Laterally loaded single pile response considering the influence of suction and non-linear behaviour of reinforced concrete sections

A hybrid BEM-p-y curves approach was developed for the single pile analysis with free/fixed head restraint conditions. The method considers the soil non-linear behaviour by means of p-y curves in series to a multi-layered elastic half-space. The non-linearity of reinforced concrete pile sections, also considering the influence of tension-stiffening, has been considered. The model reproduces the influence of suction by increasing the stress state and hence the stiffness of shallow soil-layers. Suction is modeled using the Modified-Kovacs model. The hybrid BEM-py curves method was validated by comparing results from data of 22 load tests on single piles. In addition, a detailed comparison is presented between measured and computed data on a large-diameter reinforced concrete bored single pile

Effectiveness evaluation of flood defence structures in different geomorphological contexts

The flood risk in different geomorphological contexts of two less developed countries are investigated in order to evaluate the efficacy of the existing flood defence structures. In particular, a recent floodplain crossed by a wide meandering river and a narrow mountain valley flowed by creek with a torrential regime have been chosen for such analysis in North Albania and central Mexico, respectively. Both areas have been affected by disastrous floods in past years with considerable damages to properties and people. Some safety countermeasures have been performed over time, even if in a non-systematic way. For this reason, the current inclination to flood risk was assessed by means of a freeware software designed to perform one-dimensional (1D) hydraulic modelling for a full network of natural and anthropic channels (HEC-RAS software by Hydrologic Engineering Center River Analysis System). This new analyses take into account: i) the natural morphological variability along the river path, ii) the anthropic interventions on the fluvial dynamics, iii) the landscape appearance after the soil exploitation in the past years, and iv) all the changes induced by an exceeded informal urbanization. The reconstruction of the river and bordering areas geometric data was carried out according to the physical characteristics of the local environment: a bathymetric survey and near-river DGPS acquisitions for the open spaces of the Albanian floodplain, and traditional topographic methods for the highly vegetated Mexican valley. In both cases, the results show that the existing works are, on their own, poorly efficient in containing the predictable floods. Albanians levees seem underdimensioned, while the channelling works are too narrow to contain large amounts of water and solid transport as typical of the Mexican study area. Evidently, a new territorial planning is required in these areas, and some projects are now in place. However, it would be desirable that local authorities were profitably inspired by the criticalities here mentioned

The Geohazard Safety Classification: how resilience could play a role in the geo-hydrological hazards assessment of school buildings

The impacts of adverse events related to geological hazards are unevenly distributed among communities and groups of individuals concentrated in restricted workplaces. Their consequent safety level is the result of differential exposures to these events and of diversified levels of preparation to them. Nowadays, the exposure and coping ability as co-determinants of people's safety are of particular interest for institutions managing the schools systems. According to the disaster risk reduction experts, the geo-hydrological processes can be mitigated with knowledge and planning, physical and environmental protection measures, and response preparedness. UNISDR is promoting a global culture of safety and resilience through the integration of disaster risk reduction in school curricula. The Comprehensive School Safety (CSS) framework is intended to advance the goals of the Worldwide Initiative for Safe Schools and the Global Alliance for Disaster Risk Reduction and Resilience in the Education Sector, and to promote school safety as a priority area of post-2015 frameworks for sustainable development, risk reduction and resilience. In Italy, according the latest ministerial survey (June 2010), there are 41,902 school buildings. Their alarming condition in terms of safety for their daily occupants is reflected by 39 fatalities ascribable to structural failures in the last 21 years. In 95% of these cases victims are a sad tribute due to natural phenomena. A rigorous evaluation of the total risk of a school building, as defined by the well known risk equation (R=HxVxE), would require a complete probability density function describing the exposure to specific types of events of all the pupils and personnel in the school. In addition, the probability that the inhabitants are present in the school during an event should be estimated depending on the time of day, day of week, or month of the year, as well as on local holiday schedules. The inclusion of resilience as a component of risk allows us to refine the risk awareness, focusing attention on the cultural and social meaning of risk as a shared practice among communities that are potentially at risk. This project developed a method for assessing school hazard exposure (landslide, seismic, flood) and structural fragility/safe learning facilities (seismic response, dampness, plan configuration) which is non-invasive, fairly quick and objective. This tool, which is based on the GSC (Geohazard Safety Classification) definition, was tested in central Italy and optimized for a very wide variety of situations, so that it may be exported in schools (or in similar working places) of other geographical areas. The GSC was obtained as the complementary to one of the Index of Geohazard Impact (IGI), calculated modifying the equation of the specific risk, taking into account also the resilience as a damper, amplifier or invariant of the specific risk itself (IGI=max(HixVi)/rho). The variables of this new equation (hazard, vulnerability and resilience) can be quantified on the basis of ancillary data (thematic maps), results of the data processing of field surveys (seismic noise measure according to the H/V technique, thermographic images, GPS surveys) and the answers to an online questionnaire implemented on purpose

Performance and genome-centric metagenomics of thermophilic single and two-stage anaerobic digesters treating cheese wastes

The present research is the first comprehensive study regarding the thermophilic anaerobic degradation of cheese wastewater, which combines the evaluation of different reactor configurations (i.e. single and two-stage continuous stirred tank reactors) on the process efficiency and the in-depth characterization of the microbial community structure using genome-centric metagenomics. Both reactor configurations showed acidification problems under the tested organic loading rates (OLRs) of 3.6 and 2.4 g COD/L-reactor day and the hydraulic retention time (HRT) of 15 days. However, the two-stage design reached a methane yield equal to 95% of the theoretical value, in contrast with the single stage configuration, which reached a maximum of 33% of the theoretical methane yield. The metagenomic analysis identified 22 new population genomes and revealed that the microbial compositions between the two configurations were remarkably different, demonstrating a higher methanogenic biodiversity in the two-stage configuration. In fact, the acidogenic reactor of the serial configuration was almost solely composed by the lactose degrader Bifidobacterium crudilactis UC0001. The predictive functional analyses of the main population genomes highlighted specific metabolic pathways responsible for the AD process and the mechanisms of main intermediates production. Particularly, the acetate accumulation experienced by the single stage configuration was mainly correlated to the low abundant syntrophic acetate oxidizer Tepidanaerobacter acetatoxydans UC0018 and to the absence of aceticlastic methanogens

Gli Hedge Fund sintetici: un’analisi del mercato

La tesi vuole analizzare le caratteristiche degli hedge funds sintetici, sottolineandone le similitudini e le differenze rispetto a soluzioni tradizionali quali fondi comuni e, soprattutto, hedge fund. Dopo un’analisi della letteratura volta a confrontare le diverse soluzioni di investimento, ci si soffermerà su un’analisi delle performance di mercato, arrivando ad analizzare le problematiche di gestione che caratterizzano gli hedge funds sintetici.This work wants to analyze the features of hedge funds “clones” and in particular the differences and the similarities with traditional investment solutions, as mutual funds and hedge funds above all. After a literature’s review aimed at the comparison of the different investment solutions, this work will focus on the market performance of hedge funds clones and will analyze the typical problems of these instruments

GPS-based high resolution mapping techniques in the Arno river for a correct flood risk management

An extensive high-resolution GPS mapping survey has been carried out over the entire course of the Arno river within the Florence province (62km on each river’s bank) in order to create a GIS database containing all the natural, urban, hydrological and morphological elements around the Arno and its principal tributaries within the Florence urban and suburban area. The purpose of this project is to provide local public administrations with an helpful tool for managing hydrological risk, hydraulic policy and urban planning. The geodatabase includes artificial and natural elements such as railways, roads, buildings, assets, bridges, administrative boundaries, hydraulic works, drainage outlets, dikes, hydro-morphological elements (such as bars or eroding banks) and so on. All the mapped elements were georegistered and provided with alphanumerical descriptions, including the present condition of all elements, in order to plan ordinary and extraordinary maintenance works. The spatial location of the elements is very accurate (less than ±5cm error both in plan and in elevation), with special attention to the accurate positioning for all the elements of flood containment, both natural (riverbank line) and artificial (dikes or walls). Such a complete and accurate database contains all the elements connected with the fluvial dynamic and with the hydraulic risk and will provide very accurate topographic and geometric data to be used in hydrological models. Moreover, in our opinion, realistic assessments concerning hydraulic risk and flood inundation cannot be obtained only with geometrical and topographical criteria (as currently happens with the Arno river), but should also include an evaluation of the stability of the dykes, most of which are old and have been built using heterogeneous materials in the period between First and Second World War. For this reason, the database has been integrated with geotechnical analyses and numerical modelling carried out on a test site along the Arno river course in order to establish a preliminary assessment of the criteria to evaluate dikes stability at large scale. The extension of such methodology to the whole mapped Arno dikes could provide in the near future a first attempt at integrating geotechnical dikes stability schemes into hydrological models for the prediction of flood risk

Semi-automatic delimitation of volcanic edifice boundaries: Validation and application to the cinder cones of the Tancitaro–Nueva Italia region (Michoacán–Guanajuato Volcanic Field, Mexico)

The shape and size of monogenetic volcanoes are the result of complex evolutions involving the interaction of eruptive activity, structural setting and degradational processes. Morphological studies of cinder cones aim to evaluate volcanic hazard on the Earth and to decipher the origins of various structures on extraterrestrial planets. Efforts have been dedicated so far to the characterization of the cinder cone morphology in a systematic and comparable manner. However, manual delimitation is time-consuming and influenced by the user subjectivity but, on the other hand, automatic boundary delimitation of volcanic terrains can be affected by irregular topography. In this work, the semi-automatic delimitation of volcanic edifice boundaries proposed by Grosse et al. (2009) for stratovolcanoes was tested for the first time over monogenetic cinder cones. The method, based on the integration of the DEM-derived slope and curvature maps, is applied here to the Tancitaro–Nueva Italia region of the Michoacán–Guanajuato Volcanic Field (Mexico), where 309 Plio-Quaternary cinder cones are located. The semiautomatic extraction allowed identification of 137 of the 309 cinder cones of the Tancitaro–Nueva Italia region, recognized by means of the manual extraction. This value corresponds to the 44.3% of the total number of cinder cones. Analysis on vent alignments allowed us to identify NE–SW vent alignments and cone elongations, consistent with a NE–SW σmax and a NW–SE σmin. Constructing a vent intensity map, based on computing the number of vents within a radius r centred on each vent of the data set and choosing r = 5 km, four vent intensity maxima were derived: one is positioned in the NW with respect to the Volcano Tancitaro, one in the NE, one to the S and another vent cluster located at the SE boundary of the studied area. The spacing of centroid of each cluster (24 km) can be related to the thickness of the crust (9–10 km) overlying the magma reservoir

GB-InSAR monitoring of slope deformations in a mountainous area affected by debris flow events

Abstract. Diffuse and severe slope instabilities affected the whole Veneto region (north-eastern Italy) between 31 October and 2 November 2010, following a period of heavy and persistent rainfall. In this context, on 4 November 2010 a large detrital mass detached from the cover of the Mt. Rotolon deep-seated gravitational slope deformation (DSGSD), located in the upper Agno River valley, channelizing within the Rotolon Creek riverbed and evolving into a highly mobile debris flow. The latter phenomena damaged many hydraulic works, also threatening bridges, local roads, and the residents of the Maltaure, Turcati, and Parlati villages located along the creek banks and the town of Recoaro Terme. From the beginning of the emergency phase, the civil protection system was activated, involving the National Civil Protection Department, Veneto Region, and local administrations' personnel and technicians, as well as scientific institutions. On 8 December 2010 a local-scale monitoring system, based on a ground-based interferometric synthetic aperture radar (GB-InSAR), was implemented in order to evaluate the slope deformation pattern evolution in correspondence of the debris flow detachment sector, with the final aim of assessing the landslide residual risk and managing the emergency phase. This paper describes the results of a 2-year GB-InSAR monitoring campaign (December 2010–December 2012) and its application for monitoring, mapping, and emergency management activities in order to provide a rapid and easy communication of the results to the involved technicians and civil protection personnel, for a better understanding of the landslide phenomena and the decision-making process in a critical landslide scenario