496 resultados para Taludes (Mecanica do solo)
Resumo:
The present paper conducts an analysis of all steps for the construction of diaphragm walls, from obtaining the soil parameters until its execution. Construction stages of diaphragm wall are detailed. The paper presents a detailed analysis of the main available calculation methods to obtain the soil parameters and the design of the diaphragm wall. A case history extensively documented in previous research and present in international symposiums was chosen for an analysis of construction process and excavation’s instrumentations, as well as emphasizing the importance of temporary works and construction sequence for deep excavation with cast in-situ diaphragm walls. In general, it is possible to conclude the main difficulty and uncertainty of the dimensioning are obtaining the soil parameter for diaphragm wall design. And, it is also possible to conclude the monitoring and execution control are paramount to the success of the diaphragm wall construction
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Cette étude visait à générer une carte du potentiel d'érosion pour la Ferme Santa Edwirges, située à Lorena /SP. Les résultats ont etés classifiés en faible, modéré, élève et très élève potentiel d'érosion et la carte obtenue a été comparé par rapport aux autres cartes existantes pour la zone d'étude. La méthodologie proposée se basant sur une application qualitative simple L’équation Universelle de Perte de Sol (USLE ou EUPS), en considérant les parties de l'équation: érodibilité, la topographie et l'utilisation des terres. Les donnés ont etés intégrés par l'algèbre de carte dans l’environnement SIG de ArcGIS. Pour la représentation de chacune de ces parcelles, nous avons utilisé une carte des formations superficielles de la ferme, généré à partir d'une ré-interprétation de la carte géologique, une carte de la pente et une carte d'utilisation des terres, attribuant un poids d’important pour chaque catégorie de ces cartes dans le processus d'érosion et dans l'algèbre proposée. Les résultats obtenus sont compatibles avec les zones identifiées comme les plus critiques sur terrain. La ferme a été identifiée comme de potentiel d'érosion modérée et la partie sud de la ferme le plus critique, suivi du groupe conduit par la zone de cisaillement, par contre les plaines proches des rivières ont eté identifié comme la zone plus stable avec moins de potentiel d'érosionDe la comparaison des résultats de ce travail et d'autres qui ont fait antérieurement dans la zone d’intéresse, qui ont utilisé les paramètres géotechniques dans la représentation de l'érosivité des sols, nous avons pu voir des résultats similaires, en particulier dans les zones à potentiel élevé et faible pour l'érosion. De la discussion et analyse des résultats, la méthodologie proposée à eté validée
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The research addresses the need for detailed geological and geotechnical investigations in pipeline’s design, given the diversity of geological units crossed by these works along its layout, which often extends for hundreds of miles. For its large size, this type of work often goes through different states and regions with very different characteristics in terms of topography, vegetation, geology and geotechnical conditions. For a better use of these investigations in order to avoid unnecessary costs and inefficient results, some authors recommend that steps be taken to study, seeking a progressive detail of the pipeline’s implantation area. The main objective of the study is to describe, analyze and correlate the proposals for geological and geotechnical’s investigation recommended by the authors selected. Nogueira Junior & Marques (1998) suggest that for better effectiveness of geological and geotechnical investigations associated with the deployment of pipelines, different research methods are applied sequentially in five major stages of the building. Rocha et al (2008) recommend that, for the pipeline’s implantation using horizontal directional drilling, investigations are performed in three phases of study, to be developed in coordination with the project stages. For Gelinas & Mathy (2004), when time and budget constraints permit, geotechnical investigations for directional drilling projects for pipelines must be made in four sequential phases. Heinz (2008) suggests that the geotechnical investigations for pipeline’s implantation using horizontal directional drilling at crossings of water bodies are carried out in three successive stages. By the development of research, we could see that all the different proposals recommend studies in sequential phases, starting from a more general scale for a more specific, seeking a progressive understanding of the geological model of the area where you intend to deploy the pipeline
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Population growth, together with the gradual social ascent in Brazil, reflects at the growing need for better use of urban spaces. In this context, the amount of new buildings to meet the demand in property market, the needs for creating new roads and highways, among others, make the use of geotechnical works and, more specifically, retaining walls, more and more common. One of the simplest solutions for underground works is the use of retaining structures using tie back walls for soil support, therefore, the present work deals with this kind of structures. This paper proposes the use of FTOOL software testing in predicting deformations in tie back walls, by comparing simulations of the presented model to a real and measured deformation case in Guabirotuba Formation (PR). The results showed the importance of defining the parameters such as stiffness and curtain geometry, as well as the definition of representative loads acting on it. Also, it was pointed out that the passive response of the steel rods depends on the horizontal displacement of the wall. The study concluded that the program generates very representative results when compared to field data and seems to be a promising tool for tie back structures displacement predictions
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Construction of linear engineering as, roads, ducts and multiducts as roads, has a strong feature of the diversity of land on which they are deployed. This diversity involves properties geological, geomorphological and structural variety. The purpose of this work is to characterize the physical environment in relation to their ability to support the implementation of civil works linear. To achieve this, the use of orbital remote sensing, in this case, Landsat - TM. Interpretative techniques are applied to images in order to assess the forms of relief and drainage found that they can set properties and have built a favorable meaning or not to implement these works. The results and thematic maps presented in this study allow us to promote the geoenvironmental analysis for the planning phase sustainable linear civil constructions (roads and multiducts)
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In the study line about contention, using Diaphragm Wall, revising the characteristics, vantages and constructive methods, following the application due to Terzaghi's theory. This work will be revising the advantages of the excavation equipments like the Clamshell and the Hydraulic Rolling Excavator, excavation techniques, and types of steel reinforcements, concreting, draining methodologies and comparison with other techniques. Also, will be revised a Study of Case, which by the application of two executive methodologies, will be possible to make a comparative analyses in a real construction situation.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This work presents the results of the efficiency of three protection methods of roads slopes, against the development of erosion processes.The methods anlyzed were: (1) grass planting "San Carlos" (Axonopus compressus), (2) litter, composed of remains of branches and leaves of eucalyptus E. Grandis, and (3) Compacted soil cover with a local soil with properties more resistant to erosion processes.The experiment consisted of assembly of four rectangular cells with 6 meters, three for protection systems in study and one was kept unprotected to evaluate the efficiency of the methods in study.The determination of the amount of eroded sediment was based on the sum of the solids in suspension and stored sediments in the geotextile bags.The results showed that, compared to the unprotected cell, the litter obtained a reduction of soil loss of 90%, while the grass enveloped and reduced 80% and 65% respectively.
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The soil resistance to penetration and shear can be used as indicators of soil compaction and to indicate the susceptibility of a soil to erosion. The objective of this study was to quantify and compare the impact provided by different land uses in a haplic cambissol in areas of permanent preservation, from the soil resistance to penetration and shear. The experimental area was located in an area of permanent preservation, the sub-basin of the Ribeira Iguape River - SP, with different land uses: banana cultivation - CBAN, degraded pasture - PDEG, silvopastoral system - MPIS and native forest - MNAT. The test for resistance to penetration was accomplished with a digital penetrometer compaction of manual effort, to a depth of 40 cm. The soil shear strength was determined by Vane Test at a depth between 0 and 5 cm. The degraded pasture was similar to native forest, with less resistance to penetration. The banana cultivation and silvopastoral system were the land uses with the highest resistance to penetration, bringing serious risk of erosion in areas of permanent preservation. The soil under native forest had lower shear strength. The cultivation of bananas, degraded pasture and silvopastoral system were the land uses with higher shear strength of soil, indicating that the use of these soils in areas of permanent preservation is promoting the same compression.
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The objective of this work was to evaluate Cd, Cr, Ni and Pb total contents in soil and sugar cane after four annual applications of sewage sludge and vinasse to supply all N and all K required by the crop. A field experiment was carried out on clayey Typic Haplustox. It was used a randomized block design with seven treatments and three replications. The treatments consisted in: (i) rate of sewage sludge to supply 100% of the N required by the crop; (ii) rate of sewage sludge to supply 200% of the N required; (iii) rate of vinasse to supply 100% of the K required; (iv) rate of vinasse to supply 200% of the K required; ( v) combination of the treatments ( i) and ( iii); ( vi) combination of the treatments ( ii) e ( iv); (vii) control ( mineral fertilization). The contents of Cd, Cr, Ni and Pb in sewage sludge reached maximum values of 1.58, 41.66, 35.17 and 45.25 mg kg(-1), respectively. These metals were not detected in vinasse. The residues were applied annually for four years. At the end of this period, sewage sludge and vinasse accumulated rates, that get up to 51 t ha(-1) and 762 m(3) ha(-1), respectively, did not cause alteration in Cd, Cr, Ni and Pb total contents in soil, up to 50 cm of depth, and in plant. Sewage sludge and vinasse application to supply N and K for sugar cane did not offer soil pollution risk by heavy metals.
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A presente pesquisa foi conduzida visando estudar os efeitos da calagem do solo sobre o crescimento inicial e absorção de macronutrientes por plantas de trapoeraba (Commelina benghalensis L.). A fase experimental foi conduzida em casa de vegetação, em vasos de cinco litros e o substrato foi coletado na camada arável de um Latossolo Vermelho Escuro, distrófico, classe textural franco-argilo-arenosa e valor original de pH igual a 3,8. O experimento foi instalado no delineamento inteiramente casualizado com quatro repetições e os tratamentos constaram da incorporação de quantidades correspondentes às doses 0, I, 2, 3, 4 e 5 t/ha de calcário dolomítico calcinado. Foi efetuada uma incubação por 15 dias antes do plantio das mudas da trapoeraba. Os resultados foram avaliados 49 dias após o transplante. A planta daninha respondeu intensamente à calagem incrementando a área foliar e os acúmulos de matéria seca e de N, P, Ca, Mg e S. Os padrões de distribuição dos diferentes macronutrientes nas diversas estruturas morfológicas da planta foram alterados. O acúmulo de K cresceu até a dose de 2 t/ha de calcário e depois decresceu, possivelmente devido ao antagonismo com Mg, adicionado através do calcário.
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Um ensaio foi conduzido em condições de campo, durante o verão, com o objetivo de avaliar o potencial da técnica de solarização do solo no controle da tiririca (Cyperus rotundus L.). O delineamento experimental utilizado foi o de blocos casualizados com três repetições, e os tratamentos num esquema fatorial 2 x 2 x 3, sendo duas situações de cobertura (com e sem plástico transparente de 300 mm de espessura), dois estádios de desenvolvimento da planta daninha (vegetativo e florescimento) e três períodos de cobertura com plástico (15, 30 e 60 dias). A temperatura do solo sob solarização teve um aumento médio de 4,3oC em relação à testemunha, atingindo valores superiores a 50oC em determinados horários. Observou-se, também, um acúmulo da ordem de 400 % nos teores de CO2 na atmosfera do solo solarizado. Nessas condições houve inibição da brotação dos tubérculos e diminuição no peso de matéria seca de todas as partes estudadas da planta. Houve redução da taxa de multiplicação dos tubérculos, reduzindo-a de 1:11 para 1:4, quando coberta no estádio vegetativo e para 1:9 quando a cobertura se realizou no estádio de florescimento. Houve, ainda diminuição na ordem de 20% na viabilidade dos tubérculos remanescentes.
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O objetivo deste trabalho foi avaliar a influência da disponibilidade hídrica e da acidez do solo, no teor de prolina livre da parte aérea das cultivares de guandu, IAPAR 43-Aratã e IAC Fava Larga. O delineamento experimental utilizado foi o inteiramente casualizado, em arranjo fatorial 2x3x4 (cultivar x disponibilidade hídrica x acidez), com quatro repetições. em condições de restrição hídrica severa, a cultivar IAC Fava Larga pode ser considerada tolerante, em virtude do maior acúmulo de prolina livre. A presença de alumínio no solo, associada à restrição hídrica severa, apresentou efeito sinergístico sobre os teores de prolina livre.
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O objetivo deste trabalho foi avaliar os indicadores fisiológicos da interação entre deficit hídrico e acidez do solo em plantas jovens de cana-de-açúcar. As plantas foram submetidas a três tratamentos de disponibilidade hídrica, medidos em percentagem de capacidade de campo (CC) - sem estresse (70% CC), estresse moderado (55% CC) e estresse severo (40% CC); e três tratamentos de acidez no solo, medidos em termos de saturação por bases (V) - baixa acidez (V = 55%), média acidez (V = 33%) e alta acidez (V = 23%). O experimento foi realizado em casa de vegetação a 29,7±4,3ºC e 75±10% UR. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 3x3, com quatro repetições. Após 60 dias, foram determinados os teores de solutos compatíveis - trealose, glicina betaína e prolina - na folha diagnóstico e o crescimento inicial da parte aérea. Os solutos compatíveis trealose, glicina betaína e prolina são indicadores do efeito da interação dos estresses hídrico e ácido no solo. O acúmulo dos solutos compatíveis nos tecidos foliares das plantas não é capaz de impedir a redução na produção de matéria seca da cana-de-açúcar, resultante do agravamento nas condições de disponibilidade hídrica e de acidez no solo.
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O presente trabalho teve por objetivo avaliar a lixiviação dos herbicidas sulfentrazone e amicarbazone, com e sem óleo mineral, em área de plantio de cana-de-açúcar sobre um Latossolo Vermelho-Escuro, por meio de colunas de solo. Para avaliação da lixiviação, após acumuladas as precipitações de 35, 67 e 106 mm, tubos de PVC de 10 cm de diâmetro, seccionados longitudinalmente, foram enterrados até a profundidade de 35 cm, procurando-se manter a estrutura original do solo. Os tubos foram retirados, separados em suas metades e acondicionados em casa de vegetação, onde se semearam as plantas-teste sorgo (Sorghum bicolor) e corda-de-viola (Ipomoea nil) longitudinalmente ao longo do perfil de cada metade dos tubos. O delineamento experimental utilizado foi o de blocos ao acaso em esquema de parcelas subdivididas, com quatro repetições. As parcelas consistiram da aplicação dos dois herbicidas, adicionados ou não de adjuvante, e uma testemunha sem herbicida. Nas subparcelas estudaram-se as profundidades de percolação (0,0-2,5; 2,5-5,0; 5,0-10; 10-15; 15-20; 20-25; 25-30; e 30-35 cm). Aos 20 dias após a semeadura, determinou-se a matéria seca das plântulas. Observou-se que o sulfentrazone lixiviou até 10 cm de profundidade, mesmo com 106 mm de precipitação, sem efeito diferenciado do óleo. Os efeitos foram mais pronunciados para o sorgo. O amicarbazone não interferiu na matéria seca das plântulas de sorgo. Quanto à corda-de-viola, o herbicida sob precipitação de 35 mm reduziu o desenvolvimento das plântulas, independentemente da profundidade e sem efeito diferenciado do óleo; com 67 mm de precipitação, o herbicida lixiviou pelo solo, e o óleo mineral o manteve na camada mais superficial. Com 106 mm, o herbicida foi totalmente lixiviado e não se constatou efeito do óleo.