Comparison of depth-averaged and full-3D model for the benchmarking exercise on landslide runout

Two models, with fundamental differences in their approaches, are used for modeling benchmarking exercise. The first, RASH3D, is based on a set of depth-averaged equation, solved in an Eulerian framework. The second, HYBIRD, employs a 3D Lattice-Boltzmann Model (LBM), i.e. the conservation equations are not depth-averaged and therefore multiple velocity measures are available over the depth. The model output are compared for what concerns the Yu-Tung debris flow back-analysis. Two additional cases are then analyzed using RASH3D

Hydrogeological model and hydraulic behaviour of a large landslide in the Italian Western Alps

Abstract. A study of the large, deep-seated Rosone landslide (Italian Western Alps) is presented. A large amount of geological and geomechanical data has been collected in this area, due to the presence of various villages and man-made structures, and an automatic monitoring system was installed in December 2000. Since its installation, this system has been showing a continuous slow movement with periodical accelerations that can be correlated to heavy rainfall events. A hydrogeological model has been developed to study the influence of rainfall events on the pore pressure variations inside the rock slope. The structural characteristics, inclinometric and piezometric measurements, statigraphic and seismic profiles, geomorphologic information, water balance and chemical analyses of the main springs in the slope have been taken into account to consider this problem. A numerical hydraulic investigation, based on a continuum equivalent model of the landslide, has then been carried out using the FLAC3D computer code. Some preliminary results, which highlight the role of permeability and the porosity values of the rock mass on the pore pressure variations during heavy rainfall, are shown in the paper

From depth-averaging to fully three-dimensional modelling of debris-flow dynamics

Two numerical codes, with fundamental differences in their approaches, are used for modeling the Yu Tung debris flow, which occurred in Hong Kong in 2008. The first code, RASH3D, is based depthaveraged St. Venant equations, solved in an Eulerian framework. The second code, HYBIRD, is fully 3D and based on Lattice-Boltzmann Model (LBM), i.e. the conservation equations are not depth-averaged and therefore multiple velocity measures are available over the depth. The two model output are compared and discussed

Some cases of anatomic variations observed in dissections

En el presente trabajo, los autores detallan una variación de la arteria toracodorsal en el vacuno y otra del músculo peroné largo en el cerdo.In this work the authors give detail of a variation found in the dorsal thoracic artery (Toraco Dorsalis) in Bovines. Another variation was found in the long perone muscle (Peroneus Longus) of swine.Facultad de Ciencias Veterinaria

Rock mass characterization by UAV and close-range photogrammetry: A multiscale approach applied along the vallone dell’elva road (Italy)

Geostructural rock mass surveys and the collection of data related to discontinues provide the basis for the characterization of rock masses and the study of their stability conditions. This paper describes a multiscale approach that was carried out using both non-contact techniques and traditional support techniques to survey certain geometrical features of discontinuities, such as their orientation, spacing, and useful persistence. This information is useful in identifying the possible kinematics and stability conditions. These techniques are extremely useful in the case study of the Elva valley road (Northern Italy), in which instability phenomena are spread across 9 km in an overhanging rocky mass. A multiscale approach was applied, obtaining digital surface models (DSMs) at three different scales: large-scale DSM of the entire road, a medium-scale DSM to assess portions of the slope, and a small-scale DSM to assess single discontinuities. The georeferenced point cloud and consequent DSMs of the slopes were obtained using an unmanned aerial vehicle (UAV) and terrestrial photogrammetric technique, allowing topographic and rapid traditional geostructural surveys. This technique allowed us to take measurements along the entire road, obtaining geometrical data for the discontinuities that are statistically representative of the rock mass and useful in defining the possible kinematic mechanisms and volumes of potentially detachable blocks. The main purpose of this study was to analyse how the geostructural features of a rock mass can affect the stability slope conditions at different scales in order to identify road sectors susceptible to different potential failure mechanisms using only kinematic analysis

Analysis of microseismic signals and temperature recordings for rock slope stability investigations in high mountain areas

Abstract. The permafrost degradation is a probable cause for the increase of rock instabilities and rock falls observed in recent years in high mountain areas, particularly in the Alpine region. The phenomenon causes the thaw of the ice filling rock discontinuities; the water deriving from it subsequently freezes again inducing stresses in the rock mass that may lead, in the long term, to rock falls. To investigate these processes, a monitoring system composed by geophones and thermometers was installed in 2007 at the Carrel hut (3829 m a.s.l., Matterhorn, NW Alps). In 2010, in the framework of the Interreg 2007–2013 Alcotra project no. 56 MASSA, the monitoring system has been empowered and renovated in order to meet project needs. In this paper, the data recorded by this renewed system between 6 October 2010 and 5 October 2011 are presented and 329 selected microseismic events are analysed. The data processing has concerned the classification of the recorded signals, the analysis of their distribution in time and the identification of the most important trace characteristics in time and frequency domain. The interpretation of the results has evidenced a possible correlation between the temperature trend and the event occurrence. The research is still in progress and the data recording and interpretation are planned for a longer period to better investigate the spatial-temporal distribution of microseismic activity in the rock mass, with specific attention to the relation of microseismic activity with temperatures. The overall goal is to verify the possibility to set up an effective monitoring system for investigating the stability of a rock mass under permafrost conditions, in order to supply the researchers with useful data to better understand the relationship between temperature and rock mass stability and, possibly, the technicians with a valid tool for decision-making

Impact of debris flows on filter barriers: Analysis based on site monitoring data

Debris flows are one of the most complex and devastating natural phenomena, and they affect mountainous areas throughout the world. Structural measures are currently adopted to mitigate the related hazard in urbanized areas. However, their design requires an estimate of the impact force, which is an open issue. The numerous formulae proposed in the literature require the assignment of empirical coefficients and an evaluation of the kinematic characteristics of the incoming flow. Both are generally not known a priori. In this article, we present the Grand Valey torrent site (Italian Alps). A monitoring system made up of strain gauges was installed on a filter barrier at the site, allowing the evaluation of impact forces. The system provides pivotal information for calibrating impact formulae. Two debris flows occurred during the monitoring period. We present the interpretation of videos, impact measurements, and the results of numerical analyses. The combined analysis allows a back calculation of the events in terms of forces, flow depth, and velocity. Thus, we investigate the applicability of the impact formulae suggested in the literature and of the recommended empirical coefficients. The results highlight that hydrostatic effects dominated the impact during the first event, while hydrodynamic effects prevailed in the second one

Some cases of anatomic variations observed in dissections

En el presente trabajo, los autores detallan una variación de la arteria toracodorsal en el vacuno y otra del músculo peroné largo en el cerdo.In this work the authors give detail of a variation found in the dorsal thoracic artery (Toraco Dorsalis) in Bovines. Another variation was found in the long perone muscle (Peroneus Longus) of swine.Facultad de Ciencias Veterinaria

Estimating the incidence of acute infectious intestinal disease in the community in the UK:A retrospective telephone survey

Objectives: To estimate the burden of intestinal infectious disease (IID) in the UK and determine whether disease burden estimations using a retrospective study design differ from those using a prospective study design. Design/Setting: A retrospective telephone survey undertaken in each of the four countries comprising the United Kingdom. Participants were randomly asked about illness either in the past 7 or 28 days. Participants: 14,813 individuals for all of whom we had a legible recording of their agreement to participate Outcomes: Self-reported IID, defined as loose stools or clinically significant vomiting lasting less than two weeks, in the absence of a known non-infectious cause. Results: The rate of self-reported IID varied substantially depending on whether asked for illness in the previous 7 or 28 days. After standardising for age and sex, and adjusting for the number of interviews completed each month and the relative size of each UK country, the estimated rate of IID in the 7-day recall group was 1,530 cases per 1,000 person-years (95% CI: 1135 – 2113), while in the 28-day recall group it was 533 cases per 1,000 person-years (95% CI: 377 – 778). There was no significant variation in rates between the four countries. Rates in this study were also higher than in a related prospective study undertaken at the same time. Conclusions: The estimated burden of disease from IID varied dramatically depending on study design. Retrospective studies of IID give higher estimates of disease burden than prospective studies. Of retrospective studies longer recall periods give lower estimated rates than studies with short recall periods. Caution needs to be exercised when comparing studies of self-reported IID as small changes in study design or case definition can markedly affect estimated rates

Community-wide outbreak of haemolytic uraemic syndrome associated with Shiga toxin 2-producing Escherichia coli O26:H11 in southern Italy, summer 2013

In summer 2013, an excess of paediatric cases of haemolytic uraemic syndrome (HUS) in a southern region of Italy prompted the investigation of a community-wide outbreak of Shiga toxin 2-producing Escherichia coli (STEC) O26:H11 infections. Case finding was based on testing patients with HUS or bloody diarrhoea for STEC infection by microbiological and serological methods. A case-control study was conducted to identify the source of the outbreak. STEC O26 infection was identified in 20 children (median age 17 months) with HUS, two of whom reported severe neurological sequelae. No cases in adults were detected. Molecular typing showed that two distinct STEC O26:H11 strains were involved. The case-control study showed an association between STEC O26 infection and consumption of dairy products from two local plants, but not with specific ready-to-eat products. E.coli O26:H11 strains lacking the stx genes were isolated from bulk milk and curd samples, but their PFGE profiles did not match those of the outbreak isolates. This outbreak supports the view that infections with Stx2-producing E. coli O26 in children have a high probability of progressing to HUS and represent an emerging public health problem in Europe