Timelapse ultrasonic tomography for measuring damage localization in geomechanics laboratory tests.

Variation of mechanical properties in materials can be detected non-destructively using ultrasonic measurements. In particular, changes in elastic wave velocity can occur due to damage, i.e., micro-cracking and particles debonding. Here the challenge of characterizing damage in geomaterials, i.e., rocks and soils, is addressed. Geomaterials are naturally heterogeneous media in which the deformation can localize, so that few measurements of acoustic velocity across the sample are not sufficient to capture the heterogeneities. Therefore, an ultrasonic tomography procedure has been implemented to map the spatial and temporal variations in propagation velocity, which provides information on the damage process. Moreover, double beamforming has been successfully applied to identify and isolate multiple arrivals that are caused by strong heterogeneities (natural or induced by the deformation process). The applicability of the developed experimental technique to laboratory geomechanics testing is illustrated using data acquired on a sample of natural rock before and after being deformed under triaxial compression. The approach is then validated and extended to time-lapse monitoring using data acquired during plane strain compression of a sample including a well defined layer with different mechanical properties than the matrix

Triaxial tests on frozen ground: formulation and modelling

Artificial Ground Freezing (AGF) is a controllable process that can be used by engineers to stabilise temporarily the ground, provide structural support and/or exclude groundwater from an excavation until construction of the final lining provides permanent stability and water tightness. In this work, the process of ground freezing is studied using a constitutive model that encompasses frozen and unfrozen behaviour within a unified effective-stress- based framework and employs a combination of ice pressure, liquid water pressure and total stress as state variables. The parameters of the constitutive model are calibrated against experimental data obtained from samples retrieved during construction of Napoli underground, in which AGF was extensively used to excavate in granular soils and weak fractured rock below the ground water table.Postprint (published version

Artificial ground freezing of a volcanic ash: Laboratory tests and modelling

The use of artificial ground freezing (AGF) to form earth support systems has had applications worldwide. These cover a variety of construction problems, including the formation of frozen earth walls to support deep excavations, structural underpinning for foundation improvement and temporary control of ground water in construction processes. On one hand, the main advantage of AGF as a temporary support system in comparison to other support methods, such as those based on injections of chemical or cement grout into the soil, is the low impact on the surrounding environment as the refrigerating medium required to obtain AGF is circulated in pipes and exhausted in the atmosphere or re-circulated without contamination of the ground water. On the other hand, the available methods may vary significantly in their sustainability and complexity in terms of times and costs required for their installation and maintenance. The ability to predict the effects induced by AGF on granular materials is therefore crucial to assessing construction time and cost and to optimising the method. In this work, the thermo-hydro-mechanical processes induced by artificial freezing of a soil body are studied using a constitutive model that encompasses frozen and unfrozen behaviour within a unified effective-stress-based framework. It makes use of a combination of ice pressure, liquid water pressure and total stress as state variables. The model is validated and calibrated using the results of a series of laboratory tests on natural samples of a volcanic ash (Pozzolana) retrieved during construction of Napoli underground, where the technique of AGF was used extensively to stabilise temporarily the ground and control the ground water

SASICE: Safety and sustainability in civil engineering

The performance of the built environment and the construction sector are of major importance in Europe’s long term goals of sustainable development in a changing climate. At the same time, the quality of life of all European citizens needs to be improved and the safety of the built environment with respect to man-made and natural hazards, such as flooding and earthquakes, needs to be ensured. Education has a central role to play in the transformation of a construction sector required to meet increasing demands with regard to safety and sustainability. In this work, the SASICE project is presented. The aim of this project is to promote the integration of safety and sustainability in civil engineering education. The project is organised in the context of the Lifelong Learning Programme, funded by the European Community. The coordinator organisation is the University of Bologna. Nine partner universities from different countries are involved in this transnational project. The universities participating to the project constitute a network of high level competences in the civil engineering area, with several opportunities to improve lifelong learning adopting different media: joint curricula, teaching modules and professor and student exchanges. As a response to the challenge regarding new educational methods in sustainable engineering, teaching modules are developed in 4 thematic areas: (1) Safety in construction, (2) Risk induced by Natural Hazards Assessment, (3) Sustainability in construction, and (4) Sustainability at the territorial level. The development of the teaching modules is based on an extensive analysis of the need for highly qualified education on Safety and Sustainability involving all relevant stakeholders (European and national authorities, companies, research institutes, professional organizations, and universities).The main target is enabling students to introduce these advanced topics in their study plans and curricula and reach, at the end of their studies, a specific skill and expertise in safety and sustainability in Civil Engineering. With our natural resources fading away and our infrastructure in dire need of repair, new trends and challenges in civil engineering education in the concept of “Sustainable Development” are needed to be adressed.<br/

The crossing of the historical centre of Roma by the new underground line C: a study of soil-structure interaction for historical buildings

This work deals with the soil structure-interaction problems posed by the construction of the third line of Roma underground (Line C), which, in its central stretch, crosses the historical centre of the city with significant interferences with the archaeological and monumental heritage. The paper describes the methodological approach developed to evaluate the effects of tunnelling on the existing monuments and historical buildings, starting from a careful geotechnical and structural characterisation and including the development of reliable geotechnical and structural models. Experts in several disciplines were committed to this multidisciplinary work, ranging from geologists to geotechnical and structural engineers, archaeologists, and professionals working in the field of conservation and restoration of works of art and monuments. The study of the interaction between the construction activities and the built environment was carried out following procedures of increasing level of complexity, from green field analyses, in which the stiffness of the existing buildings was neglected, to full soil-structure interaction analyses, performed in both two- and three-dimensional conditions, accounting for the stiffness of existing buildings and considering possible long-term effects. The paper illustrates the main aspects of this procedure, using the example case studies of the Basilica di Massenzio and of the building of the Amministrazione Doria Pamphili

Experimental characterisation of (localised) Deformation Phenomena in Granular Geomaterials from Sample Down to Inter-and Intra-grain Scales

AbstractThis paper outlines some recent advances in the full-field experimental characterisation of the mechanics of granular geomaterials (in particular, sands) using a range of methods that provide characterisation at different scales, from the sample-scale down to the inter- and intra-grain scale. The techniques used are “full-field” approaches involving in-situ x-ray micro-tomography, 3D-volumetric digital image analysis/correlation and grain ID-tracking, in-situ 3D x-ray diffraction and in-situ, spatially-resolved neutron diffraction. These methods provide new data on the mechanics of sand at different scales, including continuum measures of strain, porosity, and fabric plus discrete measures of particle kinematics and force transmission. The results of such measurements might be used to advance higher-order continuum theories, and provide the necessary input parameters, or to calibrate discrete grain-scale simulations of sand behaviour to explore loading paths that are inaccessible in the laboratory

Exploring young people's interpretations of female genital mutilation in the UK using a community-based participatory research approach

BACKGROUND: Female genital mutilation (FGM) is a deeply-rooted cultural practice mainly undertaken in Africa, the Middle East and Asian countries. Evidence to date suggests that although first-generation migrants to the West are abandoning FGM, the custom continues in some places, albeit in small numbers. This study examined how young people living in FGM affected communities in the United Kingdom (UK), interpreted and explained FGM. METHODS: A community-based participatory research (CBPR) approach was used to recruit and train nine young people aged 15-18 as co-researchers. These comprised eight females and one male from second-generation FGM affected communities, living in Bristol. The co-researchers then undertook focus groups and semi-structured interviews with twenty participants aged 13-15 living in Bristol, Cardiff and Milton Keynes. The qualitative data from the training workshops, interviews and focus groups were collected and analysed using thematic analysis. RESULTS: There were conflicting views among participants. Some perceived FGM as a historical tradition that was of very little, if any, relevance to them. In contrast, others perceived that the more archaic, cultural interpretation of FGM, more commonly shared by older generations, had been supplanted by a new form of FGM, which they believed to be a safe procedure, made so by the availability of highly-trained, qualified doctors and better equipment in the UK. Participants spoke of challenges encountered when attempting to raise the issue of FGM with parents. Nevertheless, they acknowledged that- being born and raised in the UK - enabled them to talk openly and to challenge others. CONCLUSION: Future strategies to address and prevent FGM in the UK will require a public health approach that is holistic, intersectional and empowering. Such measures should be relevant to young people born and raised in the UK who interpret FGM differently to previous first-generation migrant relatives and communities. Tackling FGM requires a shift away from a principal preoccupation with harm reduction and criminalisation towards collaboration and active dialogue with communities, in positive and productive ways that acknowledge and engage issues of identity, race, gender, and generation, enabling people affected by FGM to take control of their health and well-being

An integrative study on asphondylia spp. (diptera: Cecidomyiidae), causing flower galls on lamiaceae, with description, phenology, and associated fungi of two new species

An integrative study on some species of Asphondylia was carried out. Two species of gall midges from Italy, Asphondylia rivelloi sp. nov. and Asphondylia micromeriae sp. nov. (Diptera: Cecidomyiidae), causing flower galls respectively on Clinopodium vulgare and Micromeria graeca (Lamiaceae), are described and illustrated. The characteristics of each developmental stage and induced galls are described, which allowed the discrimination of these new species in the complex of Asphondylia developing on Lamiaceae plants. Molecular data based on sequencing both nuclear (ITS2 and 28S-D2) and mitochondrial (COI) genes are also provided in support of this discrimination. Phylogeny based on nuclear markers is consistent with the new species, whereas COI phylogeny suggests introgression occurring between the two species. However, these species can also be easily identified using a morphological approach. Phenology of host plants and gall midges are described, and some peculiar characteristics allow the complete and confident discrimination and revision of the treated species. Gall-associated fungi were identified as Botryosphaeria dothidea, Alternaria spp., and Cladosporium spp

(Un)healthy prison masculinities : theorising men's health in prison

This thesis explores the interconnections between masculinity, health and prison. It contests reductionist, individualist and biomedical approaches to health care management in prisons and challenges gender-blindness within criminology and social science where masculinities have been overlooked as key factors of prison culture and organisation. The research set out to explore how masculinities manifest at institutional, social and cultural levels in prison as key determinants of health. The study was conducted in an enhanced wing of an adult male training prison in Southern England. A reflexive ethnographic approach was used, comprising sustained (non-participant)observation, focus group interviewing, and in-depth, semi-structured interviews with thirty-five inmates and four prison officers. The research revealed how prison masculinities were produced and performed by inmates and prison staff, and through the discourses and practices of the prison regime. They were manifested at social and organisational levels as key determinants of health – as ‘deprivations’ associated with imprisonment and as ‘importation factors’ reflecting inmates pre-prison health status. Values of the institution and those of inmates and staff combined to create a pervasively ‘masculine’ atmosphere and culture, which adversely affected the physical and mental health of many prisoners. This thesis recommends that health policy for prisons is developed and organised with consideration to issues of gender and power. The masculine ideology that underpinned the organisational and social fabric of the prison in this study was evident in the attitudes and behaviours of inmates and staff and in the ‘progressive regime’ advocated by the Prison Service. This research shows that a broad, holistic and ‘gendered’ view of prison health can provide alternative insight into men’s health in prisons, and therefore offer a positive and productive way forward for future prison health policy, in line with the World Health Organisation’s Healthy Prisons philosophy.EThOS - Electronic Theses Online ServiceGBUnited Kingdo