Riviste Online SApienza - R.O.SA - 2 (Sapienza University of Rome)
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Landslide susceptibility assessment in pyroclastic soils: numerical analysis on the rose of capillary barriers
Get PDFLandslides in pyroclastic soils are among the most calamitous natural phenomena causing damage to people and territory every year. The mechanisms underpinning such landslides can be controlled by multiple factors, including site conditions and features of pyroclastic soils. Spatial variations of textural characteristics and related hydro-mechanical features in the overlain pyroclastic layers can yield to relevant effects on water infiltration, with potential formation of capillary barriers at the interface between different soil layers. A better knowledge of the key triggering factors, based on engineering-geological modeling, may be carried out through a detailed field and laboratory measurements, as well as performing numerical simulations. The area surrounding Palma Campania (Napoli, Italy) is largely affected by fast-moving landslides involving pyroclastic deposits. The volcanoclastic sequence is constituted upward by (white and grey) vesicular pumices and (black) dense scoriae levels, associated with the Somma-Vesuvius “Pomici di Base” Plinian eruption (22 ka). Stratigraphic sections along the carbonate slopes of Vallone Lupici reveal failure surfaces along various pyroclastic contact layers (white/gray vesicular pumice and dark dense scoria layers). Representative samples were collected at different stratigraphic heights and analyzed to define structural and textural characteristics; the obtained data were used as input parameters to perform 2D numerical simulations to explore the propagation of hydraulic front under different conditions of water flow (flow rate) and textural features of rocks. The obtained results allow us to put constrains on capillary barriers development in function of soils characteristic and rain fall intensity
Preliminary data on slow-moving landslides-affected urban areas through geological, geomorphological and insar analysis
Get PDFThe research focuses on the instability phenomena occurring on the eastern edge of the Calabria oastal Range using geological and geomorphological investigations, geognostic surveys and InSAR remote sensing technique. The study area is located in Cosenza province (Calabria, south Italy) and includes Cavallerizzo, Cerzeto, San Martino di Finita and Rota Greca villages. The geological setting is dominated by a variety of metamorphic-crystalline rocks constituting the Coastal Range structure. A normal fault, N-S oriented and located on the eastern side of the Costal Range, is responsible of the tectonic contact between the metamorphic rocks and the sedimentary deposits of the Crati Basin; while, a colluvial deposit overlies both the crystalline and the Neogene terrains. Continuous boreholes showed that the thickness of this deposit ranges from 10 to 65 m. The latter is involved in widespread landslides causing severe harmful to buildings and infrastructures. Envisat ascending dataset, processed by SBAS multi-temporal InSAR technique, was employed to measure the displacement time series referred to the interval 2003-2010. The data acquired along Envisat ascending orbit, which better cover the east-facing study area, showed a ground movement rate up to -6.5 mm/yr for the landslides in the urbanized areas; whereas, ERS descending orbit (ascending data are not available) showed movement rate of 7.5 mm/yr
The Evolution of methods for the survey and analysis of rock slopes: a review
Get PDFRockfalls are a major hazard for human activities, especially in proximity of infrastructures. The steps in the analysis of rockfallsmay include: i) the survey and characterization of rock outcrops, ii) the kinematic assessment and engineering classification of rock masses, ii) stability analysis and rockfall simulations. This research aims to present a toolbox for rockfall hazard studies and risk mitigation. The toolbox has been created combining the existing methods of survey and analysis and new and innovative techniques developed during this project. In particular, the survey techniques that have been analyzed are: i) conventional geomechanical survey, ii) reflex camera-based terrestrial photogrammetry, iii) recently developed Smartphone-based terrestrial photogrammetry and iv) UAV-based photogrammetry. Once evaluated such methods of survey, we discuss the use of gathered data for engineering rock mass classifications and rockfall analyses. The toolbox can represent an innovative and important step in engineering rock slope analyses, allowing to understand advantages and limitations of each survey/analysis technique, not only related to the quality of data and results, but also considering other important aspects, such as the cost, the time of survey and post-processing and the complexity of survey and data management
Chorthippus bornhalmi new to Lebanon and Jordan, and Eremippus persicus new to Jordan (Orthoptera: Acrididae)
Get PDFThe author reports for the first time the presence of Chorthippus (Glyptobothrus) bornhalmi Harz, 1971 in Jordan and Lebanon, and Eremippus persicus Uvarov, 1929 in Jordan
The Albanian community in Italy: characteristics and challenges between immigration and integration. The case of Lombardy and highly skilled workers
No full textIn 2021, Albanians were the second-largest nationality of first-generation migrants to Italy. This research provides a snapshot of Albanians in Italy who are working in sectors with the potential for future benefit to Albania. It examines the socio-economic characteristics, expectations, and plans of Albanians in Italy (employed in the agri-business, cultural preservation and heritage, and social enterprise sectors, as well as a residual category that includes other sectors). The Italian region with the highest number of Albanian immigrants is Lombardy, the territorial focus of this research, which comprised an in-depth questionnaire administered to 134 respondents. Key outcomes show that skilled Albanians are highly integrated into local society: most respondents have acquired Italian citizenship, 70% are in full-time work, and overall their income is higher than the national average. Their relationship with Italy is not always smooth, with many haunted by memories of difficulties in the early days following their arrival, and continued stigmatization. Despite this, most see their future in Italy while experiencing a complicated relationship with Albania, a place to return for short visits – but perhaps never to settle in again
Le temps présent du Maroc au miroir de la mémoire, de l’histoire et des manuels d’histoire marocains: cas du "dahir berbère"
Get PDFQuesto articolo ha l’obiettivo di verificare la seguente ipotesi: se i manuali di storia del Marocco, pur senza essere impermeabili ai discorsi della memoria e della storia, manifestano una grande autonomia rispetto alle questioni di attualità, fra le quali non mancano i temi controversi. Il caso di studio scelto a questo scopo è il dahir berbero, cioè il decreto reale del 16 maggio 1930 che regolava la procedura giudiziaria delle tribù amazigh, sottoponendole al diritto consuetudinario.Esamineremo di volta in volta in che modo la promulgazione di questo dahir e le sue ripercussioni politiche sono rappresentate nelle memorie nazionaliste e amazigh, come sono trattate dalla storiografia marocchina e francese e come sono insegnate nei manuali di storia marocchini. Da questi tre ambiti emerge come questo avvenimento, risalente all’epoca del protettorato francese, continui ad essere una questione controversa sul piano memoriale, storiografico ed educativo
A mere matter of bonnets? La moda tra storia ed economia
Get PDFLa ricerca storica, così come quella relativa ad altre discipline umanistiche ed economiche, ha assistito solo negli ultimi vent’anni a un incremento cospicuo degli studi su temi inerenti alla moda. Nei decenni precedenti il complesso e variegato fenomeno della moda aveva suscitato l’interesse solo degli storici del costume e degli storici dell’arte, ma non degli studiosi di storia sociale e neanche degli storici dell’economia, finanche tra coloro che hanno dedicato i loro studi a un comparto contiguo alla produzione di abbigliamento come quello tessile. Eppure nel passato la moda aveva suscitato l’interesse di filosofi e intellettuali, tra cui molti economisti. Partendo da una riflessione sui ritardi degli studi storici sulla moda, il saggio si focalizza sulla lettura data alla moda da alcuni dei maggiori economisti del passato, da Adam Smith ad Alfred Marshall, collocando le loro riflessioni nel contesto economico e sociale del tempo
Moda sostenibile e circolare tra ambiente, etica e cultura del territorio
Get PDFModa e sostenibilità sono termini e concetti apparentemente inconciliabili, ma il percorso avviato da numerose aziende del tessile, abbigliamento e calzature negli ultimi anni, ha dimostrato che si può parlare di una moda eco-sostenibile ed etica che sia, al contempo, rispettosa del territorio e delle competenze locali, anche attraverso rafforzando il legame con l’arte e la cultura locali. Oggi trasparenza e tracciabilità di filiera rappresentano fattori abilitanti dell’evoluzione delle catene del valore verso la sostenibilità e la circolarità, con un impatto positivo per il Made in Italy
The cement-bentonite diaphragm of the Malagrotta municipal waste landfill (Rome, Italy): efficiency analysis
Get PDFThe MSW landfill of the city of Rome, one of the largest in Europe, was created in the area of Malagrotta. Between the 1950s and the early 1960s, this area hosted important sand and gravel quarries, which supplied aggregates for construction projects, such as those necessary for the rapid urban expansion of Rome after the second world war. The area has a complex stratigraphy, schematically consisting (from top to bottom) of volcanic deposits, sands, gravels, and very compact gray-blue clays. This geological setting, with cavities from the previous quarrying of large volumes of aggregates (estimated at over 200 × 106 m3 in 1987), offered an ideal site for MSW disposal. Remediation and safe confinement projects were undertaken at the landfill site after the issuing of Decree of the President of the Republic 915/82 of 10 September 1982, transposing three European Directives, including Council Directive 75/442/EEC of 15 July 1975 on waste, into the Italian legislation. From a financial and technical-scientific viewpoint, the most important project to make the landfill compliant with the new legislation was the construction of a hydraulic sealing wall around the internal subareas of the landfill that would accommodate MSW. The wall consisted in a plastic diaphragm of variable depth (Fig. 1). This is one of the major barrier walls built in the world for the confinement of MSW landfills (Table 1). As part of the activities undertaken at the Malagrotta landfill site, we investigated the functional efficiency of the diaphragm. Several in situ tests were thus planned and implemented. This paper analyses the results of hydraulic stress tests carried out in appropriate sections, provided with piezometers and other measuring instruments making part of the system for monitoring the entire surface area of the landfill (161 ha). Figure 3 is a sketch of the section used for hydraulic tests, representing the entire confinement system (Fig. 2). The entire set of data confirms the efficiency of the confinement system examined. The results obtained, by imposing Darcy’s solution based on a reductio ad absurdum argument, demonstrates that the cement-bentonite diaphragm is totally “impermeable” and thus fully suitable for performing the function for which it was designed and built (Prestininzi & Romagnoli, 1991). The data shown in Table 2 corroborates this assumption, i.e. the hydraulic heads in V7 and in Z7 are linked by a linear proportionality ratio, connected with a transfer of energy pressure). The findings from our hydrogeological analysis and the application of Darcy’s law were validated by a mechanical analysis of the elastic behaviour of the diaphragm, made up of a cement-bentonite mixture. The results of the application of the equations of the elastic line revealed that the undrained behaviour of the soil-diaphragm system was in line with our analyses based on experimental data from hydraulic tests and statistical tests. By using Equations (3) and (4), we computed the values umax and Aumax for all the time steps ti. Statistical processing of the data enabled us to compare all the available results: piezometric heads in V7, piezometric heads induced in Z7, arrow umax (x = 0), and surface area Aumax acting on the diaphragm. In particular, the comparison highlighted their mutual relationships under the various conditions of stress q, thereby validating the linear proportionality of the diaphragm displacement and the origin of the piezometric changes ΔHZ7. Indeed, the data of Tables 2 and 3 shows the linear proportionality of ratios (V7/Z7) and of changes in hydraulichead with the data connected with the diaphragm displacement, ΔH(Z7)/[(Au)/(umax (x = 0)].The analysis of these results confirmed what we hadobserved during hydraulic investigations: the behaviour of the system, subjected to hydraulic stress tests, proved to be typical of undrained systems, which respond to stress changes with exchanges of energy and induced deformations at constant volume (Figs. 3, 5, 6 a) and b)). After more than 34 years since its construction, the cement-bentonite plastic diaphragm retains an excellent hydromechanical efficiency, allowing it to perform its hydraulic sealing and mechanical elastic behaviour function in the future