There has been an increasing interest in fundamental and applied research on emerging geotechnical and geoenvironmental engineering applications that pose multi-physics problems involving non-isothermal processes in unsaturated soils. Properly studying these problems requires the development of analytical models to describe the constitutive behavior of unsaturated soils under non-isothermal conditions. However, major gaps remain in the development of unified models that can properly represent the temperature dependency of unsaturated soil behavior. The effects of temperature on the stability of slopes, lateral earth pressure, and pile resistance in unsaturated soils are also not well understood. The main objective of this study is to provide new insight and robust tools to characterize and model the temperature-dependent behavior of unsaturated soils. For this purpose, novel unified models are developed for soil water retention curve, effective stress, thermal conductivity function, and small-strain shear modulus for unsaturated soils at elevated temperatures. The models are proposed by establishing or extending the unified model at isothermal conditions to nonisothermal conditions. The fundamental and main variable in all unified models is capillary pressure (also referred to as matric suction). The effect of temperature is considered on adsorption and capillarity as a function of water-air surface tension, soil-water contact angle, and enthalpy of immersion. The proposed models are verified by comparing them with experimental data reported in the literature and measurements made in this study. Overall results of the proposed models show an excellent predictive capability. Furthermore, the parametric study is conducted to understand the effect of different parameters such as soil type, temperature, drainage conditions, and among others on hydraulic and mechanical properties of unsaturated soil. Finally, the proposed models are incorporated into geotechnical applications such as slope stability, lateral earth pressure, and pile resistance involving unsaturated conditions and elevated temperatures. The variation of temperature in unsaturated soils for these applications can be notable and cannot be ignored in the design and analysis. The proposed formulations can also be readily incorporated into analytical solutions and numerical simulations of thermo-hydro-mechanical processes in unsaturated soils. The findings of the study can facilitate using numerical models to simulate various non-isothermal applications including geo-energy systems and soil-atmospheric interaction problems.

Dynamic behaviour of gravity and cantilever retaining walls is investigated by finite element method, incorporating the nonlinear elasto-plastic material properties of soil and seperation of the wall and backfill. Two dimensional finite element models are developed employing the finite element software ANSYS. The wall is modelled to rest on a soil layer allowing translational and rotational movements of the wall. Soil-wall systems are subjected to harmonic and real earthquake motions with different magnitude and frequency characteristics at the base. The maximum lateral force and its application point durinG dynamic loading are determined for each case. It is observed that the frequency content of the base motion has a significant influence on the dynamic lateral soil pressures and the lateral forces considerably increase as the base motion frequency approaches the fundamental frequency of the soil layer. The maximum lateral thrusts calculated by finite element analyses are generally found to be greater than those suggested by Mononobe-Okabe method and experimental findings. Nevertheless, the locations of the application point obtained by finite element method are found to be in good agreement with the results of experimental studies.

The subject of my thesis is the exploration the landslide, landslide stabilization, design foundation and construct buildings in Brno Bystrc. Attention will be given to slopes safety factor and especially to design four-floor building construction.

In recent years, the desperate need for reliable clean and relatively small power demand has emerged for edge-of-grid or off-grid regions to keep pace with development demands. A salient technology that has gained much attention for this purpose is the Small Modular Reactors, i.e., SMRs. SMRs differ from conventional Nuclear Power Plants (NPPs) in many aspects, specifically the enclosing structure of the reactor. The burial depth of the SMR structure is expected to reach great depths. For example, the substructure depth reaches 30 m in the SMR design proposed by NuScale (NuScale Power, 2020). Consequently, seismic analysis of deeply embedded structures with a relatively small footprint has been identified as one of the challenges to the safe implementation of SMR technology (DIS-16-04, 2016). Such structures are expected to be more sensitive to surface wave propagation and the seismic interaction with nearby substructures and nonstructural elements such as pipelines. This dissertation develops analytical and numerical methods to analyze the seismic earth pressure exerted on the SMR substructure by considering the effects of seismic surface waves, structure-soil-structure interaction (SSSI), and the interaction with nearby pipelines. The three-dimensional wave propagation theory is employed in the analysis. Solutions for the earth pressure induced by Rayleigh waves are obtained for substructures deeply embedded into homogeneous or multilayered soil profiles. In addition, the effect of thin soil layer (stiff or soft) soils in a soil profile is investigated in the presence of Rayleigh waves. Furthermore, additional earth pressure due to SSSI is examined, and a simplified procedure is proposed based on the three-dimensional wave propagation theory and a guided flow chart to track seismic wave interference. The SSSI analysis yields solutions for the optimal distance between substructures corresponding to the minimum SSSI in new designs. The interaction between substructures and nearby pipelines is explored numerically using the Spectral Element Method. SPECFEM2D software is adopted to perform the analysis, where the three-dimensional wave propagation is successfully implemented. Based on the analysis for pipelines with different configurations, general conclusions are drawn regarding the additional earth pressure on substructures and pipelines based on a comprehensive parametric study of various parameters. In addition, this research also provides an approach to determine the backfill configuration and the selection of backfill materials, which could minimize the seismic amplitudes transmitted to substructures. / Thesis / Doctor of Philosophy (PhD) / Small Modular Reactors (SMRs) are the cornerstone of recent developments in the nuclear industry. However, the SMRs technology faces several safety-related challenges, which includes the earthquake hazards related to the large embedment depth of the enclosing structure. In particular, the major concerns are about the risks related to seismic surface waves as well as the seismic interaction between nearby structural and non-structural elements (e.g., pipelines). The thesis addressed these major concerns by developing analytical and numerical methods to complement the analysis for the integrity of SMRs with sufficient seismic resistance. The solutions are verified and benchmarked using data in the literature. Future researches are suggested to further improve seismic analysis of SMRs.

Jet grouting was used to strengthen the soft soil surrounding the piles and the pile cap of two full-scale driven pile foundations. Soilcrete columns, created by jet grouting, were placed underneath the pile cap and surrounding the piles of the first foundation. Two rows of soilcrete columns were placed around the perimeter of one-side of the second. All of the jet grouting took place after construction of the pile caps. Laboratory testing of the soilcrete slurry showed the columns as having a design unconfined compressive strength of 550-650 psi, compared with the native soil strength of only 6-8 psi (850-1150 psf). Lateral loading of the pile foundation was then performed on these foundations. The results of this test were compared with a similar test performed on the same foundations under native soil conditions. The total lateral capacity of the pile foundation treated underneath the pile cap was increased by 500 kips, which equals an increase of 175%. The total lateral capacity of the pile foundation treated adjacent to the pile cap was 150%. Results of testing suggest that each of the jet-grout treated zones displaced as a rigid block. A majority of the increased lateral resistance came from the passive soil resistance acting on the face of the blocks and the adhesive soil resistance acting on the sides and bottom of the block as it displaced through the native soil. The remaining soil resistance, not accounted for by the passive and adhesive soil resistance, can potentially be attributed to increased soil pile interaction, which is predicted from the decrease in pile head rotation during loading following soil treatment.

Yes / Arching in soils has received great attention due to its significance on the soil–underground structure interaction. The state of stress on underground structures as a result of cycles of active and passive arching was neither explored nor systematically assessed. In the present study, comprehensive investigation was carried out to examine: i. the effects of displacement direction to induce active or passive arching, ii. the behaviour of subsequent arching, iii. the effect of magnitude of initial displacement on the formation of arching and iv. the influence of soil height on sequential active and passive arching. The results showed that alternating the displacement of the underground inclusion exacerbated the formation of active and passive arching leading to a substantial reduction in shear resistance and stress redistribution. It is noted that sequentially alternating displacement of the underground inclusion was detrimental to the formation of full active and passive arches irrespective of the burial height.

O objetivo desta dissertação consiste em aprofundar o entendimento dos mecanismos que controlam o atrito lateral sob arrancamento de estacas instaladas por fluidização em areia. A técnica de instalação é estudada como uma alternativa para a utilização de estacas torpedo na fixação de plataformas offshore. Trabalhou-se em laboratório com o arrancamento de estacas metálicas circulares em modelo reduzido. Foram utilizados três diâmetros de estacas modelo, simulando três diferentes escalas: 14 mm (1:76), 16,2 mm (1:67) e 21,3 mm (1:50). Foram realizados 8 ensaios de arrancamento (24 horas após a fluidização) em estacas modelo instaladas por fluidização em solo arenoso com densidade relativa de 50% e submetido à sobrecarga de 2,236 kPa. Foram também realizados 17 ensaios de arrancamento em estacas modelo pré-instaladas (sem fluidização) em areia com densidade relativa de 30%, simulando uma instalação sem perturbação do solo, uma vez que esta é a densidade relativa aproximada que a areia atinge após o processo de fluidização. Os resultados foram comparados com pesquisas anteriores de arrancamento de estacas instaladas por fluidização em areia. Para um aumento médio de 2 vezes a tensão vertical efetiva nas estacas modelo instaladas por fluidização com sobrecarga, observa-se um ganho médio de 1,8 na resistência. O coeficiente de empuxo lateral de serviço para estes ensaios não apresentou diferenças significativas em relação ao mesmo tipo de ensaio sem sobrecarga. As estacas instaladas por fluidização com sobrecarga e estacas pré-instaladas (sem perturbação) apresentam valores de constantes e independentes das profundidades instaladas, com respectivas médias de 0,15 e 0,31. O valor de parece aumentar com o tempo para as estacas fluidizadas (efeito setup) devido à reconstituição das tensões radiais. Os valores de estacas cravadas em areia densa diminuem seu valor com o aumento da profundidade instalada (e da tensão efetiva média atuante), por restrição de dilatação, tendendo ao valor de encontrado para ensaios pré-instalados realizados neste trabalho. / The main goal of this study is to deepen the understanding of the shaft friction behavior under tension loads of piles installed by fluidization in Osório sand. The installation technique is studied as an alternative for the use of torpedo piles in offshore platforms anchoring. This work was done in laboratory with metallic circular piles in reduced model. Three diameters of model piles were used, simulating three different scales: 14 mm (1:76), 16,2 mm (1:67) and 21,3 mm (1:50). Eight pullout tests (24 hours after fluidization) were carried out on model piles installed by fluidization in sandy soil with a relative density of 50% and subjected to a surcharge of 2,236 kPa. Eighteen pullout tests were performed on pre-installed (non-fluidized) model piles in sand with a relative density of 30%, simulating an installation without soil disturbance, since this is the approximate relative density reached after the process of fluidization. The results were compared with previous studies of pullout resistance of fluidized piles in sand. For an average increase of 2 times the vertical effective stress in the model piles installed by fluidization with surcharge, an average increase of 1,8 times is observed in the pullout resistance. The lateral earth pressure coefficient on the pile shaft for these tests did not show significant differences in relation to the same type of test without surcharge. For tests installed by fluidization and pre-installed tests (without soil disturbance), remains constant and independent of the installed depths, with respective averages of 0,15 and 0,31. The value seems to increase with time for fluidized tests (setup effect) due to the reconstitution of the radial tensions. The values for pullout tests in driven model piles in dense sand decrease their value with the increase of the installed depth (and the increase of the vertical effective stress), by restriction of the expansive behavior, tending to the value found for pre-installed tests carried out in this work.

Procurando diminuir as incertezas a respeito do comportamento de estacas em perfis arenosos, desenvolveu-se um campo experimental localizado em Araquari-SC, conduzido pela Universidade Federal do Rio Grande do Sul, no qual foram executados (a) ensaios de campo para definir as condições geotécnicas do solo, (b) estacas escavadas e hélice continua e (c) provas de carga estática nos elementos estruturais. O presente trabalho tem como objetivo estudar as variáveis que intervêm no mecanismo de transferência de carga ao solo. Mediante ensaios de laboratório, caracterizou-se o solo presente no campo experimental, definiram-se os parâmetros de resistência, mineralogia, forma, distribuição e tamanho das partículas, para serem usadas na retro análise do coeficiente de pressão de solo (ks) das provas de carga. Para esta finalidade foram analisados os resultados medidos em estacas escavadas executadas com bentonita e polímero. A retro análise foi realizada através do método beta (β), abordagem que permite a obtenção da capacidade lateral das estacas construídas em perfis arenosos, baseado nas tensões verticais, no coeficiente de pressão de solo e no ângulo de atrito da interface solo-estaca. Devido à interação entre as partículas do solo e concreto da estaca, estas são mobilizadas a elevados níveis de deformações, o ângulo de atrito da interface é considerado próximo ao ângulo de atrito no estado crítico da areia. O solo presente no campo experimental corresponde a areia fina com lentes de silte. Assim, os parâmetros de resistência definidos foram o ângulo de atrito no estado crítico e de pico com valores de 33,0° e 33,4° respetivamente. O ângulo no estado crítico foi utilizado na retro análise das provas de carga e como resultado foi obtido o ks, para posteriormente ser comparado ao coeficiente de empuxo no repouso (k0). Os resultados mostraram que com a profundidade o valor ks aproxima-se ao valor de k0, apresentado uma relação de ks/k0 próxima a unidade. Conclui-se que, o mecanismo de transferência de carga entre o solo e a estaca pode ser avaliado em função das tensões iniciais do depósito, expressas a partir de k0 estimado com base nos ensaios de laboratório. / In order to reduce the uncertainties regarding the behavior of piles in sandy profiles, an experimental field was developed by the Federal University of Rio Grande do Sul in Araquari-SC, where were executed (a) field tests to define soil geotechnical conditions, (b) bored and continuous flight auger piles and (c) static load tests on the structural elements. The aim of this research was to study the variables that intervene in the soil load transfer mechanism. The soil at the experimental field was characterized by laboratory tests, and parameters of resistance, mineralogy, particle shape, distribution and size were obtained for use in the back analysis of the soil pressure coefficient (ks) of the load tests. For this purpose, were analyzed the results measured on bored piles executed with bentonite and polymer. The back analysis was made using the beta method (β), which allows to estimate the lateral capacity of the piles constructed in sandy profiles, based on vertical stresses, soil pressure coefficient and friction angle of the soil-pile interface. Due to the interaction between the soil particles and the pile concrete, the first are mobilized at high deformation levels, the friction angle of the interface is considered close to the friction angle in the sand critical state. The soil present in the experimental field corresponds to fine sand with silt lenses. Thus, the resistance parameters defined were the critical state and peak friction angle with values of 33.0 ° and 33.4 ° respectively. The critical state angle was used in the back analysis of the load tests, and as a result the ks was obtained, to be subsequently compared to the at rest lateral earth pressure coefficient (k0). The results showed that, with depth, the value ks approaches the value of k0, with a relation of ks / k0 close to unity. It is concluded that the load transfer mechanism between the soil and the pile can be evaluated as a function of the initial stresses of the deposit, expressed from an estimated k0 based on the laboratory tests.

Am Übergang von Brückenbauwerken zu den angrenzenden Hinterfüllungen treten teilweise größere Unebenheiten der Fahrbahnoberfläche im Längsprofil auf. Eine Ursache dafür können Setzungen innerhalb der Hinterfüllung sein. Um diesen Anteil unter realen Bedingungen zu untersuchen, wurden an zwei Autobahnbrücken acht unterschiedlichen Hinterfüllungen ausgeführt und die Verformungen unter Verkehrsbelastung mit einem aufwändigen Messprogramm über einen Beobachtungszeitraum von bis zu vier Jahren erfasst. Im Ergebnis konnte für diese beiden Brücken gezeigt werden, dass die Setzungen unter Verkehrsbelastung nur wenige Millimeter betrugen und deutlich kleiner waren als die Höhenungenauigkeiten beim Einbau der Asphaltdeckschicht. Die Fahrbahnebenheit im Längsprofil wurde allein durch den Zustand vor Verkehrsfreigabe geprägt. Einfache Sofortmaßnahmen zur Erhöhung der Einbaugenauigkeit werden in der Arbeit vorgeschlagen. In einem weiteren Teil werden Erddruck- und Verformungsmessungen an zwei Hinterfüllungen einer integralen Rahmenbrücke vorgestellt.

In this study, new design approaches are introduced for the seismic design of block type quay walls after reviewing the conventional methodologies. Within the development of the new design approaches an inverse triangular dynamic pressures distributions are applied to define both seismic earth pressures and seismic surcharge pressures. Differently from the conventional design methodology, the hydrodynamic forces are taken into consideration while dynamic forces are specified and equivalent unit weight concept is used during the both static and dynamic calculations Compatibility of this new design approaches are tested by case studies for the site and it is seen that the numerical results are in good agreement qualitatively with field measurements.