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Piacentini Daniela Devoto Stefano Mantovani Matteo Pasuto Alessandro Prampolini Mariacristina Soldati Mauro 《Natural Hazards》2015,78(1):681-697
Natural Hazards - Persistent Scatterers Interferometry (PSI) techniques are widely employed in geosciences to detect and monitor landslides with high accuracy over large areas, but they also suffer... 相似文献
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A multidisciplinary approach for rock spreading and block sliding investigation in the north-western coast of Malta 总被引:2,自引:0,他引:2
Matteo Mantovani Stefano Devoto Emanuele Forte Arianna Mocnik Alessandro Pasuto Daniela Piacentini Mauro Soldati 《Landslides》2013,10(5):611-622
Landslides are widespread along the north-western coast of the Island of Malta and are strictly linked to the structural setting. Exemplary cases of rock spreading and block sliding phenomena characterise this stretch of coast. They are favoured by the overposition of two different geological units widely outcropping there, the Blue Clay Formation and the Upper Coralline Limestone Formation. The latter forms a wide plateau, bordered by vertical cliffs. At the foot of the cliffs, clayey terrains crop out and develop gentle slopes covered by large blocks detached and moved by rock spreading and block sliding phenomena. These mass movements are favoured by the fragile behaviour of limestones, which cap clays, otherwise characterised by visco-plastic properties. In order to investigate the kinematics and the evolution of these types of coastal landslides, a multidisciplinary and multitechnical approach was applied on a study site, named Il-Prajjet, which provides a spectacular case of rock spreading evolving into block sliding. This paper illustrates the results achieved by means of different engineering geological and geophysical techniques allied with traditional detailed geomorphological survey and mapping. In particular, the surface displacements of the landslides were determined using long-term GPS observations, acquired approximately every 6 months, over a 4.5-year period. A network of GPS benchmarks were distributed on the edge of a limestone plateau affected by rock spreading and on a series of displaced blocks making up a large block slide, finally enabling the definition of the state of activity and the rates of movement to be performed. In addition, the results deriving from two continuous fissurimeters more recently installed at the edge of two persistent joints over the block sliding area are outlined, with reference to the correlation between variations of crack apertures and precipitation input. In order to identify main structural discontinuities and to reconstruct variability of underground surface contact between clays and overlying limestones, Resistivity Tomography profiles and GPR investigations were carried out. Finally, the results obtained by combining the outputs of geophysical surveys and different field monitoring activities can be considered a first step on which numerical models can be developed and validated, in order to assess landslide hazard and risk of this stretch of Maltese coastline. 相似文献
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We have studied the lower and upper truncated Pareto law. This distribution depends on three parameters, the upper and the lower bounds and a parameter m which measures whether the distribution concentrates on larger or smaller values of the variable. We have constructed a test for the null hypothesis H
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:m = 1, which has a special significance from a theoretical point of view and also because in the samples that we consider, the estimation of m lies around 1. The truncated Pareto law is considered in the study of size frequency of rock fragmentation and we illustrate it with data corresponding to the ore size of rocks feeding an SAG mill at Chuquicamata mine in Chile. The data are the weights of the rocks for some classes defined by their mesh size and we propose an estimation method in its analysis. 相似文献
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