[pt] Na abordagem determinística compara-se o método do equilíbrio limite com o método dos elementos finitos na análise 2D da estabilidade de taludes em solo, determinando-se o valor do fator de segurança para vários exemplos de aplicação. No método dos elementos finitos quantifica-se a região da potencial superfície de ruptura que se comporta sob extensão, analisando-se a ocorrência de anisotropia de resistência ao longo da potencial superfície de deslizamento para situações envolvendo diferentes tipos de solo, ângulos de inclinação do talude e sequências de escavação. Conclui-se que o efeito da anisotropia é pouco significativo quando o ângulo de atrito do solo exceder a 10 graus. Por outro lado, devido à crescente aplicação da abordagem probabilística na prática da engenharia geotécnica, foram realizadas análises de confiabilidade de taludes empregando os métodos de Monte Carlo, do hipercubo latino e o método das estimativas pontuais alternativas, comparando-se os diferentes resultados obtidos e discutindo as principais vantagens da aplicação destes métodos. / [en] In the deterministic approach the limit equilibrium method and the finite element method are compared for 2D analysis of soil slope stability, calculating the value of the safety factor in several numerical examples. In the finite element method the region of soil under strain extension is determined and the occurrence of strength anisotropy is investigated along the potential sliding surface for situations involving different types of soil, angles of slope inclination and excavation sequences. It is concluded that the effect of the anisotropy is negligible when the angle of friction is higher than 10 degress. Moreover, due to the increasing application of the probabilistic approach in the practice of geotechnical engineering, some reliability analyses were carried out using the Monte Carlo method, the Latin hypercube method and the method of alternative point estimates, comparing their different outputs and discussing the main advantages of their application in the analysis of soil slope stability problems.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22741号 / 医博第4659号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 辻川 明孝, 教授 伊達 洋至, 教授 羽賀 博典 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21466号 / 農博第2309号 / 新制||農||1064(附属図書館) / 学位論文||H31||N5161(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 清水 浩, 准教授 中嶋 洋, 教授 飯田 訓久 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Recent tailings dam failures around the world have highlighted the real risk posed by undrained slope failures. Undrained failures are fundamentally different to drained failures in the sense that different mechanisms are involved (i.e. a slope may be stable against drained failure but unstable against undrained failure). Popular methods to assess the stability of slopes against undrained failure involve the use of limit equilibrium analyses with both drained and undrained strengths assigned in the same analysis. A potential shortcoming of these methods is that no consideration is given to strain compatibility. In this study, a limit equilibrium based method where strain compatibility is maintained on the failure surface was developed. The method, referred to as the strain mobilisation method, considers a Mohr circle of stress at failure to determine the shear strength mobilised on the failure plane for use in the stability analysis as a function of the deviator stress imposed on the triaxial test result. The mobilisation of stress on a failure plane with strain was determined based on the stress-strain relationships observed during triaxial tests. A Factor of Safety (FoS) was used to express the stability of the slope as a function of the mobilised strain and the calculated FoS results obtained using the proposed method were compared to calculated FoS results using traditional methods. This was done for three tailings materials (gold, iron and platinum) for three specific hypothetical slopes. As an additional check, the proposed method was tested on Nerlerk sand, a well-known sand showing strain-softening behaviour during undrained shearing. It was found that, in general, as mobilised strain is increased, the FoS calculated using the proposed method converges to that of traditional methods so that there was no significant difference in calculated FoS between the current methods and the proposed method that does consider strain compatibility. This indicates that the proposed method provides FoS values comparable to those calculated using currently accepted methods where the failure surface passes predominantly through a single material type. For such a case, there does not appear to be a need to consider limit equilibrium methods where strain compatibility is maintained. The proposed method provides an indication of the amount of strain that may be expected to mobilise to provide the FoS. Given that this amount of strain is not excessive, the current methods which do not consider strain compatibility perform satisfactorily and can continue to be used / Dissertation (MEng (Civil Engineering))--University of Pretoria, 2021. / Civil Engineering / MEng (Civil Engineering) / Unrestricted

The Albian-Cenomanian Nanushuk Formation located on the North Slope of Alaska is the result of fluvial, deltaic, and shoreface processes and has been the focus of recent petroleum exploration activity in the Colville Basin. The Nanushuk and underlying Torok formations together contain an estimated 8.7 billion barrels of oil and 25 trillion cubic feet of natural gas reserves within the resource-rich North Slope. The Nanushuk Formation is composed of sediment sourced from the Chukotka Peninsula to the west and deposited axially within the Colville Basin. High sedimentation rates led to rapid progradation of shoreface and deltaic systems, which effectively filled the entire basin during the Cretaceous. Resulting in a thick stratigraphic succession of marginal to deep marine sandstones and mudstones. However, considerable facies variation within the basin has led to a previous lack of understanding of the spatial distribution of depositional elements. Integration of outcrop photogrammetry, detailed measured sections, core interpretations, hand samples, and thin section microscopy from the Colville Basin in this study reveal the distribution of litho- and depo-facies within the Nanushuk Formation. Three key outcrop locales along the northern flank of the Brooks Range expose ~200 to ~1000 feet of mudstone, silty sandstone, and sandstone that record the transition from distal shoreface sedimentation to deltaic and fluvial processes over time. Progradationally-stacked parasequences are clearly identifiable in both outcrop and core, recording rapid axial progradation to the east. While shoreface processes do exist in the Nanushuk, outcrop observations show a dominance of deltaic processes, consistent with the highly progradational nature of the strata. Further, there is a trend towards more fluvially-dominated deltaic processes in the more axial part of the Colville syncline, as shown by core, compared to more wave-dominated deltaic facies associations along the margins of the axial basin where outcrops were described. These trends, both vertically and spatially, have important implications for understanding the geologic evolution of the formation and for targeting areas for further exploration within this evolving hydrocarbon play.

The construction of motorways in Slovakia faces a series of geotechnical problems due to the mountainous relief. One of these problems is also discussed in this diploma thesis, where the motorway route is led through a landslide area. The aim of the thesis is to compare two different proposals of the D1 motorway in part of Hubova - Ivachnova section. The theoretical part deals with the issue of slope movements in connection with transport line constructions. In the practical part, the proposals for specific solutions of the high embankment route variant and variant with the bridge are discussed. Both variants are designed in the Plaxis numeric program. Subsequent comparison and evaluation of variants is performed in relation to the degree of stability, deformation, structural stress and construction costs.

The thesis called Securing of Deep Cut in Slide Area focuses on the basic analysis of the problems connected to landslides and securing of the slopes. It also presents a solution of a certain problem, where the slope stability, potencional landslide launchers and subsequent remediaton are discussed.

The work deals with comprehensive design concept of a remote controlled slope mower in direct relation to the proposed technological solution. Product has been designed in order to take (capture) its place in the current, young market of commercialy used slope mowers. Main goal of this work is to create an advanced shape solution with high-end technical specifications, based on a suitable undercarriage concept.

This diploma thesis consists of a research and a practical part. The research part summarises the problem of slopes movements. The practical part deals with the determination of the slope deformation causes, at the 76th km of the D11 motorway. Causes determination was based on laboratory tests of soil samples taken from the disrupted motorway cut, made at PřF UK soil mechanics lab. Tests of grain size composition were done, plasticity of the L 26 sample was determined and critical strength of the reconstituted L26 and L27 samples was found out in the Translational apparatus box. Soils were categorized due to the according standards and the acquired data were evaluated. In the BricsCAD software, a well arranged locality situation and the slope deformation crosscut underlayed with the geophysical ERT cut were illustrated. In the GEO5 software, slope stability models were created using the Spencer Method of Slices. The slip surface and the groundwater level during the disruption were determined. The practical part also covers a proposal of a remediation appropriate for this deformation and it's modelling in GEO5. For the remediation, the slope stability level is determined. The work is based on the specialized literature, articles, research reports and standards. Powered by TCPDF (www.tcpdf.org)

This thesis is dealing with analysis of landslide on the eastern hillside of the Mužský hill, which lies on the Příhrazská plošina Plateau in Český ráj. Příhrazská plošina Plateau belongs to areas, where landslides occur very often and it is well known for a destructive landslide at Dneboh village in 1926. Landslide under the Mužský hill originated on hillside of a Tertiary volcano, which penetrated Cretaceous sandstones and claystones. That distinguishes it from other landslides in the area. Geophysical method of electrical resistivity tomography was used for finding landslides slip surface. Due to small resistivity contrast between landslide mass and underlying claystones, it was not able to identify slip surface with high certainty. The results show only some indications of it. The geophysical exploration however, proved that the landslide mass is overlaying originally exposed sandstone blocks in the accumulation part of the landslide. The whole area of the landslide was mapped into engineering geology map of slope stability at 1:2000 scale with the help of GPS. Slope map on the basis of digital model terrain acquired from LiDAR measurements was used, as a basis of new map. This slope map provided more information about older landslides around examined landslide. From results of the mapping was...