<p>Soil compaction is an inevitable result of agricultural practices. It alters physical properties of soil and tends to be undesirable as it adversely affects water and nutrient penetration. Furthermore, additional energy is spent to till the soil. Although a tremendous amount of research has been conducted in the area of soil compaction, the focus has been primarily on surface soil displacement.</p> <p>Realizing that the observed soil displacement is the cumulative effect from the compaction of subsurface layers, this research discusses the displacement and distributed pressure through the soil from a surface load. A given volume of soil of known density and moisture content was loaded at the surface with a slowly applied force using an Instron® testing machine. The distribution of the pressure and displacement profile from the surface to depth was measured to provide insight into the formation of the subsurface soil structures. The nonlinear exponential decay of the soil displacement (compaction) from the surface to a given depth converges to zero at the location of a hard, compact layer or a point where no soil movement occurs, regardless of the initial soil compaction. By increasing soil moisture content and decreasing soil bulk density, the vertical soil displacement increased at the surface and within the soil profile, and the pressure distribution decreased with depth. Changing the shape of loading surface had minimal effect on soil displacement.</p>

<p>Soil compaction is an inevitable result of agricultural practices. It alters physical properties of soil and tends to be undesirable as it adversely affects water and nutrient penetration. Furthermore, additional energy is spent to till the soil. Although a tremendous amount of research has been conducted in the area of soil compaction, the focus has been primarily on surface soil displacement.</p> <p>Realizing that the observed soil displacement is the cumulative effect from the compaction of subsurface layers, this research discusses the displacement and distributed pressure through the soil from a surface load. A given volume of soil of known density and moisture content was loaded at the surface with a slowly applied force using an Instron® testing machine. The distribution of the pressure and displacement profile from the surface to depth was measured to provide insight into the formation of the subsurface soil structures. The nonlinear exponential decay of the soil displacement (compaction) from the surface to a given depth converges to zero at the location of a hard, compact layer or a point where no soil movement occurs, regardless of the initial soil compaction. By increasing soil moisture content and decreasing soil bulk density, the vertical soil displacement increased at the surface and within the soil profile, and the pressure distribution decreased with depth. Changing the shape of loading surface had minimal effect on soil displacement.</p>

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.

Seismic safety of underground structures (culvert, subway, natural gas and water sewage systems) plays a major role in sustainable public safety and urban development. Very few experimental data are currently available and there is not generally accepted procedure to estimate the dynamic pressures acting on underground structures. This study aims to enhance the state of prevalent information necessary in understanding the dynamic behavior of box culverts and the stresses acting under dynamic excitations through experimental analyses. For this purpose, a series of shaking table tests were conducted on box-type culverts buried in dry sand. To simulate the free-field boundary conditions, a laminar box was designed and manufactured for use in a 1-g shake table. Four culvert models having different rigidities were tested under various harmonic motions in order to examine the effect of flexibility ratio on dynamic lateral soil pressures. Based on the tests results, a simplified dynamic pressure distribution acting on sidewalls of the culvert model was suggested. Then, a dynamic lateral coefficient was defined for the proposed peak pressure value in the distribution. The values of this coefficient were obtained as a function of shear strain and relative stiffness between the soil and underground structure. Finally, a simplified frame analysis approach was suggested for the assessment of the forces on the structure, to help to carry out a preliminary design of box-type culverts. In this approach, it was assumed that the culvert was fixed at bottom and subjected to lateral stresses on sidewalls and shear stresses on the upper face. For the confirmation of the method, centrifuge tests were conducted on a box-type culvert model under the Seventh Framework Programme of European Union with Grant Agreement No.227887. Results show that the proposed simplified procedure can be used in reasonable accuracy as a practical approach for the preliminary assessment of box-type culverts buried in dry sand under seismic action.

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.

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.

No description available.

The topic of diploma thesis is to design a cast-in-place tank of sewage plant. The tank has circular shape without ceiling slab and will be completely covered in by soil on sides. The tank is a simple construction with complex relation of foundation. It means the construction will be founded according to second geotechnical category. The tank has to be designed as waterproof construction, which is reached by making white tank system. Calculation was made according to ultimate limit state and limit crack width was assessed according to European standards.