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The Effects of Different Earth Pressure Coefficient at Rest in Triaxial Shear Tests on ClayIndgaard, Jo Forseth January 2017 (has links)
Triaxial shear test is the most accurate test for deciding the undrained shear strength of clay. In every test the ratio between the horizontal and vertical stresses, the coefficient of earth pressure at rest (K0′), has to be decided. It’s widely believed that the choice of this parameter will influence the results, but it’s not known to what extent. In this thesis 20 consolidated undrained active triaxial shear tests on clay has been con- ducted with a K0′ at 0.6 and 0.8. The clay was collected with a 54 mm piston sampler at the Norwegian Geo-Test Site in Trondheim, Norway, on depth of 3.0 to 7.8 meters. Besides the triaxial testing, index tests and oedometer tests was conducted on every cylinder to do a gen- eral classification of the clay. The clay has a sensitivity of 9-20, a water content of 35-51 %, a plasticity index of 27-65 % and an over consolidation ratio of 2.6-6.8. The consolidation phase of the triaxial test was conducted in five loading steps with a rest time in-between to monitor the amount of pore water expelled at each stress level. The loading steps was 50 %, 75 % and 100 % of maximum cell pressure and thereafter at 50 % and 100 % of the maximum deviator stress. The shear phase was done at a speed of 1.5 % per hour to a total of 10 % axial strain. It is not possible to reach an unambiguous conclusion from the results, but the maximum shear strength of tests with a K0′ at 0.8 is 17 % higher, while the total amount of pore water extortion is equal between the two values. The amount of creep in the latest steps is on the other hand smaller for a K0′ at 0.8. This indicates that the soil is handling the stress level better than with a K0′ at 0.6.
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Analysis of sequential active and passive arching in granular soilsAqoub, K., Mohamed, Mostafa H.A., Sheehan, Therese 17 May 2018 (has links)
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.
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Estudo do atrito lateral no arrancamento de estacas modelo instaladas por fluidização em areiaMazutti, Júlia Hein January 2018 (has links)
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.
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Estudo da interação solo-concreto das estacas escavadas do campo experimental de AraquariLavalle, Laura Vanessa Araque January 2017 (has links)
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.
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Estudo da interação solo-concreto das estacas escavadas do campo experimental de AraquariLavalle, Laura Vanessa Araque January 2017 (has links)
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.
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Estudo do atrito lateral no arrancamento de estacas modelo instaladas por fluidização em areiaMazutti, Júlia Hein January 2018 (has links)
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.
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Estudo da interação solo-concreto das estacas escavadas do campo experimental de AraquariLavalle, Laura Vanessa Araque January 2017 (has links)
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.
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Utredning och test av olika jordtryckskoefficienter med hänsyn till fraktionsstorlekar på stödkonstruktioner / Investigation and testing of different earth pressure coefficients with regard to grain size on support structuresJohansson, Alexander, Hallgren, Herman January 2022 (has links)
Introduktion – En fråga har väckts kring hur jordtryck beräknas enligt en klassiskjordtryckteori som beskrivs i läroböcker så som (Sällfors,2009), Trafikverket krav och Eurocode av företaget Vara byggkonsult AB. För att skapa en bättre förståelse så togett praktiskt test fram för att mäta jordtrycket utifrån klassiska teorier och jämförs med dessa.Metod – Den valda forskningsmetoden är en litteraturstudie och ett experimentellkvantitativ test. Framtagandet av testet är en iterativ process där metod och utformande uppdaterats efter observationer och diskussion.Resultat – Beräknade värden för den aktiva jordtryckskoefficienten med de olika metoderna varierar mellan 0,221 - 0,278 för materialet 0–4 och mellan 0,25 - 0,334 för materialet 8-16 beroende på vilken metod som avvänds. För de uppmätta värdena så varierar dessa från 0,173 - 0,279 för materialet 0–4 och 0,227 – 0,296 för materialet 8–16 beroende på vilken last som tillförts. Att värdena varierar beror på faktorer så sominre friktionsvinkel, friktion mellan stödvägg och material, beräkningsmetod, samt vilken last som använts vid utfört test.Analys – Genom att jämföra beräkningsmetoderna med de uppmätta testvärdena går det att se likheter och skillnader mellan resultaten. För materialet 0–4 går det att se en likhet mellan de beräknade värdena och de uppmätta värdena för de beräkningsmetoder där friktionen antas vara 0. För materialet 8–16 är det uppmätta värdet konstant lägre än de beräknade för alla beräkningsmetoder. För båda materialtyperna går det att se en trend där ökningen i det uppmätta värdet minskar ju högre last som läggs på.En analys utifrån frågeställning två har gjorts där modellen och metoden för utförandet av det praktiska testet analyserats. De resultat som producerats ur modellen är trovärdiga och är upprepbara till hög grad. Modellen har konstruerats med material och verktyg tillgängliga i en vanlig bygghandel. Materiallista samt ritning på konstruktionen har dokumenterats samt att metoden för genomförande av testerna är väl dokumenterad.Utifrån en analys av fraktionsstorlekens påverkan på det uppmätta trycket observeras det att ett finkornigt material som 0–4 kan uppnå ett högre tryck än ett grövre material som 8–16. De utförda testen stödjer detta då materialet 0–4 resulterar i en högre jordtryckskoefficient än materialet 8–16. Detta är dock motsägelsefullt till hur klassiskt sett så sker det en ökning i friktionsvinkel desto större fraktionsstorleken är.Diskussion – Trafikverkets metod att beräkna jordtryckskofficienten anses vara smidigare att använda i jämförelse med Eruocdes sätt, då det inte krävs mer än ett uppskattande av materialets egenskaper.Faktorer så som mänskliga faktorn är något som också tas upp i rapporten som har haft en inverkan på det slutgiltiga resultatet samt utförandet av tester. Att rita upp en modell digitalt med perfekta linjer är en sak, men att bygga ihop den i verkligheten är en annan sak. För att motverka faktorer så som mänskliga faktorn, så har en rad olika förändringar gjort på modellen samt utförandet av testerna. Enligt de resultat som framtagits så syns det att det finns en skillnad mellan de olika materialen, men detta är inte en stor skillnad. Friktionsvinklarna för materialen skiljer ivsig inte med många grader och därför har inte heller en stor kraftskillnad kunnat uppmätas.Då grundkunskapen vid undersökningens start inte var speciellt hög så lede det tillmisstag som kunde undvikits. Den tid som lagts ner på att fixa de misstagen kunde istället lagts ner på att förbättra modellen för att få ännu bättre värden. / Introduction – A question has been raised regarding how earth pressure is being calculated regarding classical textbook theory, the Swedish Transport Administration and Eurocode by the company Vara byggkonsult AB. To create a better understanding of the subject a practical test is being derived from classical theories and compared to these.Method – The chosen research method is a litterature study and an experimental quantitative test. To produce a test an iterative process is being used that is beeing updated according to observations and discussions.Results – Calculated values for the active earth pressure coefficient with the different methods vary between 0,221 – 0,278 for the material 0-4 and between 0,25 – 0,334 for the material 8-16 depending on which method is used. For the measured values, these vary from 0,173 – 0,279 for the material 0-4 and 0,227 – 0,296 for the material 8-16, depending on the load added. The fact that the values vary depends on factors such as internal friction angle, friction between the supporting wall and material, calculation method and which load was used when the test was carries out.Analysis – By comparing the calculation methods with the measured test values, it is possible to see similarities and differences between the results. For the material 0-4, it is possible to see a similarity between the calculated values for the calculation methods where the friction is assumed to be 0. For the material 8-16, the measured value is constantly lower than the calculated values for all calculation methods. For both material types, a trend can be seen where the increase in the measured value decreases the higher the load that is applied. An analysis based on question two has been done where the model and method for preforming the practical test has been analysed. The results produced from the model are credible and are repeatable to a high degree. The model has been constructed with materials and tools available in a regular hardware store. Material list and drawing of the construction have been documented and that the method for carrying out the tests is well documented.Based on an analysis of the effect of fraction size on the measured pressure, it is observed that a fine-grained material such as 0–4 can achieve a higher pressure than a coarser material such as 8–16. The tests carried out support this as material 0–4 results in a higher earth pressure coefficient than material 8–16. However, this is contradictory to how, classically speaking, there is an increase in friction angle the larger the fraction size is.Discussion – The Swedish Transport Administration's method of calculating the earth pressure coefficient is considered easier to use in comparison to Eruocde's method, as no more than an estimation of the material's properties is required.Factors such as the human factor is something that is also addressed in the report that has had an impact on the final result as well as the execution of tests. Drawing up a model digitally with perfect lines is one thing, but building it in real life is another. To counteract factors such as the human factor, a number of different changes have been made to the model and the execution of the tests.According to the results produced, it appears that there is a difference between the different materials, but this is not a big difference. The friction angles of the materials iido not differ by many degrees and therefore a large force difference has not been measured either.As the basic knowledge at the start of the survey was not particularly high, it led to mistakes that could have been avoided. The time spent on fixing those mistakes could instead be spent on improving the model to get even better values.
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