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Modelo geolocalizado para conservação de estradas não pavimentadas / Geolecated model for the conservation of unpaved roadsMoreira, Alisson Neves Harmyans 12 April 2018 (has links)
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Previous issue date: 2018-04-12 / Unpaved roads are important access routes to urban centers, serving to facilitate
the traffic of vehicles for socioeconomic purposes. In order to ensure the flow of goods
produced and the transport of people, it is necessary that this road network has adaptations
in order to prevent them from becoming channels and, consequently, erosion processes. In
this sense, it is necessary to elaborate planning practices for the conservation of these roads.
By means of field surveys and geomorphological databases, this study aimed to recommend
and quantify the drainage devices for the sub-basin of the Olaria stream with the aid of a
Geographic Information System (GIS), as well as to compare these with recommended
devices from the Estradas model. The drainage devices used in the study were energy drains
in the drainage channel and energy dissipaters in ditches. The recommendation of the
drainage devices through the GIS were from geomorphometric and soil matrix databases.
These data support the modeling, together with the geometric elements of the roads and the
physical-water data of the soils of the beds and adjacencies. It was used data of reliefs from
the image of the Topodata project, with accuracy and vertical precision of 5,529 m and 2,217
m, respectively. These results met the Class A Cartographic Accuracy Standard (PEC) for the
representation of altimetric data in the 1:50.000 scale. Regarding the morphometric data of
the segments, 90% of the slopes were compatible between the reference values of the GPS
Geodesic receiver and the tested values of Topodata, thus obtaining the same
recommendations for spines with water outlets. For the 50.1 km of unpaved roads in the subbasin
of the Olaria stream, the GIS showed that only 12.1% of the segments did not require
springs with water exits. It was recommended 953 water bars with outlets and 83 energy
dissipaters in ditches. It was noted that the incompatibilities in the recommendations are
related to the variables involved. Therefore, the geometric tracing and the excessive
recommendations of these drainage devices by the GIS show that criteria such as relief and
the soils were ignored in the implantation of the unpaved roads. / As estradas não pavimentadas são importantes vias de acessos aos centros
urbanos, servindo para facilitar o tráfego de veículos para fins socioeconômicos. Para
assegurar o fluxo de bens produzidos e o transporte de pessoas é necessário que essa rede
viária tenha adequações a fim de evitar que se transformem em canais e, consequentemente,
ocorram processos erosivos. Nesse sentido, é necessária a elaboração de práticas de
planejamento para a conservação dessas vias. Por meio de pesquisas de campo e bases de
dados geomorfológicas, este estudo teve como objetivo recomendar e a quantificar os
dispositivos de drenagem para a sub-bacia do córrego Olaria com o auxílio de um Sistema de
Informação Geográfica (SIG), bem como comparar estes dados com os dispositivos
recomendados a partir do modelo Estradas. Os dispositivos de drenagem utilizados no estudo
foram os dissipadores de energia em canal de drenagem e as lombadas com saídas d’água. A
recomendação dos dispositivos de drenagem por meio do SIG foram a partir de bases de
dados matriciais geomorfométricas e de solos. Estes dados subsidiaram a modelagem,
juntamente com os elementos geométricos das estradas e os dados físico-hídricos dos solos
dos leitos e adjacências. Utilizou-se dados de relevos a partir da imagem do projeto Topodata,
com acurácia e precisão vertical de 5,529 m e 2,217m, respectivamente. Esses resultados
atenderam a classe A do Padrão de Exatidão Cartográfica (PEC) para a representação de
dados altimétricos na escala de 1:50.000. No que tange aos dados morfométricos dos
segmentos, 90% das declividades foram compatíveis entre os valores de referência do
receptor GPS Geodésico e os valores testados do Topodata, obtendo assim, as mesmas
recomendações para as lombadas com saídas d’água. Para os 50,1 km de estradas não
pavimentadas na sub-bacia do córrego Olaria, o SIG evidenciou que apenas 12,1% dos
segmentos não necessitaram de lombadas com saídas d’água. Foram recomendadas 953
lombadas com saídas d’água e 83 dissipadores de energia em sarjetas. Notou-se que as
incompatibilidades nas recomendações estão relacionadas as variáveis envolvidas. Por
conseguinte, o traçado geométrico e o excesso de recomendações desses dispositivos de
drenagem pelo SIG evidenciam que critérios como o relevo e os solos foram ignorados na
implantação das estradas não pavimentadas.
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Optimalizace zavěšení závodního vozidla / Optimisation of Race Car SuspensionGašpar, Dominik January 2018 (has links)
The thesis deals with the kinematic characteristics of vehicle suspension and its essential parameters, analysis and optimization for use on ride on unpaved surface. Subsequent analysis of change of kinematics on driving simulations shall verify the modifications made in terms of driving characteristics of the race car
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Aggregate characteristics for unpaved highway shouldersLewis, Jessica V 12 May 2023 (has links) (PDF)
This thesis studied unpaved highway shoulders, and in particular shoulders of lower volume asphalt pavements being overlaid. The primary objective was to better understand how different shoulder aggregates perform on lower volume routes with asphalt surfaces and relatively narrow shoulders. A literature review and an evaluation of a full-scale test section containing five aggregate categories in nine test sections over a thirty-four-month period were the primary efforts performed to evaluate unpaved highway shoulders. The study concluded shoulder width measurements were not especially informative, and that California Bearing Ratio measurements were only modestly informative. Crushed concrete outperformed all other aggregates, though the remaining aggregate categories (gravel, limestone, steel slag, and reclaimed asphalt pavement) also had a reasonable case for being moved forward toward possible specification updates. The primary recommendation of this thesis is to use the data contained herein to further shoulder aggregate specifications for the Mississippi Department of Transportation.
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Evaluation of Novel Construction Technologies and Materials for Roadway Unpaved ShouldersAl khasawneh, Mohammad 22 October 2020 (has links)
No description available.
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Cattle feedlot dust – laser diffraction analysis of size distribution and estimation of emissions from unpaved roads and wind erosionGonzales, Howell B. January 1900 (has links)
Master of Science / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Large cattle feedlots emit considerable amounts of particulate matter (PM), including
TSP (total suspended particulates), PM[subscript]10 (PM with equivalent aerodynamic diameter of 10 μm or
less), and PM[subscript]2.5 (PM with equivalent aerodynamic diameter of 2.5 μm or less). Particulate
emissions result from pen surface disturbance by cattle hoof action, vehicle traffic on unpaved
roads and alleyways, and wind erosion. Research is needed to determine concentrations of
various size fractions, size distribution, and emission rates from various sources in feedlots. This
research was conducted to measure particle size distribution using laser diffraction method and
estimate emissions from unpaved roads and wind erosion.
Particle size distribution and concentrations of PM[subscript]10 and PM[subscript]2.5 at a commercial cattle
feedlot in Kansas (Feedlot 1) were measured over a 2-yr period. The feedlot had a capacity of
30,000 head and total pen area of 50 ha and was equipped with a sprinkler system for dust
control. Collocated low-volume samplers for TSP, PM[subscript]10, and PM[subscript]2.5 were used to measure
concentrations of TSP, PM[subscript]10, and PM[subscript]2.5 at the upwind and downwind edges of the feedlot. Dust
samples that were collected by TSP samplers were analyzed with a laser diffraction analyzer to
determine particle size distribution. Particle size distribution at the downwind edge of the
feedlot was also measured with micro-orifice uniform deposit impactor (MOUDI). The laser
diffraction method and MOUDI did not differ significantly in mean geometric mean diameter
(13.7 vs. 13.0 μm) but differed in mean geometric standard deviation (2.9 vs. 2.3). From laser
diffraction and TSP data, PM[subscript]10 and PM[subscript]2.5 concentrations were also calculated and were not
significantly different from those measured by low-volume PM[subscript]10 and PM[subscript]2.5 samplers (122 vs.
131 μg/m[superscript]3 for PM[subscript]10; 26 vs. 35 μg/m[superscript]3 for PM[subscript]2.5). Both PM[subscript]10 and PM[subscript]2.5 fractions decreased as
pen surface moisture contents increased, while the PM[subscript]2.5/PM[subscript]10 ratio did not change much with
pen surface moisture content.
Published emission models were used to estimate PM[subscript]10 emissions from unpaved roads
and wind erosion at Feedlot 1 and another nearby feedlot (Feedlot 2). Feedlot 2 had a capacity
of 30,000 head, total pen surface area of 59 ha, and used water trucks for dust control. Estimated
PM[subscript]10 emissions from unpaved roads and wind erosion were less than 20% of total PM[subscript]10
emissions obtained from inverse dispersion modeling. Further research is needed to establish the
applicability of published emission estimation models for cattle feedlots.
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Analýza vyprojektovaných společných zařízení v pozemkových úpravách ve vybraných k. ú. okresu Tábor / Analysis of projected common facilities in land adjustment in selected cadastral areas of the district TáborDUŠKOVÁ, Aneta January 2015 (has links)
This thesis focuses on the analysis of projected common facilities in land adjustment in selected cadastral areas of the district Tabor. For this purpose has been selected three cadastral - Doubí nad Lužnicí, and Božejovice Stoklasná Lhota. In the application part in these territories assessed the status of common facilities (measures to access land, measures for protection of agricultural land, water management measures and measures to protect and improve the environment), both in projection and the actual situation. The results obtained are compared with each other. On the obtained knowledge and information for each land adjustments are recommended proposals for measures of common facilities.
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Contribuição à modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas em empreendimentos de exploração florestal / Contribution for modeling an unpaved roads maintenance management system within an entrepreneurship of forestry explorationPinto, Paulo Ricardo Rodrigues January 2009 (has links)
Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.
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Contribuição à modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas em empreendimentos de exploração florestal / Contribution for modeling an unpaved roads maintenance management system within an entrepreneurship of forestry explorationPinto, Paulo Ricardo Rodrigues January 2009 (has links)
Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.
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Contribuição à modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas em empreendimentos de exploração florestal / Contribution for modeling an unpaved roads maintenance management system within an entrepreneurship of forestry explorationPinto, Paulo Ricardo Rodrigues January 2009 (has links)
Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.
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Behaviour Of Geosynthetic Reinforced Soil–Aggregate Systems Under Static, Repeated And Cyclic LoadsNair, Asha M 12 1900 (has links) (PDF)
Efficient road network and connectivity play vital role in the development of any country. Majority of the rural roads are unpaved and connectivity of rural roads is always a major challenge. Unpaved roads are also used for temporary transportation facilities like access roads, haul roads for mines, forest roads and parking lots. Since these roads do not have asphalt surfacing, they are subjected to early failures due to distresses like rutting, pot holes and depressions . Stabilization of unpaved roads using geosynthetics has been proved to be promising in increasing the lifespan of these roads because they facilitate economical, aesthetic and effective design of the roads. Inclusion of geosynthetic layers at the interface of subgrade soil and granular sub-base, reduces the surface heave, ensures a better stress distribution and reduces the stresses transferred to the subgrade soil, as demonstrated by earlier researchers.
Wide variety of geosynthetics like woven and nonwoven geotextiles, uniaxial and biaxial geogrids and geocells are used as reinforcement in road sections. Geotextiles improve the strength by interfacial friction, lateral restraint and membrane effect. Geogrids provide additional benefit of interlocking. Geocells are honeycomb shaped geosynthetic cellular confining systems filled with aggregates in which the reinforcement action is derived not only by friction and interlocking, but also by confinement. Load-deformation characteristics of reinforced soil-aggregate systems under static, repeated and cyclic loads is a potential topic of interest considering the fact that the design of geosynthetic reinforced unpaved roads is still under development and experimentation.
The objective of the present study is to understand the beneficial use of geosynthetics in unpaved roads and to provide clear insight into the influence of geosynthetics on the cyclic loading characteristics of unpaved roads through laboratory experiments. California Bearing Ratio (CBR) tests were carried out on unreinforced and reinforced soil-aggregate systems to study the effect of various parameters such as type of reinforcement, form of reinforcement, quantity of reinforcement, and water content of the subgrade soil on the load-penetration response of the various systems. Modified CBR tests were also carried out to understand the influence of boundary of the mould and anchorage of reinforcement on the behavior of reinforced soil-aggregate systems. Behavior of unreinforced and reinforced soil-aggregate systems under repeated and cyclic loading is also studied to understand the resilience of the composite systems. From the measured stress-strain response, the elastic and plastic strains developed in various systems are compared. Different moduli such as secant modulus, cyclic modulus and resilient modulus are computed for different systems and compared.
To investigate the effectiveness of geosynthetics in improving the load - bearing capacity, repeated load tests were carried out on model sections of unpaved road constructed in a steel test tank of size 750 mm × 750 mm × 620 mm. The effect of various parameters like the form of reinforcement, quantity of reinforcement, height of geocell layer and the position of geocell layer on the load-deformation behaviour of the unpaved model road sections was studied. Static and cyclic triaxial tests were carried out on unreinforced and reinforced granular sub-base materials to understand their stress strain behavior under static and cyclic loading conditions. The influence of quantity and form of reinforcement on the stress-strain behaviour of these materials was studied.
From the studies it is observed that the use of reinforcement increases the CBR value of the soil-aggregate systems. Studies with two different sizes of CBR moulds indicated that the boundary effect in the standard CBR mould leads to the overestimation of the CBR value, resulting in unconservative design of road sections. Providing anchorage to the reinforcement in CBR tests did not produce an appreciable change in the load-penetration behavior.
From the repeated load tests it was observed that the reinforced systems did not show any improvement in the load-deformation behaviour at low levels of rut depth. At higher rut depths, the reinforced systems developed less plastic settlements and more elastic settlements and low resilient modulus compared to unreinforced systems. From the model tests on unpaved road sections, it was observed that the improvement in the cyclic load resistance of the road due to the inclusion of geocell layer depends on the height of the geocell layer and its position. Increasing the height of geocell layer resulted in improved performance up to certain height of the geocell layer, beyond which, further increase in the height reduced the load resistance because of the inadequate granular overlay thickness and inadequate compaction of aggregate within the geocell pockets. Static and cyclic triaxial tests showed that the geogrid and geocell reinforced granular sub-base material sustained higher peak stresses and exhibited increase in modulus compared to the unreinforced specimens. Results of element and model tests carried out in this study gave important insight into the load-deformation characteristics of reinforced soil-aggregate systems under static, repeated and dynamic loads. The results provide guidelines regarding the selection of type, quantity and configuration of geosynthetic reinforcement while designing unpaved roads and the expected performance of these reinforced unpaved roads.
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