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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

O licenciamento ambiental e a atuação do poder público na realização do aterro hidráulico da Praia de Iracema / The environmental licensing and the performance of the public power in the accomplishment of it Praia de Iracema hidraulic embankment

Melo, Juliana Barroso de January 2005 (has links)
MELO, Juliana Barroso de. O licenciamento ambiental e a atuação do poder público na realização do aterro hidráulico da Praia de Iracema. 2005. 139 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente-Prodema, Fortaleza-CE, 2005. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-04-29T17:27:40Z No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) / Approved for entry into archive by guaracy araujo (guaraa3355@gmail.com) on 2016-04-29T17:43:34Z (GMT) No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) / Made available in DSpace on 2016-04-29T17:43:34Z (GMT). No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) Previous issue date: 2005 / The occupation of the costal area in Fortaleza along the last two decades has had touristic trade as the main segment. As a consequence there has been the fast occupation of this area by enterprise buildings besides other construction work aiming to make the coastal area more suitable for the demands of the touristic trade. As an example we mention the praia de Iracema hydraulic embankment (aterro hidráulico) that has caused negative impact on the coastal ecosystem such as interference on the dynamic of the tides as well as damage on the characteristics of the coastal landscape. According to the title “Environmental licensing and interventions of the Public Power on the coastal area of Fortaleza – Ceará: considerations on the praia de Iracema hydraulic embankment” this research work aims to show the importance of environmental licensing as a means to control the accomplishment of public as well as private construction work and consequently the better occupation of the coastal area along Fortaleza. The lack of an adequate ordering in the use and occupation of the coastal urban area along Fortaleza tends to maximize the problem of its exaggerated use thus causing damage to the environmental resources. It is crucial the development of preventive public policies aiming a better ordering and planning of the use of the coastal urban space allowing the preservation of natural resources and giving more guarantee to the sustainability of the economical activities, mainly tourism. For all these reasons and having in mind the ideal of sustainability of the coastal areas of the cities it is fundamental that the Public Power take good care of the established law and make use of preventive instruments such as the previous study of environmental impactand environmental licensing where all parts be effectively integrated and aiming the maintenance of good living conditions. / A ocupação do litoral de Fortaleza, ao longo das duas últimas décadas, apresentou como principal vetor o turismo. Como conseqüência houve acelerada ocupação dessas áreas, com a edificação de empreendimentos, além da realização de obras com o objetivo de melhor adequar o litoral para as demandas do setor turístico, como exemplo o aterro hidráulico da praia de Iracema, causando impactos negativos no ecossistema costeiro, como a interferência na dinâmica das marés e a descaracterização da paisagem costeira. Pelo título “O licenciamento ambiental e as intervenções do Poder Público na zona costeira de Fortaleza-CE: considerações sobre o aterro hidráulico da praia de Iracema”, a presente pesquisa tem como finalidade demonstrar a importância do instrumento de licenciamento ambiental para realização de obras públicas, além das privadas, e, conseqüentemente, a obtenção de um melhor uso e ocupação da orla marítima de Fortaleza. A ausência de uma adequada ordenação do uso e ocupação do solo urbano-litorâneo tende a maximizar o problema da utilização exacerbada – e, conseqüentemente, danos - dos recursos ambientais. Por essa razão, orientando-se pelo ideal da sustentabilidade nas zonas costeiras das cidades, é fundamental que o Poder Público zele pelas normas vigentes e faça uso de instrumentos preventivos, como a realização de estudos prévios de impactos ambientais e o licenciamento ambiental, onde todos estejam efetivamente integrados e voltados para a manutenção da qualidade de vida.
52

Estudo geotécnico visando o aumento da plataforma na ERS/122 através de aterro com materiais leves : resíduos de pneus

Tomazini, Darlan January 2015 (has links)
O crescimento econômico acarreta na necessidade de aumento de capacidade de rodovias existentes. Quando localizadas em meia-encostas, muitas vezes estão vinculadas a ocorrências de instabilidade de modo que obras de aumento da capacidade geram grande impacto. O objetivo desta pesquisa é avaliar o aumento de capacidade de um trecho da Rodovia ERS/122, minimizando os impactos através da definição da seção-tipo com dimensões mínimas, segurança para o usuário, e utilização de um material leve como aterro a ser construído na meia encosta. O principal material avaliado para utilização como aterro são restos de pneus triturados, já encontrados no mercado atual. A avaliação desta solução de aterro em meia encosta decorre principalmente do fato de evitar desmontes de rocha que ocasionariam a interrupção do tráfego em uma importante rodovia do estado. Aliado a isso, é baixa a ocorrência de solos de boa qualidade no trecho, de modo que o aterro é geralmente realizado com materiais rochosos de ocorrência local ou materiais importados. A possibilidade de diminuir a utilização de um material nobre a ser explorado na natureza, juntamente com a utilização de materiais que ainda não possuem 100% de destinação adequada, aliada ao baixo peso específico e adequada resistência ao cisalhamento, incentivaram a realização dos estudos. Ensaios de resistência ao cisalhamento e comportamento de compressão foram realizados para avaliar os parâmetros geotécnicos, a fim de obter um modelo geomecânico. Devido aos resultados de teste satisfatórios, tem sido considerado possível o uso de tais materiais. Os parâmetros obtidos em condições de confinamento foram aceitáveis para aterros de rodovias especialmente quando as aparas de pneus foram misturadas com agregados rochosos. Seu uso como um material de aterro pode ser incentivado, a fim de reduzir o uso de rochas naturais, para obter uma utilização adequada de restos de pneus e para gerar uma maior estabilidade dos aterros com a substituição de solos com comportamento geotécnico pobre. Isto é conseguido principalmente pela diminuição do peso do aterro, pela melhoraria das condições de drenagem e pela definição de uma seção transversal geometricamente segura. / Economic growth leads to the need to increase the capacity of existing highways. When crossing natural slopes often are linked to occurrences of instability so that increased work capacity generate big impact. The objective of this research is to evaluate the increase in capacity of a highway stretch ERS / 122, minimizing impacts by setting the standard section with minimum dimensions, but safe for the user, using a lightweight material as fill. The main material evaluated for use as embankment is shredded tire debris, already found on the market. The evaluation of this embankment solution on natural slopes is mainly to avoid rock blasting which would interrupt the traffic on this important State highway. As there is few occurrences of good quality soil near the construction sites, the fills are usually built with local or imported rock materials. The ability to reduce the use of rock to be exploited from nature by the use of recycled materials combined with its low specific weight and adequate shear strength encouraged this study. Tests of shear strength and compression behavior were carried out to evaluate geotechnical parameters in order to obtain a geomechanical model. Due to satisfactory test results the use of such materials has been considered possible. The parameters obtained on confined conditions were acceptable for road fills especially when scrab tires were mixed with rock aggregates. Its use as an embankment material can be incentivatedf in order to reduce the use natural rocks, to obtain an adequate use for tire scraps and to generate a greater stability for embankments as replacement of soils with poor geotechnical behavior. This is achieved mainly by decreasing landfill weight, improving the drainage conditions and definition of geometrically safe embankment cross-section.
53

Estudo geotécnico visando o aumento da plataforma na ERS/122 através de aterro com materiais leves : resíduos de pneus

Tomazini, Darlan January 2015 (has links)
O crescimento econômico acarreta na necessidade de aumento de capacidade de rodovias existentes. Quando localizadas em meia-encostas, muitas vezes estão vinculadas a ocorrências de instabilidade de modo que obras de aumento da capacidade geram grande impacto. O objetivo desta pesquisa é avaliar o aumento de capacidade de um trecho da Rodovia ERS/122, minimizando os impactos através da definição da seção-tipo com dimensões mínimas, segurança para o usuário, e utilização de um material leve como aterro a ser construído na meia encosta. O principal material avaliado para utilização como aterro são restos de pneus triturados, já encontrados no mercado atual. A avaliação desta solução de aterro em meia encosta decorre principalmente do fato de evitar desmontes de rocha que ocasionariam a interrupção do tráfego em uma importante rodovia do estado. Aliado a isso, é baixa a ocorrência de solos de boa qualidade no trecho, de modo que o aterro é geralmente realizado com materiais rochosos de ocorrência local ou materiais importados. A possibilidade de diminuir a utilização de um material nobre a ser explorado na natureza, juntamente com a utilização de materiais que ainda não possuem 100% de destinação adequada, aliada ao baixo peso específico e adequada resistência ao cisalhamento, incentivaram a realização dos estudos. Ensaios de resistência ao cisalhamento e comportamento de compressão foram realizados para avaliar os parâmetros geotécnicos, a fim de obter um modelo geomecânico. Devido aos resultados de teste satisfatórios, tem sido considerado possível o uso de tais materiais. Os parâmetros obtidos em condições de confinamento foram aceitáveis para aterros de rodovias especialmente quando as aparas de pneus foram misturadas com agregados rochosos. Seu uso como um material de aterro pode ser incentivado, a fim de reduzir o uso de rochas naturais, para obter uma utilização adequada de restos de pneus e para gerar uma maior estabilidade dos aterros com a substituição de solos com comportamento geotécnico pobre. Isto é conseguido principalmente pela diminuição do peso do aterro, pela melhoraria das condições de drenagem e pela definição de uma seção transversal geometricamente segura. / Economic growth leads to the need to increase the capacity of existing highways. When crossing natural slopes often are linked to occurrences of instability so that increased work capacity generate big impact. The objective of this research is to evaluate the increase in capacity of a highway stretch ERS / 122, minimizing impacts by setting the standard section with minimum dimensions, but safe for the user, using a lightweight material as fill. The main material evaluated for use as embankment is shredded tire debris, already found on the market. The evaluation of this embankment solution on natural slopes is mainly to avoid rock blasting which would interrupt the traffic on this important State highway. As there is few occurrences of good quality soil near the construction sites, the fills are usually built with local or imported rock materials. The ability to reduce the use of rock to be exploited from nature by the use of recycled materials combined with its low specific weight and adequate shear strength encouraged this study. Tests of shear strength and compression behavior were carried out to evaluate geotechnical parameters in order to obtain a geomechanical model. Due to satisfactory test results the use of such materials has been considered possible. The parameters obtained on confined conditions were acceptable for road fills especially when scrab tires were mixed with rock aggregates. Its use as an embankment material can be incentivatedf in order to reduce the use natural rocks, to obtain an adequate use for tire scraps and to generate a greater stability for embankments as replacement of soils with poor geotechnical behavior. This is achieved mainly by decreasing landfill weight, improving the drainage conditions and definition of geometrically safe embankment cross-section.
54

Use of geosynthetics on subgrade and on low and variable fill foundation

Eirini Christoforidou (11819009) 19 December 2021 (has links)
<p>There are significant problems during construction to establish an adequate foundation for fills and/or subgrade for pavements when the natural ground has low-bearing soils. Geosynthetics such as geogrids, geotextiles and/or geocells could provide an alternative, less costly in time and money, to establish an adequate foundation for the fill and/or subgrade. There is extensive evidence in the literature and on DOTs practices about the suitability of using geotextiles in pavements as separators. Previous studies have also shown that the use of geogrids in flexible pavements as a reinforcing mechanism could decrease the thickness of the base layer and/or increase the life of the pavement. In this study, analyses of selected pavement designs using Pavement ME, while considering geogrid-enhanced base or subgrade resilient modulus values, showed that geogrid-reinforcement, when placed at the interface between subgrade and base, did not produce significant benefits, as only a modest increase in pavement life was predicted. In addition, parametric finite element analyses were carried out to investigate the potential benefits of placing a geogrid at the base of a fill over a localized weak foundation zone. The analyses showed that the use of geogrids is beneficial only when: (a) the stiffness of the weak foundation soil is about an order of magnitude smaller than the rest of the foundation soil; and (b) the horizontal extent of the weak foundation soil is at least 30% of the base of the embankment foundation. The largest decrease in differential settlements at the surface of the fill, resulting from geogrid-reinforcement, was less than 20% and, therefore, it is unlikely that the sole use of geogrids would be sufficient to mitigate differential settlements. Based on previous studies, a geocell mattress, which is a three-dimensional geosynthetic filled with different types of materials, could act as a stiff platform at the base of an embankment and bridge over weak zones in the foundation. However, given the limited experience on the use of geocells, further research is required to demonstrate that geocells can be effectively used instead of other reinforcement methods.</p>
55

Analýza způsobu vedení trasy přes sesuvné území dálnice D1 ve SR / Analysis of the way of the route through the sloping area of the D1 motorway in the SR

Horňáková, Lenka January 2019 (has links)
The construction of motorways in Slovakia faces a series of geotechnical problems due to the mountainous relief. One of these problems is also discussed in this diploma thesis, where the motorway route is led through a landslide area. The aim of the thesis is to compare two different proposals of the D1 motorway in part of Hubova - Ivachnova section. The theoretical part deals with the issue of slope movements in connection with transport line constructions. In the practical part, the proposals for specific solutions of the high embankment route variant and variant with the bridge are discussed. Both variants are designed in the Plaxis numeric program. Subsequent comparison and evaluation of variants is performed in relation to the degree of stability, deformation, structural stress and construction costs.
56

Monitoring sedání násypů dopravních staveb / Monitoring of settlement in road constructions

Karlín, Petr January 2013 (has links)
This thesis considers some issues regarding geotechnical monitoring of settlement of subsoils on roads, highways in the Czech Republic. The first part try to explain process of construction embankments with following standards and prescriptions. Second part belongs to geotechnical monitoring of settlement of subsoils, where author had selected 7 measuring profiles for further work on archive exploration. From these exploration were excluded information about exact location. Third part is creation of 9 geotechnical models in 2D - Plaxis software, comparison with real data and short part about using this kind of work for practice use.
57

Náplavky v Praze jako veřejný prostor / Embankment of Prague, like a public place (space)

Matušková, Barbora January 2017 (has links)
This diploma thesis is devoted to the topic of riverside docks in Prague. Riverside dock is a coastal area, which is on a lower level than an embankment. Previously used as docks for cargo and passenger ships and storage of sand. Nowadays they fulfill mainly recreational and socio-cultural function. The case study is focused on one of Prague's riverside docks, the riverside dock on Rašínovo nabrezi. In this thesis, I will focus on the description and explanation of the use of the riverside dock on Rašínovo nábřeží. Concentrating on its practical operation, conflicts of interests of individual participants and the impact on the environment and on the direct surroundings.
58

Discrete Element Modelling of the Unbound Layer for Slab Tracks on High Embankment

Ghyate Forsberg, Karima, Ramak, Rogin January 2016 (has links)
According to Swedish guidelines for high speed railways on embankment, the total settlement is limited to 20 mm over a track length of 10 m during the construction service life. The main objective of this thesis was to investigate the deformation in the subgrade (unbound layer) in a slab track, since there are very few studies related to high speed railways on high earth structure, discussing particularly the unbound layer. This thesis examined the unbound layer consisting of granular material by using the discrete element method (DEM) software PFC. There was a focus on the material compaction and deformations due to traffic loading. DEM has the benefit to be able to model deformation with due consideration of processes at microscale level. Two different particle shapes were tested: balls and clumps. The results showed that the settlements were small, possibly associated to the well compacted material and the simplifications in the model, such as the shape of the particles, absence of particle breakage and the applied traffic load. The clump simulations resulted in less settlements and permanent strains compared to the ball simulations. The higher the embankment the more settlements but less strains were produced for all the three simulations. One interesting parameter to study for the balls simulation was the friction between the particles. Increased friction contributed to less settlement. The maximum height of the embankment was limited to around 3,2 m due to time restraints. Simulations for higher embankments are needed to be performed in order to better understand the effect of the embankment height on settlements.
59

Internal erosion in the pervious foundation of an embankment dam : A case study on the Lossen dam

Molinder, Gabriella January 2016 (has links)
The Lossen dam is an embankment dam in the Swedish river Ljusnan. The dam is founded on thick layers of stratified glaciofluvial sediments and till. Ever since construction, there have been problems with high pore pressures, large seepage flows and springs downstream of the right part of the dam. After the first filling of the reservoir, a large drainage trench was constructed downstream of the dam to lower pore pressures. Sinkholes and settlements downstream of the dam have occurred repeatedly over the lifetime of the dam, particularly in the area surrounding the large drainage trench. This study aims to investigate the causes of the sinkholes and assess the risks of internal erosion in the foundation and in the soil downstream of the dam. A model of the groundwater flow has been created in Visual MODFLOW. Calculations for assessing the soils susceptibility for contact erosion and suffusion have been performed, using soil gradation curves (both from the 1960s and from new samples). The results from the erosion calculations show that the probability of contact erosion being the sole cause of the internal erosion is minor. However, a majority of the soil samples tested are internally unstable (susceptible for suffusion). The possibility of backward erosion piping can not be dismissed but would need further investigation in order to be properly assessed. Due to the very heterogeneous structure of the soil in the area downstream of the dam, it is hard to predict the extent of the eroding soil layers and, thus, the future development of the erosion. A conclusion is that the soil downstream of the dam is subject to internal erosion, which is also the cause of the observed sinkholes and settlements. The internal erosion is probably not a threat to dam safety at the moment, but can possibly evolve as a problem in the future. Therefore close monitoring of the changes in seepage patterns and sediment transport is recommended. Possible solutions to stop the erosion include extending the drainage system with more pressure relief wells, and placing a filter blanket in the seepage exit area. / Lossendammen är en jorddamm i älven Ljusnan.  Dammen är byggd ovanpå tjocka lager av morän och isälvssediment. Sedan första dämningen 1962 har problem med höga portryck, stora läckageflöden och källsprång nedströms dammen uppkommit. Efter första dämningen grävdes ett stort dränagedike (kallat Slits 19) ut nedströms om dammen, för att sänka portrycken i området. Sjunkhål och sättningar har uppkommit återkommande under dammens livstid, speciellt i området kring slitsen. Målet med denna studie är att undersöka orsaken till de uppkomna sjunkhålen och sättningarna, samt att bedöma risken för fortsatt intern erosion i dammens undergrund och i jorden nedströms dammen. En modell över grundvattenflödet i området har skapats i Visual MODFLOW. Jordens fallenhet för kontakterosion och suffusion har beräknats med hjälp av kornfördelningskurvor från jordprover (majoriteten av vilka är från 60-talet, samt några nya). Resultaten från beräkningarna visar att risken för att kontakterosion initieras är liten. Däremot visar en majoritet av de testade kornfördelningskurvorna att jorden är internt instabil (har fallenhet för suffusion). Sannolikheten för att bakåtskridande erosion initieras kan inte uteslutas baserat på det underlag som förelegat, men en pålitlig bedömning skulle kräva ytterligare undersökningar. Eftersom jorden under och nedströms dammen är väldigt heterogen, och de olika lagrens storlek och utbredning är okänd, är det svårt att förutspå hur erosionen kommer att utvecklas i framtiden. Slutsatsen är att jorden nedströms dammen utsätts för fortlöpande inre erosion. Inre erosion är också orsaken till de uppkomna sjunkhålen och sättningarna. I nuläget är erosionen ingen risk för dammsäkerheten, men kan komma att bli det i framtiden. Noggrann övervakning av eventuella förändringar i läckagemönstren och sedimenttransport är viktig. Bland möjliga lösningar för att avstanna erosionen finns utökning av dränagesystemet med nya filterbrunnar, samt att lägga ett filtrerande skyddslager över området där källsprången sker.
60

Modelling internal erosion within an embankment dam prior to breaching

Vazquez Borragan, Alejandro January 2015 (has links)
There are still uncertainties in the safety of existing embankment dams. For instance, the majority of embankment dams in Sweden were built between 1950s and 1970s, designed and constructed to standards that might be unacceptable nowadays. Particularly, Vattenfall’s records stated that 40% owned embankments dams developed sinkholes (Nilsson, 1999). Moreover, internal erosion and its failure mechanisms of initiation and development are still not fully understood (Bowles et al., 2013). Also, internal threats are difficult to detect and interpret even using new instrumentation techniques. The aim of this Master Thesis is to identify failure mechanisms of embankment dams prior to breaching and hence, verify the reliability of a risk analysis after the breaching of the dam. The methodology consisted of monitoring an embankment dam prone to fail by internal erosion mechanisms. Finally the results were modelled using FEM to identify the risk of internal erosion prior to breaching.

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