A cidade de Ouro Preto registra diversas ocorrências de movimentos de massa em seu distrito sede e apresenta quantidade considerável de bairros localizados em áreas de risco. A atração exercida pela indústria mineradora e, mais recentemente, pela atividade turística e educacional, resultou no direcionamento e na intensificação da expansão urbana para as áreas onde se recomenda a não construção. Tais atividades, em conjunto, contribuem para a saturação da ocupação nos terrenos estáveis, os quais são alvos de intensa valorização, principalmente quando localizados na zona de proteção especial, dificultando sobremaneira o acesso à moradia pelos grupos menos favorecidos. A espacialização dos riscos resulta da atuação histórica e degradante dos sujeitos sociais sobre elementos físicos predisponentes e traduz escolhas políticas relativas ao planejamento e à gestão do território urbano. A abordagem geográfica do risco consiste na análise de sua tradução espacial, ou seja, na compreensão da sua localização, na sua caracterização, nas suas causas e nas consequências, atentando-se para a relação entre a sociedade e a natureza. Assim, objetivamos, nesta dissertação, analisar, sob a perspectiva da construção social do risco, o processo de formação das áreas de risco suscetíveis à ocorrência de movimentos de massa no distrito sede de Ouro Preto, por meio da articulação entre condições do meio físico, sujeitos sociais e práticas de gestão. Para tanto, fez-se necessário o resgate do processo de ocupação no município de Ouro Preto e a análise da relação entre as condições naturais, a degradação ambiental, a valorização do espaço e as práticas de gestão na formação e intensificação dos riscos. Por fim, verificamos as condições de habitabilidade e os impactos socioambientais encontrados nas áreas mais problemáticas, por meio de trabalhos de campo em bairros selecionados / The city of Ouro Preto records various incidents of soil movement at the headquarters district and has a substantial quantity of territories localized at risk areas. The attraction exerted by mining industry and mostly recent touristic and educational activities resulted in intensification of urban expansion towards area not recommended for occupation. These aggregated activities contribute to saturate the occupation in the stable land, which are object of intense appreciation, mainly when situated in special protection zones, complicating the access to housing by disadvantaged groups. The spatial distribution of risks results of historical and degrading action of social subjects on predisposing physical elements and construe political choices related to management and planning of urban territories.The geographical approach of risk consists in its spatial analysis perceiving location, characterization, causes and consequences being observant to the relation between society and nature. Thereby, this dissertation objective is in the perspective of social risks construction to analyze the risk areas formation susceptible to soil movement at the Ouro Preto headquarters district by the articulation between physical environment, social subjects and management practices. To achieve this dissertation purposes was necessary the study of occupation process in Ouro Preto and the relationship analysis between natural conditions, environment degradation, spatial appreciation and management practices to the formation and intensification of risks. Finally, it is verified the habitability conditions and social environmental impacts found at risk areas by fieldwork

In this study, bending moment distributions developed in laterally loaded passive pile and passive pile groups in cohesionless soil were investigated in laboratory conditions through model pile experiments. Different from the active pile loading, the lateral load was given directly to the piles using a movable large direct shear box. In these experiments strain gauges fastened to the piles and a computer based data reading system were used. The strain values were measured at five levels on the piles. The behavior of a single pile and a pile group having five piles were investigated through strain measurements in order to observe bending moment distribution on the piles. After evaluating the test results, the behavior of passive single pile was found to be similar to the results obtained in early studies. Negative bending moments were observed at the specified depths above the shear plane and positive bending moments were measured at the level of the shear plane and below the shear plane. Maximum bending moments were obtained at 0.7L (L: Length of Pile) for single piles and piles in the group. Above the shear plane, maximum bending moments within the pile group were found to be developed on the piles nearest to the loading. On the shear plane maximum bending moments were developed on the piles farthest from the loading just like active piles. Below the shear plane, maximum bending moments were developed mainly on the piles nearest to the loading.

A cidade de Ouro Preto registra diversas ocorrências de movimentos de massa em seu distrito sede e apresenta quantidade considerável de bairros localizados em áreas de risco. A atração exercida pela indústria mineradora e, mais recentemente, pela atividade turística e educacional, resultou no direcionamento e na intensificação da expansão urbana para as áreas onde se recomenda a não construção. Tais atividades, em conjunto, contribuem para a saturação da ocupação nos terrenos estáveis, os quais são alvos de intensa valorização, principalmente quando localizados na zona de proteção especial, dificultando sobremaneira o acesso à moradia pelos grupos menos favorecidos. A espacialização dos riscos resulta da atuação histórica e degradante dos sujeitos sociais sobre elementos físicos predisponentes e traduz escolhas políticas relativas ao planejamento e à gestão do território urbano. A abordagem geográfica do risco consiste na análise de sua tradução espacial, ou seja, na compreensão da sua localização, na sua caracterização, nas suas causas e nas consequências, atentando-se para a relação entre a sociedade e a natureza. Assim, objetivamos, nesta dissertação, analisar, sob a perspectiva da construção social do risco, o processo de formação das áreas de risco suscetíveis à ocorrência de movimentos de massa no distrito sede de Ouro Preto, por meio da articulação entre condições do meio físico, sujeitos sociais e práticas de gestão. Para tanto, fez-se necessário o resgate do processo de ocupação no município de Ouro Preto e a análise da relação entre as condições naturais, a degradação ambiental, a valorização do espaço e as práticas de gestão na formação e intensificação dos riscos. Por fim, verificamos as condições de habitabilidade e os impactos socioambientais encontrados nas áreas mais problemáticas, por meio de trabalhos de campo em bairros selecionados / The city of Ouro Preto records various incidents of soil movement at the headquarters district and has a substantial quantity of territories localized at risk areas. The attraction exerted by mining industry and mostly recent touristic and educational activities resulted in intensification of urban expansion towards area not recommended for occupation. These aggregated activities contribute to saturate the occupation in the stable land, which are object of intense appreciation, mainly when situated in special protection zones, complicating the access to housing by disadvantaged groups. The spatial distribution of risks results of historical and degrading action of social subjects on predisposing physical elements and construe political choices related to management and planning of urban territories.The geographical approach of risk consists in its spatial analysis perceiving location, characterization, causes and consequences being observant to the relation between society and nature. Thereby, this dissertation objective is in the perspective of social risks construction to analyze the risk areas formation susceptible to soil movement at the Ouro Preto headquarters district by the articulation between physical environment, social subjects and management practices. To achieve this dissertation purposes was necessary the study of occupation process in Ouro Preto and the relationship analysis between natural conditions, environment degradation, spatial appreciation and management practices to the formation and intensification of risks. Finally, it is verified the habitability conditions and social environmental impacts found at risk areas by fieldwork

Expansive soils are widely distributed in arid and semi-arid regions around the world and are typically found in a state of unsaturated condition. These soils are constituted of the clay mineral montmorillonite that is highly active and contributes significantly to volume changes of soils due to variations in the natural water content conditions. The volume changes of expansive soils often cause damage to lightly loaded structures. The costs associated with the damage to lightly loaded structures constructed on expansive soils in the United States alone were estimated as $2.3 billion per year in 1973, which increased to $13 billion per year by 2009. In other words, these damages have increased more than five fold during the last four decades. Similar trends in damages were also reported in other countries (e.g., Australia, China, France, Saudi Arabia, United Kingdom, etc.). Numerous methods have been proposed in the literature over the past 50 years for the prediction of the volume change movement of expansive soils. However, the focus of these methods has been towards estimating the maximum potential heave, which occurs when soils attain the saturation condition. The results of heave estimation considering saturated soil conditions are not always useful in engineering practice. This is because most of damages due to expansive soils often occur prior to reaching the saturation condition. A reliable design of structures on expansive soils is likely if the anticipated soil movements in the field can be reliably estimated over time, taking into account the influence of environmental factors. Limited studies are reported in the literature during the past decade in this direction to estimate/predict the expansive soil movements over time. The existing methods, however, suffer from the need to run expensive and time consuming tests. In addition, verification of these studies for different natural expansive soils has been rather limited. A simple approach, which is referred to as a modulus of elasticity based method (MEBM), is proposed in this study for the prediction of the heave/shrinkage movements of natural expansive soils over time. The proposed MEBM is based on a simplified constitutive relationship used for the first time to estimate the vertical soil movements with respect to time in terms of the matric suction variations and the corresponding values of the modulus of elasticity. The finite element program VADOSE/W (Geo-Slope 2007) for simulating the soil-atmospheric interactions is used as a tool to estimate the changes in matric suction over time. A semi-empirical model that was originally proposed by Vanapalli and Oh (2010) for fine-grained soils has been investigated and extended for unsaturated expansive soils to estimate the variation of the modulus of elasticity with respect to matric suction in the constitutive relationship of the proposed method. The MEBM has been tested for its validity in five case studies from the literature for a wide variety of site and environmental conditions, from Canada, China, and the United States. For each case study, factors influencing the volume change behavior of soils, such as climate conditions, soil cracks, lawn irrigation, and cover type (pavement, vegetation), are successfully modeled over the period of each simulation. The proposed MEBM provides good predictions of soil movements with respect to time for all the case studies. The MEBM is simple and efficient for the prediction of vertical movements of natural expansive soils underlying lightly loaded structures. In addition, a new dimensionless model is also proposed, based on the dimensional analysis approach, for the estimation of the modulus of elasticity which can also be used in the constitutive relationship of the MEBM. The dimensional model is rigorous and takes into account the most significant influencing parameters such as matric suction, net confining stress, initial void ratio, and degree of saturation. This model provides a comprehensive characterization of the modulus of elasticity of expansive soils under unsaturated conditions for different scenarios of loading conditions (i.e., both lightly and heavily loaded structures). The results of the present study are encouraging for proposing guidelines based on further investigations and research studies for the rational design of pavements, shallow and deep foundations placed on/in expansive soils using the mechanics of unsaturated soils.

[pt] O conhecimento dos esforços de flexão e normal provocados por movimentação de solo é importante para a análise de integridade estrutural de dutos. A existência de tensões residuais é um dos principais obstáculos para obtenção de resultados precisos na determinação de tais esforços. Este trabalho foi desenvolvido com o objetivo de analisar o comportamento das tensões residuais de fabricação em tubos ao longo de sua circunferência e de seu comprimento. Foram feitas medições de tensões residuais em corpos de prova de um tubo novo e de outros retirados de operação utilizando a técnica de furo cego e uma nova técnica de seccionamento. As medições foram realizadas ao longo da circunferência e em diferentes seções dos tubos. As medições com a técnica de seccionamento proposta, denominada técnica do furo elíptico, mostraram-se coerentes com as medições com o furo cego, principalmente para as tensões longitudinais. A partir dos resultados obtidos nos experimentos realizados, foram feitas recomendações e propostas metodologias para separar as tensões residuais de fabricação das tensões atuantes no duto em operação. Para cada método proposto foi feita uma simulação para avaliar seus erros. As tensões residuais de fabricação circunferenciais e longitudinais possuem magnitudes consideráveis (por vezes até próximas à resistência ao escoamento dos tubos). Desprezá-las em medições realizadas em campo, como é feito na maioria das vezes para calcular os esforços existentes, pode acarretar grandes erros na determinação dos esforços agindo sobre o duto. Os resultados das simulações mostraram que, se as tensões residuais forem baixas, os esforços de trabalho obtidos desconsiderando-as são próximos dos valores reais. No mais, os procedimentos propostos para a determinação dos esforços, mediante a separação das tensões residuais existentes, apresentaram erros menores ou, no mínimo, próximos aos encontrados quando o cálculo foi feito negligenciando-se as tensões residuais. / [en] The knowledge of the bending and axial efforts caused by soil movement is important for the structural integrity analysis of pipelines. The existence of residual stresses is one of the main obstacles for obtaining good results in the determination of such efforts. This work was developed to analyze the behavior of the residual stresses of manufacturing in pipes throughout its circumference and length. Measurements of residual stresses had been made in samples of a new pipe and others samplers removed from operation, using the hole drilling technique and a new sectioning technique. The measurements had been carried throughout the circumference and different sections of the pipes. The measurements with the sectioning technique proposed, called elliptical hole technique, are coherent with the measurements of the hole drilling technique, mainly for the longitudinal stresses. From the experimental results, recommendations had been made and methodologies had been proposed to separate the manufacturing residual stresses from the operating stresses in the pipelines. For each method considered in this work, a simulation was made to evaluate its errors. The circumferential and longitudinal residual stresses of manufacturing have considerable magnitudes (sometimes next to the yield strength of the pipes). Not considering the residual stresses in measurements carried through in situ to calculate the existing loads, as it is made most of the time, can cause significant errors in the determination of the efforts acting on the pipeline. The results of the simulations had shown that, if the residual stresses are low, the work loads obtained when the residual stresses are not considered are comparable with the correct loads. The procedures proposed for the determination of loads, considering the separation of the existing residual stresses, had presented smaller errors or closer to those when the calculation was made neglecting the residual stresses.

Ce travail s'inscrit dans la continuité des travaux de recherche menés au laboratoire Géoressources (Ecole des Mines de Nancy) et à l'INERIS depuis plusieurs années. Il concerne l’évaluation de la vulnérabilité des ouvrages situés dans des zones de mouvement de terrains d’origine naturelle ou anthropique. L’objectif de la thèse est de développer un modèle analytique permettant l’évaluation du tassement différentiel d’un ouvrage soumis à un mouvement de terrain et de calculer le taux de transmission de ces mouvements en fonction de la rigidité relative de l’ouvrage. Le modèle d’interaction sol-structure développé, tient compte de l’influence des contraintes de cisaillement dans le bâti et le terrain et d’un comportement poste-rupture du sol grâce à l’introduction d’une limite de plasticité. Le sol a été modélisé par les éléments de Pasternak afin de prendre en compte l'influence des déformations de cisaillement dans le sol, alors que le bâtiment est modélisé par la poutre d'Euler-Bernoulli et par la poutre de Timoshenko. L’existence potentielle d’un vide (décollement) sous le bâtiment a également été prise en compte dans le modèle analytique développé. Le taux de transmission des mouvements en champ libre du terrain au bâtiment a été calculé et présenté en fonction de la rigidité relative en flexion du bâtiment par rapport au terrain. Pour valider le développement entrepris, les résultats du modèle analytique ont été comparés aux résultats de modèles existants, analytiques, numériques et expérimentaux développés principalement par l'Université de Cambridge. Les résultats obtenus sont très satisfaisants et permettant de confirmer la robustesse du modèle analytique développé / This work is a continuation of the research work conducted in the Géoressources Laboratory and INERIS since several years. It concerns the assessment of the vulnerability of masonry structures influenced by natural or induced ground movements. The origins of the movement are may be, mining subsidence, tunneling, and shrinkage-swelling of clayed ground. The objective of the thesis is to develop an analytical model to evaluate the differential settlement of a structure in relation to the free field ground movement and given a set of phenomena: soil-structure interaction, influence of shear deformations in the structure and the ground, influence of non- linearities induced by the ground yielding. The soil was modeled by Pasternak elements to take into account the influence of shear deformations in the soil, while the building is modeled by the Euler-Bernoulli beam and by the beam of Timoshenko. The possibility of having a gap under the building was also taken into account. The deflection transmission ratio is then calculated and plotted according to are lative stiffness ratio which depend on both the structure and the soil stiffness A numerical model is also developed and results are compared with those of the analytical model. Other results of several numerical and experimental models principally developed at the University of Cambridge are also used for this comparison. Results show significant consistence between all these results. This demonstrates the significance of the analytical soil-structure model developed in this thesis