Dissertations / Theses: 'Geotechnical analysis'

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Faria, P. de D. "Shakedown analysis in geotechnical engineering." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636956.

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Many problems in geotechnology are concerned with the response of earth materials to cyclic loads. These loads are either generated by forces of nature such as sea waves, currents, winds, and earthquakes or as a consequence of engineering operations such as blasting, pile driving and rotating machines. For most design purposes related to static loads it is logical to use as a design basis either the elastic range where no plastic deformation occurs or the plastic range, in which large plastic deformation can occur. However, when cyclic loading is involved few design methods are available since a pattern for the response of the body to cyclic loads is not well known. When a body is subjected to cyclic loading some modes of adaptation or non adaptation can occur as a response to the loads such as elastic shakedown, alternating plasticity and ratchetting. Despite its extensive use in structural problems very few applications of the shakedown approach to soil masses can be found in literature. Therefore the present work aims to extend the elastic shakedown concepts to geotechnical problems. Initially the shakedown concepts are introduced, its theorems and their importance for geomechanical problems are highlighted. Later the use of Melan's static shakedown theorem for the present study is shown. Shakedown analyses of plane stress and plane strain problems are presented. In this study the shakedown formulation is based on the concept of a residual stress field obtained by means of a numerical formulation using a visco-plastic algorithm. Two numerical codes linked with a mesh generator were implemented as tools for the treatment of the shakedown problems. Numerical examples and applications are shown to illustrate the usefulness of the present approach.

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Chandarana, Upasna Piyush, and Upasna Piyush Chandarana. "Optimizing Geotechnical Risk Management Analysis." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625550.

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Mines have an inherent risk of geotechnical failure in both rock excavations and tailings storage facilities. Geotechnical failure occurs when there is a combination of exceptionally large forces acting on a structure and/or low material strength resulting in the structure not withstanding a designed service load. The excavation of rocks can cause unintended rock mass movements. If the movement is monitored promptly, accidents, loss of ore reserves and equipment, loss of lives, and closure of the mine can be prevented. Mining companies routinely use deformation monitoring to manage the geotechnical risk associated with the mining process. The aim of this dissertation is to review the geotechnical risk management process to optimize the geotechnical risk management analysis. In order to perform a proper analysis of slope instability, understanding the importance as well as the limitations of any monitoring system is crucial. Due to the potential threat associated with slope stability, it has become the top priority in all risk management programs to predict the time of slope failure. Datasets from monitoring systems are used to perform slope failure analysis. Innovations in slope monitoring equipment in the recent years have made it possible to scan a broad rock face in a short period with sub-millimetric accuracy. Instruments like Slope Stability Radars (SSR) provide the quantitative data that is commonly used to perform risk management analysis. However, it is challenging to find a method that can provide an accurate time of failure predictions. Many studies in the recent past have attempted to predict the time of slope failure using the Inverse Velocity (IV) method, and to analyze the probability of a failure with the fuzzy neural networks. Various method investigated in this dissertation include: Minimum Inverse Velocity (MIV), Maximum Velocity (MV), Log Velocity (LV), Log Inverse Velocity (LIV), Spline Regression (SR) and Machine Learning (ML). Based on the results of these studies, the ML method has the highest rate of success in predicting the time of slope failures. The predictions provided by the ML showed ~86% improvement in the results in comparison to the traditional IV method and ~72% improvement when compared with the MIV method. The MIV method also performed well with ~75% improvement in the results in comparison to the traditional IV method. Overall, both the new proposed methods, ML and MIV, outperformed the traditional inverse velocity technique used for predicting slope failure.

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DYMINSKI, ANDREA SELL. "ANALYSIS OF GEOTECHNICAL PROBLEMS WITH NEURAL NETWORKS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2000. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2001@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Nos últimos anos, a aplicação da técnica de redes neurais tem sido difundida em diversas áreas do conhecimento, inclusive na engenharia civil. Em meados da década de 90, iniciaram-se no Brasil estudos no sentido de avaliar a eficiência desta técnica numérica na modelagem do comportamento de solos e na análise de problemas envolvendo engenharia geotécnica. Este trabalho é resultado de parte destes estudos, onde algumas das potencialidades do uso das redes neurais em geotecnia podem ser observadas. São apresentadas três aplicações diferentes de redes neurais feedforward em geotecnia, tendo sido treinadas com o algoritmo LM (Levenberg-Marquardt). A primeira aplicação diz respeito à simulação de resultados de provas de carga dinâmica, analisadas pelo método CAPWAP, através de redes neurais, sendo assim viabilizada a realização de uma pré- análise do comportamento da estaca ainda em campo, o que geralmente não acontece quando se trata da análise CAPWAP tradicional. A segunda aplicação relaciona-se com a análise do comportamento mecânico de dois tipos de solo bastante diferentes entre si: a areia de Ipanema e o solo residual gnáissico do Rio de Janeiro. Para tal, foram utilizados resultados de ensaios de cisalhamento direto, submersos e não submersos, e ensaios de compressão triaxial, drenados e não drenados. A terceira aplicação refere-se à simulação das características do subsolo do sítio da Usina Nuclear Angra 2, localizada no litoral do estado do Rio de Janeiro. As informações disponíveis eram advindas de boletins de sondagens do tipo SPT. Foram realizadas simulações envolvendo a disposição das camadas dos diferentes tipos de solo que poderiam existir no local, o nível de água subterrâneo, a resistência à penetração do solo e a topografia do terreno. Em todos os casos foram obtidos resultados bastante satisfatórios. Portanto, conclui-se que a técnica das redes neurais apresenta grande viabilidade na resolução de problemas geotécnicos de diferentes características, muitas vezes se mostrando tanto ou mais eficiente que as técnicas numéricas tradicionais.
During the last years, neural networks applications have been disseminated in many knowledge areas, including civil engineering. In the middle 90`s, a research work had been started in Brazil, in order to investigate the efficiency of neural networks in the analysis of soil behavior and problems involving geotechnical engineering. This thesis is the result of part of these studies, where some potentialities of neural networks technique are presented. Three different feedforward NNs applications in geotechnical engineering are presented. Levenberg- Marquardt algorithm was used for training. The first application is the simulation of results of dynamic pile tests, obtained from CAPWAP analysis, showing that it is possible to do a field pre-analysis of the pile behavior, which is still unpracticable when the traditional CAPWAP method is used. The second application is related to the study of two different soils behavior:sand from Ipanema and residual gnaissic soil from Rio de Janeiro. Results of submerged and non submerged direct shear tests and drained and undrained triaxial compression tests were used. The third application involves the simulation of subsoil characteristics of Angra 2 Nuclear Power Plant site. The available information came from SPT bulletins. Simulations involving several types of soil layers spatial distribution, water level position, penetration strength of soils and local topography were performed. The obtained results were very satisfactory. It can be concluded that the neural networks technique presents great applicability in resolution of geotechnical problems with different characteristics, showing an efficiency as good or even better than other traditional numerical techniques.
En los últimos anos, la aplicación de técnicas de redes neurales se ha difundido en diversas áreas del conocimento, incluso en la ingeniería civil. A mediados de la década de 90, se iniciaran en Brasil estudios para evaluar la eficiencia de esta técnica numérica em modelos de comportamiento de suelos y en el análisis de problemas de ingeniería geotécnica. Este trabajo es el resultado de parte de estos estudios, donde pueden ser obseravdas algunas de las potencialidades del uso de las redes neurales en geotecnia. Se presentan tres aplicaciones diferentes de redes neurales fedforward en geotecnia, entrenadas con el algoritmo LM (Levenberg Marquardt). La primera aplicación se refiere a la simulación de resultados de pruebas de carga dinámica, analizadas por el método CAPWAP, a través de redes neurales, realizando un pré análisis del comportamiento de la estaca en campo, lo que generalmente no sucede cuando se trata del análisis CAPWAP tradicional. La segunda aplicación se relaciona con el análisis del comportamiento mecánico de dos tipos de suelo bastante diferentes entre sí: la arena de Ipanema y el suelo residual gnáisico de Rio de Janeiro. Para esto, se uilizaron resultados de ensayos de cisallamiento directo, submersos y no submersos, y ensayos de compresión triaxial, drenados y no drenados. La tercera aplicación se refiere a la simulación de las características del subsuelo del sitio de la Planta Nuclear Angra 2, localizada en el litoral del estado del Rio de Janeiro. Las informaciones disponibles provenian de boletines del tipo SPT. Se realizaron simulaciones que involucraban la disposición de los diferentes tipos de suelo que podrían existir en el local, el nível de agua subterránea, la resistencia a la penetración del suelo y la topografia del terreno. En todos los casos fueron obtenidos resultados bastante satisfactorios. Por lo tanto, se concluye que la técnica de redes neurales presenta gran viabilidad en la resolución de problemas geotécnicos de diferentes características, muchas veces mostrándose tanto o más eficiente que las técnicas numéricas tradicionales.

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Rockaway, Thomas D. "Spatial assessment of earthquake induced geotechnical hazards." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/20038.

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Hamade, Tarek. "Geotechnical design of tailings dams - a stochastic analysis approach." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116869.

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Mine tailings dams are geotechnical structures that are designed to provide adequate and safe storage of tailings materials both during and after the end of mine life. The design of tailings dams is currently based on limit equilibrium methods (LEM) which are used to calculate slope stability safety factors under various operational loads. The minimum safety factor obtained from these analyses is retained to be the design safety factor. LEM's however suffer from a number of shortcomings most notably the lack of information on dam deformation and the interaction between effective stress and pore pressure. For this, advanced numerical modeling techniques accounting for the hydro-mechanical coupling occurring in the dam structure have been developed. These models provide much greater insight into the geotechnical behavior of the tailings dam. However, both LEM and numerical modeling approaches are deterministic in nature; thus, they do not take into consideration the inherent uncertainty of the construction material properties – a fact that is well known to the geotechnical engineer, yet, needs to be addressed.In this thesis, stochastic analysis approaches such as the Monte Carlo (MC) method are adopted to investigate the effect of the inherent uncertainty in material properties on the design factor of safety. Both LEM and coupled hydro-mechanical numerical models are first developed and the results for deterministic models are compiled. These are then compared with the result obtained from stochastic analyses. A case study of a new water retention tailings dam project design with well documented geotechnical data is adopted throughout the thesis study. First the LEM analysis was pursued followed by a sensitivity analysis to determine the most influential parameters on the design safety factor. Next, a fully coupled hydro-mechanical model was developed with FLAC2D in which the construction sequence was simulated in seven stages. The factor of safety (FOS) was calculated at the end of every stage using the Strength Reduction Technique (SRT). Following that, the Point Estimate Method (PEM) was then used to obtain the probability of unsatisfactory performance by considering the dam's core angle of friction, cohesion and permeability as stochastic variables. The coefficient of variation for the material properties was varied and its consequence on the probability was recorded. Next, the MC method was adopted to calculate the tailings dam's probability of unsatisfactory performance as well as its reliability. The effect of changing the probability density function (PDF) of the stochastic input parameter on the output reliability was further analyzed. Furthermore, the effect of randomness at the local level was studied using the Random Monte-Carlo (RMC) method and compared to the output of the MC method.Finally, the effect of the coefficient of correlation between the dam's core angle of friction and its cohesion on the impoundment's reliability was analyzed. This was followed by an advanced stochastic analysis using the MC method that included a third stochastic variable, the dam's core permeability. The incorporation of both mechanical and hydraulic parameters as stochastic variables lowered the impoundment's reliability; thus, highlighting the power and novelty in the hydro-mechanical stochastic analysis hybrid approach. The results of all analyses are presented in the thesis along with the findings in the conclusion.
Les digues des résidus miniers sont des ouvrages géotechniques conçus pour offrir un stockage adéquat et sécuritaire des résidus et ce pendant et après la fin de la vie de la mine. La conception des digues à résidus est actuellement basée sur les méthodes d'équilibre limite (LEM) qui sont utilisés pour calculer les facteurs de sécurité de la stabilité des pentes sous diverses charges opérationnelles. Le facteur de sécurité minimal obtenu à partir de ces analyses est considéré comme facteur de sécurité de conception. Ils sont présentement utilisés dans la conception géotechnique. Cependant, LEM a des lacunes notamment le manque d'information sur la déformation d'une digue et de l'interaction entre les contraintes effectives et la pression interstitielle. Ainsi, les techniques de modélisation numérique avancées qui considèrent le couplage hydro-mécanique survenant dans la structure de la digue ont été développées. Ces modèles procurent un aperçu plus précis du comportement géotechnique de la digue à résidus. Cependant, les deux approches LEM et modélisation numérique sont déterministe. Par conséquent, ces approches ne tiennent pas compte de l'incertitude inhérente aux propriétés des matériaux de construction et ceci est un fait bien connu par l'ingénieur géotechnicien et pourtant ceci doit être abordé.Dans cette thèse, les approches d'analyse stochastiques tels que le Monte Carlo (MC) sont adoptées pour étudier l'effet de l'incertitude inhérente aux propriétés du matériau sur le coefficient de sécurité. Les deux LEM et les modèles numériques hydro- mécaniques couplés sont d'abord développés et après les résultats des modèles déterministes sont compilés. Ces derniers sont ensuite comparés aux résultats obtenus à partir des analyses stochastiques.Une étude de cas d'une nouvelle conception d'une digue à rétention d'eau à résidus avec des données géotechniques bien documentées est adoptée dans cette étude. Tout d'abord, l'analyse LEM a été poursuivi et suivi par une analyse de sensibilité pour déterminer les paramètres les plus influents sur le facteur de sécurité de la conception.Ensuite, un model couplé d'hydro-mécanique a été développé avec FLAC2D dans lequel la séquence de construction a été simulée en sept étapes. Le coefficient de sécurité (FOS) a été calculé à la fin de chaque étape en utilisant la technique de réduction de la résistance (SRT). Par la suite, la méthode d'estimation ponctuelle (PEM) a été utilisée pour obtenir la probabilité d'un rendement insatisfaisant en tenant compte de l'angle de base de la digue, de la friction, de la cohésion et de la perméabilité comme variables stochastiques. Le coefficient de variation des propriétés du matériau a été varié et ses conséquences sur la probabilité ont été enregistrées. Ensuite, la méthode de MC a été adoptée pour calculer la probabilité de rendement insatisfaisant de la digue à résidus ainsi que sa fiabilité. Par ailleurs, l'effet de la modification de la fonction de densité de probabilité (PDF) du paramètre d'entrée stochastique sur la fiabilité de sortie a encore été analysé. En outre, l'effet du hasard au niveau local a été étudiée en utilisant le hasard Monte-Carlo (RMC) et la méthode par rapport à la sortie de la méthode de MC. Enfin, l'effet du coefficient de corrélation entre l'angle de friction du noyau et la cohésion sur la fiabilité de la digue a été analysé. Ceci a été suivi d'une analyse stochastique avancé à l'aide de la méthode MC qui comprenait une troisième variable stochastique qui est la perméabilité du noyau. L'incorporation de paramètres à la fois mécaniques et hydrauliques en tant que variables stochastiques ont réduit la fiabilité de la digue, ainsi, mettant en évidence l'impact de l'analyse stochastique hydro-mécanique avec l'approche hybride. Les résultats de toutes les analyses sont présentés dans la thèse suivante ainsi que les découvertes dans la conclusion.

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Orazalin, Zhandos Y. "Analysis of large deformation offshore geotechnical problems in soft clay." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111442.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 269-281).
Although finite element (FE) methods are well established for modeling geotechnical problems in soil masses and soil-structure interaction, most prior research on large deformation problems has been limited to simplified assumptions on drainage conditions and constitutive behavior. This thesis investigates two large deformation problems in soft clay and proposes a methodology for performing coupled flow and deformation analyses with advanced effective stress models. The first part of the research focuses on realistic 3-D finite element analyses (using AbaqusTM Standard) of a conductor (steel pipe pile) embedded within soft marine clay subjected to large lateral deformations caused by drift/drive-off of a drilling vessel. The proposed analyses use coupled pore pressure-displacement procedures together with the MIT-E3 soil model to represent the anisotropic, non-linear and inelastic effective stress-strain-strength properties of deepwater marine sediments with input parameters derived from a series of laboratory element tests performed on reconstituted Gulf of Mexico (GoM) clay. The numerical predictions are evaluated through comparison with experimental results from centrifuge tests with a well-instrumented model conductor. The FE results accurately predict the measured bending moment distribution along the length of the conductor and the spread of plastic strains within the conductor itself. The study has also shown the effects of soil behavior on local pile-soil interactions, enabling simplified analyses using macro-elements. The FE results have been used to calibrate input parameters for BWGG framework (Gerolymos & Gazetas, 2005), the Bouc-Wen (BW) model extended by Gerolymos and Gazetas (GG), that simulates generalized hysteretic pile-soil interactions and allows for degradation in soil resistance associated with geometric non-linearities. The second application considers the effects of partial drainage for large deformation, quasi-static piezocone penetration in clay. The proposed axisymmetric FE analysis procedure introduces automated remeshing and solution mapping technique (similar to RITSS; Hu & Randolph, 1998) within a commercial FE solver. We have analyzed the penetration resistance for a piezocone device using two elasto-plastic soil models (MCC, MIT-E3) and the recent elasto-viscoplastic MIT-SR soil model (Yuan, 2016) over a range of steady penetration velocities. The MCC predictions are in very good agreement with laboratory measurements of tip resistance and penetration pore pressures measured in centrifuge model tests in reconstituted kaolin. The results from more advanced soil models illustrate the impacts of anisotropic, rate dependent soil behavior on penetration tests in natural clays and are within the range of empirical measurements. The proposed analyses provide a complete framework that can now be used to investigate effects of partial drainage that occurs in piezocone tests for soils (such as silts) of intermediate permeability.
by Zhandos Y. Orazalin.
Ph. D.

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Janrungautai, Sirisin. "The Study on Uncertainty Modeling and Risk Analysis Geotechnical Problems." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/148293.

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Knutsson, Roger. "Tailings Dam Performance : Modeling and Safety Analysis of a Tailings dam." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18084.

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Storage and management of mine waste are both needed in the mining industry. After mineral extraction of the ore, there are generally leftovers with insufficient economical value that need to be taken care of. The finest grained fractions are referred to as tailings. Since every mine site and every tailings impoundment is unique, there is unfortunately not an universal answer to proper management that can be applied everywhere. Even though local guidelines and regulations can be considered to give a best practice in terms of design, there is correspondingly a need for dam safety stewardship on an operational level. Without such stewardship, not even the best designed dams or facilities would be fully controlled in terms of safety. Conversely, even badly designed dams can be operated in safe manners with good stewardship and surveillance programs. The coupling between design and stewardship is therefore important in order to reach proper tailingsmanagement.In the design of tailings dams, a certain value of the factor of safety for slopes of the dams is normally striven for to secure stability. The value is generally based on national regulations and/or guidelines. In Sweden the factor of safety should not be lower than 1.5 under normal conditions. In the guidelines, recommendations are often given on dam surveillance and field measurements of e.g. pore water pressure, deformations and seepage. Field measurements are taken, but are generally assessed in terms of trends (change with time) and not by comparison to anticipated performance.In this study, numerical modeling has been used for stability analyses and dam performance, as predictions of deformations and pore water pressure levels. An upstream tailings dam located in northern Sweden has been used as a case. The granular materials being part of the model based were described based upon geotechnical investigations (field and lab). The tailings material was modeled, on a constitutive level, by the Hardening Soil model. Good agreement betweensimulated behavior and laboratory tests was achieved. Other dam materials were simulated by the Mohr-Coulomb model.The model was built as a staged construction model where historical events between 1992 and 2013 were simulated. The historical events included dam raises, increased beach elevations, remedial works etc. The simulations of historical events were used for facilitating comparison with field measurements. By means of inclinometer data, horizontal deformations were measured and evaluated for a period of six years. These deformations were accurately simulated, which was considered to verify the numerical model. By this verification, the model is considered accurate enough to be used for simulating future events. Both stability and corresponding dam performance were computed, by simulating a period of 10 years. The stability analyses were used for the set-up of rockfill support plans, i.e. where and when remedial works are needed in order to maintain a certain safety level. The corresponding values in deformations and pore water pressures were used for the set-up of alert levels for each measuring unit. These alert levels will help the engineer in field with data interpretation, where the simulated values are compared with field measurements taken. The proposed methodology is recommended for tailings dams in general, which reduces the gap between design and stewardship. Hence, one step closer to proper tailings management is taken.
Godkänd; 2015; 20151026 (rogknu); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Roger Knutsson Ämne: Geoteknik/Soil Mechanics Uppsats: Tailings Dam Performance Modeling and Safety Analysis of a Tailings Dam Examinator: Professor Sven Knutsson Institutionen för samhällsbyggnad och naturresurser Avdelning Geoteknologi Luleå tekniska universitet Diskutant: Technical Director Annika Bjelkevik Tailings Consultant Scandinavia AB Stockholm Tid: Fredag 27 november 2015 kl 13.00 Plats: F1031, Luleå tekniska universitet

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Del, Potro Rodrigo. "Geotechnical analysis of the stability of stratovolcanoes : Teide edifice, Canary Islands." Thesis, Lancaster University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514452.

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ARAUJO, LUIZ GONZAGA DE. "NUMERICAL STUDIES OF THE STABILITY OF GEOTECHNICAL MATERIALS THROUGH LIMIT ANALYSIS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1997. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2084@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
O presente trabalho apresenta um estudo de problemas de estabilidade, freqüentemente,encontrados, em Engenharia Geotécnica, através da técnica da Análise Limite associada ao Método dos Elementos Finitos (MEF).Inicialmente, faz-se uma revisão das formulações da Análise Limite, via MEF,encontradas, com maior freqüência, na literatura técnica especializada.Uma formulação mista que é descrita em detalhe na tese foi escolhida para implementação. Extensões das formulações da Análise Limite de meios contínuos são propostas para contemplar características de maciços rochosos fraturados. É proposto,também, um procedimento numérico para tratar de problemas de estabilidade de meios que exibem fluxo plástico não associado.As implementações realizadas foram validadas através de problemas cujas soluções podem ser obtidas por via analítica.Finalmente, um número considerável de problemas de interesse em Engenharia Geotécnica é estudado utilizando a implementação realizada. Os resultados destes estudos sugerem a viabilidade da utilização da técnica estudada na solução de problemas práticos de Engenharia Civil.
This work presents a study of stability problems often encountered in Geotechnical Engineering, through the use of Limit Analysis in conjunction with the Finite Element Method (FEM).Initially, a literature survey of the most often found formulations in Limit Analysis through the FEM is carried out.A mixed formulation of Limit Analysis was chosen for implementation and its details are fully described. Extensions of the formulation to deal with stability problems in fractured rock media are also proposed and described. A numerical procedure to take into account the effect of non associative plastic flow is proposed.The implementations carried out were validated through problems to which analytical solutions could be found.Finally, a considerable number of problems of interest to Geotechnical Engineering is studied with the implemented formulation. The results of these studies suggest that Limit Analysis can be considered as a viable tool in the solution of practical problems in Geotechnical Engineering.

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Warren, Sean N. "Limit equilibrium stability analysis utilizing geotechnical data at Mount Baker, Washington /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1461537.

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Thesis (M.S.)--University of Nevada, Reno, 2008.
"December 2008." Includes bibliographical references (leaves 109-112). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2009]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web. Library also has electronic version on CD-ROM

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Chabuk, Ali Jalil. "Analysis of Landfill Site Selection-Case Studies Al-Hillah and Al-Qasim Qadhaas, Babylon, Iraq." Licentiate thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-347.

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The selection of a landfill site is considered as a complicated task because the whole process is based on many factors and restrictions. This study shows the present status of solid waste management, solid waste sources, staffing for solid waste collection, machinery and equipment used in the waste collection process, finance and financial management at Babylon Governorate and its Qadhaa. The management of collection and disposal of waste in Babylon Governorate and its Qadhaa is done through open dumping of waste and the quality of the collection process is poor. This is the case in Al-Hillah Qadhaa, which is located in the central part of the governorate, Iraq and Al-Qasim Qadhaas, which is situated in the southern part of the Babylon Governorate, Iraq. These sites do not conform to the scientific and environmental criteria applied in the selection of landfill sites. In the first part of the current study, to find out how much solid waste will be produced in the future; two methods were used to calculate the population growth in Al-Hillah and Al-Qasim Qadhaas to the year 2030. The results showed that the total waste in 2030 according to the first and second methods respectively will be 394,081 tonnes and 472,474 tonnes in Al-Hillah Qadhaa, and (54,481 tonnes and 76,374 tonnes) in Al-Qasim Qadhaa. The cumulated quantity of solid waste expected to be produced between 2020 and 2030 according to the first and second methods respectively was 3,757,387 tonnes and 4,300,864 tonnes in Al-Hillah Qadhaa, whilst in Al-Qasim Qadhaa it was 519,456 tonnes and 695,219 tonnes. The generation rate in 2020 will be (0.88 and 0.62) kg/ (capita. day) in Al-Hillah and Al-Qasim Qadhaas respectively; in year 2030, the generation rate will be (0.97 and 0.69) kg/ (capita. day) based on method 2 and an expected incremental increase in generation rate of 1 kg/ (capita. day) per year. The second part of this study aims to find the best sites for landfills in Al-Hillah and Al-Qasim Qadhaas. For this reason, 15 criteria were adopted in this study (groundwater depth, rivers, soil types, agricultural land use, land use, elevation, slope, gas pipelines, oil pipelines, power lines, roads, railways, urban centres, villages and archaeological sites) using GIS (geographic information system), which has a large capacity for managing input data. In addition, the AHP (analytical hierarchy process) method was used to derive the relative weightings for each criterion using pairwise comparison. The suitability index map for candidate landfill sites was obtained. Two suitable candidate landfill sites were found to fulfill the scientific and environmental requirements in each Qadhaa, with areas of 9.153 km2 and 8.204 km2 respectively in Al-Hillah Qadhaa, and with areas of 2.766 km2 and 2.055 km2 respectively in Al-Qasim Qadhaa. The area of these sites can accommodate solid waste from 2020 until 2030 based on the required areas, which were 4.175 km2 and 4.778 km2 (Ali-Hillah Qadhaa) and 0.577 km2 and 0.772 km2 in (Al-Qasim Qadhaa) according to the first and second methods respectively.

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13

Hardy, Stuart. "The implementation and application of dynamic finite element analysis to geotechnical problems." Thesis, Imperial College London, 2003. http://hdl.handle.net/10044/1/7146.

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Prasad, Anamika 1979. "Development of user interface for numerical limit analysis of geotechnical stability problems." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/85751.

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Peeters, Bieke. "Two-dimensional analysis of the failure mechanisms of an embankment supported by rows of dry deep mixing columns." Thesis, KTH, Jord- och bergmekanik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208177.

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McKay, Sara E. "Geotechnical analysis of horizontal drains as a landslide mitigation method in western Washington /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1437660.

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Thesis (M.S.)--University of Nevada, Reno, 2006.
"August, 2006." Includes bibliographical references (leaves 93-97). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.

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17

Kontoe, Stavroula. "Development of time integration schemes and advanced boundary conditions for dynamic geotechnical analysis." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435799.

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Hicks, Malcolm Andrew. "Geotechnical Investigations of Wind Turbine Foundations Using Multichannel Analysis of Surface Waves (MASW)." Thesis, University of Canterbury. Geological Sciences, 2011. http://hdl.handle.net/10092/6519.

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The geophysical technique known as Multichannel Analysis of Surface Waves, or MASW (Park et al., 1999) is a relatively new seismic characterisation method which utilises Rayleigh waves propagation. With MASW, the frequency dependent, planar travelling Rayleigh waves are created by a seismic source and then measured by an array of geophone receivers. The recorded data is used to image characteristics of the subsurface. This thesis explains how MASW was used as a geotechnical investigation tool on windfarms in the lower North Island, New Zealand, to determine the stiffness of the subsurface at each wind turbine site. Shear‐wave velocity (VS) profiles at each site were determined through the processing of the MASW data, which were then used to determine physical properties of the underlying, weathered greywacke. The primary research site, the Te Rere Hau Windfarm in the Tararua Ranges of the North Island, is situated within the Esk Head Belt of Torlesse greywacke (Lee & Begg, 2002). Due to the high level of tectonic activity in the area, along with the high rates of weathering, the greywacke material onsite is highly fractured and weathering grades vary significantly, both vertically and laterally. MASW was performed to characterise the physical properties at each turbine site through the weathering profile. The final dataset included 1‐dimensional MASW shear‐wave evaluations from 100 turbine sites. In addition, Poisson’s ratio and density values were characterised through the weathering profile for the weathered greywacke. During the geotechnical foundation design at the Te Rere Hau Windfarm site, a method of converting shear wave velocity profiles was utilised. MASW surveying was used to determine VS profiles with depth, which were converted to elastic modulus profiles, with the input parameters of Poisson’s ratio and density. This study focuses on refining and improving the current method used for calculating elastic modulus values from shear‐wave velocities, primarily by improving the accuracy of the input parameters used in the calculation. Through the analysis of both geotechnical and geophysical data, the significant influence of overburden pressure, or depth, on the shear wave velocity was identified. Through each of the weathering grades, there was a non‐linear increase in shear wave velocity with depth. This highlights the need for overburden pressure conditions to be considered before assigning characteristic shear wave velocity values to different lithologies. Further to the dataset analysis of geotechnical and geophysical information, a multiple variant non‐linear regression analysis was performed on the three variables of shear wave velocity, depth and weathering grade. This produced a predictive equation for determining shear wave velocity within the Esk Head belt ‘greywacke’ when depth and weathering data are known. If the insitu geological conditions are not comparable to that of the windfarm sites in this study, a set of guidelines have been developed, detailing the most efficient and cost effective method of using MASW surveying to calculate the elastic modulus through the depth profile of an investigation site.

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FARFAN, ALDO DURAND. "APPLICATIONS OF LIMIT ANALYSIS TO GEOTECHNICAL PROBLEMS MODELLED AS CONVENTIONAL AND COSSERAT CONTINUA." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2000. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2000@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O presente trabalho trata da aplicação da análise limite numérica (ALN) a problemas geotécnicos. Os meios (solo ou rocha) são considerados como contínuos convencionais e como contínuos de Cosserat. Da aplicação da formulação mista da análise limite e da discretização do meio por uma malha de elementos finitos é obtido um problema de programação matemática (PM). A aplicação desta metodologia nos contínuos de Cosserat (2D) fornece problemas de programação linear (PL) e nos contínuos convencionais (2D e 3D), problemas de programação não-linear (PNL). A solução do problema de PM foi através dos programas de otimização: LINDO (PL), LINGO (PNL), MINOS (PNL) e LANCELOT (PNL). Também foram implementados os algoritmos não lineares -Quase Newton com deflexão- e -Han-Powell-. A formulação é validada em problemas cuja solução analítica é conhecida ou em dados experimentais. Estes exemplos mostram a rapidez e a eficácia da ALN para a determinação da carga de colapso e do mecanismo de ruptura do problema.
The present work treats of the application of the numerical limit analysis (NLA)to geomechanics problems. The soil or rock mass is considered as conventional continuous and Cosserat continuous. A mathematical programming (MP) problem is obtained through the application of the mixed formulation of limit analysis and the finite elements mesh. The application of this methodology in the Cosserat continuous (2D) supplies linear programming (LP) problems and in the conventional continuous (2D and 3D) nonlinear programming (NLP) problems. The solution of the problem of MP was through the LINDO (LP), LINGO (NLP), MINOS (NLP) and LANCELOT (NLP) programs. It was also implemented nonlinear algorithms -Quasi-Newton feasible point method- and -Han-Powell-.The formulation is validated in problems whose analytic solution is known or in experimental data. These examples show the speed and the effectiveness of NLA for the determination of the collapse load and of the mechanism of rupture of the problem.
EL presente trabajo trata de la aplicación del análisis límite numérica (ALN) a problemas geotécnicos. Los medios (suelo o roca) son considerados como contínuos convencionales y como contínuos de Coserat. De la aplicación de la formulación mixta del análisis límite y de la discretización del medio por una malla de elementos finitos se obtiene un problema de programación matemática (PM). La aplicación de esta metodología en los contínuos de Coserat (2D) nos lleva a problemas de programación lineal (PL) y en los contínuos convencionales (2D y 3D), problemas de programación no lineal (PNL). La solución del problema de PM fue a través de los programas de optimización: LINDO (PL), LINGO (PNL), MINOS (PNL) y LANCELOT (PNL). También fueron implementados los algoritmos no lineares quase- Newton con deflexión y Han Powell . Se evalúa la formulación propuesta en problemas donde se conoce la solución analítica o en datos experimentales. Estos ejemplos muestran la rapidez y la eficacia de la ALN para la determinación de la carga de colapso y del mecanismo de ruptura del problema.

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Arulrajah, Atputharajah. "Field measurements and back-analysis of marine clay geotechnical characteristics under reclamation fills." Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/2251.

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Due to the scarcity of land at coastal regions around the world, land reclamation is commonly carried out for the future expansion of various infrastructure facilities. Marine clay is present at the coastal regions of Southeast Asia. Land reclamation on this highly compressible soil foundation often requires the use of soil improvement works to eliminate significant future settlements from occurring. The combination of prefabricated vertical drains with preloading is one of the most widely used ground improvement methods in land reclamation projects. The best means available for field measurement and back-analysis of the marine clay geotechnical characteristics under reclamation fills is by carrying out extensive field instrumentation and in-situ tests. In-situ testing of marine clay was carried out at a test site. In-situ penetration testing was used to analyse the degree of consolidation, the improved shear strengths, overconsolidation ratio and the effective stress of marine clay prior to reclamation as well as after surcharge loading. In-situ dissipation testing was used to determine the coefficient of consolidation due to horizontal flow and horizontal hydraulic conductivity of the marine clay prior to reclamation as well as after surcharge loading. The in-situ penetration and dissipation tests were carried out by means of the field vane shear, piezocone, dilatometer, self-boring pressuremeter and BAT permeameter. Field instrumentation methods, assessment and hack-analysis of marine clay behaviour under reclamation fills forms the crux of this research.The factors that affect the field instrumentation assessment of marine clays treated with prefabricated vertical drains, forms an integral part of this research study. Settlement gauges and piezometers were used to monitor the performance of the vertical drains and to assess the degree of consolidation of the improved soil at two case study sites. The field settlement data were back-analysed by the Asaoka and Hyperbolic methods to predict the ultimate settlement of the reclaimed land under the surcharge fill. Back-analysis of the field settlement and piezometer monitoring data also enabled the coefficient of consolidation due to horizontal flow to be closely estimated. Finite element modeling of marine clay and prefabricated vertical drains was carried out and compared with the field surface settlement results at the two case study sites.

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21

Arulrajah, Atputharajah. "Field measurements and back-analysis of marine clay geotechnical characteristics under reclamation fills." Curtin University of Technology, Department of Civil Engineering, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16008.

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Due to the scarcity of land at coastal regions around the world, land reclamation is commonly carried out for the future expansion of various infrastructure facilities. Marine clay is present at the coastal regions of Southeast Asia. Land reclamation on this highly compressible soil foundation often requires the use of soil improvement works to eliminate significant future settlements from occurring. The combination of prefabricated vertical drains with preloading is one of the most widely used ground improvement methods in land reclamation projects. The best means available for field measurement and back-analysis of the marine clay geotechnical characteristics under reclamation fills is by carrying out extensive field instrumentation and in-situ tests. In-situ testing of marine clay was carried out at a test site. In-situ penetration testing was used to analyse the degree of consolidation, the improved shear strengths, overconsolidation ratio and the effective stress of marine clay prior to reclamation as well as after surcharge loading. In-situ dissipation testing was used to determine the coefficient of consolidation due to horizontal flow and horizontal hydraulic conductivity of the marine clay prior to reclamation as well as after surcharge loading. The in-situ penetration and dissipation tests were carried out by means of the field vane shear, piezocone, dilatometer, self-boring pressuremeter and BAT permeameter. Field instrumentation methods, assessment and hack-analysis of marine clay behaviour under reclamation fills forms the crux of this research.
The factors that affect the field instrumentation assessment of marine clays treated with prefabricated vertical drains, forms an integral part of this research study. Settlement gauges and piezometers were used to monitor the performance of the vertical drains and to assess the degree of consolidation of the improved soil at two case study sites. The field settlement data were back-analysed by the Asaoka and Hyperbolic methods to predict the ultimate settlement of the reclaimed land under the surcharge fill. Back-analysis of the field settlement and piezometer monitoring data also enabled the coefficient of consolidation due to horizontal flow to be closely estimated. Finite element modeling of marine clay and prefabricated vertical drains was carried out and compared with the field surface settlement results at the two case study sites.

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Majala, Jonas. "Frequency analysis of accelerometer measurements on trains." Thesis, Luleå tekniska universitet, Geoteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-63930.

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23

Kolat, Cagil. "Developing A Geotechnical Microzonation Model For Yenisehir (bursa) Settlement Area." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612163/index.pdf.

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The purpose of this study is to develop a geotechnical microzonation model regarding the suitability of the residential areas in Yenisehir (Bursa, Turkey), which is a currently developing settlement area in a seismically active region. For this purpose, soil properties and dynamic soil behaviors of the study area were assessed. Soil classification, soil amplification, natural soil predominant period, resonance phenomena and liquefaction potential of the study area were evaluated using borehole data and microtremor measurements. The raw data obtained from the previous studies carried out at Yenisehir were used for these assessments. The liquefaction potential for the study area was evaluated both in two-dimensional planimetric and three-dimensional volumetric assessments. Two geotechnical microzonation maps were produced for the study area according to the surface damage due to liquefaction (according to two different methods), soil amplification and distance to streams maps
by using Geographical Information Systems (GIS) based Multi-Criteria Decision Analysis. The weight values were assigned to the layers using Analytical Hierarchical Process method by pairwise comparisons. Evaluating geotechnical microzonation maps produced, the safest areas were found on the northern sites of the study area. The most critical areas were found to be in the middle and the southeast parts of the study area.

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Bertel, Jeffrey D. "Analytical study of the spectral-analysis-of-surface-waves method at complex geotechnical sites." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4625.

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Thesis (M.S.) University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.

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25

Hürlimann, Marcel. "Geotechnical analysis of large volcanic landslides: The La Orotava events on Tenerife,Canary Islands." Doctoral thesis, Universitat Politècnica de Catalunya, 1999. http://hdl.handle.net/10803/6217.

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Los grandes deslizamientos volcánicos son uno de los procesos geológicos más devastadores y pueden representar un importante peligro para la población de las zonas volcánicas. Este tipo de deslizamientos puede sobrepasar volúmenes de decenas o incluso centenares de kilómetros cúbicos. En Tenerife, siete grandes deslizamientos han afectado durante los últimos ~6 millones de años la morfología subaérea y submarina de la isla.
En este estudio se ha realizado un extenso análisis de los eventos que han formado el valle de "La Orotava" en la parte Norte de Tenerife. El estudio incluye una investigación de campo, ensayos de laboratorio y análisis de estabilidad. En el laboratorio, las propiedades mecánicas de un suelo residual han sido investigadas mediante cortes directos y ensayos triaxiales. Durante el análisis de estabilidad, los resultados de los ensayos de laboratorio han sido incorporados a diferentes tipos de modelos de estabilidad. Finalmente, las condiciones mecánicas de los modelos dos y tres dimensionales han sido estudiados mediante el método de equilibrio límite y métodos de elementos finitos.
Los resultados de los análisis revelan que la estabilidad de las laderas volcánicas puede ser reducida debido a diversos factores, como geológicos, morfológicos, climáticos y volcánicos. Los suelos residuales - bastante comunes en Tenerife - pueden haber actuado como superficie de rotura a causa de su débil comportamiento mecánico. Por otra parte, los estrechos y profundos barrancos han definido los límites laterales de los deslizamientos. Además de ello, los acantilados, el clima húmedo y especialmente la constante intrusión de diques, han llevado la ladera a condiciones de estabilidad críticas. Finalmente, una aceleración sísmica causada por un seísmo fuerte y cercano provocó muy probablemente el deslizamiento catastrófico.
En Tenerife, se ha observado una relación temporal entre los colapsos de caldera y los grandes deslizamientos, lo que permite suponer que los fuertes terremotos asociados a los colapsos de caldera hayan provocado los deslizamientos.
Large volcanic landslides are one of the most hazardous of geological processes. They have occurred about once every 25 years during the last 500 years, and are a serious risk for the population due to their great volume and mobility. In spite of their destructive potential there are few comprehensive studies analysing large landslides on volcano flanks, and the mechanisms of such mass movements are not yet resolved. Within the last few years, several hypotheses concerning the potential causes of volcanic landslides have been proposed including processes such as dike intrusion, volcanic spreading, hydrothermal alteration, seismic shocks and caldera collapse events.
Tenerife exhibits three large subaerial valleys originated by giant flank failures with ages ranging from Upper Pliocene to Middle Pleistocene. The northern submarine flank of the island is characterised by a voluminous apron of landslide debris. The La Orotava valley has been selected for analysis due to the amount of available data concerning its structure and evolution, and has been used as a test site to validate new assumptions that could be applied to other volcanic areas.
The site investigation has revealed that the present morphology of the La Orotava valley was formed by two different failures: one in the western sector and the other in the eastern sector. The mechanical stability of the preslide volcano flank was strongly reduced by geologic, morphologic, climatic and volcanological factors which play a fundamental role in the initiation of the landslides. Widespread residual soils (paleosols) might have acted as potential slip surfaces, while deep erosive canyons probably evolved into the lateral limits of the failures. A high coastal cliff and a humid climate have also contributed to the critical stability conditions. The location of the landslide amphitheatre is perpendicular to the active Dorsal rift zone and adjacent to the Las Cañadas caldera, both important influences on the stability of the volcano slopes. On Tenerife, the relationship between large volcanic landslides and vertical caldera collapses is supported by a temporal coincidence of at least two failures with caldera collapse events.
The mechanical behaviour of a residual soil sampled in the La Orotava valley has been analysed. Red coloured residual soils are generally located at the top of phonolitic pyroclastic deposits and are proposed as potential slip surfaces due to their very weak behaviour and their flat, homogeneous characteristics. They represent the only planar surface within the succession making up the volcano slopes. Their weak mechanical behaviour is characterised by volumetric collapse during shearing, a substantial reduction of shear strength for high normal stresses, and a significant increase of pore water pressure during undrained loading. The last feature is fundamental to the stability of volcano flanks since it strongly reduces the soil strength. Earthquakes, common processes in active volcanic areas, and saturated conditions can generate high excess pore pressures indicating the importance of regional climate and seismicity.
The stability analysis has considered three different mechanisms: 1) ground acceleration due to seismicity - including both tectonic earthquakes and volcano-tectonic seismic shocks produced by caldera collapse; 2) horizontal stress due to dike intrusion, and; 3) vertical shear stress due to caldera collapse. The results indicate that ground acceleration principally decreases the mechanical stability of volcano flanks, enabling failure. Horizontal stresses due to dike intrusion can also influence slope stability, but preferably act as a preparing factor destabilising the slope, and not as a final triggering mechanism. The 3D numerical simulations show the significant effect of deeply incised canyons creating high shear stress at their base.
Applying the results to the La Orotava events, the following scenario is assumed: First, deep narrow canyons, weak residual soils, humid climate, coastal cliff and persistent dike intrusion have significantly reduced the mechanical stability of the volcano slope and determined the limits of the failing mass. Then, seismicity generated by the caldera collapse episode at the end of the Guajara cycle at ~0.56 Ma triggered the catastrophic landslides.
The results of the mobility analysis show the important influence of water on the runout distances of landslides. Subaqueous drag forces reduce the velocity, while hydroplaning effects strongly increase the runout distance. For Tenerife, the model indicates that a sliding mass can advance great distances, tens of kilometres away from the island, at water depths exceeding 3000 m, as can be observed in the bathymetric data.

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Javakhishvili, Zurab. "The coupled finite-boundary element method applied to the analysis of geotechnical engineering problems." Thesis, London South Bank University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261020.

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Han, Bo. "Hydro-mechanical coupling in numerical analysis of geotechnical structures under multi-directional seismic loading." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/28683.

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This thesis numerically investigates the seismic behaviour of geotechnical structures under multi-directional loading by employing the coupled hydro-mechanical (HM) formulation of the Imperial College Finite Element Program (ICFEP). The scope of the research work can be summarised as follows: Firstly, the stability of the generalised-α method (CH method) for the coupled consolidation formulation, is analytically investigated for the first time and the corresponding theoretical stability conditions are derived. The analytically derived stability conditions are validated by finite element (FE) analyses considering a range of loading conditions and soil permeability values. Secondly, the site response due to the vertical component of the ground motion is systematically investigated by employing analytical and numerical methods. The compressional wave propagation mechanism in saturated porous soils is investigated by the coupled HM formulation. Furthermore, the undertaken coupled FE analyses explore the effects of the parameters characterising the hydraulic phase, i.e. the soil permeability and soil state conditions, on the vertical site response. Thirdly, three-directional (3-D) site response analyses are conducted for the HINO site of the Japanese KiK-net down-hole array earthquake monitoring system. Different aspects of the numerical modelling for the site response analysis, such as the constitutive model, the use of 3-D input motion and the coupled consolidation formulation, are investigated and validated by the recordings from the KiK-net system. Further parametric studies investigate the impact of the variation of the water table, the soil permeability and the 3-D input motion on the multi-directional site response. Finally, the seismic response of a well-documented Chinese rockfill dam, the Yele dam, is investigated with the dynamic plane-strain FE analysis, accounting for the HM coupling and nonlinear soil response. The numerical predictions are compared against the available static and dynamic monitoring data, which allows for a rigorous validation of the developed numerical model. Furthermore, parametric studies of the Yele dam are conducted to explore the effects of several critical factors on the seismic response of rockfill dams, i.e. the reservoir simulation method, the permeability of materials comprising the dam body, the vertical ground motion and the reservoir water level.

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Madden, Patrick. "The influence of structural details, geotechnical factors and environs on the seismic response of framed structures." Thesis, University of Dundee, 2014. https://discovery.dundee.ac.uk/en/studentTheses/c24ae223-999c-407c-bd3f-b461708dcbb3.

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Seismic events around the globe directly affect all ranges of structures, from complex and expensive ‘skyscrapers’ to simple frame structures, the latter making up a higher proportion of the number of structures affected as they are a much more common type of structure. The impact of a seismic event can be devastating, especially if adequate predictions of their impact and imposed structural response are not made during the design stage of the structure. Knowing what response to expect allows the engineer to design the structure to survive an event and protect the occupants. The structural response to a seismic event is very complex and can be affected by a wide range of structural, geotechnical and environ parameters. While larger, expensive structures make use of expensive, time consuming, finite element analytical procedures to determine their response the cheaper, simpler, frame structures have to make do with existing, simplified, spectral method predictions. This research firstly involves finite element analysis of simple frame structures, considering different structural and geotechnical parameters which may influence the seismic response, namely the stiffness of the structural joints, the geometry of the structure (influencing the individual structural element flexibility) and the foundation conditions (fixed base or shallow foundations with soil structure interaction). A range of frames, of varying geometry, are considered which mobilise different amounts of inter-storey drift, local rotation and global rotation response. The influence of soil structure interaction (SSI) and frame rigidity (i.e. the properties of the joints) on the response behaviour is investigated. The finite element database is then used to validate improved methods for predicting the spectral response parameters, specifically the natural period and damping of equivalent single degree of freedom (SDOF) systems, which include the effects of frame rigidity, geometry and SSI. Dynamic centrifuge testing is also carried out in order to further validate the improved spectral model for the case of real soil with shear dependant stiffness. The physical model testing is also extended to consider how environs, such as other structures in close proximity, influence the response of a structure.

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Finlayson, K. A. "Geophysical evaluation of the geotechnical properties of Quaternary sediments from the continental margin, northwest of the UK." Thesis, Bangor University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310918.

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Bossi, Giulia <1984&gt. "Statistical analysis of the error associated with the simplification of the stratigraphy in geotechnical models." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6958/.

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The uncertainties in the determination of the stratigraphic profile of natural soils is one of the main problems in geotechnics, in particular for landslide characterization and modeling. The study deals with a new approach in geotechnical modeling which relays on a stochastic generation of different soil layers distributions, following a boolean logic – the method has been thus called BoSG (Boolean Stochastic Generation). In this way, it is possible to randomize the presence of a specific material interdigitated in a uniform matrix. In the building of a geotechnical model it is generally common to discard some stratigraphic data in order to simplify the model itself, assuming that the significance of the results of the modeling procedure would not be affected. With the proposed technique it is possible to quantify the error associated with this simplification. Moreover, it could be used to determine the most significant zones where eventual further investigations and surveys would be more effective to build the geotechnical model of the slope. The commercial software FLAC was used for the 2D and 3D geotechnical model. The distribution of the materials was randomized through a specifically coded MatLab program that automatically generates text files, each of them representing a specific soil configuration. Besides, a routine was designed to automate the computation of FLAC with the different data files in order to maximize the sample number. The methodology is applied with reference to a simplified slope in 2D, a simplified slope in 3D and an actual landslide, namely the Mortisa mudslide (Cortina d’Ampezzo, BL, Italy). However, it could be extended to numerous different cases, especially for hydrogeological analysis and landslide stability assessment, in different geological and geomorphological contexts.
L’incertezza nella determinazione del profilo stratigrafico e dei parametri meccanici dei singoli terreni è tra i principali problemi dell’ingegneria geotecnica, in particolare per l’analisi dei fenomeni franosi. Lo studio presenta un nuovo approccio nella modellazione geotecnica che si basa sulla generazione stocastica di diverse distribuzioni di strati di terreno, seguendo una logica booleana - il metodo è stato perciò chiamato BoSG (Boolean Stochastic Generation – Generazione Stocastica Booleana). Con questo metodo è possibile randomizzare la presenza di uno specifico materiale interdigitato in una matrice uniforme. Nell’impostare un modello geotecnico, infatti, generalmente si eliminano alcuni dati stratigrafici per semplificare il modello stesso, assumendo che la significatività dei risultati non ne risenta. La metodologia proposta permette di quantificare l'errore associato a questa semplificazione. Inoltre, può essere utilizzata per determinare le zone più significativi nelle quali possibili ulteriori indagini geotecniche sarebbero più efficaci per la definizione del modello geotecnico. Per la modellizzazione bidimensionale e tridimensionale è stato utilizzato il software commerciale alle differenze finite FLAC. La distribuzione dei materiali è stata randomizzata attraverso un programma in MatLab specificamente codificato che genera automaticamente dei file di testo con le configurazioni del terreno. E’ stata inoltre programmata una routine per automatizzare il calcolo FLAC con diverse file di dati al fine di massimizzare la numerosità campionaria. In questa tesi la metodologia è stata applicata ad un pendio semplice in 2D, un pendio semplice in 3D e una frana reale: la frana di colata di Mortisa (Cortina d'Ampezzo, BL). Il metodo, tuttavia, potrebbe essere applicato ad altri casi, in particolare per studi di idrologia sotterranea, per l’analisi di stabilità di altre frane e in diversi contesti geologici e geomorfologici

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31

Howie, C. T. "Computer program development for the analysis of inelastic beam and soil behaviour in geotechnical design." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/18236.

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Computer-aided engineering requires the correct implementation of design methods in computer programs so as to play a beneficial role in engineering practice. This thesis describes the development of a computer program to analyse geotechnical engineering problems based on the principles of beam-soil interaction where the beam is supported by a single or two-layer soil system. In 1867, a foundation model was proposed by Winkler in which the elastic foundation beneath a horizontal beam could be viewed as a series of independent springs. Foundation reaction to beam deflection is, therefore, linear. A stiffness matrix, for use in matrix methods of structural analysis, has been developed to define this beam-soil interaction, and such a method can be incorporated into a computer program. Furthermore, an iterative technique was created to allow for inelastic soil response when using the elastic stiffness matrix. However, such a technique did not consider realistic soil behaviour, and has limitations is used for practical design. This research' work describes how use can be made of the pressure-displacement response relationship for a soil to bring greater realism to beam-soil modelling and analysis. Such a relationship is commonly determined in geotechnical design procedures through a plate load test in the field. In addition, the iterative technique is extended to include non-linear beam behaviour as well, and plastic hinging of the beam material is incorporated to enable limitation of inelastic response. While previous research has only considered foundations of a single soil only, a procedure to model a two-layered system is developed. Two-layered foundations are required for proper modelling of soldier pile support systems, an area of structural design in geotechnics chosen to demonstrate realistic design potential for the computer program. The two-layered principle is based on the derivation of a control parameter to differentiate between response from just the upper soil layer, and a combined response from both soil layers. The procedure is relatively simple, and no extra information is required other than the two pressure displacement relationships for the individual soil layers. A desktop computer program is described which incorporates the inelastic analysis features, as well as the two-layered soil system. The program makes use of a graphical user interface to offer the user an easy, interactive environment for analysing beam-on-soil foundation problems. As such, the program can be used directly, or for further research into beam-soil interaction. The program is applied in the analysis of both field and laboratory tests to ascertain its accuracy in predicting beam-soil interaction. The laboratory test measures the deflection of a horizontal beam on a single soil foundation medium, where the beam is loaded by a single jack at approximately mid-span. Computer predictions for such a test were in very close agreement with the laboratory observations, despite the small magnitude of beam displacements, and the fact the beam-soil system suffered a bearing capacity failure which affected the beam deflection. The field test was performed to investigate the performance of a flexible soldier pile under high anchor loading. Results of the computer analyses again show the program's predictions to be in very close agreement with the field measurements. Currently, the program does not include the facility to model soil layers behind a soldier pile, but the method developed in this thesis can easily incorporate multiple pressure-displacement curves for different soils. Final conclusions drawn express a need for more research into soldier pile systems before the techniques of this work can be used for routine design. Nevertheless, the development of the program has made a significant contribution to advancing the use of computer-aided design in this field of geotechnical engineering.

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32

Bentler, David J. "Finite Element Analysis of Deep Excavations." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30767.

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This dissertation describes enhancements made to the finite element program, SAGE, and research on the performance of deep excavations. SAGE was developed at Virginia Tech for analysis of soil-structure interaction problems (Morrison, 1995). The purpose of the work described in this text with SAGE was to increase the capabilities of the program for soil-structure analysis. The purpose of the research on deep excavations was to develop a deeper understanding of the behavior of excavation support systems. The significant changes made to SAGE during this study include implementation of Biot Consolidation, implementation of axisymmetric analysis, and creation of a steady state seepage module. These changes as well as several others are described. A new manual for the program is also included. A review of published studies of deep excavation performance and recent case histories is presented. Factors affecting the performance of excavation support systems are examined, and performance data from recent published case histories is compared to data from Goldberg et al.'s 1976 report to the Federal Highway Administration. The design, construction, and performance of the deep excavation for the Dam Number 2 Hydroelectric Project is described. Finite element analyses of the excavation that were performed with SAGE are presented and discussed.
Ph. D.

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33

He, Longxue Verfasser], and Michael [Akademischer Betreuer] [Beer. "Advanced Bayesian networks for reliability and risk analysis in geotechnical engineering / Longxue He ; Betreuer: Michael Beer." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2020. http://nbn-resolving.de/urn:nbn:de:101:1-2020031901080232795085.

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34

He, Longxue [Verfasser], and Michael [Akademischer Betreuer] Beer. "Advanced Bayesian networks for reliability and risk analysis in geotechnical engineering / Longxue He ; Betreuer: Michael Beer." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2020. http://d-nb.info/1206685883/34.

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35

Shillaber, Craig Michael. "Toward Sustainable Development: Quantifying Environmental Impact via Embodied Energy and CO2 Emissions for Geotechnical Construction." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/64935.

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With rising awareness that future generations may not have access to the resources and quality of life that exist today, sustainable development has become a priority within civil engineering. One important component of sustainable development is environmental stewardship, which concerns both the resources taken from the environment, and the wastes and byproducts emitted to the environment. To facilitate more sustainable development, environmental accounting is necessary within civil and geotechnical engineering design and construction. Historically, geotechnical practice has focused on maximizing design performance while minimizing monetary costs, and well established methods exist for quantifying these factors. Quantitative consideration of environmental consequences has seldom played a large role in geotechnical design and construction, and clear guidelines and a methodology for such an assessment are not available within the geotechnical profession. Therefore, this research has focused on establishing a method for quantitative streamlined environmental Life Cycle Analysis of energy and carbon dioxide (CO2) emissions for geotechnical ground improvement works, known as the Streamlined Energy and Emissions Assessment Model (SEEAM). The boundaries for the SEEAM extend from raw material extraction through the completion of construction, including the energy and CO2 emissions associated with construction materials, construction site operations, and the transportation of construction materials and wastes. The methodology relies on energy and CO2 emissions coefficients, which represent typical industry average values and not necessarily the specific processes contributing to a project. Therefore, there is uncertainty in SEEAM analyses, which is addressed via a Monte Carlo simulation framework that assumes the energy and CO2 emissions coefficients each follow a lognormal distribution. Data sets of total energy and CO2 emissions generated by the Monte Carlo simulation framework with the SEEAM may be used to statistically compare the energy and CO2 emissions of different geotechnical design alternatives. Such comparisons can help facilitate designing for minimum environmental consequences, thus advancing sustainable development within geotechnical engineering. For clarity, the development and application of the SEEAM is illustrated using two different geotechnical case history projects, including rehabilitation of levee LPV 111 in New Orleans, LA, and the construction of foundations for a replacement dormitory on the Virginia Tech campus.
Ph. D.

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36

Yu, Hai-Sui. "Cavity expansion theory and its application to the analysis of pressuremeters." Thesis, University of Oxford, 1990. http://ora.ox.ac.uk/objects/uuid:96cfe772-8f4b-4995-a890-1138c2be1458.

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The successful application of in-situ testing of soils heavily depends on development of methods of interpretation of the tests. The purpose of this thesis is to develop a consistent theoretical basis for the interpretation of pressuremeter tests in cohesive and frictional materials. The research programme is based on cavity expansion theory with additional details provided by a large strain finite element analysis. A unified analytical solution is developed for the expansion and contraction of both cylindrical and spherical cavities in dilatant elastic-plastic soils. For the first time, explicit solutions for the pressure-expansion and pressure-contraction relationships are derived without any restriction being imposed on the magnitude of the deformation. In addition, the finite element method is adopted for solving the cavity expansion problem. This is mainly due to the fact that only in special cases when simple material models and boundary conditions are involved has it been possible to solve the problem analytically. A finite element analysis of the cone-pressuremeter test in sand is described. A series of two-dimensional finite element calculations on both the self-boring pressuremeter test and the cone-pressuremeter test is performed. In modelling the penetration process of cone-pressuremeter tests, the stresses evaluated by the cavity expansion theory are used as the starting condition for the finite element analysis. Emphasis is placed on quantifying the effects of pressuremeter geometry on derived deformation and strength parameters. In the finite element formulation, a special effort is devoted to developing a lower order finite element suitable for analysing axisymmetric elastic-plastic problems which involve incompressibility constraints. The formulation of a new six-noded isoparametric displacement finite element is presented. To account for large strain (rotation) effects, an Eulerian description of deformation is adopted and the Jaumann stress rate is used in the soil constitutive equations. The suitability of the conventional interpretation methods for pressuremeter tests is critically assessed in the light of the finite element results. Based on the numerical results, improved procedures for obtaining in-situ soil parameters from pressuremeter tests in both clay and sand have been proposed.

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37

Iannelli, Michael. "Determination of Seismic Earth Pressures on Retaining Walls through Finite Element Analysis." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1724.

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Seismic pressures on displacing or rigid retaining or basement walls have been derived based on the original work of Mononobe and Okabe, who used a shake table to calculate dynamic pressures of displacing retaining walls existing in cohesionless soils. Since this original work was done over eighty years ago, the results of Mononobe and Okabe, colloquially known as M-O theory, have been applied to different conditions, including non-displacing basement walls, as well as changes in soil properties. Since the original work of M-O, there have been numerous studies completed to verify the accuracy of the original calculation, most notably the work of Seed and Whitman (1970), Wood (1973), Sitar (Various), and Ostadan (2005). This has resulted in varying opinions for the accuracy of M-O theory, whether it is grossly unconservative or conservative, as well as its effectiveness for situations where the wall does not displace enough to engage active soil conditions. This study examines (3) different wall cases, a cantilever retaining wall, gravity retaining wall, and rigid basement wall, through an implcit finite element analysis, under simple sinusoidal boundary accelerations. The soil is modeled using the Drucker-Prager model for elastic-plastic properties. The dynamic pressure increment is observed for different driving frequencies, with the anticipation that an in-phase and out of phase response between the soil and structure will be achieved, resulting in both lower and higher than M-O pressure values.

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38

Bi, Renneng [Verfasser], and Joachim [Akademischer Betreuer] Rohn. "Geotechnical mapping and landslide susceptibility analysis in Badong county (Three Gorges Region / China) / Renneng Bi. Gutachter: Joachim Rohn." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2015. http://d-nb.info/1075839416/34.

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39

Bridgeman, Jonathan G. "Understanding Mississippi Delta Subsidence through Stratigraphic and Geotechnical Analysis of a Continuous Holocene Core at a Subsidence Superstation." Thesis, Tulane University School of Science and Engineering, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10789629.

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Land-surface subsidence can be a major contributor to the relative sea-level rise that is threatening many coastal communities. Loosely constrained subsidence rate estimates across the Mississippi Delta make it difficult to differentiate between subsidence mechanisms and complicate modeling efforts. New data from a nearly 40 m long, 12 cm diameter core taken during the installation of a subsidence monitoring superstation near the Mississippi River, southeast of New Orleans, provides insight into the stratigraphic and geotechnical properties of the Holocene succession at that site. Stratigraphically, the core can be grouped into four units. The top 12 m is dominated by clastic overbank sediment with interspersed organic-rich layers. The middle section, 12–35 m, consists predominately of mud, and the bottom section, 35–38.7 m, is marked by a transition into a Holocene-aged basal peat (~11.3 ka) which overlies densely packed Pleistocene sediment. Radiocarbon and OSL ages are used to calculate vertical displacement and averages subsidence rates as far back as ~3.5 ka, yielding values as high as 8.0 m of vertical displacement (up to 2.34 mm/yr) as obtained from a transition from mouth bar to overbank deposits. We infer that most of this was due to compaction of the thick, underlying mud package. The top ~80 cm of the core is a peat that represents the modern marsh surface and is inducing minimal surface loading. This is consistent with the negligible shallow subsidence rate as seen at a nearby rod-surface elevation table–marker horizon station. Future compaction scenarios for the superstation can be modeled from the stratigraphic and geotechnical properties of the core, including the loading from the planned Mid-Barataria sediment diversion which is expected to dramatically change the coastal landscape in this region.

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40

Kalm, Helen. "Acoustic Soil-Rock Probing : A Case Study in Gubbängen." Thesis, KTH, Jord- och bergmekanik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256081.

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Soil-rock probing (Jb-probing) is the most common probing method in Sweden. Due to the penetration capacity of the Jb-probing it can be performed in both soil and rock. However, the capacity also results in inherent limitations and uncertainties, such as the difficulty identifying the soil layer sequences of soft soils. In order to attain a more detailed soil layer sequence it is necessary to perform complementary probing and sampling methods, an inefficient and consequently costly procedure. By instead implementing non-interfering complementary methods performed simultaneously as the Jb-probing the method may be rationalized. The so-called acoustic Jb-probing method may be a potential complement to the Jb-probing. In this thesis a continued study of the acoustic Jb-probing method is performed by means of a case study in Gubbängen with the focus on the potential additional information that the spectrogram (a visual representation of the frequency spectra) may contain compared to the Jb-parameters alone. This was done by obtaining vibration signals during Jb-probing using a triaxle geophone installed four meters from the boreholes. Vibration signals were collected from 13 boreholes. The vibration signals were then analyzed in time- and frequency domain which were compared to corresponding Jb-parameters and classified soil types. The results showed that the clay layers held the most promise for discovering additional information in the spectrogram, however this does not exclude potential in other soil types. Additionally, it was shown that the geophone ought to be fastened in the ground in order to attain satisfactory data. Overall, the acoustic Jb-probing method is a favorable way of collecting and analyzing data, which with continued development of the operational and computational process may be an economical alternative to the conventional method.

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41

Marshall, Michael Scott. "Slope Failure Detection through Multi-temporal Lidar Data and Geotechnical Soils Analysis of the Deep-Seated Madrone Landslide, Coast Range, Oregon." PDXScholar, 2016. https://pdxscholar.library.pdx.edu/open_access_etds/2656.

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Landslide hazard assessment of densely forested, remote, and difficult to access areas can be rapidly accomplished with airborne light detection and ranging (lidar) data. An evaluation of geomorphic change by lidar-derived digital elevation models (DEMs) coupled with geotechnical soils analysis, aerial photographs, ground measurements, precipitation data, and numerical modeling can provide valuable insight to the reactivation process of unstable landslides. A landslide was selected based on previous work by Mickleson (2011) and Burns et al. (2010) that identified the Madrone Landslide with significant volumetric changes. This study expands on previous work though an evaluation of the timing and causation of slope failure of the Madrone Landslide. The purpose of this study was to evaluate landslide morphology, precipitation data, historical aerial photographs, ground crack measurements, geotechnical properties of soil, numerical modeling, and elevation data (with multi-temporal lidar data), to determine the conditions associated with failure of the Madrone Landslide. To evaluate the processes involved and timing of slope failure events, a deep seated potentially unstable landslide, situated near the contact of Eocene sedimentary and volcanic rocks, was selected for a detailed analysis. The Madrone Landslide (45.298383/-123.338796) is located in Yamhill County, about 12 kilometers west of Carlton, Oregon. Site elevation ranges from 206 meters (m) North American Vertical Datum (NAVD-88) near the head scarp to 152 m at the toe. The landslide is composed of two parts, an upper more recent rotational slump landslide and a lower much older earth flow landslide. The upper slide has an area of 2,700 m2 with a head scarp of 5-7 m and a volume of 15,700 m3. The lower earth flow has an area of 2300 m2, a head scarp of 15 m, and a volume of 287,500 m3. Analysis of aerial photographs indicates the lower slide probably originated between 1956 and 1963. The landslide is located at a geologic unit contact of Eocene deep marine sedimentary rock and intrusive volcanic rock. The landslide was instrumented with 20 crack monitors established across ground cracks and measured periodically. Field measurements did not detect ground crack displacement over a 15 month period. Soil samples indicate the soil is an MH soil with a unit weight of 12 kN/m3 and residual friction angle of 28φ'r which were both used as input for slope stability modeling. Differential DEMs from lidar data were calculated to generate a DEM of Difference (DoD) raster to identify and quantify elevation changes. Historical aerial photograph review, differential lidar analysis, and precipitation data suggest the upper portion of the landslide failed as a result of the December 2007 storm.

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42

Johansson, Lukas, and Dan Valtersson. "Stability Analysis of Non-overflow Section of Concrete Gravity Dams : A Longtan Dam case study." Thesis, Luleå tekniska universitet, Geoteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70724.

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43

Ngo-Tran, Cong Luan. "The analysis of offshore foundations subjected to combined loading." Thesis, University of Oxford, 1996. http://ora.ox.ac.uk/objects/uuid:96a07b7a-58f8-4a5d-9dfd-68509546368c.

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This thesis is concerned with four different types of offshore foundations, namely gravity foundations, jack-up foundations, the mudmats for piled jacket structures and caisson foundations for jacket structures. In most applications, these can be idealised as circular rigid foundations. Unlike onshore foundations, offshore foundations are subjected to large horizontal and moment loads. This research used the finite element method to examine the elastic behaviour and stability of circular footings under combined loading. Due to the circular shape of the footings and the combination of vertical, horizontal and moment loads, three dimensional finite element analysis was used. In-depth analyses of the elastic behaviour of circular footings under combined loading (V,H,M) were performed. The vertical stiffness coefficient was investigated using two dimensional axi-symmetric analyses whereas three dimensional analyses were used to examine the other coefficients. Different features of offshore foundations such as footing embedment and cone angle were taken into consideration. Based on the numerical results, a set of empirical expressions for elastic stiffness coefficient was derived. For footing stability calculations, large horizontal or moment loads can cause the footing to lose contact with the soil, or cause the footing to slide relative to the soil. In finite element analyses, this loss of contact and sliding are modelled by interface elements. A new zero-thickness iso-parametric interface element was formulated for both two and three dimensional analyses. An exact close formed solution for integration of the stress-strain relationship (for the two dimensional interface element) was found. The element is then used to explore footing stability. It was shown that by using a yield criteria which allows the interface to behave as either frictional or cohesive interface, depending upon the normal stress, numerical stability is achieved. The footing stability was examined by establishing the bearing capacity envelope. The envelopes for footings on undrained clays were established for surface flat strip footings and for surface flat circular footings. The effects of soil strength varying with depth, cone angle and embedment on the bearing capacity envelope were also investigated.

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44

Ross, Zachary E. "Probabilistic Fault Displacement Hazard Analysis For Reverse Faults and Surface Rupture Scale Invariance." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/457.

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p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Times New Roman'} A methodology is presented for evaluating the potential surface fault displacement on reverse faults in a probabilistic manner. This methodology follows the procedures put forth for Probabilistic Fault Displacement Hazard Analysis (PFDHA). Empirical probability distributions that are central to performing a PFDHA are derived from field investigations of reverse faulting events. Statistical analyses are used to test previously assumed properties of scale invariance with respect to magnitude for normalized displacement. It is found that normalized displacement is statistically invariant with respect to magnitude and focal mechanism, allowing for the combination of a large number of events into a single dataset for regression purposes. An empirical relationship is developed using this single dataset to be used as a fault displacement prediction equation. A PFDHA is conducted on the Los Osos fault zone in central California and a hazard curve for fault displacement is produced. A full sensitivity analysis is done using this fault as a reference, to test for the sources of variability in the PFDHA methodology. The influence of the major primary variables is quantified to provide a future direction for PFDHA.

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45

Kim, Sang-Hwan. "Model testing and analysis of interactions between tunnels in clay." Thesis, University of Oxford, 1996. http://ora.ox.ac.uk/objects/uuid:2cac5df0-379e-4fd0-bb19-b4611c2175ba.

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This dissertation describes a study of the interaction between closely spaced tunnels during shield tunnel construction, concentrating on the study of the short-term incremental behaviour of the liner. Carefully controlled physical model tests were carried out and the test results were complemented by a limited amount of numerical analysis. In the physical model tests described in this dissertation, two groups of tests were carried out at a laboratory scale; one set of tests studied closely spaced parallel tunnels and the other set investigated perpendicular tunnels. An important feature of the study was that a novel model tunnelling machine was designed and developed as part of the research. Thin steel tubes were used to model the tunnel linings. The experimental technique adopted in the preparation of clay samples (which is a well-established procedure) was found to produce high quality samples. Good repeatability was achieved in preparing the kaolin samples. The tunnelling machine allowed tunnel liners to be installed using similar procedures to those adopted in the construction of full scale shield tunnels using an earth pressure balance approach. The instrumentation system used in this experimental programme are shown to produce reliable data. During the model tests measurements were made of liner strains, pore water pressures and total stresses acting on the liner. Errors in the data logging system were shown to be very small (of the order of less than 2% of peak values). The mechanisms governing the structural interaction between closely spaced tunnels are highly complex. The tunnel installation was shown to modify the stresses acting on the liner of the adjacent tunnel. These stress increments led, in turn, to line deformations and induced bending moments. The nature of the interaction mechanisms depends on the geometric configuration of the tunnels, the liner properties, and overconsolidation ratio. For the parallel tunnels, the pillar width ratio (W/D) is an important parameter governing the magnitude of the interaction effects. the interaction effects increase as the pillar width ratio is reduced. Increasing the liner flexibility was found to reduce the induced bending moments but to increase the induced displacements. The interaction effects were larger in overconsolidated clay than normally consolidated clay. The worst case for interaction effects occurs when the pillar width is small, the liner is flexible and the value of OCR is large. Three-dimensional considerations suggest that interaction between parallel tunnels may be more severe than those measured in the corresponding perpendicular tunnel tests. However, the different nature of the mechanisms in the two cases appear to be more significant than this geometric effect.

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46

Wei, Yukun. "Slope stability assessment through field monitoring." Thesis, KTH, Jord- och bergmekanik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239955.

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Deterministic methods have been used in geotechnical engineering for a long period, such as slope stability calculations. However, only applying deterministic methods is subjective and imperfect. There is a demand to develop a systematic methodology to link the assessed slope stability and field measurement data, which is also known as inverse analysis and forward calculation. Based on the Nya Slussen project, this thesis includes the development of a methodology, deterministic calculation for 4 cross sections using finite element program Plaxis 2D and probabilistic calculation for one section. Deterministic analyses showed satisfying results for all the studied cross sections since their factors of safety exceeded the minimum requirement. In probabilistic design, three parameters were found to have the most uncertainties through sensitivity analysis (undrained shear strength of clay, Young’s modulus of clay and friction angle of fill). Inverse analysis was done by testing different values of them in Plaxis and to try to match the displacement components provided by field measurement. After finding the best optimization for all the parameters, forward calculation gave a final factor of safety. It is suggested that both of the methods should be utilized together for better assessment.

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47

Zhou, Jian-Qing. "Numerical analysis and laboratory test of concrete jacking pipes." Thesis, University of Oxford, 1998. http://ora.ox.ac.uk/objects/uuid:8a22f2c1-4311-4400-b78f-aedaeae72144.

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Pipe jacking is a trenchless construction technique for the installation of underground pipelines. Although pipe jacking is widely used, fundamental research is still needed to understand fully the factors affecting the process and to prevent unexpected failure. With the time and financial limitation, it is difficult to explore all aspects of these factors with experiments; and it is also difficult to study them by analytical methods because of the complexity of the problem. This thesis describes the use of the finite element technique to study the pipe performance under different environments and the laboratory tests of several different joint designs. The emphasis of the current research is on the performance of the concrete pipes during jacking under working conditions and to seek possible improvements in the design of pipes and pipe joints by numerical modelling. In the finite element modelling, a simplified two-dimensional model is used for a preliminary study, then the analyses are carried out with three-dimensional models A, B and C representing a complete pipe, a pipe with surrounding soil and a symmetric three-pipe system respectively. Several factors affecting the pipe performance have been examined, for example, the properties of the packing material, the stiffness of the surrounding soil, the misalignment angle at the pipe joint, and the interaction between the pipe and surrounding soil. The numerical results show that the misalignment of the pipe is the dominating factor inducing both tensile stresses and localized compressive stresses in the concrete pipe, especially with a high misalignment angle which results in separation between packing material and the pipe. The packing materials with high Poisson's ratio and high stiffness also induce higher tensile stresses in the pipe, and the influence of Poisson's ratio is significant. Under 'diagonal' loading, both the stiffness of the surrounding soil and the interaction between the pipe and the surrounding soil have a significant effect on the stresses within the concrete pipe. Under 'edge' loading, the greatest potential damage is at the pipe joint due to the tensile stresses in the hoop direction; while under 'diagonal' loading, the damage is most likely the cracking on the external surface of the pipe along a line connecting the two diagonal loaded corners. The results show that the Australian model gives somewhat good prediction about the maximum normal stress and the diametrical contact width at pipe joint. Based on the numerical results, several different joint designs for improving the pipe strength have been proposed and tested in the laboratory. Both the laboratory tests and the back analyses suggest that the local reinforcement and the local prestressed band at the pipe joint will improve the pipe strength.

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48

Björklind, Malin. "Soil profile analysis by vibration theory and the natural frequency : Applied on a case project." Thesis, Luleå tekniska universitet, Geoteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67151.

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To explore soil conditions at sites of infrastructure projects a number of geotechnical soundings are performed at appropriate intervals. Results are, in the nature of their set up, limited to the specific points at which the sounding is performed. To safely assume the area between bore holes a new method is applied and tried at the case railroad project Stenkumla – Dunsjö. By applying vibration theory in conjunction with the studied soils’ geodynamic properties the natural frequency for the soil can be calculated. The properties of the natural frequency also makes it possible to detect in vibration measurements. The method studied in this master thesis is that of utilizing the natural frequency of the soil to try and establish a soil profile from vibration measurements. An important step in the method is to transform the vibration with the Fast Fourier Transform algorithm. This allows the comparison and analysis of natural frequencies. The measurements were performed by using and attaching an accelerometer to a train. Results are partly transformed measurement data in frequency graphs and partly natural frequency calculations according to the site investigations. These are compared in the analysis section to try to confirm the methods’ reliability and to see if the method can be used to refine geotechnical investigations. The reliability of the method is tested by watching for the expected frequencies from the calculations in the measurement data. The method show more consistency closer to the ground surface rather at greater depths. It is also more reliable for stark contrast layers, i.e. if the soil layers have much of the same properties then it is difficult to spot the differing natural frequencies, as they are too similar. In trying to establish the soil profile between bore holes the method is inconclusive, partly due to the fact that the investigated area consists of relatively alike soil layers that make the result graphs difficult to get information from. However, the suggested soil profiles from the analysis of this part of the master thesis bear resemblances to bore holes close by, so the method can be usable in some regard. Quality of measurement results would probably be better by running the train faster than was done in this master thesis. The quality of the analysis would also benefit from performing specific soundings to establish the soils’ geodynamic properties rather than using recommended empirical formulas as were used here. The primary possible application for this method is to use it as a prioritizing tool at an early stage in infrastructure projects. Running the vibration measurement and getting a preliminary picture of the soil conditions could act as a way of steering investigations resources to where greater shifts in the data occur.
I det förberedande skedet inför infrastrukturprojekt genomförs geotekniska undersökningar för att kartlägga jordförhållanden. Detta genomförs bland annat med ett antal olika borrhålsmetoder. Genom sin utförandeform levererar dessa resultat som, strikt uttryckt, är knutna till de specifika punkter där de utförs. I detta examensarbete provas en ny metod där jordprofilen mellan- och vid punkten för borrhål ska kartläggas. Metoden provas ut på järnvägsprojektet Stenkumla – Dunsjö. Vibrationsteori och geodynamiska egenskaper hos jorden utnyttjas för att fastställa olika jordlagers egenfrekvens. Egenfrekvensens definition gör det möjligt att detektera denna i vibrationsmätningar. Metoden som provas i examensarbetet är att genom vibrationsmätningar fastställa jordprofilen baserat på jordlagrens egenfrekvens. Ett viktigt steg i metodens process är att transformera resultatet från vibrationsmätningen med Fast Fourier Transformation, en algoritm för databehandling. Genom att applicera Fast Fourier Transformation kan en jämförelse mellan egenfrekvenser från olika källmaterial göras. De primära vibrationsmätningarna genomfördes genom att fästa en accelerometer på ett tåg. Resultat består i transformerade grafer från vibrationsmätningar samt egenfrekvensberäkningar baserade på de geotekniska undersökningarna vid projekt Stenkumla – Dunsjö. På detta följer en jämförande analys där metodens tillförlitlighet och applicerbarhet runt geotekniska undersökningar diskuteras. Tillförlitligheten testas genom att identifiera beräknade förväntade värden på egenfrekvensen i mätdatat från tåget. Metoden visar högre tillförlitlighet närmare markytan än djupare ner i jordprofilen. Metodens precision är mer utvecklad för jordprofiler där jordlagren är differentierade från varandra i dess egenskaper. Detta uppstår som en följd av att mer lika drag hos jordlagren får liknande egenfrekvens, vilket gör dem svårare att identifiera och särskilja i frekvensspektrat. Metoden visade sig vara ofullständig i att fastställa en jordprofil mellan geotekniska borrprover. En anledning till detta är att det område som användes för vibrationsmätningar består av en jordprofil utan allt för varierande egenskaper, vilket gör att en tillräckligt tillförlitlig analys är omöjlig med den mängd data som fanns att tillgå. Den jordprofil som itererades fram i analysavsnittet har dock liknande uppbyggnad som de jordprofiler som fastställts av geotekniker i den geotekniska undersökningsrapporten, vilket ändå tyder på viss användningspotential. Kvalitén på vibrationsmätningen skulle förbättras av att öka farten, och så vibrationen, på tåget som mätaren var fäst på. En annan förbättringsmöjlighet är att få tillgång till uppmätta geodynamiska egenskaper hos jorden istället för de empiriska formler som användes i detta arbete. Det primära användningsområdet för metoden är att använda den som ett prioriteringsverktyg i ett tidigt skede vid infrastrukturprojekt. Genom att genomföra en vibrationsmätning kan en preliminär bild av jordförhållandena erhållas. Detta kan sedan användas som ett sätt att styra geotekniska undersökningsresurser mer effektivt mot områden där stora avvikelser i vibrationsdatat identifierats.

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49

Dunne, Helen P. "Finite element limit analysis of offshore foundations on clay." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:ba9c9beb-e055-4f46-a9f9-b2d10bd292b7.

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Capacity analysis is a common preliminary step in the design of offshore foundations. Inaccuracies in traditional capacity analysis methods, and the advancement of numerical modelling capabilities, have increasingly led designers to optimise foundations using more complex methods. In this thesis, the ultimate limit state capacity of a range of foundation types is investigated using finite element limit analysis. Novel three-dimensional finite element limit analysis software is benchmarked against analytical solutions and conventional displacement finite element analysis. It is then used to find lower and upper bounds of foundation capacity, with adaptive mesh refinement used to reduce the bound gap over successive iterations of the solution. Rigid foundations subjected to short term loading on clay soil are analysed. The undrained soil is modelled as a rigid--plastic von Mises material, and attention is given to modelling any normal and/or shear stress limits at the foundation/soil interface. Shallow foundations, suction anchor foundations, and hybrid mudmat/pile foundations are considered. Realistic six degree-of-freedom load combinations are applied and results are reported in the form of normalised design charts, and tables, that are suitable for use in preliminary design. Relationships between loading combinations and failure mechanisms are also explored. A number of case studies based on authentic foundation designs are analysed. The results suggest that finite element limit analysis could provide an attractive alternative to displacement finite element analysis for preliminary foundation design calculations.

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Burd, Harvey John. "A large displacement finite element analysis of a reinforced unpaved road." Thesis, University of Oxford, 1986. http://ora.ox.ac.uk/objects/uuid:d23051b7-fabd-4acd-9d79-207ca9f5942b.

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A series of finite element predictions of the behaviour of a reinforced unpaved road consisting of a layer of fill compacted on top of a clay subgrade with rough, thin reinforcement placed at the interface, is described in this thesis. These numerical solutions are obtained using a large strain finite element formulation that is based on the displacement method, and are restricted to the case of plane strain, monotonic loading. Separate elements are used to model the soil and reinforcement. In the finite element formulation, an Eulerian description of deformation is adopted and the Jaumann stress rate is used in the soil constitutive equations. Elastic perfectly-plastic soil models are used which are based on the von Mises yield function for cohesive soil and the Matsuoka criterion for frictional material. Emphasis is placed on obtaining new closed form solutions to parts of calculations that are performed numerically in many existing finite element formulations. The solution algorithm is based on a "Modified Euler Scheme". The computer implementation of the formulation is checked against an extensive series of test problems with known closed form solutions. These include the analysis of finite deformation of a single element of material and the calculation of small strain collapse loads. Finite cavity expansion is also studied. This numerical formulation is used to perform back analyses of a series of reinforced unpaved road model tests. The reinforcement tensions, and the stresses at the interface with the surrounding soil, are calculated using the numerical model and discussed with a view to identifying the mechanisms of reinforcement. Two existing analytical design models of the reinforced unpaved road are described and critically reviewed in the light of the finite element results.

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Dissertations / Theses on the topic 'Geotechnical analysis'

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