Esta dissertação apresenta os resultados e análises do monitoramento de um recapeamento asfáltico executado com camada intermediária de geotêxtil. A pista experimental vem sendo solicitada desde 1999, em uma pesquisa que se encontra na sua terceira fase, atingindo 1.103.885 ciclos de carga de 100 kN aplicados. Nessa última fase de estudo o tráfego foi aplicado entre Setembro de 2008 e Fevereiro de 2009, totalizando 121.685 ciclos de carga de eixo de 100 kN. A pista foi dividida em três regiões, sendo empregado em duas delas geotêxteis impregnados com asfalto. Durante o período de estudo foram monitorados parâmetros de resposta estrutural, através de medidas de deflexões e bacias defletométricas, parâmetros de comportamento, através de medidas de deformações permanentes e mapeamento de trincas, e por fim parâmetros ambientais, através das medidas de temperatura do ar e precipitações. Foram também aplicados modelos de previsão de desempenho para o caso de reflexões de trincas. O monitoramento do trincamento na pista mostrou que as regiões com geotêxtil tiveram melhor desempenho quando comparadas à região sem camada intermediária. O comprimento de trincas no final do estudo foi de 764 cm na região sem camada intermediária, 328 cm na região com geotêxtil G150 e 554 cm na região com geotêxtil G150 TF. Foram extraídos corpos de prova da pista, sobre algumas trincas, de modo a se visualizar o modo de desenvolvimento do trincamento, e também para buscar se identificar onde ocorreu trincamento por reflexão. Não foi possível extrair CPs de todas as trincas face a proximidade das mesmas e das dimensões da sonda rotativa, porém do material retirado observou-se ocorrência de trincamento por reflexão, trincamento por fadiga e também trincamento conhecido como top-down cracking (TDC). Os resultados evidenciam que a inclusão de geotêxteis como camada de absorção de tensões aumenta significativamente a vida de recapeamentos asfálticos executados sobre pavimentos trincados. / This dissertation presents the results of the monitoring and analysis of an overlay executed with intermediate geotextile layer. The experimental track has been requested since 1999, in a research that is in its third phase, reaching 1.103.885 cycles of 100 kN axle load applied. In this last phase of the study, the traffic was applied between September 2008 and February 2009, totaling 121.685 cycles of 100 kN axle load. The track is divided into three regions, two of them uses geotextiles impregnated with asphalt. During the study period were monitored parameters of structural response, by means of deflections and basins, parameters of behavior, by means of permanent deformation and mapping of cracks, and finally environmental parameters, through the measures of air temperature and rainfall. Models were also applied to predict the performance of the overlay. The monitoring of cracking showed that regions with geotextile had improved performance when compared to the region without intermediate layer. The length of cracks at the end of the study was 764 cm in the region without intermediate layer, 328 cm in the region with geotextile G150 and 554 cm in the region with geotextile G150 TF. Samples were extracted from the track to see how the cracking was developed and also to identify where there was reflective cracking. On the material removed was observed occurrence of reflective cracking, fatigue cracking and also top-down cracking (TDC). The results show that geotextiles increases the life of concrete asphaltic overlays.

A eficiência das geomembranas como barreiras para controle e desvio de fluxo está diretamente relacionada com a integridade de sua superfície. Nos sistemas de impermeabilização basal, como utilizados em aterros sanitários, as geomembranas podem entrar em contato com materiais perfurantes e cortantes, como a brita do sistema de drenagem. Para prevenir perfurações e outros danos em geomembranas, são empregadas camadas de proteção, como geotêxteis não-tecidos e areia. Este estudo avalia o desempenho de geotêxteis não-tecidos de fibras curtas de poliéster (PET) e de polipropileno (PP), além de uma configuração com areia, como camadas de proteção para geomembranas de policloreto de vinila (PVC) e de polietileno de alta densidade (PEAD). Foram realizados ensaios índices, ensaios de puncionamento hidrostático e ensaios de carregamento estático em grande escala, para verificar os mecanismos de ruptura das geomembranas e o comportamento da resistência ao puncionamento com a adoção de camadas de proteção. Os resultados demonstraram desempenho superior, como elemento de proteção, dos geotêxteis de maior resistência mecânica e mecanismos de rupturas diferenciados entre geomembranas de PEAD e de PVC. / The efficiency of geomembranes as barriers for flow diversion is directly related to its integrity. In basal lining systems, such as those used in landfills and waste disposal lagoon, geomembranes can get into contact with sharp materials, such as gravel from the drainage system, which can induce excessive deformation and holes. To prevent geomembrane damage, nonwoven geotextiles and sand are usually employed as protective layers. This paper deals with the performance of polyester (PET) and polypropylene (PP) nonwoven geotextiles and a sand layer, as protective layers for polyvinyl chloride (PVC) and high density polyethylene (HDPE) geomembranes. Index, hydrostatic puncture and large-scale uniaxial compression tests were performed and have allowed understanding the geomembrane damage mechanism and the influence of protective layers properties in increasing the geomembrane performance against puncture. The test results have shown that the behavior in puncture protection is related to the mechanical resistance of geotextile and that the rupture mechanism is different for the different types of geomembrane used in the study.

Este trabalho apresenta um estudo sobre deformações de geotêxteis ao longo do tempo, considerando interações entre reforço e solo confinante em muros de solo reforçado. O programa experimental desenvolvido para esse fim envolveu duas etapas básicas. Na primeira etapa, um novo equipamento foi desenvolvido na Escola de Engenharia de São Carlos/USP, para a realização de ensaios de fluência com um elemento de solo reforçado. O equipamento desenvolvido permite simular o mecanismo típico de transferência de carga em estruturas de solo reforçado, isto é, o solo solicita o geotêxtil. Esse equipamento também possibilita que solo e geotêxtil apresentem deformações ao longo do tempo de forma interativa. Nessa etapa, o programa de ensaios foi conduzido utilizando-se uma areia pura e um geotêxtil de polipropileno. Na segunda etapa deste trabalho, modelos de muros de solo reforçado foram ensaiados em centrífuga na Universidade do Colorado em Boulder, EUA. Os referidos modelos foram construídos utilizando-se uma areia e mantas de poliéster e de polipropileno. Alguns modelos foram carregados até a ruptura com acréscimo de aceleração, enquanto outros foram observados, no decorrer do tempo, sob aceleração constante. Nos ensaios para investigação de fluência, deformações significativas foram observadas, ocorrendo, inclusive, a manifestação de ruptura em determinados modelos, após algumas horas de ensaio. Os ensaios realizados nas duas etapas do trabalho revelaram aspectos importantes relativos à interação solo-reforço. Com base na interpretação dos resultados experimentais, apresenta-se uma discussão sobre mecanismos de deformação, em função do tempo, em muros de solo reforçado. / This thesis presents a study on the time- ependent deformations of geotextiles in reinforced soil walls considering the long-term interactive behavior between the reinforcement and the confining soil. The experimental program comprised two distinct phases. In the first phase, a new equipment was designed and constructed at the School of Engineering at Sao Carlos/USP, Brazil, in an attempt to perform creep tests with an element of reinforced soil. This equipment simulates the typical load transfer mechanism in reinforced soil structures, that is, the load is transferred from the soil to the reinforcement. This equipment also allows long-term interactive deformations between the soil and the geotextile. The testing program of this phase was conducted using a pure dry sand and a polypropylene geotextile. In the second phase of this research, models of reinforced soil walls were tested in a centrifuge facility at the University of Colorado at Boulder, USA. The models were built using a pure dry sand and a polyester or polypropylene geotextile. The models were either loaded until failure increasing the centrifugal acceleration or tested under constant acceleration. Considerable strains were observed in the creep tests, and some of the models failed after a few hours. The testing programs carried out in this study revealed important aspects of the soil-reinforcement interaction. Based on the analyses of the experimental results a broad discussion on long-term deformation mechanisms in reinforced soil walls is made herein.

Orientador: José Euclides Stipp Paterniani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-23T10:41:16Z (GMT). No. of bitstreams: 1 Cavalhieri_CaioPompeu_M.pdf: 3818458 bytes, checksum: 75bf1f2391a40c8e0f8f527257f97c8a (MD5) Previous issue date: 2013 / Resumo: Idealizadas para prevenir e controlar problemas associados à intensificação de processos erosivos, cercas-silte ou silt-fences são cada vez mais comuns em canteiros de obra. Feitas com mantas de geotêxtil estruturadas sob a forma de barreiras verticais, essas cercas promovem a detenção das águas pluviais que escoam sobre a superfície do terreno e, dessa maneira, favorecem a remoção de sedimentos em suspensão no runoff por meio da combinação dos efeitos de sedimentação e filtração. Assim, considerando-se a relevância que as mantas de geotêxtil têm sobre a qualidade de todo o processo, este estudo avaliou o desempenho de geotêxteis não-tecidos em relação à remoção de sólidos suspensos. Para tanto, experimentos foram realizados em laboratório e, com o intuito de aproximar os ensaios ainda mais da realidade, os experimentos foram feitos com: (a) mantas em duas situações distintas (sem nenhum tipo de uso e retirada de um canteiro de obra após dois anos de uso contínuo como cerca-silte); (b) solo coletado no mesmo canteiro de onde veio o geotêxtil usado (para compor o runoff dos ensaios em média com 800 UNT); (c) escoamento do runoff na direção horizontal; e, por fim, (d) parâmetros de ensaio baseados em critérios de projeto e também na equação de chuva da área mais próxima da obra de onde vieram as amostras de solo e geotêxtil usado. De maneira geral, os dois tipos de geotêxtil (novo e usado) favoreceram a redução de sólidos em suspensão durante os ensaios, embora esse efeito tenha sido estatisticamente mais significativo na manta retirada da obra. Além disso, valores de turbidez menores do que 40 UNT (parte inferior aos 5,0 UNT preconizados para consumo humano) estiveram associados a taxas de escoamento relativamente baixas (menores do que 20 mm/min). Entretanto, há que se considerar que, em determinados contextos, baixas taxas de escoamento também têm potencial para gerar repercussões indesejáveis. Daí a importância de se contar com a boa fundamentação de projetos, atividades de instalação e serviços de manutenção, de maneira que os resultados esperados sejam compatíveis com os obtidos em situações reais / Abstract: Developed to prevent and control problems associated with the intensification of erosion, silt or silt-fences-fences are increasingly common in construction sites. Made with geotextiles structured in the form of vertical barriers, these fences detain rainwater runoff and, thus, promote the removal of suspended sediments through sedimentation and filtered. Considering the relevance geotextiles have on the quality of the entire process, this study evaluated the performance of non-woven geotextiles regarding the removal of suspended solids. Therefore, experiments were performed in the laboratory and were made with: (a) blankets in two distinct situations (without any use and removed from a construction site after two years of continuous use as fence-silt); (b) soil collected in the same plot where the geotextile was used as silt-fence (to compose the runoff tests averaged 800 UNT); (c) runoff flow in the horizontal direction; and finally, (d) test parameters based on design criteria and also the rain equation of the closest area to the work from which the samples of soil and geotextile came from. In general, the two types of geotextile (used and new) promoted reduction of suspended solids during the tests, although this effect was statistically significant over the blanket removal of the work. Furthermore, turbidity values lower than 40 NTU (5.0 NTU at the bottom recommended for human consumption) were associated with relatively low flow rates (less than 20 mm / min). However, it is necessary to consider that, in certain contexts, low flow rates also have the potential to generate undesirable impacts. Hence the importance of relying on consistent projects, activities of installation and maintenance services, so that the expected results can be consistent with those obtained in real situations / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Orientador: Pérsio Leister de Almeida Barros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-22T04:55:08Z (GMT). No. of bitstreams: 1 Linhares_RaquelMariano_M.pdf: 5654140 bytes, checksum: 3419102ebbcf423e217e71ff2b761f76 (MD5) Previous issue date: 2013 / Resumo: No presente trabalho foram realizados ensaios em modelos físicos em escala reduzida de fundação rasa sobre solo arenoso fofo reforçado com geotêxtil tecido, visando avaliar o seu comportamento sob carregamento estático vertical. Propõe-se empregar o reforço numa posição inicial não-planar, semelhante àquela adquirida após deslocamentos de 30% da largura da base da sapata (B). Os efeitos da compactação das camadas superiores ao reforço e a variação de seu comprimento também são investigados. Os ensaios foram divididos em 3 grupos: ensaios sobre areia fofa com compacidade homogênea, ensaios de recarregamento e ensaios sobre areia fofa com camadas superiores compactadas. Os resultados indicam que um aumento do comprimento do reforço planar de 3B para 5B não é justificado do ponto de vista do aumento da capacidade de carga ou da atenuação de deslocamentos, em nenhum dos casos. A pequenos deslocamentos, a modificação do posicionamento inicial do reforço de horizontal para não-planar não se justifica, porém, em maiores deslocamentos há um ganho não desprezível na capacidade de carga. Os ensaios de recarregamento mostraram que a protensão do reforço resultante da compactação do solo melhora a capacidade de carga em 2 vezes e atenua em até 75% os deslocamentos. O posicionamento inicial referente a um deslocamento de 30% de B mostrou-se satisfatório; deslocamentos excedentes não trazem maior eficiência ao conjunto. O esforço de compactação gera ganhos similares na capacidade de carga independente do posicionamento inicial do reforço. A atenuação de deslocamentos pode chegar até a 2,6 vezes se comparada ao mesmo caso reforçado com areia homogênea / Abstract: In the present study, some small-scale model tests of a strip footing foundation on loose sand reinforced with woven geotextile were conducted. The main objective was to investigate the effect of the initial placement geometry of the reinforcement on the foundation response to static vertical loads. A non planar placement geometry similar to the one which results from a vertical displacement of about 30% of the foundation width was adopted. The effects of the top layers compaction and the variation of reinforcement length and initial placement were evaluated. The tests were separated in 3 groups: tests on loose sand with homogeneous compacity, reload tests and tests on loose sand with compacted top layers. Results show that an increase on reinforcement length from 3 to 5 times the footing width is not worth the increase in bearing capacity nor the attenuation of settlements, in none of the several cases studied. At little displacements, the modification of initial reinforcement placement, from horizontal to non-planar, seems not to be justified; although after some displacement there is a gain in the bearing capacity. The reload tests showed that the soil compaction creates a prestressing condition on the reinforcement, which improves the bearing capacity in about 2 times and attenuates the settlements up to 75%. The initial placement in about 30% of footing width displacement has proved to be satisfactory; greater displacements do not generate greater system efficiency. The compaction effort of the upper layers creates an improvement that doesn't depend on the reinforcement initial placement. The displacement attenuation can reach up to 2.6 times if compared with the same reinforced case in homogeneous sand ground / Mestrado / Geotecnia / Mestra em Engenharia Civil

No description available.

Recycled concrete aggregate (RCA) is often used as a replacement of virgin aggregate in road foundations (base course), embankments, hot-mix asphalt, and Portland cement concrete. However, the use of RCA in exfiltration drainage systems, such as French drains, is currently prohibited in many states of the U.S. The French drain system collects water runoff from the road pavement and transfers to slotted pipes underground and then filters through coarse aggregate and geotextile. The primary concerns with using RCA as a drainage media are the fines content and the precipitation of calcium carbonate to cause a reducing in filter fabric permittivity. Additional concerns include the potential for rehydration of RCA fines. The performance of RCA as drainage material has not been evaluated by many researchers and the limited information limits its use. A literature review has been conducted on the available information related to RCA as drainage material. A survey was issued to the Departments of Transportation across the nation in regards to using RCA particularly in French drains. Some state highway agencies have reported the use of RCA as base course; however, no state reports the use of RCA in exfiltration drainage systems. This thesis describes the investigations on the performance of RCA as backfill material in French drains. RCA was tested for its physical properties including, specific gravity, unit weight, percent voids, absorption, and abrasion resistance. RCA cleaning/washing methods were also applied to evaluate the fines removal processes. The potential for RCA rehydration was iv evaluated by means of heat of hydration, pH, compressive strength, and setting time. The permeability of RCA was tested using the No. 4 gradation. Long term permeability testing was conducted to evaluate the tendency for geotextile clogging from RCA fines. Calcium carbonate precipitation was also evaluated and a procedure to accelerate the precipitation process was developed. The results show that RCA has a high abrasion value, that is, it is very susceptible to break down from abrasion during aggregate handling such as transportation, stockpiling, or placing. The most effective cleaning method was found to be pressure washing with agitation. RCA has not demonstrated the tendency to rehydrate and harden when mixed with water. The permeability test results show that the No. 4 gradation does not restrict the flow of water; the flow rate is highly dependent on the hydraulic system itself, however excessive fines can cause large reductions in permeability over time. It has been determined that No. 4 gradation of RCA can provide a suitable drainage media providing the RCA is properly treated before its use.

A water-filled geomembrane tube is considered for the purpose of temporary flood protection. With proper design, this tube can be a cheap and efficient breakwater, temporary levee, or cofferdam. This thesis considers a single tube resting on clay and sand foundations. A finite difference program, FLAC, is used in the numerical analyses. The tube is assumed to be infinitely long, and it is modeled two-dimensionally. Beam elements are used to model the tube. The tube is inflated with water. The hydrostatic pressure in the tube is converted to point loads and applied at the beam nodes in the direction perpendicular to the chord connecting two adjacent nodes. Two of FLAC's built-in soil models are used: elastic and Mohr-Coulomb. The Mohr-Coulomb model is used in all the cases except the preliminary analyses, in which the elastic soil model is used. The Mohr-Coulomb soil model is able to model the soil's nonlinear stress-strain and path-dependent deformation behavior. A tube without external water is placed on clay with various shear strengths to study how the clay consistency affects the height and the stresses in the tube. A tube with external water on one side is placed on medium dense sand. A wooden block is placed on the side opposite the floodwater. Three types of block geometry and two sizes are studied. The floodwater level is increased until the system fails. Three failure modes, rolling, sliding, and piping, are studied. The effect of pore pressure on these failure modes is examined. The influence of a filter placed under part of the tube and block is also investigated. The tube's tensile forces, shear forces, moments, and settlements are included. Soil stresses and pore pressures at the soil-tube interfaces are computed. The cross-section of the tube at various external water levels, and the pore pressures in the soil, are calculated. These results are compared with experimental results that were obtained by graduate students in geotechnical engineering at Virginia Tech. / Master of Science

Using geotextiles in secondary roads to stabilize weak subgrades has been a well accepted practice over the past thirty years. However, from an economical point of view, a complete life cycle cost analysis (LCCA), which includes not only costs to agencies but also costs to users, is urgently needed to assess the benefits of using geotextile in secondary road flexible pavement. In this study, a comprehensive life cycle cost analysis framework was developed and used to quantify the initial and the future cost of 25 representative design alternatives. A 50 year analysis cycle was used to compute the cost-effectiveness ratio for the design methods. Four flexible pavement design features were selected to test the degree of influence of the frame's variables. The analysis evaluated these variables and examined their impact on the results. The study concludes that the cost effectiveness ratio from the two design methods shows that the lowest cost-effectiveness ratio using Al-Qadi's design method is 1.7 and the highest is 3.2. The average is 2.6. For Perkins' design method, the lowest value is 1.01 and the highest value is 5.7. The average is 2.1. The study also shows when user costs are considered, the greater TBR value may not result in the most effective life-cycle cost. Hence, for an optimum secondary road flexible pavement design with geotextile incorporated in the system, a life cycle cost analysis that includes user cost must be performed. / 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.