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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Stabilitní poměry sesuvného svahu v údolí Jíloveckého potoka v Semilech / Slope stability of Jizera river valley slopes in Semily region

Kujan, Ondřej January 2016 (has links)
The thesis deals with slope stability of a landslide "U Čtrnácti pomocníků", which is located in the north-eastern part of the city Semily in the Liberec district. The thesis is divided into theoretical and practical part. The theoretical part was carried out literature search on the issue and the natural conditions around the wider area of interest. The practical part consists of individual sections within which the research were conducted archival documentation, mapping areas of interest, own technical work, sampling and geophysical measurements and laboratory work and stability calculations. Also the engineering geological model of the landslide was created. The results of the practical part are used as the basis for the final engineering geological evaluation of this area.
332

Analýza svahových pohybů v severozápadní části Příhrazské plošiny a vyhodnocení vlastností pískovce vzhledem ke stabilitní situaci / Slope movement analysis in the northwestern part of the Příhrazská plošina platform and evaluation of sandstone properties relative to the stability situation

Vorlíček, Petr January 2017 (has links)
The Northwestern part of the Příhrazská platform is known for its processes, the first scientifically studied movement occurred here in 1926 and had catastrophic consequences. This work deals with the evaluation of the selected continuous slope movements in the north- western part of Příhrazská platform and builds on previous measurements. The measured movements are compared with meteorological data, with the surrounding hydrogeological borehole data, and compared with other monitoring site in the vicinity. In the second part, the work focuses on clarifying the problem of the increased susceptibility of the monitored rock tower for weathering and comparison of the properties of sandstone material from this tower with surrounding sandstones from the vicinity and other localities. Attention is especially paid to the influence of the biological crusts, whose significant influence is confirmed. For the investigation field and laboratory methods were used in combination with the use of computer programs.
333

Rutschsichere Böschungen: Ein Verbundprojekt am ZAFT entwickelt neue Lösungen für die Sanierung von rutschgefährdeten Oberflächen

Kammel, Enrico, Engel, Jens 25 July 2014 (has links)
Die Oberflächen von Erdbauwerken sind neben den von der Funktion abhängigen Beanspruchungen z. B. als Verkehrsdamm, Deponieböschung oder Deich, auch witterungsbedingten Einwirkungen ausgesetzt. Frost-Tau-Wechsel können zur Auflockerung der obersten Schichten führen und Tauperioden sowie starke Niederschläge zur Sättigung des Bodens. In letzter Zeit häufen sich Rutschungen der oberflächennahen Bereiche an Verkehrsdämmen, Lärmschutzwällen und teilweise auch an Deichen. Ursachen sind die unzureichende Festigkeit des Bodens, die fehlende Stabilisierung durch Bewuchs und Beanspruchungen durch abströmendes Wasser. Das Forschungsprojekt am ZAFT hat zum Ziel, die oberste Schicht von Böschungen zu verbessern. Es sollen wirtschaftliche Alternativen zu den klassischen Verfahren des Erd- und Grundbaus entwickelt werden, mit denen die flächendeckende Sicherung von Erdbauwerken möglich wird.
334

Development of an Educational Tool for Deterministic and Probabilistic Slope Stability Analysis

Thiago Fernandes Leao (8098877) 10 December 2019 (has links)
<div>This research consists of the development of a new educational tool for calculations of 2D slope stability problems, named PNW-SLOPE. Slope stability has been considered one of the most important topics in geotechnical engineering for many years, so this is a subject which students should build a good background in the university. This program was created in Microsoft Excel with the aid of VBA (Visual Basic for Applications). The use of VBA allowed the creation of a good user interface, therefore those who are using the program can easily follow the instructions to create, analyze the model and check the results. Even though there are many commercial programs with the same application, this research presents a new alternative, more focused on educational purposes. PNW-SLOPE is divided in several modules.The first consists of the geometry definition of the slope. The second module consists of a deterministic slope stability analysis considering limit equilibrium method and the method of slices. The third module consists of a probability analysis considering Monte Carlo simulation. With these two options, users can compare both analysis and understand how important is the consideration of probability analysis in Geotechnical Engineering. This is a pertinent topic nowadays, since reliability analysis is increasingly being incorporated in standards and design codes throughout the world. An additional module was created for rock slope stability problems in which the failure results from sliding on a single planar surface dipping into the excavation. Several examples are presented to demonstrate some of the features of PNW-SLOPE and results are verified with commercial programs such as Geostudio Slope/w and Rocscience Slide 2018.</div>
335

Study of a vertical slot fish ladder : Evaluation of flow dynamics through a standardized bypass and the effect of predesigned roughness elements

Revilla, Iñigo, Pons, Laia January 2020 (has links)
Migrating freshwater fish population has been significantly declined, mostly by the obstruction of their migratory routes by hydropower dams. To diminish such impacts, fish ladders have been developed to facilitate the passage of migrating fish. However, fish ladders are associated with mortality and migratory failure, resulting in an ecological problem which has been a concern for years. The paper contained in the following pages focuses on studying the viability of an innovative modular design for a fish ladder developed by Fiskvägsteknik AB. The design is based in a vertical slot fishway (VSF) to which some roughness elements are attached to modify the flow. The aim of this bypass system is to restore the original biological continuity and diversity in the Swedish rivers, therefore solving a long-lasting ecological problem that hydroelectric production has caused over the years. Through a computational analysis, the flow has been evaluated as a function of the parameters that present an influence over its behaviour. First, a study of the changes in flow velocity influenced by four different slopes: 5 %, 10 %, 15 % and 20 %, has been performed with the objective to find an appropriate inclination according to the capabilities of the fish species considered. The lowest slopes have resulted to be the most appropriate ones, coinciding with low values of turbulent kinetic energy and lower flow velocities. The second step has been checking the effect of roughness elements on the bottom part of the structure tilted a 5%. The flow velocity has shown a considerable decrease, falling in the range of the fish swimming capabilities established. As for the streamlines of the flow, they were altered compared to the cases without the roughness elements.
336

[pt] ANÁLISE NUMÉRICA DA INFLUÊNCIA DA TEMPERATURA NA ESTABILIDADE DE UM TALUDE DE ROCHA / [en] NUMERICAL ANALYSIS OF THE INFLUENCE OF TEMPERATURE ON THE STABILITY OF A ROCK SLOPE

JIMMY ALEXIS VASQUEZ NAJARRO 31 March 2016 (has links)
[pt] Neste trabalho se faz uma análise numérica da influência da temperatura na estabilidade de um talude em rocha. Com esta finalidade, analisou-se um escorregamento de rocha que ocorreu na cidade do Rio de Janeiro, Brasil, no ano 2009. Nos estudos feitos, depois do escorregamento, por parte de Geo-Rio (Geo-Rio, 2009) não se encontrou nenhuma evidência de algum fator desencadeante, como água subterrânea, pluviosidade, sobrecarga na crista do talude, que poderia haver desencadeado o escorregamento; por tal motivo se fez a consideração de que o fator desencadeante poderia ser a flutuação da temperatura na rocha. Chavez (Chavez, 2007) fez um trabalho experimental para avaliar a influência das oscilações térmicas na estabilidade de um maciço rochoso, isto ajudou para determinar as equações de variação da temperatura, e assim poder definir as condições de contorno para a modelagem. A modelagem se faz no software 3DEC (3 Dimensional Distinct Element Code) (Itasca, 2007). O software representa o meio descontínuo através de uma montagem de blocos, esta característica é de utilidade, já que pode representar, de forma aproximada, as geometrias dos blocos que escorregam. O método numérico que utiliza o 3DEC é o método de elementos distintos ou discretos. Na análise foi feita em duas etapas, na primeira a temperatura do modelo se mantem constante, e na segunda a temperatura do modelo varia respeito ao tempo. Dentro destas duas etapas também foi mudado o ângulo de atrito. Os resultados obtidos indicaram que quando se tem flutuação da temperatura, com alta frequência, e um menor valor de ângulo de atrito, se geram as condições para que aconteça o escorregamento do talude. / [en] This research made a numerical analysis of the influence of the temperature on the stability of the rock slope. For this purpose, it analyzed a landslide of rock that occurred in the Rio de Janeiro, Brasil, in 2009. The studies made by Geo-Rio (Geo-Rio, 2009) after the landslide, did not find any evidence of a triggering factor, such as underground water, rainfall, overload on the top of the slope, which could be triggered the slipping; therefore was done the consideration that the triggering factor could be the fluctuation of the rock temperature. Chavez (Chavez, 2007) made an experimental study to evaluate the influence of the temperature fluctuation on the stability of the rock mass; this helped to determine the equations of the variation of the temperature, and be able to define the boundary conditions for the numerical model. The modeling was done in 3DEC software (3 Dimensional Distinct Element Code) (Itasca, 2007). The software represents the discontinuous medium such as assemblage of discrete blocks; this feature is useful because it can represent, approximately, the geometries of the slide blocks. The numerical method that 3DEC uses is the discrete element method. The analysis was done in two stages, the first stage the temperature model keeps constant, and in the second stage the temperature of the model varies with respect to time. In these two stages was also changed the angle of friction. The results indicated that when one has fluctuation of the temperature, with high frequency, and slow value of the angle friction are generated the conditions for that the slope slipping.
337

Implementation and Evaluation of a Recommender System Based on the Slope One and the Weighted Slope One Algorithm

Ye, Brian, Tieu, Benny January 2015 (has links)
Recommender systems are used on many different websites today and are mechanisms that are supposed to accurately give personalized recommendations of items to a set of different users. An item can for example be movies on Netflix. The purpose of this paper is to implement an algorithm that fulfills five stated goals of the implementation. The goals are as followed: the algorithm should be easy to implement, be effective on query time, accurate on recommendations, put little expectations on users and alternations of algorithm should not have to be changed comprehensively. Slope One is a simplified version of linear regression and can be used to recommend items. By using the Netflix Prize data set from 2009 and the Root-Mean-Square-Error (RMSE) as an evaluator, Slope One generates an accuracy of 1.007 units. The Weighted Slope One, which takes the relevancy of items into the calculation, generates an accuracy of 0.990 units.  Adding Weighted Slope One to the Slope One implementation can be done without changing the fundamentals of the Slope One algorithm. It is nearly instantaneous to generate a recommendation of a movie with regular Slope One and Weighted Slope One. However, a precomputing stage is needed for the mechanism. In order to receive a recommendation of the implementation in this paper, the user must at least have rated two items. / Rekommendationssystem används idag på många olika hemsidor, och är en mekanism som har syftet att, med noggrannhet, ge en personlig rekommendation av objekt till en mängd olika användare. Ett objekt kan exempelvis vara en film från Netflix. Syftet med denna rapport är att implementera en algoritm som uppfyller fem olika implementationsmål. Målen är enligt följande: algoritmen ska vara enkel att implementera, ha en effektiv tid på dataförfrågan, ge noggranna rekommendationer, sätta låga förväntningar hos användaren samt ska algoritmen inte behöva omfattande förändring vid alternering.  Slope One är en förenklad version av linjär regression, och kan även användas till att rekommendera objekt. Genom att använda datamängden från Netflix Prize från 2009 och måttet Root-Mean-Square-Error (RMSE) som en utvärderare, kan Slope One generera en precision på 1.007 enheter. Den viktade Slope One, som tar hänsyn till varje föremåls relevans, genererar en precision på 0.990 enheter. När dessa två algoritmer kombineras, behövs inte större fundamentala ändringar i implementationen av Slope One. En rekommendation av något objekt kan genereras omedelbart med någon av de två algoritmerna, dock krävs det en förberäkningsfas i mekanismen. För att få en rekommendation av implementationen i denna rapport, måste användaren åtminstone ha värderat två objekt.
338

Experimental evaluation of matrix suction and shear resistance of partially saturated sandy clay

Melo, Paola Mejia, Linares Ramos, Alexander, Ramirez, Gary Duran, Guillen, Jose Luis Cardenas 30 September 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / At present, the construction of highways in Andean areas the connect the various most important towns and cities in South America has become has become a key element for its development, since these routes and viaducts allow free access to cover basic needs of education, work, food and health of the population. Much of the land in these areas is clay soils whose behavior is quite unpredictable because they present abrupt volume changes according to the variation of saturation in the soil. People who travel on roads on slopes of this type of soil are at high risk due to the slippage that the slopes suffer each year. The most recent was on April 3, 2020 because of the heavy rainfall that was registered in the area; there was a landslide that affected communication channels in the department of Cajamarca in Peru [1]. In this type of slopes landslides occur when the clayey soil is specifically saturated, because under these conditions the soil is not stable and loses cohesion between its particles, therefore it is important to make slope stability studies taking into account the partially saturated soil. This article presents results of tests allow to recognize the physical characteristics of the clay soil in the province of Chepén in Cajamarca. In addition, the filter paper method is used to elaborate the soil-water characteristic curve and a series of direct shear tests are carried cut at different degrees of saturation. With these results, the partially saturate soil fault surface is constructed that allows visualizing the value of the shear stress of the soil according to the saturation to which it is subjected. This value will be important for calculating the safety factor that the slope floor must have of the resistance shear of the soil according to the saturation, this value will be important for the calculation of the safety factor that the floor of the slope must have so that it does not fall. Therefore, considering this condition of the partially saturated soil in the slope stability analysis provides values of the safety factor that are closer to reality, without the need to carry out the analysis in the most critical condition, such as what it done in classical soil mechanics.
339

Stratigraphic Architecture and Depositional History of Laterally-accreted Channel Fills in the Lower Isaac Formation, Windermere Supergroup, British Columbia, Canada

Dumouchel, Iain January 2015 (has links)
Continental slope channels, which serve as the primary conduits for sediment transport into the deep marine, occasionally become sites of sediment deposition with excellent reservoir potential. Increasingly reported in the literature are subsurface channel fills exhibiting shingled seismic reflectors that are interpreted to have formed by lateral channel migration. In lower Isaac Formation channels inclined strata are observed but at a lateral scale that is far below industry-seismic detection. Distinctively these flat-based channels are filled with coarse-grained sandstone that transitions abruptly and obliquely upwards into thin, fine grained turbidites. Like rivers, lateral accretion in Isaac channels is interpreted to be the result of the interaction of inertial and pressure forces, but in highly turbulent, highly density-stratified turbidity currents. This resulted in the formation of two superimposed secondary circulation cells that caused enhanced erosion on the outer bank and preferential deposition of coarse-grained sediment along the inner bank.
340

Die Nutzung von Ressourcen durch den Elbebiber Castor fiber albicus Matschie 1907 an einem Fließgewässer in Nordwestdeutschland - Die Bedeutung naturnaher und anthropogener Strukturen von Ufer und Böschung für das Verhalten eines semiaquatischen Säugetieres / Use of riverbank-structures and resources by Castor fiber albicus Matschie 1907 in northwest Germany: The significance of near-natural and anthropogenic structures of riverbank and slope for the behaviour of a semiaquatic mammal

Klenner-Fringes, Brigitte 16 April 2002 (has links)
The semiaquatic mammals - amongst them the beaver Castor fiber - are inhabitants of the land-water-ecotone, which is characterized by length and low depth.Due to specific adaptations to their habitats, semiaquatic mammals are highly dependent on the specific structures and resources of the ecotone riverbank. Anthropogenic influences on the ecotone riverbank often cause destruction of the resources that leads to a decrease of structural diversity.Being a primary consumer, the beaver mainly uses the water as a medium for locomotion and escape. The equipment of the riverbank, mainly the bankside vegetation, is of great importance concerning foraging. The presence and the quantity of certain biofacts like feeding or cutting places and scent mounds give a hint on the value of different structures and resources of the bankside with regard to certain modes of behaviour. They also give information on different qualities of the used and unused parts of the bankside.Biofacts of beaver-activity were recorded along 20 km of riverbank during a five-year-period. The results of the statistical analysis show that beavers - concerning species-specific mode of behaviour - prefer certain riverbank structures. Biofacts and near-natural structures such as steep bank, riparian forest and willows correlate significantly positive whereas biofacts and anthropogenic structures as slope, farmland or absence of woody plants show significantly negative correlation. There is a strong connection between the number of biofacts - that is use of the riverbank or slope - and structural diversity. Based on these results, an eco-ethological model has been developed which makes it possible to predict behaviour in dependence on the specific structures and resources of the banks and slopes of anthropogenic influenced streams.

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