Orientador: Pérsio Leister de Almeida Barros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-16T06:19:41Z (GMT). No. of bitstreams: 1 Constancio_LucasAmarante_M.pdf: 4405049 bytes, checksum: 0e339df263cb9591f816add6ac404af7 (MD5) Previous issue date: 2010 / Resumo: Este trabalho visa avaliar o ganho de capacidade de carga de uma fundação superficial em areia fofa, através da inclusão de reforço de material geossintético. Para tanto, propõe-se observar o aumento da capacidade de carga do solo, com uma única camada de reforço em geotêxtil tecido, para uma fundação superficial do tipo sapata corrida. Através de um modelo reduzido que atende os critérios para atingir o estado plano de deformação, avalia-se a capacidade de carga do solo sem reforço, com reforço planar horizontal e faz-se uma nova proposta de disposição geométrica de tal elemento, buscando maior ganho de capacidade de carga e atenuação de deformações. O modelo reduzido é ensaiado no interior de um tanque que permite o acompanhamento das deformações através de sua face translúcida, além da aquisição dos dados de carga aplicada e recalque da fundação. Com a aquisição dos dados, é possível estabelecer comparações entre as diferentes situações analisadas, através da análise dos gráficos de carga-recalque. O trabalho mostra que é possível obter-se um ganho na capacidade de carga com inclusão do reforço e também que é possível chegar a capacidades de carga ainda maiores, apenas readequando a geometria do posicionamento do reforço com uma angulação do geotêxtil. Por fim, este trabalho contribui para a compreensão dos fatores envolvidos na complexa interação entre solo e reforço para fundações apoiadas sobre solos reforçados, campo este, que ainda precisa de refinamento, pesquisa, novas abordagens e contribuições / Abstract: This study aims to evaluate the gain in bearing capacity of a shallow foundation on a soft sand, through the inclusion of geosynthetic reinforcement. For this, the bearing capacity of a soft sandy soil carrying a shallow strip footing, without any reinforcement, and with a single layer of reinforcement of a woven geotextile is observed. Through the use of a reduced model, which satisfy the criteria for reaching a plane strain state, the bearing capacity of the unreinforced soil, the soil reinforced with planar horizontal and the soil reinforced with a new proposed geometric arrangement seeking greater gain of bearing capacity and the attenuation on deformation are evaluated. The reduced model is placed in a tank which allows the monitoring of deformations through its translucent face, and acquisition of applied load and foundation settlement data. After the acquisition of data it is possible to make comparisons between the different situations analyzed by examining the plots of load versus settlement. The results show that it is possible to obtain a gain in capacity with the inclusion of reinforcement and that it is possible to reach even higher bearing capacity just adjusting the geometry of the reinforcement placement, providing an inclination to the geotextile sheet. Finally, this work adds to the understanding of the different factors affecting the complex iteration mechanisms involved in foundations over reinforced soils, a field that still needs refinement and research, new approaches and contributions / Mestrado / Geotecnia / Mestre em Engenharia Civil

Os geotêxteis não-tecidos desempenham, dentre outras funções, papel relevante na filtração e drenagem de solos. Nesta função, necessitam ter vazios suficientemente grandes para permitir a livre passagem de água e, ao mesmo tempo, vazios suficientemente pequenos para impedir o arraste de partículas, de sorte a evitar a erosão interna do solo. Critérios de dimensionamento para atender a ambos os requisitos estão disponíveis na literatura e são utilizados com sucesso há vários anos. Uma situação menos estudada e compreendida refere-se ao desempenho desses geotêxteis na filtração de água com sólidos em suspensão. Trata-se de uma situação tida como crítica, pela possibilidade de colmatação do geotêxtil por essas partículas, de acordo com diferentes mecanismos. Neste trabalho, verifica-se o desempenho, em laboratório, de geotêxteis não-tecidos frente à filtração de suspensões de solo em água, tal qual poderia ocorrer por ocasião de enxurradas. Nessa perspectiva, tenta-se verificar qual poderia ser o desempenho desses geotêxteis quando utilizados para compor sistemas de proteção da entrada de estruturas de captação de água, como bocas de lobo e bueiros. O trabalho utiliza um geotêxtil não tecido de fibras curtas, fabricado a partir de poliéster e suspensões contendo bentonita e uma areia fina argilosa, solo típico da região de São Carlos, em diferentes concentrações. Estabelecem-se correlações entre diferentes características e propriedades dos geotêxteis estudados e estuda-se o mecanismo de colmatação, que em geral ocorreu para todos os geotêxteis, em intervalos de tempo associados às características do geotêxtil e à concentração de solo na suspensão. As severas condições de colmatação observadas e o comprometimento da permeabilidade dos geotêxteis sugerem que para as concentrações de solo utilizadas, os geotêxteis não seriam capazes de cumprir com a proteção da entrada de estruturas de drenagem. / Nonwoven geotextiles play an important role in filtration and drainage of soils, among other functions. In these functions, they need to have large enough internal voids to allow free passage of water and at the same time these voids should be small enough to prevent the passing of particles and preventing piping formation or erosion of soil. Design criteria to satisfy both requirements are available in the literature and have been used successfully for many years. A topic that has not been deeply addressed refers to the performance of geotextiles on filtration of water with suspended solids since the possibility of geotextile clogging is real, impairing its behavior. In this work, the performance of nonwoven geotextiles in laboratory tests designed to observe the filtration of water containing solid particles in suspension is addressed. The tests were devised trying to understand what could be the performance of these geotextiles when used to compose inlet protection systems for drainage structures, such as culverts. The study used nonwoven short-fibers geotextile, made of polyester and suspensions containing bentonite and clayey fine sand, a typical soil of São Carlos area, Brazil, in different concentrations. The laboratory test results show that there exist correlations among different characteristics and properties of geotextiles studied and allowed to evaluate the mechanism of clogging, which generally occurred for all geotextiles, in time intervals associated to some characteristics of the geotextile and to the soil concentration in suspension. The severe clogging observed and the reduction of permeability of geotextile suggest that, for the solids concentration used, the geotextiles could not protect the entrance of drainage structures.

M.Ing. (Civil Engineering) / The purpose of this study was to determine the effectiveness of a sisal fibre natural geotextile in controlling the rate and extent of soil erosion. The effectiveness of this locally produced material was compared to other natural fibre geotextiles and other methods commonly used for the control of soil erosion. The different materials and methods were tested under the same conditions to compare the relative effectiveness of these products. The various erosion control products were subjected to laboratory tests. A rainfall simulator and an adjustable slope simulator were used to simulate the process of soil erosion. During these tests the effectiveness of the different products in controlling soil erosion was measured and conclusions were made about the effectiveness of the products. Mechanical sieve analysis tests were used to determine the erodibility of the different soil particles. Field trials that made use of the sisal fibre geotextile are also discussed.

Geotextiles have been used for many years in different parts of the world to promote soil conservation and to combat erosion. Such geotextiles may be synthetic (usually some form of plastic, sometimes with wire), or natural (usually some form of fibrous material). Work carried out at the University of Wolverhampton (UK) on the effectiveness of mats made from palm tree leaves sourced from the Gambia, West Africa led to a research project funded by the EU, which ran from October 2005 to February 2009, comprising the participation of four EU countries (UK, Belgium, Hungary and Lithuania) and six developing” countries (Brazil, Gambia, South Africa, Thailand, China and Vietnam). Research carried out in South Africa used mats made from the leaves of the Lala palm (Hyperhene coriacea). These mats are easy to make, flexible, durable and completely biodegradable. They cover approximately 40% of the soil surface, allowing space for vegetation to emerge, and add 1.3 kg of dry organic matter to each m2 of soil. Furthermore, they have a water retention capacity of 1.8 l kg-1 m-2, their N, K, S and P percentages are high, they have low sodium and aluminium values and a favourable C/N ratio. Firstly, trials were done on 20 South African soils and 10 mine tailings materials using a rainfall simulator. The soils varied considerably with respect to their textural, chemical and mineralogical properties as well as annual precipitation and geological origin. Erosion parameters varied greatly within, and to a much lesser extent between, the two different materials. Several significant correlations were obtained. Sediment load (SL) had the best correlation with kaolinite content and with fine sand content, while for runoff, the best correlation was with organic carbon content. When the samples were covered with palm mats values for final infiltration rate (FI) percentage stable aggregates (SA) and inter-rill erodibility (Ki) values were similar to those of bare materials and the amount of runoff was slightly higher. SL, however, was reduced by +65%. The next stage was to carry out a range of field trials, using runoff plots. Plots at four localities (Bergville, Ladybrand, Roodeplaat and Mabula) were used. Results showed that average runoff under the palm mats decreased by between 38% and 70%, compared to bare soil. Sediment concentration under the mats decreased by between 38% and 89%, using three combinations of slope, mat density and mesh size. Splash erosion at Roodeplaat decreased by between 62% and 68%, while re-vegetation at Ladybrand and Mabula increased by between 38% and 58%, with organic carbon content and topsoil accumulation also increasing under the mats. Various trials (using both the rainfall simulator and runoff plots) were carried out to evaluate the effects of reduced mat density and increased mesh size. Results from the other participating countries (25% to 95% reduction in runoff) confirm that there is much potential to use organic, bio-degradable, easy to manufacture geotextiles such as palm leaf mats, especially to combine employment opportunities with enhanced environmental protection in many susceptible areas of South Africa. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Plant Production and Soil Science / unrestricted

Orientadores: José Euclides Stipp Paterniani, Túlio Assunção Pires Ribeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-29T00:00:03Z (GMT). No. of bitstreams: 1 Santos_FlaviaFerreiradeSouzados_D.pdf: 6754875 bytes, checksum: 9a804a4e184846e60d2063d6b1aa1326 (MD5) Previous issue date: 2015 / Resumo: O nãotecido sintético é um material de fácil obtenção e baixo custo, cujo uso na filtração lenta juntamente com areia acarretou em resultados satisfatórios, em termos de qualidade de água produzida e facilidade de operação. Esta pesquisa teve como objetivo avaliar o desempenho de um filtro lento com meio filtrante constituído exclusivamente por nãotecido sintético em diferentes espessuras e compará-lo ao desempenho de um filtro lento de areia tradicional. Construiu-se um sistema piloto de filtração em que os dois filtros lentos operavam em paralelo sob influência de três taxas de filtração (3, 6 e 9 m3.m-2.dia-1). No decorrer das carreiras de filtração foram monitorados a evolução da perda de carga de cada filtro, os parâmetros físico-químicos e bacteriológicos da água bruta e água tratada pelo filtro de areia e por cada uma das 12 espessuras (entre 1 e 40 cm) do filtro de nãotecido. O filtro lento de nãotecido proporcionou carreiras de longa duração, quando comparado ao filtro de areia, além de reduzir a frequência e a complexidade do processo de limpeza do filtro. A formação da schmutzdecke foi observada na camada superficial do filtro de nãotecido, o qual teve período de amadurecimento semelhante ao filtro de areia, aproximadamente 15 dias. O desempenho satisfatório do filtro lento de nãotecido abrangeu as três taxas de filtração avaliadas. Em termos de remoção de cor aparente e turbidez da água bruta, atendeu os padrões de potabilidade de água designados pela legislação vigente. E, em termos de remoção de bactérias heterotróficas, coliformes totais e E. coli, o filtro de nãotecido alcançou eficiência superior a 99,5%, estatisticamente similar ao filtro lento de areia. Os resultados obtidos indicam que a espessura ótima de nãotecido sintético para remoção de cor aparente e turbidez da água seria de 25 cm, e sugerem que a espessura de 15 cm de nãotecido seria suficiente para remoção de bactérias, com possibilidade de emprego de taxa de filtração considerada elevada para o tratamento por filtração lenta (9 m3.m-2.dia-1). Desta forma, concluiu-se que o meio filtrante constituído exclusivamente por nãotecido sintético de 25 cm de espessura tem potencial para substituir a areia no tratamento de água por filtração lenta, uma vez que obteve desempenho similar ao filtro lento de areia, além de simplificar os procedimentos operacionais e de manutenção do filtro / Abstract: Non-woven synthetic fabric is an easily available and low-cost material which has brought satisfactory results in terms of both the quality of produced water and its operational value. The aim of this research is to assess the performance of a slow filter made up exclusively of non-woven synthetic fabrics of a number of different thicknesses and to compare it to that of a traditional sand filter. A pilot filtering system was built where the two slow filters operate in a parallel way under the influence of three filtering rates (3, 6 and 9 m3.m-2.d-1). Along the filtering runs the evolution of the headloss and the physical-chemical and bacteriological parameters of both raw water and water treated through the 12 thicknesses (ranging from 1 to 40 cm) of non-woven were monitored as well as that filtered through sand. The slow non-woven filter yielded long-term runs when compared to the sand filter, as well as reducing the frequency and complexity of the filter¿s cleaning process. The formation of schmutzdecke was observed on the superficial layer of non-woven filter, a process which had a similar maturing period to that of the sand filter, approximately 15 days. The satisfactory performance of the slow non-woven synthetic fabric filter covered all three filtering rates. In terms of the removal of apparent color and turbidity of raw water it met the drinkability standards set by the existing legislation. In terms of the removal of heterotrophic bacteria, total coliform and E. coli the non-woven filter obtained an efficiency level above 99,5%, statistically similar to the slow sand filter. The results indicate the optimal thickness of non-woven synthetic fabric for apparent colour and turbidity removal to be 25 cm, and suggest that a 15cm thickness would be enough to remove, with the possibility of using filtering rates considered elevated by slow filtering treatment standards (9 m3.m-2.d-1). Therefore, it concludes that the filter medium constituted exclusively of 25-cm-thick non-woven synthetic fabric has the potential to substitute sand in slow-filtering water treatment once it has obtained similar performance to the slow sand filter / Doutorado / Agua e Solo / Doutora em Engenharia Agrícola

The purpose of a geotextile separator beneath a granular base, or subbase in a flexible pavement system is to prevent the road aggregate and the underlying subgrade from intermixing. It has been hypothesized that in the absence of a geotextile, intermixing between base course aggregate and soft subgrade occurs. Nine heavily instrumented flexible pavement test sections were built in Bedford County Virginia to investigate the benefits of geosynthetic stabilization in flexible pavements. Three groups of different base course thicknesses (100, 150 and 200mm) test sections were constructed with either geotextile or geogrid stabilization or no stabilization. Woven geotextile was used in sections 2, 5 and 8. Geogrids were used in sections 3, 6 and 9, and sections 1, 4 and 7 were controls. Six Falling weight deflectometer (FWD) tests were performed on all the nine sections over 30 months. The nine sections were subjected to at least 5 load drops with wide loading range each time. The measured deflections were analyzed using the MODULUS back-calculation program to determine layer moduli. The measured deflections were used together with elastic, viscoelastic and the MODULUS program to determine the extent of intermixing at base-subgrade interface. The study concluded that a transition layer would develop when a separator is absent, especially in the weak sections (designed to fail in three years). Other measurements such as in-situ stresses, rut depth, and subsurface profiling (using ground penetrating radar) support the conclusion of the development of a transition layer. / Master of Science

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Innovative and versatile coastal protection structures made of Geotextile Sand Containers (GSCs) are increasingly being incorporated into coastal management solutions because of their cost effective and environmentally friendly characteristics. This is as opposed to conventional ‘hard’ coastal protection solutions that utilise rocks and or concrete units to protect the coastline. With GSC structures being a relatively new coastal protection solution, few design and construction guidelines are available. Research into the behaviour of GSC structures under wave attack is on-going with particular emphasis on the hydraulic processes that affect GSC structures and cause them to fail. The use of GSC revetments as coastal protection solutions has become more popular in South Africa during recent times, particularly along the coastline of KwaZulu-Natal. However, the chosen design of these GSC revetments falls outside the range of applicability of the available design charts and stability equations. Therefore the hydraulic stability of these structures is largely unknown. The primary objective of this study is to investigate the effect of structure slopes and packing arrangements on the hydraulic stability of GSC revetments. The application of available design charts and stability equations was also evaluated. Two-dimensional physical modelling was undertaken and a total of 12 GSC revetment permutations were tested during the physical modelling test series. The results of the physical modelling showed that the structure slope had the most significant effect on the hydraulic stability. Steeper structure slopes were more hydraulically stable than gentler structure slopes. The packing arrangements of the GSCs had less of an effect on the hydraulic stability of the GSC revetments. Single layer GSC armour revetments matched or out-performed the equivalent double layer GSC revetments; while GSC revetments with GSCs orientated with the long axis perpendicular to the wave attack performed marginally better than the equivalent GSC revetments with GSCs orientated with the long axis parallel to the wave attack. The available design charts and stability equations were assessed against the results of the physical modelling and showed varying degrees of correlation. The stability equation proposed by Recio (2007) proved to be particularly accurate. / AFRIKAANSE OPSOMMING: Innoverende en veelsydige kusbeskermingstrukture wat van geotekstielsandhouers (GSH’s) gemaak is, word al hoe meer by kusbestuursoplossings ingesluit weens die kostedoeltreffendheid en omgewingsvriendelike aard daarvan. Dít is in teenstelling met konvensionele ‘harde’ kusbeskermingsoplossings, wat van rotse en/of betoneenhede gebruik maak om die kuslyn te beskerm. Aangesien GSH-strukture ’n betreklik nuwe kusbeskermingsoplossing is, is weinig ontwerp- en konstruksieriglyne beskikbaar. Navorsing oor die werkverrigting van GSH-strukture onder golfaanslag duur voort, met bepaalde klem op die hidrouliese prosesse wat GSH-strukture beïnvloed en die werking daarvan benadeel. Die gebruik van GSH-bedekte hellings as kusbeskermingsoplossings het in die laaste tyd al hoe gewilder geword in Suid-Afrika, veral langs die kus van KwaZulu-Natal. Tog val die gekose ontwerp van hierdie GSH-bedekte hellings buite die toepaslikheidsbestek van die beskikbare ontwerpriglyne en stabiliteitsvergelykings. Die hidrouliese stabiliteit van hierdie strukture is dus grotendeels onbekend. Die hoofoogmerk van hierdie studie was om ondersoek in te stel na die effek van struktuurhellings en pakformasies op die hidrouliese stabiliteit van GSH-bedekte hellings. Die toepaslikheid van beskikbare ontwerpriglyne en stabiliteitsvergelykings is ook geëvalueer. Tweedimensionele fisiese modellering is onderneem en altesaam 12 GSH-bedekte hellings is gedurende die fisiese-modelleringstoetsreeks getoets. Die resultate van die fisiese modellering toon dat die struktuurhelling die beduidendste effek op hidrouliese stabiliteit het. Steiler struktuurhellings was hidroulies meer stabiel as platter hellings. Die pakformasies van die GSH’s blyk ’n kleiner effek op die hidrouliese stabiliteit van die GSH-bedekte hellings te hê. GSH-bedekte hellings wat met ’n enkele laag GSH’s versterk is, het ewe goed of beter presteer as die keermure met ’n dubbele laag GSH’s, terwyl GSH-bedekte hellings met die lang-as van die GSH’s loodreg op die rigting van die golfaanslag effens beter presteer het as dié met die lang-as parallel met die golfaanslag. Die beskikbare ontwerpriglyne en stabiliteitsvergelykings is geëvalueer aan die hand van die resultate van die fisiese modellering, en het ’n wisselende mate van korrelasie getoon. Veral die stabiliteitsvergelyking van Recio (2007) blyk besonder akkuraat te wees.

Apesar das vantagens relacionadas ao uso de estruturas de contenção em solo reforçado, a maioria das obras em nosso país ainda é executada por soluções convencionais. A ausência de um conhecimento mais profundo sobre o real comportamento das estruturas em solo reforçado, principalmente em termos de deslocamentos, certamente impede uma utilização mais intensa desse tipo de obra no Brasil. Com isso, para contribuir para um melhor entendimento do desempenho de estruturas em solo reforçado, foram construídos oito protótipos de estrutura de contenção em solo reforçado com geotêxtil, com 4,0 m de altura cada. Todas as estruturas foram instrumentadas, principalmente visando os deslocamentos, para avaliar o comportamento de campo. Adicionalmente, foi realizada a análise, em longo prazo, de um talude íngreme com 15,3 m de altura, construído no estado americano de Idaho, em que foram realizadas leituras até cinco anos após o fim da construção. Esse trabalho apresenta os resultados de cada protótipo construído, juntamente com os resultados do talude íngreme em Idaho, tanto em curto, quanto em longo prazo. As análises desenvolvidas compreendem, além da avaliação dos resultados individuais de cada estrutura, uma análise paramétrica entre todos os protótipos, investigando entre outros fatores, o tipo de solo, tipo de geossintético e geometria interna das estruturas. Além disso, foi realizada uma abordagem especial sobre a análise em longo prazo do protótipo 7. Dentre as conclusões mais importantes obtidas nesta pesquisa, podem-se citar as grandes deformações de fluência registradas no protótipo 7, a tendência de formação de uma superfície potencial de ruptura linear para os protótipos construídos com solo granular e de espiral logarítmica para os protótipos construídos com solos coesivos, a importância da coesão no bom comportamento das estruturas e a redução das movimentações verticais das estruturas com o acréscimo do teor de areia na granulometria do solo / Despite the important advantages associated with the use of geotextiles as reinforcement, most retaining walls in Brazil still use more conventional. The lack of field monitoring data regarding the internal and face displacements of these structures has certainly prevented broader use of this reinforced soil technology. This study addresses several aspects related to the behavior of geotextile-reinforced soil structures, such as the deformability of reinforcement materials under the confinement of soil, and quantification of the actual failure mechanisms. To achieve these goals, eight 4.0 m high geotextile-reinforced soil retaining wall prototypes were built and instrumented in order to quantify their behavior under ambient atmospheric conditions. Granular and poorly draining backfills were used in this study. Innovative construction methods and instrumentation were developed specifically for this research program. A significant laboratory testing program was conducted to quantify the stress-strain properties of the soils and geosynthetics involved in the construction of the walls. As a reference, the behaviors of these prototype structures were compared with that of a long term analysis of a steep slope in Idaho, USA. This wall is 15.3 m high, with displacement measurements carried out until five years after the end of the construction. A parametric analysis was conducted for the prototypes, in order to investigate the effects of soil type, reinforcement type and internal geometry of the structures. Among the most important conclusions obtained in this research, it is the large creep strains observed in prototype 7, the tendency of a linear potential slip surface observed for the walls constructed with granular backfills, and a log spiral slip surface for the prototypes constructed with cohesive backfills, the importance of the apparent cohesion in the behavior of the structures, and the reduction of the vertical movements of the structures with the increase of the amount of sand in the grain size distribution of the soil

O método de desaguamento por leitos de drenagem foi desenvolvido por Cordeiro a partir do ano de 1993 (CORDEIRO, 2001) para o desaguamento de lodos de Estações de Tratamento de Água. A sua aplicação para lodos de lagoas de estabilização de esgotos foi feita por Fontana et al. (2007). Este trabalho teve por objetivo avaliar a utilização de leitos de drenagem no desaguamento de lodos produzidos em reatores UASB. Para tanto foram realizados ensaios em laboratório, utilizando testes do tempo de drenagem, para avaliar a influência de diferentes doses e tipos de polímeros no desaguamento do lodo. Alguns geotêxteis foram utilizados como meio filtrante nos funis de Buchner e também avaliados pelo teste do tempo de drenagem. Após escolhidas a manta e o polímero que apresentaram os melhores resultados em laboratório, foram desenvolvidos ensaios em escala piloto, com a utilização de três unidades cobertas de leitos de drenagem, cada um com dimensões de 1,58 m x 1,09 m por 0,5 m de altura. Para a avaliação do efeito das diferentes doses de polímero em escala piloto, foram utilizadas doses de polímero de 0 a 8 g/kg de sólidos totais (peso seco) e mantida a taxa de aplicação de sólidos em 15 kgST/m².ciclo (a concentração de sólidos no lodo foi de aproximadamente 27 g/L). Os resultados indicaram que com doses de polímero =2 g/kgST (peso seco) obtinha-se teor de sólidos no lodo de cerca de 13% após 1 dia e 20% após 10 a 15 dias. Para se atingir teor de sólidos de 25 a 30% o período de secagem necessário foi de cerca de 30 dias. Embora que mesmo sem a aplicação de polímeros o comportamento do lodo fosse semelhante ao de lodos condicionados com polímero, em relação à evolução do teor de sólidos em função dos períodos de secagem, observou-se certa dificuldade na remoção do lodo desaguado e principalmente na limpeza das mantas geotêxteis. Para avaliar diferentes taxas de aplicação superficial de sólidos, foram ensaiadas taxas entre 9 e 22 kgST/m².ciclo. A evolução do teor de sólidos, ao longo do período de secagem dos 3 ensaios realizados, indicou que taxas mais altas de aplicação de sólidos não diminuem as velocidades de secagem, sugerindo que, inclusive, taxas mais altas poderiam ser ensaiadas. / The method of dewatering sludge through Drainage Beds was originally developed in 1993 by Cordeiro (CORDEIRO, 2001) with sludge from Water Treatment Plants. Fontana et al. (2007) used sludge from wastewater stabilization ponds with positive results. The purpose of this research is the evaluation of the drainage bed method to dewater sludge from UASB reactors. Several laboratory trials were performed, measuring drainage times to assess the influence of different polymer types and doses on sludge dewatering. Few geotextiles were used as filter on the drainage time test to evaluate their performance. Once the polymer and the geotextile that best performed in the laboratory were chosen, several pilot experiments were performed with the use of three covered units of drainage beds, each measuring 1.58m x 1.09m (width) x 0.5m (height). For the evaluation of different polymer conditioning doses on a pilot scale, doses from 0 to 8 g/kg of total solids (dry weight) were used and the applied rate of solids kept at 15 kgTS/m².cycle (the concentration of solids in the sludge was of approximately 27 g/L). Results indicated that with the use of polymer doses =2 g/kgTS (dry weight), approximately 13% of total solids in the sludge was observed after one day, which increased to approximately 20% after 15 days. To reach 25% to 30% of total solids in the sludge, the drying time required was circa 30 days. Even without the application of polymers, the behavior of sludge in terms of total solids during the drying period was similar to the sludge conditioned with polymers. Although, with the unconditioned sludge, some difficulty to remove the dewatered sludge cake was observed, mainly in cleaning of the geotextile sleeves. In order to evaluate different application rates of solids, the pilot experiments included rates between 9 and 22 kgTS/m².cycle. The behavior of the total solids in the cake during the drying period of the three experiments suggested that the higher rates of application of solids does not reduce the drying speed, indicating that higher rates can be targeted in future research projects.

O presente trabalho investiga o desempenho de geotêxteis e de solos como elementos de proteção para geomembranas de polivinil clorado (PVC) e de polietileno de alta densidade (PEAD). Foram utilizadas geomembranas de PVC com espessuras de 1,0 e 2,0 mm e de PEAD com espessuras de 1,5 e 2,0 mm. Como camadas de proteção utilizaram-se geotêxteis não tecidos de poliéster (PET), com gramaturas de 130, 300, 400 e 600 g/\'M POT.2\', e de polipropileno (PP), com gramatura de 400 e 600 g/\'M POT.2\', além de uma areia de granulometria fina a média e uma areia argilosa típica da região Centro-Oeste do Estado de São Paulo. O estudo foi conduzido através da construção de um aterro experimental para simulação dos danos de instalação em campo e da realização de ensaios índice e de desempenho em laboratório. A eficiência dos materiais de proteção foi avaliada através da análise qualitativa e quantitativa das amostras de geomembranas danificadas. Os resultados dos ensaios de laboratório índice mostraram que a introdução do geotêxtil aumenta a resistência à punção da geomembrana, e que o acréscimo de resistência é função das características de resistência à tração do geotêxtil e da geomembrana. O maior incremento de resistência à punção foi observado na geomembrana com menor resistência à tração. Os resultados dos ensaios de campo mostraram que a introdução do elemento de proteção reduz os danos mecânicos apesar da alteração de algumas das propriedades físicas e de desempenho nas geomembranas. Da análise dos resultados, verificou-se que a eficiência dos geotêxteis no campo não é função de suas características de tração, conforme constatado nos ensaios índices. A análise também sugere que os danos mecânicos no campo foram mais intensos do que nos ensaios de desempenho em laboratório. / The performance of non-woven geotextiles and soils as protection elements of polyvinyl chloride (PVC) and high density polyethylene (HDPE) geomembranes is studied. The materials used comprised PVC geomembranes of 1,0 and 2,0 mm thickness and HDPE geomembranes of 1,5 and 2,0 mm thickness while the protective layers were of non-woven polyester (PET) geotextiles with mass per unit area of 130, 300, 400 e 600 g/\'M POT.2\' and polypropylene (PP) with mass per unit area of 400 e 600 g/\'M POT.2\'. It was also used protective layers made of a fine to medium sand and a typical clayey sand of central area of the State of São Paulo. The study was based on an experimental landfill built to simulate the damage associated to construction procedures and on index and performance laboratory tests. Through qualitative and quantitative analysis of damaged geomembranes, the behavior of each protective element was evaluated. Index laboratory test results have shown that the geotextile is able to increase the geomembrane puncture strength and that the strength increase is related to the tensile strength of geotextile and geomembrane. For similar geotextiles, the larger increase in puncture strength was observed for the geomembrane that presented the lower tensile strength. Visual observation of field tests has shown that the introduction of protective layers reduces the mechanical damage; however some physical and performance properties of geomembrane have changed. It was also observed that the performance of geotextiles in the experimental landfill does not depend on the tensile strength, as observed in laboratory index tests. Test results also suggest that field damage associated to the landfill construction are more intense than that observed in laboratory tests such as the dynamic puncture test.