The paper deals with the assessment of rockfall risk to persons travelling in vehicles along the SS163 road, an important transportation corridor supporting a high vehicle traffic within the well-known tourist area of the Amalfi Coast (southern Italy). To this aim, the Rockfall Hazard Rating System (RHRS) and quantitative risk assessment (QRA) procedures, in this latter case for three rockfall risk scenarios, are applied. With reference to a large portion (33.820 out of a total of 50.365 km) of the SS163 road, the obtained QRA results highlight that, although the estimated individual risk to life satisfies the adopted tolerable risk criterion, the computed societal risk cannot be tolerated. Starting from this result, site-specific QRA analyses—carried out with reference to some road sections chosen on the basis of the RHRS results—allow the detection of the SS163 portions where the individual risk to life exceeds the tolerable risk threshold and, then, the recourse to mitigation measures could reveal necessary. In this regard, RHRS and QRA methods can be considered complementary tools in prioritizing the road sections where construction funds can be profitably spent in order to mitigate the rockfall risk with reference to both direct consequences (life loss) and indirect ones (traffic delay and diversions). 相似文献
This paper demonstrates an innovative role for experts in supporting participatory policy processes with an application to landslide risk management in the Italian town of Nocera Inferiore. Experts co-produce risk mitigation options based on their specialized knowledge taking account of local knowledge and values by directly coupling stakeholder discourses with option design. Drawing on the theory of plural rationality and based on a literature review, interviews and a public questionnaire, stakeholder discourses are elicited on the landslide risk problem and its solution. Armed with the discourses and in close interaction with stakeholders, experts provide a range of technical mitigation options, each within a given budget constraint. These options are subsequently deliberated in the participatory process with the intent of reaching compromise recommendations for landslide risk mitigation. As we show in an accompanying paper, “Compromise not consensus. Designing a participatory process for landslide risk mitigation” (this issue), the provision of multiple co-produced policy options enhances stakeholder deliberation by respecting legitimate differences in values and worldviews. 相似文献
This paper demonstrates an innovative role for experts in supporting participatory policy processes with an application to landslide risk management in the Italian town of Nocera Inferiore. Experts co-produce risk mitigation options based on their specialized knowledge taking account of local knowledge and values by directly coupling stakeholder discourses with option design. Drawing on the theory of plural rationality and based on a literature review, interviews and a public questionnaire, stakeholder discourses are elicited on the landslide risk problem and its solution. Armed with the discourses and in close interaction with stakeholders, experts provide a range of technical mitigation options, each within a given budget constraint. These options are subsequently deliberated in the participatory process with the intent of reaching compromise recommendations for landslide risk mitigation. As we show in an accompanying paper, “Compromise not consensus. Designing a participatory process for landslide risk mitigation” (this issue), the provision of multiple co-produced policy options enhances stakeholder deliberation by respecting legitimate differences in values and worldviews.
This paper reports on a quantitative estimation of the risk to residents at the toe of Mount Albino, a carbonatic relief covered by shallow deposits of pyroclastic soils, which threatens the municipality of Nocera Inferiore (southern Italy). The quantitative risk analysis (QRA) focuses on one type of mass transport phenomena typical for the context at hand, namely the hyperconcentrated flows. The methodological approach includes three main steps: hazard analysis, consequence analysis and risk estimation. Based on historical incident data, the hazard analysis makes use of a high-resolution digital terrain model and advanced models that incorporate relevant geological and geotechnical input data collected via in situ investigations and laboratory tests. The consequence analysis takes into account information on the exposed persons (age, gender) and their vulnerability. The estimated risk to life is calculated at the individual level (risk to the average and most exposed person). The reported procedure is one of the first QRA’s applications to instabilities which potentially affect natural slopes in Italy, and it was successfully used as technical basis for a public participatory process in Nocera Inferiore, designed and developed to support decisions about risk mitigation measures.
The shallow deposits of unsaturated pyroclastic soils covering the slopes in the Campania region (southern Italy) are systematically affected by various rainfall-induced slope instabilities. The type and triggering of these instabilities depend on several factors, among which in situ soil suction—as an initial condition—and rainfall—as a boundary condition—play a fundamental role. Based on the available database—which includes a comprehensive catalogue of historical data, in situ soil suction measurements and soil laboratory tests along with the results of geomechanical analyses—this paper discusses the relationships among in situ soil suction and rainfall conditions and induced slope instability types. The goal is to reach a better understanding of past events and gain further insight into the analysis and forecasting of future events. In particular, the paper outlines how the season strongly affects the spatial distribution and the type of slope instability likely to develop. For example, erosion phenomena essentially occur at the end of the dry season and originate hyperconcentrated flows while first-time shallow slides prevail in the rainy season and later propagate as debris flows or as debris avalanches. 相似文献
Slow-moving landslides yearly induce huge economic losses worldwide in terms of damage to facilities and interruption of human activities. Within the landslide risk management framework, the consequence analysis is a key step entailing procedures mainly based on identifying and quantifying the exposed elements, defining an intensity criterion and assessing the expected losses. This paper presents a two-scale (medium and large) procedure for vulnerability assessment of buildings located in areas affected by slow-moving landslides. Their intensity derives from Differential Interferometric Synthetic Aperture Radar (DInSAR) satellite data analysis, which in the last decade proved to be capable of providing cost-effective long-term displacement archives. The analyses carried out on two study areas of southern Italy (one per each of the addressed scales) lead to the generation, as an absolute novelty, of both empirical fragility and vulnerability curves for buildings in slow-moving landslide-affected areas. These curves, once further validated, can be valuably used as tools for consequence forecasting purposes and, more in general, for planning the most suitable slow-moving landslide risk mitigation strategies. 相似文献
We analyzed the fractal and multifractal properties of the earthquake time series occurred around the Enguri dam in West Georgia by applying the methods of detrended fluctuation analysis and multifractal detrended fluctuation analysis. We examined the interevent time series in two periods: (1) 1960–1980, in which the investigated area was characterized by the natural seismicity; and (2) 1981–2012, in which the quasi-periodic change of the reservoir water level affected the earthquake generation. Our findings show that the water level variation may influence the fractal properties of earthquake temporal distribution in the local area around the Enguri dam. In particular, it is observed that the time distribution features of seismicity occurred in the second period are more persistent than the natural seismicity occurred in the first period. Furthermore, the seismic process of the second period shows a lower multifractal degree than that of the first period, indicating that the influence of quasi-periodic fluctuation of water level features the seismicity as more regular compared to the natural seismicity. 相似文献
The paper focuses on the behaviour of a model strip footing, resting on a saturated dense sandy soil, subjected to centred
or eccentric vertical loading. Experimental tests, carried out on a small-scale physical model, are able to reproduce effective
stress levels equivalent to those prevailing in prototype problems, thanks to the maintenance of a downward steady-state seepage
in the soil. The test program consists of three series of tests, each corresponding to an imposed value of hydraulic gradient,
and each involving five load eccentricities; one series, in particular, is carried out with still water. Relevant points of
load–settlement curves are related to the evolution of soil-footing collapse mechanism, evidenced by the distortion of some
vertical coloured sand strips. The collapse mechanism is formed either by one or two sliding surfaces, depending on both load
eccentricities and hydraulic gradient values. Significant differences are shown to occur between centred and eccentric loading
footing response. Shear strength parameters obtained from back-analyses carried out on load values recorded at the appearance
of each sliding surface on the free soil surface, in both hypotheses of associated and non-associated flow rule validity,
are adopted to draw, for each test, a theoretical collapse mechanism consisting, in plane strain, of a log-spiral line with
adjacent-end tangents; the obtained theoretical sliding surfaces, in turn, are compared to the experimental ones, showing
that these latter are either stress characteristic or zero-extension lines depending mainly on cumulative footing displacements
and current effective stress level in the soil. 相似文献
