régimen retributivo de la electricidad renovable desde la perspectiva del principio de protección de la confianza del derecho de la Unión Europea. Se detiene en la jurisprudencia del Tribunal de Justicia sobre el alcance de dicho principio en el ámbito normativo; en especial, en el criterio del «operador económico prudente y diligente». El análisis identifica carencias en la jurisprudencia de los tribunales españoles («riesgo regulatorio»), como la errónea aplicación del estándar del inversor prudente, o la falta de ponderación del interés de la Unión.
De nuevo sobre la prevalencia del derecho estatal y la inaplicación judicial del derecho autonómico
2017
En varias sentencias recientes, el Tribunal Constitucional ha entendido por primera vez aplicable la clausula de prevalencia en caso de incompatibilidad sobrevenida norma basica-norma autonomica de desarrollo; ha negado dicha aplicacion cuando la incompatibilidad es originaria. Se plantea si tiene sentido esta distincion, y si la clausula de prevalencia deberia extenderse a los casos de choque entre titulos competenciales. La solucion que se apunta es afirmativa cuando el choque se produzca entre una norma basica en una materia y una norma autonomica dictada en otra materia distinta; aunque formalmente el titulo autonomico se califique como exclusivo.