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Stabilita skalních svahů a její porušování / Rock slope stability and failuresPacholíková, Andrea January 2013 (has links)
This Master's thesis deals with the issue of rock face stability on the natural heritage site of Stře- šovické skály. The author has documented the rock face of the Cretaceous sandstones in aim to identify e unstable stones, blocks or whole parts of the rock face and potentially destabilizing trees or shrubs. The area of interest was divided into 8 sections that have been separately described and measured. Four rock samples have been macroscopically described, surface hardness has been also measured in the field in order to verify technical parameters of the Cenomanian sandstones, forming the rock terrace. The strike and slip of fractu- res was measured with a geological compass. The results of these measurements were then drawn in stereo- graphic projection using the Openstereo 0.1.2 software. The field exploration has shown that the hazard of rock failure is considerably high in several do- cumented profiles. Finally, the author recommended measures that should be taken to reduce the risk with regard to the fact that the area under investigation is a natural heritage site, so that extensive remediation is not possible.
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Análise dos perfis longitudinal e transversal de pistas de pouso e decolagem com a utilização do GPS em aeroportos do DAESP / Analysis of the longitudinal and transverse profiles of runways of landing and take-off with the use of GPS in airports of DAESPDinato, Antônio Carlos 05 October 2001 (has links)
Esta dissertação tem por objetivo testar procedimentos para analise da geometria dos aeródromos do estudo através de levantamento topográfico com o uso do nível e GPS (Global Positioning System). Os testes foram conduzidos em quatro aeródromos do Estado de São Paulo, administrados pelo DAESP (Departamento Aeroviário do Estado de São Paulo), a saber: Araraquara, Bauru, Marília e São José do Rio Preto. Foram analisados as declividades longitudinais, transversais, comprimento e largura da pista e a altitude do ponto de referência. O documento normativo usado como referência foi o \"Anexo XIV\" (Aerodromes) da ICAO (International Civil Aviation Organization). Foram feitos levantamentos cadastrais dos projetos originais dos aeródromos e levantamentos de campo. Em cada aeródromo o receptor GPS foi instalado em ponto de coordenadas e altitude conhecidas. Na etapa final foram comparados os dados de projeto com os valores encontrados no campo. Os valores encontrados mostraram algumas variações com os de projeto, principalmente quanto à declividade transversal onde a norma recomenda que seja de 1,5%. Foram encontrados valores com declividades menores que esse e até valores negativos. O sistema GPS mostrou-se, eficiente e preciso para esse tipo de levantamento. / The objective of this work is to test procedures for analysis of the geometry of aerodromes, through topographical survey with level and GPS (Global Positioning System) instrument. The tests were led in four aerodromes of the São Paulo State, administered by DAESP (Departamento Aeroviário do Estado de São Paulo), namely: Araraquara, Bauru, Marília and São José do Rio Preto. The longitudinal slopes, transverse slopes, length of runway, width of runway, the elevation of reference point were analyzed. The normative document used as reference was the Annex XIV (Aerodromes) of ICAO (International Civil Aviation Organization). For each aerodrome it was made a cadastral research of the original project and field survey. For each aerodrome the GPS receiver was located in a point of known coordinates and altitude. In the final stage the original project data were compared with the ones found in the field survey. The values from field have some variations in relation to those found in the project mainly with in the case of transverse slope where the norm recommends that it must be 1,5%. The survey had shown values less than 1,5% and also negative slopes. The GPS system has shown to be efficient and enough accurate for this kind of survey.
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Etude des effets sismo-induits et stabilité des pentes en zone urbanisée via modélisation numérique / Seismically induced effects and slope stability in urbanized zones by numerical modelingDomej, Gisela 29 October 2018 (has links)
Les phénomènes d’instabilité générés par les séismes dans les pentes représentent un risque naturel majeur à l’échelle mondiale. Ce risque a, de plus, tendance à croître du fait d’une urbanisation croissante dans des zones à fort aléa, comme en témoignent de nombreux évènements catastrophique à travers le passé. Pour garantir la sécurité des personnes et des biens face à ce type d’aléa, il faut améliorer les prédictions des déplacements générés par les séismes dans les pentes.Les premiers travaux scientifiques visant à corréler les caractéristiques des instabilités dans les pentes aux paramètres sismiques sont de nature empirique et remontent aux années 1980. Ces méthodes ne permettent pas d’expliquer tous les mouvements de terrain observés à travers le monde, notamment lorsque les effets de site modifient sensiblement la distribution des mouvements dans les pentes et génèrent des déplacements plus grands ou plus petits que ceux prédits par les lois empiriques qui négligent les effets de site.La première partie de cette thèse présente une nouvelle base de données mondiale de 277 glissements de terrain d’origine sismique ou non. L’analyse statistique conduite sur les données de cette base a montré que la forme géométrique moyenne des glissements de terrain reste stable lorsque le volume des instabilités augmente.La deuxième partie de la thèse est dédiée à l’analyse de la stabilité du glissement de terrain de Diezma (Espagne) au moyen de trois méthodes : la Méthode de NEWMARK (1965) basée sur le principe de l’équilibre limite en 2D qui suppose des conditions elasto-parfaitement-plastiques ; l’analyse par différences finies dans le domaine temporel avec le code FLAC en 2D et en 3D qui suppose des conditions visco-elasto-parfaitement-plastiques ; et l’analyse par recombinaison modale dans le domaine fréquentiel avec le code CESAR-LCPC en 2D et en 3D qui suppose des conditions visco-élastiques.Situé dans une région sismiquement active, le glissement de terrain de Diezma est susceptible d’être affecté par des séismes. Une analyse des déplacements induits dans ce versant par onze signaux sismiques différents a été menée dans l’objectif d’établir des corrélations entre les paramètres macro-sismiques des scenarios sismiques appliqués et les déformations calculées par les trois méthodes.Les résultats montrent des différences marquées à la fois qualitatives et quantitatives. Les conclusions principales sont : (a) Les déplacements obtenus par les trois méthodes ont des ordres de grandeur différents et peuvent donc conduire à une surestimation ou à une sous-estimation des déplacements ; (b) Les deux méthodes numériques montrent que les déplacements sont fortement conditionnés par la géométrie des modèles ; seule la méthode par différences finies fait apparaître une réponse en termes de déplacements qui dépend du scénario sismique considéré; (c) Les résultats des simulations2D et 3D ne sont pas comparables ; des analyses complémentaires doivent encore être menées pour guider l’utilisateur dans le choix de la méthode la plus appropriée; (d) La Méthode de NEWMARK (1965), dont l’utilisation reste très répandue de nos jours, est tout à fait appropriée à l’étude de cas simples mais elle peut se révéler inexacte lorsque la structure géologique / topographique du versant conduit à un fort effet de site car ce dernier n’est pas pris en compte par cette méthode / Seismically induced slope deformation is a worldwide common phenomenon that poses an increasing and considerable threat to fast expanding urbanization, and a great number of catastrophic events throughout the past attest thereof. For this reason, displacement predictions allowing for proper slope surveillance became a major concern.Early attempts to relate slope failures to seismic parameters are of empirical nature and date back to the 1980s. Although having proven stable, these relations are frequently disturbed by site effects causing outliers in terms of smaller or greater displacements than expected.The first part of this thesis presents a newly build chronological database of 277 globally distributed seismically and non-seismically induced landslides. A comprehensive statistical analysis was conducted on the data of this database with the main result that – statistically seen – the average geometrical shapes of landslides differ only proportionally.The second part of the thesis is dedicated to a comparative slope stability analysis of the Diezma Landslide (Spain) by means of three methods: the limit-equilibrium based NEWMARK-Method (1965) in 2D under elasto-perfectly-plastic conditions; finite-difference analysis in the time domain with the code FLAC in 2D and 3D under visco-elasto-perfectly-plastic conditions; and modal recombination analysis in the frequency domain with the finite-element code CESAR-LCPC in 2D and 3D under visco-elastic conditions.Located in a seismically active region, the Diezma Landslide is likely to be affected by earthquakes and was therefore considered as a suitable model case. A broad analysis of expected displacements was conducted using eleven strong-motion seismic scenarios. Moreover, the thesis searches for potential relations between macro-seismic parameters of the applied earthquake scenarios and the predicted deformations obtained from the three methods.It appeared that – due to the functionality of the methods – results differ quantitatively as well as qualitatively, and so does their suitability. Major findings are: (a) Results from the three methods are of different orders of magnitude and, thus, can easily lead to over- or under-estimations of displacements; (b) Both numerical methods reveal a strong influence of the model-geometry on the predicted displacements, whereas a scenario-dependent slope behavior manifested itself only within the finite difference analysis; (c) The switch from 2D to 3D does not necessarily result in a similar performance in each dimension and results must be critically judged before further use; (d) The NEWMARK-Method (1965) has proven itself once more to be appropriate for first slope assessments but not for sophisticated evaluations of ground response to seismic shaking
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Análise numérica da influência de chuvas extremas na estabilidade de taludes. / Numerical analysis of influence of extreme rainfall in slope stability.Zambrana, Veroska Dueñas 13 November 2014 (has links)
Escorregamentos de taludes no Sudeste do Brasil são causados principalmente, pelo efeito da água proveniente das chuvas. Nos últimos anos, vem se incrementando o número de desastres naturais, ao passo são registradas mudanças climáticas, que podem exercer influência na ocorrência de chuvas extremas. Muitas encostas permanecem grande parte do ano com o solo em estado não saturado, porém variações nas condições ambientais podem ocasionar mudanças bruscas da sucção, reduzindo ou até mesmo eliminando-a e gerando pressões neutras positivas. A dissertação apresenta, um estudo sobre a influência das chuvas, consideradas extremas, no processo de infiltração e de este nos eventos de escorregamentos, considerados catastróficos pela sua dimensão, e que causaram prejuízos ambientais, econômicos e sociais no Brasil. Para o estudo foram selecionados dois eventos de escorregamentos translacionais rasos relativamente típicos, considerados catastróficos, um deles aconteceu na região da Serra de Cubatão em janeiro do ano 1985, e o outro na Região Serrana do Rio de Janeiro em janeiro de 2011. Estes dois eventos apresentaram características de precipitações e mecanismos de escorregamentos próprios, que permitem ilustrar os diferentes mecanismos atuantes em cada caso. / Landslide in southeastern Brazil, are mainly caused by the effect of water from rainfall in infiltration process, in recent years has been increasing the number of natural disasters, while climate change that may exercising influence on the occurrence of extreme rainfall are recorded . Many slopes remain a large part of the year with unsaturated soil condition; however, changes in environmental conditions can cause sudden changes of suction, reducing or even deleting it and generate positive pore pressures. This dissertation presents a study about the influence of rainfall, considered extreme in the infiltration process and this one in the events regarded by their size of catastrophic landslides, which caused environmental, economic and social losses in Brazil. For the study were selected two events of shallow translational landslides relatively typical, considered catastrophic, one of them occurred in the Serra de Cubatão region on January 1985 and the other in the mountainous region of Rio de Janeiro on January 2011. Both events exhibit characteristics of rainfall and sliding mechanisms themselves, allowing illustrate the different mechanisms active in each case.
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Análise dos perfis longitudinal e transversal de pistas de pouso e decolagem com a utilização do GPS em aeroportos do DAESP / Analysis of the longitudinal and transverse profiles of runways of landing and take-off with the use of GPS in airports of DAESPAntônio Carlos Dinato 05 October 2001 (has links)
Esta dissertação tem por objetivo testar procedimentos para analise da geometria dos aeródromos do estudo através de levantamento topográfico com o uso do nível e GPS (Global Positioning System). Os testes foram conduzidos em quatro aeródromos do Estado de São Paulo, administrados pelo DAESP (Departamento Aeroviário do Estado de São Paulo), a saber: Araraquara, Bauru, Marília e São José do Rio Preto. Foram analisados as declividades longitudinais, transversais, comprimento e largura da pista e a altitude do ponto de referência. O documento normativo usado como referência foi o \"Anexo XIV\" (Aerodromes) da ICAO (International Civil Aviation Organization). Foram feitos levantamentos cadastrais dos projetos originais dos aeródromos e levantamentos de campo. Em cada aeródromo o receptor GPS foi instalado em ponto de coordenadas e altitude conhecidas. Na etapa final foram comparados os dados de projeto com os valores encontrados no campo. Os valores encontrados mostraram algumas variações com os de projeto, principalmente quanto à declividade transversal onde a norma recomenda que seja de 1,5%. Foram encontrados valores com declividades menores que esse e até valores negativos. O sistema GPS mostrou-se, eficiente e preciso para esse tipo de levantamento. / The objective of this work is to test procedures for analysis of the geometry of aerodromes, through topographical survey with level and GPS (Global Positioning System) instrument. The tests were led in four aerodromes of the São Paulo State, administered by DAESP (Departamento Aeroviário do Estado de São Paulo), namely: Araraquara, Bauru, Marília and São José do Rio Preto. The longitudinal slopes, transverse slopes, length of runway, width of runway, the elevation of reference point were analyzed. The normative document used as reference was the Annex XIV (Aerodromes) of ICAO (International Civil Aviation Organization). For each aerodrome it was made a cadastral research of the original project and field survey. For each aerodrome the GPS receiver was located in a point of known coordinates and altitude. In the final stage the original project data were compared with the ones found in the field survey. The values from field have some variations in relation to those found in the project mainly with in the case of transverse slope where the norm recommends that it must be 1,5%. The survey had shown values less than 1,5% and also negative slopes. The GPS system has shown to be efficient and enough accurate for this kind of survey.
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A field- and laboratory-based investigation of shallow debris flow initiation on unburned slopes in southern CaliforniaBrady, Jordan E. 01 August 2019 (has links)
Debris flows are a known hazard in southern California where growing numbers of people are moving into the urban-wildland interface, threatening lives and property. A common location to see a debris flow head scarp is the upper one-third to one-half of an unburned slope at or near the head of a first-order catchment, particularly in areas of relatively shallow soils overlying bedrock. Unburned, relatively steep slopes with gently rounded shoulders and thin soil over bedrock in southern California were investigated to determine if there is a position on these types of slopes where near-surface water levels and the associated pore pressures are relatively and consistently higher during and after rainfall events than the rest of the slope, resulting in an area of preferential shallow slope failure and debris flow initiation. It was hypothesized that this position, if it exists, would be on the upper one-third to one-half of the slope near a change from a shallower slope to a steeper slope (the slope shoulder). It was further hypothesized that elevated subsurface pore pressures at this location would contribute to it being an area of preferential shallow slope failure. The near-surface water levels at two field sites in southern California were monitored for three field seasons. In the laboratory, a meso-scale simulator was constructed and used to replicate field conditions using an adjustable artificial slope and simulated rainfall. The field research showed that areas of higher water levels can exist on the upper one-third to one-half of hillslopes meeting the designated criteria. The laboratory simulations showed elevated water levels in the same general area as the field data. Laboratory simulations also suggested that this is an area of preferential shallow slope failure. The angle of the slope influenced how long a slope took to fail and how much water was needed to do so, with gentler slopes requiring more time and approximately double the amount of water than steeper slopes.
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Soil Erosion Studies on Steep Slopes of Humid-Tropic PhilippinesPresbitero, Alan Ludovice, n/a January 2003 (has links)
An in-situ water-induced soil erosion study of two years duration was conducted at a low slope of about 10%, and also on steep slopes of about 50%, 60% and 70% at the experimental site located at a soil and water research area contiguous to the Department of Agricultural Engineering and Applied Mathematics of the Visayas State College of Agriculture (ViSCA). ViSCA is located in the town of Baybay at the island of Leyte in humid tropical Philippines (latitude of 10 degrees 44' north and longitude of 124 degrees 48' east). The study has the following aims, namely: 1) to investigate the effect of local farming practices on soil erosion, particularly at steep slopes; 2) to study the hydrology and soil erosion processes in steep slope conditions in humid tropical climate; and 3) to apply and determine the limitations of a physical process-oriented sediment transport model for water-induced soil erosion model (Griffith University Erosion System Template, GUEST) to a very permeable soil under very high rainfall conditions. In the context of the steep slope experiments at ViSCA: a) across the slope planting of corn is equally effective in controlling soil loss as hedged farming alone or in combination with peanut intercrop; b) across the slope planting of corn in hedged runoff plots is as effective in controlling soil loss as when combined with peanut intercrop; c) farmers practice of planting a rowcrop like corn along the slope (providing ready-made downslope pathways for runoff water thus, encouraging flow-driven soil erosion) produces significant soil loss, often larger than from a bare runoff plot; d) hedgerows significantly reduced sediment concentration provided they remain intact; e) "failure" in hedgerows, often results in massive soil loss, being even greater than that in a comparable bare runoff plot. (Failure is manifested by runoff breaching the litter barrier at the base of the hedgerow in a localized position, leading to concentrated flow and extension of rills upslope from base of hedgerow) of hedged runoff plot (even though contour planted) and f) application of stubble in combination with across slope planting in hedged runoff plots (with or without a closely growing intercrop) provided both maximum surface cover (aerial and contact) and protection against soil loss in steep slopes. These conclusions are likely to apply to crops similar to corn, with an intercrop similar to peanut in morphology and root system. These conclusions might also be expected to apply to low slopes, though the effect of such protection might not be as pronounced as in steep slope runoff plots. Soil erosion mechanisms in steep slopes are dominated mainly by the runoff-driven processes of entrainment and re-entrainment. Average sediment concentration c and total soil loss M are shown to be functions of positive coefficient runoff related regressors and a parameter that measures rills formed and permanently imprinted on soil surface, and of negative coefficient regressors related to surface contact cover, at least for the steep slopes considered in this study. The relatively high streampower associated with overland flow on steep slopes suggests that overland flow dominates over rainfall impact as a source of soil sediment concentration. This was confirmed by the low value of the measured ratio of soil sediment concentration shed by net-rainfall detachment trays to that lost from the bare runoff plots. On the effect of surface contact cover on average sediment concentration c, the following findings were made, namely: a) surface contact cover of only about 20% to 30% is sufficient to reduce c to low levels, assuming the cover is well distributed; b) an "exponential-decay" form of relationship existed between surface contact cover and the average sediment concentration from the non-bare soil without normalizing with respect to sediment concentration from a reference bare soil runoff plot; and c) such nonlinear relationship is indicative of the dominating runoff processes of entrainment and re-entrainment compared to the linear form of relationships if rainfall driven processes of detachment and re-detachment dominate. In runoff dominated soil erosion processes, surface contact cover (including both living and dead vegetative cover close enough to the soil surface to impede overland flow) is more significant in curtailing soil erosion than aerial surface cover. ...continued.
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Tailings beach slope predictionFitton, Timothy, tfitton@hotmail.com January 2007 (has links)
Tailings (mining waste) disposal is a significant consideration for the mining industry, with the majority of the ore processed in most mining operations ending up as tailings. This creates large volumes of tailings, which must be handled and stored responsibly to avoid potential environmental catastrophes. The most common form of tailings storage facility is the impoundment, where tailings are contained within a basin, with beaches forming around the perimeter of the impoundment and a pond standing in the middle. A relatively new method of tailings storage is to create a 'stack', whereby the tailings solids form a large heap, with the discharge of tailings slurry from the apex of the heap. It is of significant value for mine operators and tailings engineers to be able to predict the shape of the beach that forms in either of these disposal scenarios. The key to being able to do this relies on a method of prediction of the beach slope. The aim of this work is to develop a method of tailings beach slope prediction for tailings slurries that are sub-aerially discharged from a pipe. In this thesis a literature review is undertaken, investigating existing methods for the prediction of tailings beach slopes. These methods are validated against relevant industrial and experimental data. Two separate phases of experimental work have taken place in an effort to investigate tailings deposition behaviour, one at mine sites and the other in a laboratory on a small scale. Three new tailings beach slope prediction models are presented; a simple empirical model enabling quick approximate predictions; an a priori tailings beach slope prediction model based on existing theories of open channel flow, sediment transport and rheology, which is more powerful due to the greater degree of theory in its foundation; and a new semi-empirical model that shares some of the theoretical aspects of the a priori model but offers better predictions due to its empirical calibration to the experimental data. The experimental results, along with 3 other independently collected sets of relevant industrial and experimental data, are used to validate the beach slope prediction models found in the literature, as well as the new beach slope models presented in this thesis. Statistical evaluation of the performance of all of these models is presented to enable comparison. Finally, a new beach shape model is presented for the three dimensional geometric forecasting of the beach surface of a tailings stack. Historic tailings discharge data is run through the beach shape model, and the shapes predicted by the model are compared with aerial survey data of a real tailings stack for validation of the shape model. This work not only presents a new method of tailings stack shape prediction, but also a plausible theory for explaining the concavity of tailings beaches. The stack shape model also has the potential to be developed further for the three dimensional modelling of tailings beaches formed in other types of storage facilities, such as impoundments or valleys.
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Driveline Observer for an Automated Manual GearboxJuhlin-Dannfelt, Peter, Stridkvist, Johan January 2006 (has links)
<p>The Automated Manual Transmission system Opticruise is dependent on signals from sensors located in different parts of the Scania trucks. These signals are of different qualities and have different update frequencies. Some signals and quantities that are hard or impossible to measure are also of importance to this system.</p><p>In this thesis a driveline observer for the purpose of signal improvement is developed and estimations of unknown quantities such as road incline and mass of the vehicle are performed. The outputs of the observer are produced at a rate of 100 Hz, and include in addition to the mass and road incline also the speed of the engine, output shaft of the gearbox, wheel and the torsion in the driveline. Further the use of an accelerometer and the advantages gained from using it in the observer are investigated.</p><p>The outputs show an increased quality and much of the measurement noise is successfully removed without introducing any time delays. A simulation frequency of 100 Hz is possible, but some dependency toward the stiffness of the driveline is found. The observer manages to estimate the road slope accurately. With the use of an accelerometer the road slope estimation is further improved and a quickly converging mass estimation is obtained.</p>
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Boundary violations in forensic inpatient facilities : survey tool development and survey resultsDaniels, Therese Anne 17 July 2008
The primary objective of this study was to determine the incidence rate of boundary violations (BV) in forensic inpatient treatment settings, the extent and the nature of the violations, and the characteristics of individuals at risk to commit them. The Client-Staff Interactions (C-SI) survey was developed and used for these purposes. The survey was administered to 154 staff members in three inpatient settings. The tool demonstrated good internal consistency. Preliminary principal components analysis of the 10 summed section scores suggested three orthogonal higher-order components (Boundary Violations, Interfering Factors, and Supportive Factors). The results confirmed that while BV were occurring within the treatment settings, nonsexual violations were reported more frequently than sexual BV, and staff reported significantly less BV for themselves compared to their peers. The data supported the hypothesis and the proposed model, The Continuum of Boundary Domains (Daniels & Wong, 2007) that BV could be located on a continuum with underinvolvement at one end of the continuum and overinvolvement at the other end. It appears that some staff interpreted boundary crossings (BC) as BV rather than an acceptable therapeutic approach. <p> Reports of negative emotions were positively correlated with reports of BV, such that staff members who experienced higher levels of negative emotions also reported more BV. Supportive factors, such as seeking supervision and being engaged in activities that support the team, were correlated only with BC; however, engaging in these supportive activities did not decrease staff members negative emotional experiences. Staff under the age of 40 reported more disinterest (DIS) than staff who were over the age of 50, and degree-level prepared staff reported more DIS than diploma-level prepared staff. Some post-hoc explanations were offered for these observations. <p> It is recommended that continuing in-service education and discussions about appropriate boundaries are necessary to increase staff members knowledge regarding various types of BV, in particular disinterest (DIS) as a form of BV. The Continuum of Boundary Domains model can be used to conceptualize the various forms of BV.
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