A team from Brigham Young University and I performed full-scale lateral load tests on individual and grouped 12.75x0.375 inch pipe piles spaced at varying distances behind an MSE wall. The individually loaded pile which acted as a control was spaced at 4.0 pile diameters from the wall face, and the three grouped piles which were loaded in unison were spaced at 3.0, 2.8, and 1.8 pile diameters from the wall face and transversely spaced at 4.7 pile diameters center-to-center. The purpose of these tests was to determine the extent of group effects on lateral pile resistance, induced loads in soil reinforcements, and MSE wall panel deflections compared to those previously observed in individually laterally loaded piles behind MSE walls. The computer model LPILE was used in my analysis of the measured test data. The p-multipliers back-calculated with LPILE for the grouped piles were 0.25, 0.60, and 0.25 for the grouped piles spaced at 3.0, 2.8, and 1.8 pile diameters from the wall, respectively. These values are lower than that predicted for piles at the same pile-to-wall spacings using the most recent equation for computing p-multipliers. I propose the use of an additional p-multiplier for grouped piles near an MSE wall, a group-effect p-multiplier, to account for discrepancies between individual and grouped pile behaviors. The group effect p-multipliers were 0.35, 0.91, and 0.74 for the grouped piles spaced at 3.0, 2.8, and 1.8 pile diameters from the wall, respectively. The average group-effect p-multiplier was 0.66. Additionally, I used LPILE to analyze test data from Pierson et al. (2009), who had previously performed full-scale lateral load tests of individual and grouped shafts. In said analysis, the group of three 3-foot diameter concrete shafts spaced at 2.0 shaft diameters from the wall face and transversely spaced at 5.0 shaft diameters center-to-center had an average group effect p-multiplier of 0.78. As in previous studies, the induced forces in soil reinforcements in this study were greatest either near the locations of the test piles or at the MSE wall face. The most recent equation for calculating the maximum induced force in a soil reinforcement strip was reasonably effective in predicting the measured maximum loads when superimposed between the test piles, with 65% and 85% of the data points falling within the one and two standard deviation boundaries, respectively, of the original data used to develop the equation. Deflection of the MSE wall panels was greater during the grouped pile test than was previously observed for individually loaded piles under similar pile head deflections--with a maximum wall deflection of 0.31 inch compared to the previous average of 0.10 inch for pile head deflections of about 1.25 inches.

Reinforced piled embankment technique is becoming increasingly utilised for the construction over soft grounds. Most of the studies focused on studying the behaviour of piled embankments that are loaded with static surcharge load. However, less attention has been given to the behaviour of piled embankments under cyclic loading conditions. In this study, an experimental programme has been undertaken to improve our understanding for the behaviour of unreinforced and reinforced shallow piled embankments subject to cyclic loadings that are applied over a specific area of the embankment. The results showed that arching of the soil was adversely affected during the initial stages of cyclic loading regardless of the embankment height. However, regain of strength and recovery of the arching effect was observable during further stages of cyclic loadings. Inclusion of reinforcement layers was found to enhance the performance of load transfer mechanisms. The surface settlement increased with raising the embankment height and reduced with increasing the number of reinforcement layers. Two preliminary experimental studies have been carried out in order to be able to understand and design the main experiment. The results showed that with increasing number of reinforcement layers, enormous cycles of loading could be applied without experiencing excessive deformation or loss of bearing resistance. Furthermore, it was observed that alternating the direction of movement significantly affected the formation of arching during the initial cycles irrespective of the embankment height. / Higher Education Institute of the Libyan Government

A execução de obras apoiadas em solos moles constitui um desafio para a engenharia geotécnica. Pela baixa capacidade de suporte do solo mole, tais obras estão sujeitas a sofrer colapso, geralmente por ruptura do solo de base; e recalques excessivos, que ocorrem ao longo do tempo por efeito do adensamento do solo mole. Em virtude destes problemas, quaisquer soluções que promovam o aumento da capacidade de carga do solo mole representam uma enorme contribuição ao tema. Este trabalho apresenta resultados de uma série de provas de carga realizadas em laboratório sobre uma camada de areia apoiada em solo mole. A camada de areia foi ensaiada em três condições: sem reforço, reforçada apenas por geocélulas e pela associação de geocélulas e geogrelha. Foram utilizadas geocélulas de geotêxtil com ligações costuradas e geocélulas de polietileno com ligações soldadas nas alturas de 5, 10 e 15 cm. Os resultados apontam uma melhora significativa quando do confinamento com geocélulas, tanto em termos de recalque quanto de capacidade de suporte. A utilização de geocélulas conjugadas a um reforço basal com geogrelha permitiu uma melhora do desempenho ainda mais significativa / Works resting on soft soils represent a large task to geotechnical engineers. Due to the soft soil low bearing capacity, such works might present a rotational failure or present large settlements that occurwith time due to consolidation. For these problems any technical contribution that would allow an increase fo the bearing capacity of the soft soils would represent an enormous help to geotechnical engineering. This work presents results of laboratory loading plate tests carried out on a sandy layer resting on the topo of a soft soil deposit. The sandy layer was tested in there different conditions: unreinforced, reiforced with geocells and with geocells and geogrids. Geocells made out of strips of non woven geotextile with sewed joints and made from welded joint poliethylene strips were used. The results of plate tests showed a significant improvement not only in terms of bearing capacity but also in terms of settlement reduction when geocells alonge were used. The use of geocells associated with geogrids allowed further improvements in the bearing capacity and settlement reductions

A execução de obras apoiadas em solos moles constitui um desafio para a engenharia geotécnica. Pela baixa capacidade de suporte do solo mole, tais obras estão sujeitas a sofrer colapso, geralmente por ruptura do solo de base; e recalques excessivos, que ocorrem ao longo do tempo por efeito do adensamento do solo mole. Em virtude destes problemas, quaisquer soluções que promovam o aumento da capacidade de carga do solo mole representam uma enorme contribuição ao tema. Este trabalho apresenta resultados de uma série de provas de carga realizadas em laboratório sobre uma camada de areia apoiada em solo mole. A camada de areia foi ensaiada em três condições: sem reforço, reforçada apenas por geocélulas e pela associação de geocélulas e geogrelha. Foram utilizadas geocélulas de geotêxtil com ligações costuradas e geocélulas de polietileno com ligações soldadas nas alturas de 5, 10 e 15 cm. Os resultados apontam uma melhora significativa quando do confinamento com geocélulas, tanto em termos de recalque quanto de capacidade de suporte. A utilização de geocélulas conjugadas a um reforço basal com geogrelha permitiu uma melhora do desempenho ainda mais significativa / Works resting on soft soils represent a large task to geotechnical engineers. Due to the soft soil low bearing capacity, such works might present a rotational failure or present large settlements that occurwith time due to consolidation. For these problems any technical contribution that would allow an increase fo the bearing capacity of the soft soils would represent an enormous help to geotechnical engineering. This work presents results of laboratory loading plate tests carried out on a sandy layer resting on the topo of a soft soil deposit. The sandy layer was tested in there different conditions: unreinforced, reiforced with geocells and with geocells and geogrids. Geocells made out of strips of non woven geotextile with sewed joints and made from welded joint poliethylene strips were used. The results of plate tests showed a significant improvement not only in terms of bearing capacity but also in terms of settlement reduction when geocells alonge were used. The use of geocells associated with geogrids allowed further improvements in the bearing capacity and settlement reductions

Yes / Reinforced piled embankment technique is becoming increasingly utilised for the construction over soft grounds due to its efficiency on reducing potential settlement, speed of construction and associated cost. Most of previous studies focused on developing understanding for the behaviour of thick embankments that are loaded with a static surcharge load. Data for the behaviour of shallow piled embankments under cyclic loadings are scarce. In this study, an experimental programme was undertaken using a fully instrumented testing rig to generate data and improve our understanding for the behaviour of unreinforced and reinforced shallow piled embankments subject to monotonic and cyclic loadings that were applied over a predetermined area of the embankment. The experimental results showed that collapse of soil arching is imminent and occurs during the first few cycles of load. However, regain of strength and recovery of the arching effect was observable during further stages of cyclic loadings due to densification of the embankment material and deformation of the soft subsoil. Inclusion of reinforcement layers was found to enhance the performance of load transfer mechanisms by concentrating stresses on pile caps. The results clearly showed a significant reduction in surface settlement, soft subsoil settlement and heaving with increasing the number of reinforcement layers.

I takt med att våra städer växer ställs det högre krav på exploateringen av nya områden. Befolkningen i våra städer ökar, detta medför att behovet av bostäder, infrastruktur, skolor och kollektivtrafik med mera ökar. För att tillgodose samhällets krav såväl som skapa attraktiva miljöer finns ett stort intresse i att omvandla tidigare obebodda områden till nya stadsdelar. För att tillgodose vår miljö och natur krävs att samtliga resurser och tillgångar värnas så att nästkommande generation ska kunna bedriva liv på vår planet. De områden som exploateras i dagsläget kan ha komplexa grundläggningsförutsättningar, exempelvis bestå av mark som är förorenad, något som ställer höga krav på grundläggningsarbetet.Denna rapport syftar till att undersöka ifall metoden förhöjd grundläggning är ett alternativ för kommande exploateringar. I rapporten jämförs en traditionell grundläggningsmetod med en förhöjd grundläggningsmetod. Områden som masshantering, grundvattenhantering, samordning samt behovet att stödkonstruktioner avhandlas här då de är centrala i jämförelsen. Ett referensområde söder om Stockholm studeras där komplexa grundläggningsförutsättningar råder som dessutom utgör en bra grund för att göra jämförelsen så verksam som möjligt. Rapporten avhandlar ungefärliga kostnader för grundläggning i de område som studeras ovan, även tillståndsprocesser för hantering av grundvatten samt frågan kring samordning utgör en central del kring de resultat och slutsatser rapporten påvisar.Resultaten visar att kostnadsbesparingar kan göras med metoden förhöjd grundläggning utifrån ett antal givna förutsättningar. De största besparingarna som kan göras är med mindre masshantering samt minskat behov av stödkonstruktioner. Resultatet påvisar en nyanserad bild av konsekvenserna där även negativa aspekter med förhöjd grundläggning lyfts fram. Samordning mellan inblandade aktörer blir än mer relevant då metoden vänder på den traditionella byggnadsordningen. Rapporten ger ett underlag till frågeställningen kring huruvida metoden är tillämpbar eller ej, där rapporten påvisar konkreta för- och nackdelar. / As our cities continue to grow, there is a high demand for exploitation of new areas. Population continue to shift to cities, which means that the need for housing, infrastructure, schools, public transportation, and more is increasing. To meet society's demands and create attractive environments, there is a great interest in transforming previously uninhabited areas into new neighborhoods. To ensure the protection of our environment and nature, all resources and assets must be preserved. The areas being exploited currently may have complex conditions for buildings and may include contaminated land. Which puts high demands on the foundation work.This report aims to investigate whether elevated foundations are an alternative for future developments. The report compares traditional foundation methods with elevated foundation. Areas such as mass management, groundwater management, coordination, and the need for retaining walls are discussed as they are central to the comparison. A reference area south of Stockholm is also discussed, where complex foundation conditions exist. This makes the comparison as effective as possible. The report covers costs as well as the licensing process for groundwater management and the issue of coordination, which are central to the results and conclusions the report presents.The results show that cost savings can be achieved with the elevated foundations under certain conditions. The area where the largest savings can be made is mass management and the reduced need for support structures. The results show a nuanced picture of the consequences, where negative aspects of Elevated Foundation are also highlighted. Coordination among actors involved becomes even more relevant as the method turns the traditional building order upside down. The report provides as advantages and disadvantages a basis for the question of whether the method is applicable or not.

As estruturas de solo reforçado tornaram-se uma alternativa eficiente para a construção de aterros e muros de contenção. No entanto, o seu uso é limitado pelas especificações técnicas, que recomendam apenas materiais granulares, por apresentarem alta resistência e capacidade de livre drenagem. Todavia, nem sempre se dispõem deste tipo de material nas proximidades das obras, o que pode torná-las onerosas, devido aos custos de transporte. Os solos não convencionais, definidos como solos de granulometria fina (caracterizados como argilas, siltes, e solos areno-siltosos), merecem atenção, pois são encontrados em abundância em muitos locais do nosso território. Casos históricos brasileiros de obras instrumentadas revelam a eficiência destes materiais na composição de aterros de estruturas de solo reforçado, devido ao bom desempenho técnico ao longo de sua vida útil. Acredita-se que o uso de inclusões permeáveis possa contribuir na aceleração da drenagem da água das camadas de maciços construídos com solos finos, permitindo a dissipação mais rápida do excesso de pressões neutras. Para elucidar estas questões foram realizados ensaios de compressão triaxial rápidos (UU) e adensados rápidos (CU), com o intuito de avaliar o desempenho de solos não convencionais reforçados com inclusões permeáveis e impermeáveis. Utilizaram-se como reforços papel alumínio (reforço inextensível e impermeável) e geotêxtil (reforço extensível e permeável), o que permitiu comparações dos resultados obtidos dos ensaios com corpos de prova reforçados com os obtidos de corpos de prova não reforçados. Os solos utilizados foram duas argilas silto-arenosas, uma de comportamento laterítico e a outra não laterítico e uma areia fina com aproximadamente 40% de finos (material com diâmetro inferior à peneira 200), com comportamento não laterítico. Verificou-se que a combinação de solos finos com reforços permeáveis resultou num ganho de resistência ora em termos de ângulo de atrito interno, ora em relação à coesão, apenas a areia fina obteve ganho de resistência ao ser reforçada com o papel alumínio. Observou-se que a argila silto-arenosa, com comportamento laterítico, e a areia fina apresentaram uma interação mais eficiente com os reforços de geotêxtil. Constatou-se ainda que os reforços permeáveis promoveram a drenagem da água dos corpos de prova / The reinforced soil structures became an efficient alternative for the construction of embankments and retaining walls. However, the use of these structures are limited by design specifications which recommend the use of granular materials that present high shearing strength and free drainage capacity. Some granular soils are not always available in the proximities of works, in these cases, costs of transportation can be high. The marginal soils, defined as fine grain-size (characterized as clays, silts, and sandy-silty) soils, deserve attention because they are found in abundance in many places on our territory, besides that, brazilian historical cases of instrumented structures have shown their efficiency when used as backfill of reinforced soil structures. It is also believed that the use of permeable inclusions can contribute to the acceleration of water drainage, which allows faster dissipation of pore pressure. To contribute to the understanding of these aspects of reinforced soil behavior, triaxial compression tests, unconsolidated-undrained (UU) and consolidated-undrained (CU), were carried out in order to check the performance of reinforced marginal soil when reinforced with permeable and impermeable inclusions. Aluminum foil (inextensible and impermeable reinforcement) and geotextile (extensible and permeable reinforcement) were used as reinforcement, allowing the comparison of results of tests using reinforced and non-reinforced samples. The soils used were two sandy silty clays - a lateritic and a non-lateritic soil - and fine sand with 40% of fines, presenting non-lateritic behavior. It was verified that the combination of cohesive soil and permeable reinforcements resulted on an increase of resistance parameters, angle of internal friction and cohesion. It was observed that the lateritic sandy silty clay and the fine sand presented more efficient interaction with the geotextile reinforcements. Also, it was verified that the permeable reinforcements promoted faster water drainage

Grande percentagem do território brasileiro é coberta por solos finos (% passando peneira # 200 > 50%), geralmente de origem tropical, que poderiam ser classificados como solos de baixa capacidade de drenagem. Estes solos não atendem às recomendações técnicas para solos de aterro de estruturas reforçadas, conforme exigido pela AASHTO e BS 8006. Neste trabalho foi avaliado experimentalmente um dos parâmetros mais importantes de projeto de Terra Armada, que condiciona o mecanismo de transferência de carga, o coeficiente de atrito aparente solo-fita metálica (f*). Foi avaliada a influência das características dos solos para as classes de solos estabelecidas pela NBR 9286/86 para o caso de fitas metálicas, e, dos critérios que sustentam o uso de fitas poliméricas, sob diversas tensões verticais atuantes nas fitas, simulando o efeito da profundidade. As informações foram obtidas através de ensaios de arrancamento de fitas metálicas e poliméricas realizados em laboratório e depois comparadas aos resultados teóricos da norma e àqueles preconizados para o uso de fitas poliméricas. Os ensaios realizados com as fitas em solo não convencional 1 e em areia mal graduada, mostraram que para profundidades equivalentes a tensões verticais até 50 kPa, os dois tipos de inclusões possuem valores de coeficiente de interação com o solo maiores que a unidade, isso tornaria razoável o seu uso sob o ponto de vista deste parâmetro e nas condições da realização dos ensaios, quando comparado com a norma, e com os critérios que sustentam o uso das fitas poliméricas em técnica de solo armado. No entanto, para maiores profundidades, a interação apresenta uma tendência de diminuição. O solo não convencional 2 valores da interação muito baixos. Foram instalados strain gages ao longo do comprimento das fitas para monitoramento dos esforços no maciço. Nota-se que esforços elevados ocorreram nas regiões mais próximas do ponto de aplicação da força de arrancamento. / A large percentage of Brazil\'s territory is covered with fine tropical soil (50% passing #200) which can be classified as soils with low drainage capacity. These soils do not meet the technical recommendations for backfill of reinforced soil structures by AASHTO and BS 8006. This paper presents the result of an experimental evaluation of one of the most important design parameters of mechanically stabilized earth with concrete wall facing. The apparent friction coefficient of soil-steel strips and soil-polymeric strips is the project parameter. Also was evaluated the influence of soil characteristics for soil types listed by the NBR 9286/86 for metal strips and for the criteria that support the use of polymeric strips. The evaluation included the application of different vertical stresses on the strips simulating the effect of depth. The information obtained from pullout tests performed in laboratory was compared to the standard theoretical values and design values for polymeric strips. Tests performed on strips in nonconventional soil (1) and poorly graded sand showed that at depths equivalent to vertical stresses up to 50 kPa the two types of inclusions have coefficients of interaction greater than unity, which appears reasonable. Therefore, such soils can be used as backfill soils in the conditions tested and at equal or lesser stress levels. Nonconventional soil (2) showed low value of the friction coefficient. The strain gages installed along the length of the strips recorded the distribution of tensile stress in pull-out tests. Higher tensile stress was recorded by the gages nearest the point of application of the pull-out force.

[pt] As atuais técnicas propostas para a destinação final dos pneus não são 100 por cento eficientes, existindo um grande déficit do material em questão. Um outro material que necessita de uma destinação final é o PET (polietileno tereftalato), que hoje em dia, apesar da grande quantidade reciclada, necessita de mais opções de destinação. O estudo apresentado propõe a utilização da borracha triturada (em forma de fibras e em pó - granulometria inferior a 2mm) em diferentes teores (de 5 por cento e 10 por cento, em relação ao peso seco da bentonita) e do PET triturado (na forma de fibras e em pó), como reforço de uma bentonita, para aumento dos parâmetros de resistência desta. O objetivo da pesquisa consiste em avaliar a possibilidade da utilização da borracha e do PET como melhoramento de bentonita em obras geotécnicas, como por exemplo em camadas impermeabilizantes para aterros sanitários, visto que com a utilização da borracha e do PET em obras geotécnicas seria possível a destinação de um grande volume desses materiais. Para o desenvolvimento do estudo experimental foram realizados ensaios de caracterização física e de caracterização mecânica, como ensaios de cisalhamento direto e adensamento. Com resultados obtidos a partir dos ensaios de cisalhamento direto e ensaio de adensamento, pode se perceber que as misturas B90BF10 e B90PETT10 se mostraram mais favoráveis a utilização como barreira impermeabilizando para aterros sanitários, tendo em vista o aumento nas resistências de Pico, pós pico e residual, além do aumento do coeficiente de adensamento (cv) e redução da permeabilidade (k). / [en] The current techniques proposed for the final destination of the tires are not 100 percent efficient, and there is a great deficit of the material in question. Another material that needs an end destination is the PET (polyethylene terephthalate), which nowadays, despite the large amount recycled, needs more disposal options. the present study proposes the use of crushed rubber (in the form of fibers and powder - granulometry of less than 2 mm) in different contents (5 percent and 10 percent, in relation to the dry weight of bentonite) and crushed PET (in the form of fibers and powder), as reinforcement of a bentonite, to increase the resistance parameters of this one. The objective of the research is to evaluate the possibility of using rubber and PET as an improvement of bentonite in geotechnical works, such as waterproofing layers for sanitary landfills, since with the use of rubber and PET in geotechnical works it would be possible to allocate a large volume of these materials. For the development of the experimental study, physical characterization and mechanical characterization tests were performed, such as direct shear tests and densification. With results obtained from the direct shear tests and the densification test, it can be seen that the mixtures B90BF10 and B90PETT10 were more favorable to use as a waterproofing barrier for sanitary landfills, in view of the increase in peak and residual, besides the increase of the coefficient of densification (cv) and reduction of the permeability (k).

Grande percentagem do território brasileiro é coberta por solos finos (% passando peneira # 200 > 50%), geralmente de origem tropical, que poderiam ser classificados como solos de baixa capacidade de drenagem. Estes solos não atendem às recomendações técnicas para solos de aterro de estruturas reforçadas, conforme exigido pela AASHTO e BS 8006. Neste trabalho foi avaliado experimentalmente um dos parâmetros mais importantes de projeto de Terra Armada, que condiciona o mecanismo de transferência de carga, o coeficiente de atrito aparente solo-fita metálica (f*). Foi avaliada a influência das características dos solos para as classes de solos estabelecidas pela NBR 9286/86 para o caso de fitas metálicas, e, dos critérios que sustentam o uso de fitas poliméricas, sob diversas tensões verticais atuantes nas fitas, simulando o efeito da profundidade. As informações foram obtidas através de ensaios de arrancamento de fitas metálicas e poliméricas realizados em laboratório e depois comparadas aos resultados teóricos da norma e àqueles preconizados para o uso de fitas poliméricas. Os ensaios realizados com as fitas em solo não convencional 1 e em areia mal graduada, mostraram que para profundidades equivalentes a tensões verticais até 50 kPa, os dois tipos de inclusões possuem valores de coeficiente de interação com o solo maiores que a unidade, isso tornaria razoável o seu uso sob o ponto de vista deste parâmetro e nas condições da realização dos ensaios, quando comparado com a norma, e com os critérios que sustentam o uso das fitas poliméricas em técnica de solo armado. No entanto, para maiores profundidades, a interação apresenta uma tendência de diminuição. O solo não convencional 2 valores da interação muito baixos. Foram instalados strain gages ao longo do comprimento das fitas para monitoramento dos esforços no maciço. Nota-se que esforços elevados ocorreram nas regiões mais próximas do ponto de aplicação da força de arrancamento. / A large percentage of Brazil\'s territory is covered with fine tropical soil (50% passing #200) which can be classified as soils with low drainage capacity. These soils do not meet the technical recommendations for backfill of reinforced soil structures by AASHTO and BS 8006. This paper presents the result of an experimental evaluation of one of the most important design parameters of mechanically stabilized earth with concrete wall facing. The apparent friction coefficient of soil-steel strips and soil-polymeric strips is the project parameter. Also was evaluated the influence of soil characteristics for soil types listed by the NBR 9286/86 for metal strips and for the criteria that support the use of polymeric strips. The evaluation included the application of different vertical stresses on the strips simulating the effect of depth. The information obtained from pullout tests performed in laboratory was compared to the standard theoretical values and design values for polymeric strips. Tests performed on strips in nonconventional soil (1) and poorly graded sand showed that at depths equivalent to vertical stresses up to 50 kPa the two types of inclusions have coefficients of interaction greater than unity, which appears reasonable. Therefore, such soils can be used as backfill soils in the conditions tested and at equal or lesser stress levels. Nonconventional soil (2) showed low value of the friction coefficient. The strain gages installed along the length of the strips recorded the distribution of tensile stress in pull-out tests. Higher tensile stress was recorded by the gages nearest the point of application of the pull-out force.