Dissertations / Theses: 'Laterite Soils'

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Andriamanamihaja, Rakoto Hasina Harivelo. "Erosion and stream sedimentation due to pipeline construction in laterite soils - Madagascar –." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123247.

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Madagascar - Ambatovy region, AMBATOVY Project - Sherritt International. The Ambatovy Project, a mine for nickel and cobalt ore located in the centre of the country, required the construction of a slurry pipeline to transport the ore 220 km to be processed on the east coast. The pipeline and its maintenance road traverses primary forests, the sensitive Torotorofotsy Wetlands and include 172 stream crossings in sensitive laterite soils. The restoration and rehabilitation of the cut and fill geotechnical works and stream crossings is important technical works within the environmental portfolio and for project cost reductions.The surface water erosion of the soil and the associated stream sedimentation are studied. These processes are classified based on the characteristics of the vegetation/land use, the slopes and the type of laterite soil. Three representative sites are chosen for a detailed study using field observations and field measurements (TSS in streams). These results are compared to numerical modeling results using RUSLE (Revised Universal Soil Loss Equation model) for surface erosion within GeoWEPP (Geo-spatial interface for Water Erosion Prediction Project), a USGS (US Geological Survey) –LESAM (Landscape-based Environmental System Analysis & Modeling) model which conducts continuous and process-based simulations of small watersheds, for soil erosion and sedimentation.At the three selected sites, the use of GeoWEPP as a tool to explore possible mitigation measures using geotechnical engineering methods combined with revegetation is investigated and discussed. The results of these studies will be used to suggest measures to mitigate environmental impacts associated with the pipeline construction for the Ambatovy Project. Madagascar – région d'Ambatovy, Projet AMBATOVY - Sherritt International. Le Projet Ambatovy, une mine de nickel et cobalt située au centre de l'ile, a requiert la construction d'un pipeline de pulpe pour pouvoir transporter le minerai sur 220kms, pour pouvoir être acheminé et transformé sur la côte Est. Le pipeline et son réseau routier de maintenance traverse des forêts primaires, la sensible région du marais de Torotorofotsy et incluant 172 cours d'eau sensibles reposant sur le sol latéritique. La restauration et la réhabilitation des tranchées de remblai et déblai grâce aux travaux géotechniques sont d'importants travaux techniques pour les cours d'eaux notamment au niveau de l'impact environnemental et jouant sur la réduction des couts du projet. Le phénomène de l'érosion de surface au niveau des cours d'eau et la sédimentation des rivières y associée ont été étudiés. Les processus sont classés sur base des caractéristiques de la végétation, de la pente et du type de sol latéritique. Trois sites représentatifs sont choisis aux fins d'une étude détaillée avec usage des données et observations de terrain (MES dans les rivières). Ces résultats sont par la suite comparés aux résultats avec usage des modèles numériques utilisant RUSLE (Revised Universal Soil Loss Equation model) pour l'érosion de surface dans GeoWEPP (Geo-spatial interface for Water Erosion Prediction Project), un modèle provenant de USGS (US Geological Survey) –LESAM (Landscape-based Environmental System Analysis & Modeling) qui conduit notamment des simulations en mode continu et sous base de processus pour les petits bassins versants, concernant l'érosion et la sédimentation.Au niveau de ces trois sites sélectionnés, l'utilisation de GeoWEPP comme utile de prédiction et de « design » des mesures de mitigation possibles par usage de solutions d'ingénierie géotechnique combinée à la re-végétalisation ont pu être étudiés et comparés. Les résultats de ces études pourront être utilisés en tant que suggestion de mesures de mitigation des impacts environnementaux relatifs à la construction du pipeline du Projet Ambatovy.

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Yusran, Fadly Hairannoor. "Soil organic matter decomposition : effects of organic matter addition on phosphorus dynamics in lateritic soils." University of Western Australia. School of Earth and Geographical Sciences, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0120.

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[Truncated abstract] Relationships between the persistence of organic matter added to soil, the dynamics of soil organic carbon (C) and phosphorus (P) were examined in four experiments on lateritic soils of Western Australia. The main objective was to quantify the release of P following organic matter application in soils which have high P adsorbing capacity. Another objective was to confirm that due to its recalcitrant materials, the effect of peat lasted longer in soil than other sources of organic matter in terms of increasing plant-available P fractions. Three experiments were conducted under glasshouse conditions for various lengths of time, with nine- to twelve-month incubations to investigate these hypotheses. As expected, organic matter with lower C:N ratios than peat (lucerne hay) decomposed more rapidly compared with peat, and the most active mineralisation took place within the first three months of incubation. Soil organic-C (extracted by 0.5 M K2SO4) had a significant positive correlation with P extracted with 0.5 M NaHCO pH 8.53. For a higher application rate (120 ton ha-1), peat was better than wheat straw and lucerne hay in increasing extractable bicarbonate-P concentrations in soil, especially at incubation times up to 12 months. Throughout the experiment, peat was associated with a steady increase in all parameters measured. In contrast to peat, nutrient release from lucerne hay and wheat straw was rapid and diminished over time. There was a tendency for organic-C (either in the form of total extractable organic-C or microbial biomass-C) to steadily increase in soil with added peat throughout the experiment. Unlike wheat straw and lucerne hay, extractable organic-C from peat remained in soil and there was less C loss in the form of respiration. Therefore, peat persisted and sequestered C to the soil system for a longer time than the other source of organic matter. Freshly added organic matter was expected to have a greater influence on P transformation from adsorbed forms in lateritic soils than existing soil organic matter. By removing the existing soil organic matter, the effect of freshly applied organic matter can be determine separately from that of the existing soil organic matter for a similar organic-C content. In order to do this, some soil samples were combusted up to 450° C to eliminate inherent soil organic matter. The release of P was greater when organic-C from fresh organic matter was applied to combusted soils than in uncombusted soils that contained the existing soil organic matter. The exception only applied for parameters related to soil micro-organisms such as biomass-C and phosphatase. For such parameters, new soil organic matter did not create conditions favourable for organisms to increase in activity despite the abundance of organic matter available. More non-extractable-P was formed in combusted soils compared to bicarbonate-P and it contributed to more than 50% of total-P. As for the first experiment, peat also showed a constant effect in increasing bicarbonate extractable-P in the soil

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Löhr, Stefan Carlos. "Controls on iron in soils and soil waters of a forested, coastal catchment in subtropical Australia." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/47012/1/Stefan_L%C3%B6hr_Thesis.pdf.

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Soluble organic matter derived from exotic Pinus vegetation forms stronger complexes with iron (Fe) than the soluble organic matter derived from most native Australian species. This has lead to concern about the environmental impacts related to the establishment of extensive exotic Pinus plantations in coastal southeast Queensland, Australia. It has been suggested that the Pinus plantations may enhance the solubility of Fe in soils by increasing the amount of organically complexed Fe. While this remains inconclusive, the environmental impacts of an increased flux of dissolved, organically complexed Fe from soils to the fluvial system and then to sensitive coastal ecosystems are potentially damaging. Previous work investigated a small number of samples, was largely laboratory based and had limited application to field conditions. These assessments lacked field-based studies, including the comparison of the soil water chemistry of sites associated with Pinus vegetation and undisturbed native vegetation. In addition, the main controls on the distribution and mobilisation of Fe in soils of this subtropical coastal region have not been determined. This information is required in order to better understand the relative significance of any Pinus enhanced solubility of Fe. The main aim of this thesis is to determine the controls on Fe distribution and mobilisation in soils and soil waters of a representative coastal catchment in southeast Queensland (Poona Creek catchment, Fraser Coast) and to test the effect of Pinus vegetation on the solubility and speciation of Fe. The thesis is structured around three individual papers. The first paper identifies the main processes responsible for the distribution and mobilisation of labile Fe in the study area and takes a catchment scale approach. Physicochemical attributes of 120 soil samples distributed throughout the catchment are analysed, and a new multivariate data analysis approach (Kohonen’s self organising maps) is used to identify the conditions associated with high labile Fe. The second paper establishes whether Fe nodules play a major role as an iron source in the catchment, by determining the genetic mechanism responsible for their formation. The nodules are a major pool of Fe in much of the region and previous studies have implied that they may be involved in redox-controlled mobilisation and redistribution of Fe. This is achieved by combining a detailed study of a ferric soil profile (morphology, mineralogy and micromorphology) with the distribution of Fe nodules on a catchment scale. The third component of the thesis tests whether the concentration and speciation of Fe in soil solutions from Pinus plantations differs significantly from native vegetation soil solutions. Microlysimeters are employed to collect unaltered, in situ soil water samples. The redox speciation of Fe is determined spectrophotometrically and the interaction between Fe and dissolved organic matter (DOM) is modelled with the Stockholm Humic Model. The thesis provides a better understanding of the controls on the distribution, concentration and speciation of Fe in the soils and soil waters of southeast Queensland. Reductive dissolution is the main mechanism by which mobilisation of Fe occurs in the study area. Labile Fe concentrations are low overall, particularly in the sandy soils of the coastal plain. However, high labile Fe is common in seasonally waterlogged and clay-rich soils which are exposed to fluctuating redox conditions and in organic-rich soils adjacent to streams. Clay-rich soils are most common in the upper parts of the catchment. Fe nodules were shown to have a negligible role in the redistribution of dissolved iron in the catchment. They are formed by the erosion, colluvial transport and chemical weathering of iron-rich sandstones. The ferric horizons, in which nodules are commonly concentrated, subsequently form through differential biological mixing of the soil. Whereas dissolution/ reprecipitation of the Fe cements is an important component of nodule formation, mobilised Fe reprecipitates locally. Dissolved Fe in the soil waters is almost entirely in the ferrous form. Vegetation type does not affect the concentration and speciation of Fe in soil waters, although Pinus DOM has greater acidic functional group site densities than DOM from native vegetation. Iron concentrations are highest in the high DOM soil waters collected from sandy podosols, where they are controlled by redox potential. Iron concentrations are low in soil solutions from clay and iron oxide rich soils, in spite of similar redox potentials. This is related to stronger sorption to the reactive clay and iron oxide mineral surfaces in these soils, which reduces the amount of DOM available for microbial metabolisation and reductive dissolution of Fe. Modelling suggests that Pinus DOM can significantly increase the amount of truly dissolved ferric iron remaining in solution in oxidising conditions. Thus, inputs of ferrous iron together with Pinus DOM to surface waters may reduce precipitation of hydrous ferric oxides and increase the flux of dissolved iron out of the catchment. Such inputs are most likely from the lower catchment, where podosols planted with Pinus are most widely distributed. Significant outcomes other than the main aims were also achieved. It is shown that mobilisation of Fe in podosols can occur as dissolved Fe(II) rather than as Fe(III)-organic complexes. This has implications for the large body of work which assumes that Fe(II) plays a minor role. Also, the first paper demonstrates that a data analysis approach based on Kohonen’s self organising maps can facilitate the interpretation of complex datasets and can help identify geochemical processes operating on a catchment scale.

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Gogo-Abite, Ikiensinma. "SLOPE STABILITY OF LATERITE SOIL EMBANKMENTS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3487.

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Embankments are key elements in the infrastructural development of structures such as dams, bridges, and roads. Residual soils are generally used as fills in the construction of embankments in areas were residual soils such as laterite is the dominant soil types. Laterite soils have the characteristics of losing its shear strength with time and in fully saturated conditions and its properties varies from region to region. The soil property is influenced by the chemical composition and the environment. The binding agent iron oxide in such soils changes its composition with time and in the presence of moisture. Sudden failures of embankments founded of laterite soils which were, otherwise, checked and found to be safe with high factor of safety, have been observed. This study is performed to investigate the stability of embankments with sudden loss of strength with time and when it is fully saturated. The research includes an investigation of the properties of laterite soils around the world, with particular emphasis on Nigeria. Initially, information is gathered from different sources about the strength-based properties of such soils. Previous research in Nigeria is used as a basis for obtaining real-world soil data. Next, stability analyses are performed using SLOPE/W with shear strength parameters for total stress (short-term), effective stress (long-term), and fully saturated soil conditions. A probability analysis is conducted for the fully saturated conditions because of the variability in the input parameters. Three slope configurations (1:1, 2:1, and 3:1) are considered. The study revealed that the laterite soils embankments lose most of its stability over time period and in full saturation soil conditions. Both these conditions significantly compromise the strength of the soil and the related stability of slopes. To consolidate all information, a database of the properties of laterite soils in some localities of Nigeria was created on the geographic information system (GIS), in order provide a quick access to information on laterite soils in Nigeria. M.S. Department of Civil and Environmental Engineering Engineering and Computer Science Civil Engineering

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Gomes, Ribamar de Jesus. "Estudo geotecnico de um solo superficial da cidade de Bragança Paulista - SP." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258204.

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Orientador: David de Carvalho Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo Made available in DSpace on 2018-08-09T15:24:02Z (GMT). No. of bitstreams: 1 Gomes_RibamardeJesus_M.pdf: 3281674 bytes, checksum: 135d37dcb38ea7208dfdb87b862c01d7 (MD5) Previous issue date: 2006 Resumo: Estuda-se o comportamento geotécnico de um perfil de solo tropical típico da região de Bragança Paulista - SP. Esse perfil é classificado pela pedologia como um Latossolo Vermelho Amarelo. Para atingir esse objetivo foram realizados ensaios de caracterização, ensaios triaxiais e ensaios edométricos no teor de umidade natural e saturado. Nos ensaios de caracterização constatou-se o comportamento laterítico do solo. Nos ensaios edométricos quando os corpos de prova foram inundados nas tensões normalmente adotadas em projetos de fundações de edificações de pequeno e médio porte, construções características da cidade, constatou -se indícios de expansibilidade e colapsibilidade, apontando para a necessidade de estudos mais aprofundados sobre esses fenômenos em outras localidades do município Abstract: The survey has the objective to investigate the geotechnical behavior of a typical soil profile at Bragança Paulista city - São Paulo State - Brazil. This profile is classified by the pedology as Red Yellow Oxisoil. To achieve this aim were accomplished characterization geotechnical tests, triaxial tests and consolidation tests. In the characterization tests was proved the lateritic behavior of the soil. In the consolidation tests when the samples were saturated in the tensions normally stipulated in edifications foundations projects at small and medium conveyance the results had pointed colapsible and expansive soil existence at the referred city Mestrado Geotecnia Mestre em Engenharia Civil

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Freitas, Milena Cardoso de. "Avaliação de técnica de melhoria de solos colapsíveis por meio de colunas de solo laterítico compactado." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-28112016-095823/.

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A fundação direta é limitada em solos colapsíveis pois o efeito do colapso é mais acentuado nas camadas superficiais do terreno. Diante deste cenário, nesta pesquisa foi avaliada uma nova técnica de reforço de solo com a finalidade de viabilizar o uso de fundações diretas para controlar e reduzir o recalque das fundações devido ao colapso. A técnica proposta consiste na execução de colunas de solo laterítico compactado, inseridas na camada colapsível. O processo de compactação das colunas provoca a densificação do solo ao seu entorno, e consequentemente reduz a compressibilidade da massa de solo reforçado. Neste trabalho também foi verificado se a compactação radial do solo em torno da coluna estava relacionada com a geometria do pilão utilizado. Para compreender estes efeitos, foram realizados ensaios em laboratório, em escala reduzida, para avaliar qualitativamente duas geometrias de pilões diferentes, uma cônica e outra cilíndrica (tradicionalmente utilizada na engenharia de fundações). Como resultado desta análise, concluiu-se que a geometria cônica apresentou uma maior compactação lateral do solo no entorno da coluna, comparando-se com a geometria cilíndrica. Para analisar a eficiência do método de reforço proposto, foram executadas e ensaiadas colunas em escala real no solo colapsível do Campo Experimental de Fundações da Escola de Engenharia de São Carlos da Universidade de São Paulo. Para esta análise, foram realizadas provas de carga em placa em solo com e sem reforço. Os ensaios foram realizados com e sem a inundação do terreno para se verificar o efeito da inundação no comportamento do solo reforçado. Desta forma, foi possível avaliar o ganho de capacidade de carga e a redução dos recalques devido à execução dos elementos de reforço ensaiados. Por meio dos resultados obtidos nas provas de carga em placa constatou-se a eficiência do método na redução do recalque e no aumento da capacidade de carga. Comparando-se as curvas dos ensaios de placa com e sem reforço, observou-se um aumento da capacidade de carga de quatro vezes em consequência da instalação do reforço. The use of shallow foundation is limited on collapsible soils due to the collapse effect pronounced in superficial layers. Considering this scenario, this research presents a new soil reinforcement technique in order to reduce the settlement of foundations due to the collapse. The proposed technique involves the execution of compacted lateritic soil columns inserted into the collapsible soil. The compaction of these columns causes the densification of the surrounding soil and consequently reduces compressibility of the reinforced soil mass. In this work, it was also evaluated the effect of the hummer geometry on the radial compaction of the soil around the column. For this evaluation, laboratory tests were conducted using two different geometries of hammer, one conical and other cylindrical (traditionally used in foundation engineering). The results showed that the conical geometry provided greater lateral compaction of the soil around the column compared to the cylindrical geometry. The efficacy of the compacted lateritic soil columns was evaluated by the results of plate load tests performed on the collapsible soil of the Experimental Field of the University of São Paulo in São Carlos city. The tests were carried out on a plate installed in the ground with and without reinforcement. The gain on bearing capacity and settlement reductions due to the reinforcement were verified by using these tests results. The tests were performed in natural and in flooded condition to verify the efficiency of the soil reinforcement in the flooding situation. Based on the results of the plate load tests, it was verified the efficacy of the method to reduce the effect of collapse. The load-displacement curves of the load tests showed that the solution evaluated provided an increase of 400% on the ultimate capacity of the plate installed on the collapsible soil tested in this investigation.

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Oyelami, Charles Adebayo. "Suitability of Lateritic Soils as Construction Material in Sustainable Housing Development in Africa : a Geological Perspective." Thesis, University of Pretoria, 2017. http://hdl.handle.net/2263/63285.

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Lateritic soils which have been described as highly weathered tropical or sub-tropical residual soils with varying proportions of particle sizes ranging from clay size to gravel, were studied in an attempt to establish its suitability or otherwise as sustainable material in building bricks and housing developments that will meet the present challenge of sustaining the environment without costing too much and maintaining a high standard of strength, durability and aesthetics. Index properties of the lateritic soils tested revealed them as mostly well-graded, comprising both cohesive (silt and clay) and cohesionless (sand and gravel) soil fraction. The mineralogical analysis shows the presence of sesquioxides in the clay portion which were found to be very useful in the natural binding process as well as in the presence of a stabiliser (cement). The geotechnical analysis on the lateritic soil revealed a strong compressive strength with a relatively sound dry density which could guarantee a good durability in resulting bricks made from these soil materials. Further test on the strength and durability of compressed earth bricks (CEBs) made from these lateritic soils revealed a brick with compressive strength ranging between 6.33 and 15.57 MPa which are considered to be of very good strength coupled with its sound durability strength established over a period more than one year under different kinds of severe weather and seasonal conditions. In conclusion, sesquioxides presence and mineralogy of lateritic soils were found to be largely responsible for their good compressive and durability strength which made them good and sustainable materials for CEBs. Thesis (PhD)--University of Pretoria, 2017. Geology PhD Unrestricted

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Azevedo, Luiz Otavio Roffee. "Infra-Red Spectrophotometry and X-Ray Diffractometry as Tools in the Study of Nickel Laterites." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/231213.

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Nickel silicate laterite deposits developed on ultra-mafic rocks are similar in many general respects but they vary considerably in detail. The mineralogy of these surficial deposits is very complex and difficult to determine because of the fine grained nature and solid solution characteristics of the hydrous secondary minerals and because many of the phases are actually mineraloids that are poorly ordered or amorphous. To try some new approaches toward clarification of these phases, 24 samples from New Caledonia and Puerto Rico ranging from the ophiolite-ultramafic olivine-pyroxene-chromite-serpentine substrate rocks upward through intermediate phases of weathering to the final oxide -hydroxide iron cap phase were analyzed with the infrared spectrophotometer (IR -10) and with the automated X –ray diffractometer. Four limonite samples were also mineralogically analyzed. Goethite, secondary quartz, cryptomelane, hematite, chromite, talc, thuringite, and garnierite have been identified in various samples as weathering profile products.

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Ndiaye, Massamba. "Contribution à l'étude de sols latéritiques du Sénégal et du Brésil." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00977354.

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Cette étude porte sur les matériaux graveleux latéritiques utilisés dans de nombreux pays pour la construction des couches de fondation et de base des chaussées routières. Au Sénégal, les matériaux sont sélectionnés par référence aux règles du CEBTP de 1972, révisées en 1980. Les graveleux latéritiques doivent respecter des fuseaux granulométriques avant ou après compactage. Des conditions sont aussi imposées à l'indice CBR, à l'indice de plasticité et à l'optimum Proctor. Les recherches présentées dans ce rapport concernent différentes questions :- quel est l'effet du compactage à différentes énergies sur la fragmentation des particules solides et la modification de la courbe granulométrique ? Comment en tenir compte dans la sélection des matériaux et donc leur classification ? Comment se comportent ces matériaux dans les chaussées sous l'effet du compactage à la mise en œuvre puis de la circulation ?- peut-on trouver une corrélation entre l'indice CBR et les paramètres granulométriques ou géotechniques du sol ? Les corrélations sont-elles valables pour tous les sites ou seulement à l'échelle d'une carrière ?- comment réagit le sol graveleux latéritique lorsqu'on le mélange avec un autre matériau dépourvu de particules fines pour améliorer sa plasticité et sa résistance ?- comme une partie des recherches a eu lieu au Brésil, le rapport compare les procédures expérimentales utilisées au Brésil et au Sénégal. La pertinence de l'utilisation des coefficients de fragmentabilité et dégradabilité, introduits dans la classification des sols latéritiques de Rodrigues et al. pour caractériser l'évolution des graveleux latéritiques, a été évaluée par des essais de laboratoire sur le matériau de la carrière de Lam-Lam et le même matériau mis en œuvre en couche de base sur deux routes du Sénégal. Le coefficient de dégradabilité ne différencie pas les matériaux et le coefficient de fragmentabilité semble être un meilleur paramètre. L'étude de l'évolution des classes granulaires des latérites de deux carrières du Sénégal et deux carrières du Brésil sous compactage CBR confirme l'importance de la fragmentation des particules les plus grandes et le décalage des courbes granulométriques vers les sols plus fins, mais ces changements dépendent de la nature des latérites testées. Il en résulte que l'étude des matériaux graveleux latéritiques doit continuer de se faire à l'échelle de la carrière. La méthode de régression linéaire multiple a été appliquée à la prévision de l'indice CBR des matériaux prélevés dans deux carrières sénégalaises (40 prélèvements à Sindia et 46 à Dougar). Cette étude a montré que l'on peut trouver des approximations acceptables à l'échelle de chaque carrière pour calculer l'indice CBR à partir des courbes granulométriques et à partir de six paramètres choisis pour leur influence potentielle sur cet indice : le passant au tamis 80µm, les caractéristiques de courbure et d'étendue de la courbe granulométrique, l'indice de plasticité et les caractéristiques Proctor. Mais les formules établies sur un site sont inadaptées à la prévision de l'indice CBR sur d'autres sites, ce qui confirme que les analyses doivent se faire à l'échelle de la carrière. La lithostabilisation des latérites de Lam-Lam et de Sindiapar mélange avec 30% et 10% de sable de KeurMassar pour abaisser leur indice de plasticité naturel a eu l'effet attendu sur la plasticité, tout en respectant les critères granulométriques. Mais l'effet de l'ajout du sable sur l'indice CBR est inattendu et devra être étudié : diminution pour la latérite de Lam-Lam et augmentation pour la latérite de Sindia. La comparaison des normes françaises et brésiliennes a montré que, malgré de légères différences, les résultats sont globalement équivalents. La plus grande différence concerne l'indice CBR, qui est déterminé avec des énergies de compactage différentes et donne des résultats plus faibles au Brésil. Mais les conditions imposées aux matériaux sont adaptées à ces valeurs

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Berti, Carolina. "Avaliação da capacidade de suporte de solos "in situ" em obras viarias atraves do Cone de Penetração Dinamica : estudo experimental." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258212.

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Orientador: Cassio Eduardo Lima de Paiva Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo Made available in DSpace on 2018-08-06T16:48:11Z (GMT). No. of bitstreams: 1 Berti_Carolina_M.pdf: 4127695 bytes, checksum: f8e52fd73231b7c47f0a12b5c7e759cc (MD5) Previous issue date: 2005 Resumo: Esta pesquisa procurou estabelecer uma correlação entre os valores de capacidade de suporte resultantes dos ensaios CBR (Califórnia Bearing Ratio) versus DCP (Dynamic Cone Penetrometer), realizados com o solo proveniente de vias não-pavimentadas dentro do Campus da UNICAMP, situado em Campinas, São Paulo. O Cone de Penetração Dinâmica (DCP) é caracterizado como um equipamento simples, portátil e de baixo custo, cujo ensaio revela ser praticamente não-destrutivo. Com ele é possível determinar o perfil de resistência de camadas de solo compactadas ou em seu estado natural, controlar a execução de obras viárias e avaliar estruturas de pavimentos. Uma investigação do solo através de ensaios DCP e CBR conduziu ao desenvolvimento de modelos de regressão, correlacionando a capacidade de suporte obtida através de ensaios ¿in situ¿ com o auxílio do DCP, e ensaios de laboratório utilizando o ensaio de CBR e DCP. Através das informações contidas na literatura técnica, dos procedimentos experimentais efetuados e das análises de regressão realizadas, ficou evidenciado o relacionamento entre o DCP e o CBR, validando as correlações estabelecidas e propondo modelos próprios, aumentando a confiabilidade dos resultados dos ensaios DCP para avaliação da capacidade de suporte de solos Abstract: This research establishes a correlation among the strength or supporting values of the tests: CBR (California Bearing Ratio) versus DCP (Dynamic Cone Penetrometer), accomplished with the soil originating from no-paved roads inside of the Campus of UNICAMP. The Cone of Dynamic Penetration (DCP) it is characterized as an equipment simple, portable and of low cost, whose tests reveals to be practically no-destructive. DCP test determines the profile of resistance of soil layers compacted or in your natural state, to control the execution of road buildings and to evaluate structures of pavements. An investigation of the soil through DCP and CBR tests led to the development of regression models, correlating the strength measures obtained through in-situ tests with the aid of DCP and laboratory tests using the CBR and DCP. Through the information contained in the technical literature, of the made experimental procedures and of the regression analyses accomplished, the relationship was evidenced between DCP and CBR, validating the established correlations and proposing own models, increasing the reliability of the results of the DCP tests for determining strength values of soils Mestrado Transportes Mestre em Engenharia Civil

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Santos, Eliana Fernandes dos. "Estudo comparativo de diferentes sistemas de classificações geotécnicas aplicadas aos solos tropicais." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-29052007-163758/.

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Neste trabalho apresenta-se um estudo comparativo de sistemas de classificações geotécnicas aplicadas aos solos tropicais. Para 38 solos do interior paulista foram realizados ensaios de classificação/identificação pelo método das pastilhas segundo os procedimentos de Nogami e Villibor (1994b) e Godoy e Bernucci (2002) e ensaios de azul de metileno (Fabbri, 1994). Além disso, foram executados ensaios de permeabilidade buscando-se relações entre esta variável e o comportamento (laterítico/não laterítico) dos solos e suas características físicas. Também foram analisados resultados de ensaios de sucção na umidade ótima, obtidos por Takeda (2005). Inicialmente foram analisados resultados dos ensaios de difração de raios-X, microscopia eletrônica de varredura e da classificação MCT, todos obtidos por Takeda (2005), onde foi constatada uma coincidência entre a gênese dos solos e seu comportamento (laterítico/ não laterítico). A partir desta constatação, foram confrontados os resultados obtidos através do método das pastilhas, segundo os dois procedimentos destacados acima, e dos ensaio de azul de metileno com a classificação MCT. Nesta etapa, foi verificada uma concordância de 81,6% entre o método das pastilhas de Nogami e Villibor (1994b) e a MCT. Os resultados dos ensaios de azul de metileno (Fabbri, 1994) concordaram com a MCT em 92,1%. Com relação ao método das pastilhas de Godoy e Bernucci (2002), observou-se que este procedimento necessita de revisões. Os coeficientes de permeabilidade não revelaram uma relação clara com o comportamento laterítico ou não laterítico dos materiais. Também não foi observada uma relação entre este coeficiente e características físicas dos solos, quando tomadas isoladamente. Os valores de sucção mostraram que os solos com maiores teores de argila apresentam maiores valores de sucção. Também se observou que para iguais teores de argila, solos de comportamento laterítico apresentaram sucções menores que os solos de comportamento não laterítico. This work presents a comparative study of different tropical soils geotechnical classification systems. Classification/identification tests of tablet method as proposed by Nogami and Villibor (1994b) and Godoy and Bernucci (2002) and methylene blue adsorption tests (Fabbri, 1994) were done for 38 soil samples of São Paulo state countryside, in Brazil. Futhermone, hydraulic conductivity tests were performed in intent of search relations between this variable and the soil behavior (lateritic/non lateritic), and its physical characteristics. Suctions results (Takeda, 2005) on optimum water content, also were analyzed . Initially XRD and SEM test\'s results, and MCT classification\'s results, obtained from Takeda (2005), were analyzed, where a coincidence between soil genesis and its behavior (lateritic/non lateritic) was observed. At this point, the methylene blue adsorption test and tablet method\'s results were compared with the ones obtained from MCT classification. At this time, tablet method as proposed by Nogami and Villibor (1994b) and MCT classification presented a 81.6% of agreement rate. Methylene blue adsorption showed a agreement rate of 92.1% with the MCT classification. The tablet method proposed by Godoy and Bernucci (2002) seemed to need some revision. The hydraulic conductivity values didn\'t show any clear relationship with the soil\'s lateritic/non lateritic behavior. A relation between the hydraulic conductivity and the physical characteristics wasn\'t observed, when these last ones was correlated, one by one, with the hydraulic conductivity. The suction values showed that the most clay content leads to higher suctions values. Lateritic soils with the same clay content showed lower suctions values then non lateritic soils with the same clay content.

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Bernucci, Liedi Légi Bariani. "Considerações sobre o dimensionamento de pavimentos utilizando solos lateríticos para rodovias de baixo volume de trafego." Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-07042017-101955/.

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Este trabalho apresenta diversas considerações a respeito do dimensionamento de pavimentos de baixo custo que utilizam solos lateríticos em sua estrutura. Esses pavimentos são construídos para rodovias de baixo volume de tráfego que, apesar de serem utilizadas por pequeno número de veículos diariamente, podem ser solicitadas por veículos muito pesados, provenientes das regiões agrícolas, usineiras e industriais. A despeito dos solos lateríticos não atenderem as especificações tradicionais e das estruturas serem incompatíveis com as normas de dimensionamento vigentes, as soluções de baixo custo têm mostrado um bom desempenho em rodovias de baixo volume de tráfego. Foram estudadas diversas variáveis intervenientes no projeto do pavimento: a composição do tráfego nessas rodovias; o clima atuante no Estado de São Paulo, responsável por umidades de equilíbrio inferiores aquelas nas quais os solos foram compactados; e as propriedades geotécnicas dos solos lateríticos. Foram enfocadas as características desses solos que auxiliam na sua identificação em campo e em laboratório, e que podem ser exploradas para o bom desempenho dos pavimentos. A partir de ensaios de módulos de resiliência, mostra-se a importância da coesão dos solos lateríticos, responsável por sua estabilidade e comportamento adequado em bases de pavimentos. Finalmente, são verificadas as estruturas de pavimentos de baixo custo com base nos conceitos do método norte-americano de dimensionamento de pavimentos de AASHTO-1986. Os resultados corroboram o uso de estruturas esbeltas, normalmente adotadas no Estado de São Paulo. This thesis proposes to study several aspects of the design of low-cost pavements structurally consisting of lateritic soils. These pavement are utilized for low-volume roads; although used on a daily basis by a small number of vehicles, they might also be requested by heavy trucks typical for agricultural and industrial areas. Thin-layered pavements of lateritic soils have been successfully used in low-volume roads in the State of São Paulo, is spite of the fact that these soils do not conform to traditional specifications and that such structures are not in accordance to current design requirements. Several factors relevant to the pavement design have been analyzed: traffic composition on such roads; climatic conditions of the state of São Paulo, responsible for equilibrium moisture contents lower than those at which the soils were originally compacted; and the geotechnical properties of lateritic soils. Emphasis is given to soil characteristic useful to field and laboratory identification and necessary to ensure good performance of the pavement. The importance of the cohesion of lateritic soils, responsible for the stability and good performance of pavement bases, is demonstrated by means of resilient moduli test results. Finally, the structure of low-cost pavements has been verified within the framework of the AASHTO-1986 pavement design method, The results support the use of thin-layered pavement structures, widely adopted in the State of São Paulo.

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JUNIOR, FRANCISCO DE ASSIS COSTA. "STUDY OF THE EFFECT OF INFILTRATION OF CAUSTIC SODA ON THE STRENGTH CHARACTERISTICS OF A LATERITIC SOIL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2001. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2064@1.

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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR Este trabalho apresenta um estudo do comportamento mecânico, em especial nas características de resistência, de um solo laterítico submetido à contaminação de licores cáusticos a diferentes concentrações. O programa experimental envolveu ensaios de caracterização, ensaios químicos, difração de raios-X, microscopia eletrônica de varredura e ensaios triaxiais com diferentes valores de concentrações cáusticas. Propriedades mecânicas foram determinadas mediante a execução de ensaios triaxiais CID a diferentes concentrações cáusticas, assim como as interações físico- químicas que foram determinadas mediante ensaios químicos de pH, capacidade de troca catiônica e ataque sulfúrico. Os resultados do programa experimental demonstraram uma acentuada variação de volume do solo, a qual está ligada à presença dos licores cáusticos e, por outro lado, também indicaram que os parâmetros de resistência ao cisalhamento do solo são pouco afetados pelos licores cáusticos. This work presents the results of a laboratory study on the effects of infiltration of a caustic liqueur on the stress- strain- strength behavior of a sandy lateritic soil. The experimental program consisted of general characterization,chemicals tests, X-ray diffraction analysis, electron microscopy and triaxial tests using the caustic liqueur at different concentrations.Mechanic and hydraulic properties were obtained performing triaxial CID tests with different caustic concentrations. Physical- chemical interactions were evaluated through of determination of pH, cation exchange capacity and sulfuric attack tests. The results obtained showed that soil suffers large volume changes under percolation of the liqueur, with these changes being a function of the caustic concentration, on the other hand, the shear strength parameters are little affected by the liqueur.

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Mathian, Maximilien. "Étude de l'enregistrement minéralogique des événements paléoclimatiques dans les sols tropicaux : nouveaux apports de la datation de kaolinites par irradiations expérimentales." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS161/document.

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Les latérites couvrent plus de 30% des surfaces émergées. Comprendre leur évolution future est essentiel pour prédire les changements qui affecteront le fonctionnement de la Zone Critique dans les siècles à venir. La littérature a pu montrer que les horizons indurés de ces sols comportaient plusieurs générations de minéraux secondaires qui pouvaient être reliées à différents événements paléoclimatiques. Des études isotopiques ont montré que les horizons non indurés de ces sols pouvaient aussi posséder des générations distinctes de minéraux secondaires. La datation par Résonance Paramagnétique Électronique, a été appliquée sur des kaolinites de latérites dans le but d’identifier si ce minéral possède bien plusieurs générations au sein d’un même profil et si ces dernières étaient corrélables avec des événements paléoclimatiques globaux ou régionaux. Au cours de cette thèse, deux régolithes du Plateau du Karnataka (Inde), quatre du bassin du Rio Négro (Brésil) et un de la région de Syerstone (Australie) ont été étudiés. Les résultats de ces datations ont permis de distinguer différentes générations de kaolinites au sein de chacun des profils étudiés. Ces dernières sont par ailleurs toutes corrélables avec des périodes de fortes précipitations liées aux évolutions climatiques régionales et/ou globales. Ces résultats confirment aussi l’existence du phénomène de rajeunissement profils latéritiques au cours des temps géologiques. Le travail de cette thèse corrobore l’hypothèse de l’évolution épisodique de ces sols tropicaux et souligne leur importante stabilité dans les temps géologiques Laterites are covering a third of the continental surfaces. Understanding their evolution through the ongoing climate change is critical to predict the future Critical Zone transformation. Laterite duricrusts can contain several generations of secondary minerals that can be correlated with distinct paleoclimatic events. Isotopic studies showed that loose laterites may also be formed by several generations of secondary minerals. The objective of this PhD was to confirm that loose laterites contain several generations of kaolinites and that they formed during regional and/or global paleoclimatic events. With this aim in view, a recent dating methodology, the Electron Paramagnetic Resonance dating of kaolinites, was used on tropical regolith profiles from three continents with distinct geodynamic histories: India (Karnataka plateau), South America (Rio Negro basin, Brazil) and Australia (Syerstone region, New South Wale). The data set of this PhD confirms that a regolith contains several generations of kaolinites. All the identified generations of the present study can be correlated with regional paleoclimatic events or with tropical weathering favourable periods initiated by global paleoclimatic trends. Kaolinite generations formed preferentially during high precipitations periods and result from the rejuvenation of laterite profiles. The results of this PhD confirm that laterites have an episodic evolution

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MONCADA, MONICA PRISCILLA HERNANDEZ. "LABORATORY EVALUATION OF COLLAPSE AND SOLUTE TRANSPORT CHARACTERISTICS OF A LATERITIC SOIL UNDER INFILTRATION OF A CAUSTIC LIQUEUR." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5129@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO Neste trabalho se analisam as características de colapso de um solo laterítico submetido à percolação de um licor cáustico a diferentes concentrações. O solo é uma areia quartzosa com uma pequena fração de finos cauliníticos. O licor é um efluente industrial, resultante da produção de alumínio, a base de soda cáustica. Mediante o presente estudo, determinou-se o efeito da infiltração do licor cáustico sobre três aspetos: colapsividade, transporte de solutos e características de sucção. Isto foi feito através de um programa experimental que incluiu ensaios de caracterização física-química do solo e do licor, ensaios edométricos, em edômetros especiais, para avaliar as características de colapso e de transporte de solutos, e ensaios de sucção pelo método do papel filtro. Os resultados do programa experimental mostraram que o solo é colapsível em presença de água, sendo sua colapsividade aumentada em presença do licor cáustico. Também indicaram que os parâmetros de transporte e sucção são fortemente afetados pela percolação do licor. A mudança destes parâmetros é função da concentração do licor. In this work, characteristics of collapse of a laterítico soil submitted to percolation of a caustic liqueur to different concentrations are analysed. The soil comprises a quartzitic sand with a small fraction of kaolinitic clay. The liqueur is a caustic fluid, from an aluminium industry. In the present study, effects of the caustic liqueur infiltration were observed considering three aspects: collapse, solute transport and soil suction characteristics. This was done through an experimental program that included physical and chemical characterization of the soil and liqueur, special oedometer tests to evaluate simultaneously collapse characteristics and solute transport, and suction tests using the filter paper method. The results of the experimental program showed that the soil suffers volume change in presence of water, and its colapsivity is increased in presence of the caustic liqueur. They also indicated that the transport and suction parameters are affected strongly by the percolation of the liqueur.

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16

Mathian, Maximilien. "Étude de l'enregistrement minéralogique des événements paléoclimatiques dans les sols tropicaux : nouveaux apports de la datation de kaolinites par irradiations expérimentales." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS161.

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Les latérites couvrent plus de 30% des surfaces émergées. Comprendre leur évolution future est essentiel pour prédire les changements qui affecteront le fonctionnement de la Zone Critique dans les siècles à venir. La littérature a pu montrer que les horizons indurés de ces sols comportaient plusieurs générations de minéraux secondaires qui pouvaient être reliées à différents événements paléoclimatiques. Des études isotopiques ont montré que les horizons non indurés de ces sols pouvaient aussi posséder des générations distinctes de minéraux secondaires. La datation par Résonance Paramagnétique Électronique, a été appliquée sur des kaolinites de latérites dans le but d’identifier si ce minéral possède bien plusieurs générations au sein d’un même profil et si ces dernières étaient corrélables avec des événements paléoclimatiques globaux ou régionaux. Au cours de cette thèse, deux régolithes du Plateau du Karnataka (Inde), quatre du bassin du Rio Négro (Brésil) et un de la région de Syerstone (Australie) ont été étudiés. Les résultats de ces datations ont permis de distinguer différentes générations de kaolinites au sein de chacun des profils étudiés. Ces dernières sont par ailleurs toutes corrélables avec des périodes de fortes précipitations liées aux évolutions climatiques régionales et/ou globales. Ces résultats confirment aussi l’existence du phénomène de rajeunissement profils latéritiques au cours des temps géologiques. Le travail de cette thèse corrobore l’hypothèse de l’évolution épisodique de ces sols tropicaux et souligne leur importante stabilité dans les temps géologiques Laterites are covering a third of the continental surfaces. Understanding their evolution through the ongoing climate change is critical to predict the future Critical Zone transformation. Laterite duricrusts can contain several generations of secondary minerals that can be correlated with distinct paleoclimatic events. Isotopic studies showed that loose laterites may also be formed by several generations of secondary minerals. The objective of this PhD was to confirm that loose laterites contain several generations of kaolinites and that they formed during regional and/or global paleoclimatic events. With this aim in view, a recent dating methodology, the Electron Paramagnetic Resonance dating of kaolinites, was used on tropical regolith profiles from three continents with distinct geodynamic histories: India (Karnataka plateau), South America (Rio Negro basin, Brazil) and Australia (Syerstone region, New South Wale). The data set of this PhD confirms that a regolith contains several generations of kaolinites. All the identified generations of the present study can be correlated with regional paleoclimatic events or with tropical weathering favourable periods initiated by global paleoclimatic trends. Kaolinite generations formed preferentially during high precipitations periods and result from the rejuvenation of laterite profiles. The results of this PhD confirm that laterites have an episodic evolution

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17

Rizzo, Rodrigo Pelho [UNESP]. "Avaliação da eficácia de barreiras de proteção ambiental produzidas com solo arenoso estabilizado quimicamente." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/90738.

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Made available in DSpace on 2014-06-11T19:24:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-26Bitstream added on 2014-06-13T18:21:09Z : No. of bitstreams: 1 rizzo_rp_me_ilha.pdf: 2484817 bytes, checksum: d447a4c31b21a9373e9067be45abcaad (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) As barreiras de proteção ambiental são os dispositivos mais usados na atualidade para reduzir riscos associados à infiltração de fluidos nocivos no subsolo. O presente trabalho dedicou-se ao estudo, em laboratório, de misturas de solo arenoso fino laterítico com cal e cimento para a produção de barreiras desta natureza. Para tanto, foram compactadas misturas a fim de produzir corpos de prova submetidos a ensaios, visando à avaliação da condutividade hidráulica e da capacidade de retenção de soluções de origem orgânica (chorume e água residuária) e inorgânica (soluções contendo os íons K+, Na+ e Cl-) destas misturas. A condutividade hidráulica foi avaliada com ensaios de permeabilidade em duas condições: à carga variável (corpos de prova de 10cm de diâmetro e 12cm de altura) e em área plena (corpos de prova miniatura – 5cm de altura e diâmetro). Para avaliação da capacidade de retenção foram considerados dois tipos de ensaios: em colunas (25cm de altura e 7cm de diâmetro) e em corpos miniatura (5cm de altura e diâmetro). Os resultados obtidos mostram que os materiais produzidos em tais condições atendem aos requisitos técnicos para seu uso como barreiras de proteção ambiental. Os valores de condutividade hidráulica obtidos foram menores que os exigidos e os processos de retenção observados mostraram resultados muito bons para os fluidos de origem orgânica e resultados bastante promissores para as soluções inorgânicas. Natural liners are the most useful environmental protection systems in order to reduce soil and ground water pollution risks. In this work we made laboratory tests to evaluate hydraulic conductivity and ions retention capability in mixtures produced with soil-cement and soil-lime. Mixtures were compacted, resulting specimens for laboratory tests of hydraulic conductivity and retention capability with organic (leachate and wastewater) and inorganic (solutions with K+, Na+ e Cl-) solutions. For hydraulic conductivity evaluation was used two kinds of tests: variable charge (specimens with 10cm of diameter and 12cm high) and total section test (specimens with 5cm of diameter and high). For retention capability we used also two kinds of tests: column test (specimens with 7cm of diameter and 25cm high) and total section test (specimens with 5cm of diameter and high). Obtained results show that the produced materials obey technical necessities for barriers usage. Hydraulic conductivity obtained show values lesser than the necessary, while capability retention results show good results also for organic and inorganic solutions.

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Júnior, Walter Sidronio da Silva. "Estudo para a utilização de resíduo da fabricação de papel na construção rodoviária." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-14092010-102353/.

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A indústria de papel e celulose representa um dos mais expressivos setores industriais do mundo, sendo de grande importância para a economia mundial. Na América do Sul, devido à grande disponibilidade de recursos florestais, O Brasil e o Chile são os maiores produtores de celulose. O Brasil produz em torno de 6 milhões de toneladas de polpa por ano, dos quais 98% são branqueadas, segundo pesquisas da Unicamp (2004). A produção de papel passou por evoluções ao longo dos anos, que possibilitou o melhoramento da qualidade e velocidade de produção, fazendo com que este setor industrial gerasse um aumento na capacidade produtiva, acarretando um aumento do volume de resíduos gerados pela indústria de papel e celulose. O alto consumo de papel e seus métodos de produção endossam o rol das atividades humanas mais nocivas ao planeta. Para produzir 1 tonelada de papel são necessárias 2 a 3 toneladas de madeira, uma grande quantidade de água (mais do que qualquer outra atividade industrial) e muita energia (está em quinto lugar na lista das que mais consomem energia). O principal objetivo deste trabalho é apresentar resultados da avaliação, em laboratório, de propriedades físicas e mecânicas de misturas constituídas de solo, cal e resíduo da fabricação de papel, visando sua utilização na construção rodoviária. Os ensaios de compactação foram realizados na energia equivalente ao Proctor Normal e o comportamento mecânico das misturas foi avaliado mediante os resultados obtidos dos ensaios de compressão simples, compressão diametral e triaxial cíclico. Para a realização destes ensaios escolheram-se os teores de 0 e 40% de resíduo e os teores 0,5 e 10% de cal. Avaliou-se, também, a rigidez do material mediante o módulo tangente inicial (Eo) e módulo de resistência (Mr). Os corpos-de-prova foram ensaiados sem imersão e após imersão em água por 4 horas, decorridos 7 dias de cura em câmara úmida. Posteriormente, analisou-se a influência do tempo de cura para 0, 2, 7, 28 84 dias de permanência em câmara úmida. Para determinar a periculosidade do resíduo foram executados ensaios ambientais de lixiviação e solubilização. Os resultados mostraram que a adição do resíduo e a influência da água agiram como agentes redutores das propriedades mecânicas. Entretanto, as misturas de solo-cal e solo-resíduo-cal atendem às especificações técnicas da State of the art 5 - Lime stabilization (TRB, 1987), oferecendo uma solução viável para a utilização destas misturas na construção rodoviária. Observou-se, também, que o aumento do tempo de cura e teor de cal conduziu a valores crescentes de resistência e rigidez. Os ensaios ambientais realizados no solo, resíduo da fabricação de papel e na mistura solo-resíduo-cal foram essenciais para se obter parâmetros que permitam acompanhar o desequilíbrio que possa surgir no meio ambiente decorrente da aplicação deste resíduo em camadas de base e sub-base de pavimentos. The paper and pulp industry represent one of the most expressive industrial sector around the world, being of great importance to the world economy. In South America, because of the wide forest resources, Brazil and Chile are the largest pulp-producing. Brazil produces around 6 million tons of pulp per year, among which 98% of the pulp are produced by the bleaching process, according to research from Unicamp (2004). The paper production has undergone changes through the years, which enabled the improvement of the quality and speed of production. It made that this industrial sector has an increase of productive capacity and of waste\'s volume produced for the paper and pulp industry. The high consumption of paper and its productions ways increase the contingent of human most harmful activities o the planet. To produce 1 ton of paper are necessary from 2 to 3 tons of wood, a lot of water (more than any other industrial activity) and a lot of energy (it is in the fifth place in the list of industries that consume more energy). The main goal of this paper is present results of assessment, in laboratory, of physical and mechanical properties of mixtures of soil, lime and residue from the manufacture of paper, for their use in road construction. The compaction tests were made in the equivalent energy to the normal Proctor and the mechanical behavior of the mixtures was evaluated on the strength of the results of tests for unconfined compressive strength, diametrical compression and cyclic loading triaxial. For these tests have been chosen the levels of 0 and 40% of waste and the levels 0,5 and 10% of lime. It was evaluated also the stiffness of the material by the initial tangent modulus (Eo) and resilient modulus (Mr). The samples were tested without immersion and after immersion in water for 4 hours, after 7 days of cure in a moist chamber. Subsequently, it was analyzed the influence of curing time for 0, 2, 7, 28 and 84 days of stay in a moist chamber. To determine the dangerousness of the residue were performed environmental testing of leaching and solubility. The results showed that the addition of waste and the influence of water acted as reducing agents of mechanical properties. However mixtures of soil-lime and soil-residue-lime meet the technical specifications of the State of the art 5 - Lime stabilization (TRB, 1987), providing a feasible solution to the use of such mixtures in road construction. Observed also that increasing the curing time and content of lime led to increasing values of strength and stiffness. The environmental testing conducted in the soil residue from the manufacture of paper and the mixture soil-residue-lime were essential for obtaining parameters for monitoring the imbalance that may arise in the environment resulting from the application of this waste in layers of base and sub base\'s pavements.

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Braucher, Régis. "Utilisation du 10Be cosmogenique produit in-situ pour l'étude de la dynamique des laterides en zone intertropicale." Aix-Marseille 3, 1998. http://www.theses.fr/1998AIX30045.

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Les cosmonucleides produits in-situ resultent de l'interaction des particules energetiques issues du rayonnement cosmique avec les mineraux exposes a la surface de la terre. Le nucleide cosmogenique 10be (t1/2 = 1,5ma) a ete utilise dans ce travail afin d'etudier les modes de developpement des laterites et de quantifier les processus les affectant. Au cours de cette etude, differents systemes lateritiques ont ainsi ete investigues aussi bien en afrique qu'au bresil. La distribution des concentrations en 10be mesurees par spectrometrie de masse par accelerateur dans des quartz issus de filons et preleves dans des profils de sols permet 1/ de determiner la nature autochtone ou allochtone des processus impliques lors de la mise en place des sequences etudiees, 2/ de quantifier les taux d'erosion ou d'enfouissement affectant ces surfaces, et 3/ de mettre en evidence et d'estimer l'extension de l'activite biologique. L'examen de l'evolution de la concentrations en 10be le long de stones-lines permet de preciser sans ambiguite leur origine allochtone ou autochtone et, dans ce dernier cas, deux types de modeles developpes au cours de ce travail permettent alors d'estimer la vitesse des deplacements lateraux superficiels des sols.

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Rizzo, Rodrigo Pelho. "Avaliação da eficácia de barreiras de proteção ambiental produzidas com solo arenoso estabilizado quimicamente /." Ilha Solteira : [s.n.], 2004. http://hdl.handle.net/11449/90738.

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Orientador: José Augusto de Lollo Banca: Reinaldo Lorandi Banca: Milton Dall'Aglio Sobrinho Resumo: As barreiras de proteção ambiental são os dispositivos mais usados na atualidade para reduzir riscos associados à infiltração de fluidos nocivos no subsolo. O presente trabalho dedicou-se ao estudo, em laboratório, de misturas de solo arenoso fino laterítico com cal e cimento para a produção de barreiras desta natureza. Para tanto, foram compactadas misturas a fim de produzir corpos de prova submetidos a ensaios, visando à avaliação da condutividade hidráulica e da capacidade de retenção de soluções de origem orgânica (chorume e água residuária) e inorgânica (soluções contendo os íons K+, Na+ e Cl-) destas misturas. A condutividade hidráulica foi avaliada com ensaios de permeabilidade em duas condições: à carga variável (corpos de prova de 10cm de diâmetro e 12cm de altura) e em área plena (corpos de prova miniatura - 5cm de altura e diâmetro). Para avaliação da capacidade de retenção foram considerados dois tipos de ensaios: em colunas (25cm de altura e 7cm de diâmetro) e em corpos miniatura (5cm de altura e diâmetro). Os resultados obtidos mostram que os materiais produzidos em tais condições atendem aos requisitos técnicos para seu uso como barreiras de proteção ambiental. Os valores de condutividade hidráulica obtidos foram menores que os exigidos e os processos de retenção observados mostraram resultados muito bons para os fluidos de origem orgânica e resultados bastante promissores para as soluções inorgânicas. Abstract: Natural liners are the most useful environmental protection systems in order to reduce soil and ground water pollution risks. In this work we made laboratory tests to evaluate hydraulic conductivity and ions retention capability in mixtures produced with soil-cement and soil-lime. Mixtures were compacted, resulting specimens for laboratory tests of hydraulic conductivity and retention capability with organic (leachate and wastewater) and inorganic (solutions with K+, Na+ e Cl-) solutions. For hydraulic conductivity evaluation was used two kinds of tests: variable charge (specimens with 10cm of diameter and 12cm high) and total section test (specimens with 5cm of diameter and high). For retention capability we used also two kinds of tests: column test (specimens with 7cm of diameter and 25cm high) and total section test (specimens with 5cm of diameter and high). Obtained results show that the produced materials obey technical necessities for barriers usage. Hydraulic conductivity obtained show values lesser than the necessary, while capability retention results show good results also for organic and inorganic solutions. Mestre

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Kublik, Cristiane. "ENSAIOS DE PLACAS EM SOLO LATERÍTICO NA CIDADE DE SANTO ÂNGELO." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/7758.

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This thesis presents a study of the behavior of a soil profile typical of the Santo Ângelo city, the board is tested. This study aimed to investigate the behavior of natural soil, waterlogged, compacted and with addition of cement for their application in shallow foundations. The load tests were conducted in an area next to the building of the laboratories of the Civil Engineering Course, at Universidade Regional Integrada do Alto Uruguai e das Missões , URI, in Santo Ângelo. The geotechnical characterization tests were conducted in disturbed and undisturbed samples collected from trenches and pits during the test plate. Pedologicaly soil consists of a thick surface horizon (horizon A and B) classified as Typic. This texturally soils were classified as silty clays and silty clays, sandy, porous and unsaturated. In terms of resistance of these soils show a cohesion of 10 kPa and a friction angle of 32 degrees. These values are reduced as flooded, mainly in relation to cohesion. The flooding also reduces the strength parameters, causes a collapse that was assessed by means of direct shear tests and compression tests contained doubles. The collapse of values measured was between 1% and 3%. The effect of flooding there was also confined compression tests, with the stress reduction of pre-densification and increased compressibility. In plate tests verified the influence of flooding on the deformability and strength of these soils. Flooding increased deformability and reduced the resistance, but it was found that a natural rain prior to testing in natural soil was more effective than a process of artificial flooding. For tests on compacted soil and soil-cement had decreased deformability and increased resistance of these soils. This increased rigidity and resistance was more intense in the soil-cement. Therefore, the use of compression techniques and the addition of cement increases the load capacity of soils for use in shallow foundations. Esta dissertação apresenta um estudo do comportamento de um perfil de solo típico da cidade de Santo Ângelo, submetido a ensaios de placa, cujo principal objetivo é verificar o comportamento do solo natural, inundado, compactado e com adição de cimento visando a sua aplicação em fundações superficiais. As provas de carga foram realizadas numa área ao lado do prédio dos laboratórios do Curso de Engenharia Civil da Universidade Regional Integrada do Alto Uruguai das Missões (URI), na cidade de Santo Ângelo. Os ensaios de caracterização e geotécnicos foram realizados em amostradas deformadas e indeformadas, coletadas em trincheira e cavas durante os ensaios de placa. Pedologicamente o solo é constituído por um espesso horizonte superficial (horizonte A e B), classificado como Latossolo. Texturalmente esse solos foram classificados como argilas siltosas e argilas siltoarenosas, porosas e não saturadas. Em termos de resistência, eles apresentam uma coesão de 10 kPa e um ângulo de atrito de 32º. Esses valores são reduzidos tanto quanto inundados, principalmente em relação à coesão. A inundação, além de reduzir os parâmetros de resistência, ocasiona um colapso que foi avaliado por meio dos ensaios de cisalhamento direto e ensaios de compressão confinada duplos. Os valores de colapso medidos situaram-se entre 1% e 3%. O efeito da inundação verificou-se também nos ensaios de compressão confinada, com a redução da tensão de pré-adensamento e o aumento da compressibilidade. Nos ensaios de placa, verificou-se a influência da inundação na deformabilidade e resistência desses solos. A inundação aumentou a deformabilidade e diminuiu a resistência, mas verificou-se que uma chuva natural, anterior ao ensaio, no solo natural, foi muito mais efetiva que um processo de inundação artificial. Nos ensaios realizados no solo compactado e solo-cimento, ocorreu uma diminuição da deformabilidade e aumento da resistência desses solos. Esse aumento de rigidez e resistência foi mais intenso no solo-cimento. Portanto, a utilização de técnicas de compactação e adição de cimento aumenta a capacidade de carga de solos para utilização em fundações superficiais.

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Klinsky, Luis Miguel Gutiérrez. "Proposta de reaproveitamento de areia de fundição em sub-bases e bases de pavimentos flexíveis, através de sua incorporação a solos argilosos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-07082008-162426/.

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Um dos maiores problemas do setor da fundição de metais é a produção de resíduos sólidos, constituídos basicamente pelas areias residuais. Geralmente, o uso de aditivos e ligantes no processo de fundição limita a reutilização da areia, o que obriga as indústrias a destinar esse resíduo a depósitos de descarte, apesar da boa qualidade que a areia apresenta para outros usos, principalmente na engenharia civil. No Brasil, a produção de fundidos em 2006 alcançou três milhões de toneladas, com a geração de, aproximadamente, uma tonelada de resíduo para cada tonelada de metal produzida. Nesse sentido, procuram-se alternativas para reutilizar a areia de fundição em grandes quantidades, que permitam reduzir os custos de descarte pelas siderúrgicas e a utilização na construção de pavimentos fornece oportunidades para o reuso nas diferentes camadas estruturais. O objetivo deste trabalho é avaliar o reaproveitamento da areia de fundição como material de construção em sub-bases e bases de rodovias, através de sua incorporação a solos argilosos lateríticos da região de Sertãozinho/SP, que tem grande produção de fundidos e, conseqüentemente, de resíduos e também carece de jazidas de solos arenosos para a construção de rodovias e vias urbanas. No estudo foi utilizada a técnica de montagem de solos artificiais a partir de dois solos lateríticos argilosos e do resíduo areia de fundição e da areia virgem. Os solos artificiais foram submetidos aos ensaios de: limite de liquidez e plasticidade, granulometria por peneiramento e sedimentação, mini-MCV, perda de massa por imersão, mini-CBR, expansão, contração, infiltrabilidade e permeabilidade em corpos-de-prova de dimensões reduzidas e na energia intermediária, CBR na energia intermediária e triaxial dinâmico. Para determinar a periculosidade do resíduo foram executados ensaios ambientais de massa bruta, lixiviação e solubilização. A partir dos resultados obtidos nestes ensaios foi possível analisar a variação das propriedades tecnológicas e ambientais dos solos em função do teor de areia de fundição adicionada. Os solos lateríticos argilosos com 60% de areia de fundição adicionada apresentaram propriedades mecânicas que atendem as especificações do DER-SP (1991) e do Manual de Pavimentação do DNIT (2006). Os ensaios ambientais mostraram que a areia de fundição, utilizada nesta pesquisa, apresenta características que se enquadram dentro dos parâmetros da CETESB, o que permite que o resíduo seja avaliado para seu reaproveitamento na construção de rodovias. Com base na análise dos resultados conclui-se que o resíduo areia de fundição é de uso promissor nas camadas de base e sub-base de rodovias de baixo volume de tráfego. One of the biggest problems of the foundry industry is the solid residues production, constituted basically by sands. The use of additives and binders in the foundry process reduces the reuse of the sand and the remainder is discarded in industrial landfills or stockpiled on site, although the good quality of the sand as aggregate for manufactured products such as Portland cement, asphalts and geotechnical applications such as road bases, structural fills, embankments and manufactured soils. The foundry production, in year 2007, in Brazil, exceeded three millions tons, and it is had that for each ton of produced metal, a ton of foundry residue results approximately. The long term sustainability, economics and reuse practices suggest that alternative use practices must be done for the foundry sand and the roadways construction supply such opportunities. The purpose of this work is to evaluate the reuse of foundry sand as a construction material for road bases and sub-bases, trough its incorporation to clay lateritic soils from Sertaozinho, Sao Paulo state region. This region has a highly production of foundry metals and residues, and does not have natural sandy soils deposits for the construction of highways and urban roads. The technique used in this study was de soil assembly; foundry sand and virgin sand were mixed with two clay lateritic soils in different proportions. Tests were made in the soil-sand mixes to evaluate the sand addition influence in the mechanic soil behaviour, which are: liquid limit and plastic limit, granulometry, mini-MCV, immersion lost mass, mini-CBR at the intermediate energy, expansion, contraction, CBR at the intermediate energy, infiltrability, permeability and dynamic triaxial. Also, environment tests - leaching and solubility - were made to establish the hazard of the foundry sand. The results show that lateritic clay soils with 60% of foundry sand added has adequate mechanical properties to be used as base and sub-base material for low traffic pavements, according to the DER-SP(1991) specifications and the DNIT Manual Pavement (2006). The environment tests indicate that the foundry sand residue, used in this work, has promising use in road bases and sub-bases.

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Ribeiro, Madalena Maria Pereira. "Contribuição ao estudo da deformação permanente dos solos de subleito." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-06092013-110219/.

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Esta pesquisa apresenta uma contribuição ao entendimento do efeito da variação do estado de tensões e variação de umidade na compactação, na suscetibilidade à deformação permanente dos solos de subleito. Assim, um programa experimental foi desenvolvido considerando as variáveis o estado de tensões e a umidade, que são importantes na análise da evolução da deformação permanente dos solos de subleito. Para esta avaliação, foi utilizado um solo arenoso laterítico proveniente da região de Dois Córregos, estado de São Paulo, Brasil. Foram realizados ensaios de caracterização e ensaios triaxiais de cargas repetidas (módulo de resiliência e deformação permanente). Adicionalmente, foi analisado o efeito do acúmulo de deformação permanente nos valores de módulo de resiliência, que foi efetuado a partir de ensaios realizados antes e após o ensaio de deformação permanente. Além disso, de posse dos resultados de deformação permanente foi verificada a ocorrência do Shakedown. Concluiu-se que um aumento de tensões causa um aumento na deformação permanente, não sendo possível avaliar o efeito da variação de umidade na deformação permanente. Observou-se a ocorrência do Shakedown, porém não foi possível definir seu limite. Não foi possível o enquadramento da deformação permanente no modelo de Monismith, sendo proposto, por meio de regressão múltipla, um modelo para avaliação da deformação permanente, considerando as variáveis, umidade, número de aplicações de carga e estado de tensões. This research presents a contribution to understanding the effect of the variation of the state of stress and water content in the evolution of the permanent deformation of subgrade soils. A lateritic sandy soil from the region of Dois Córregos, State of São Paulo, Brazil, was used throughout the characterization and triaxial repeated loads tests (resilient module and permanent deformation tests). Additionally, it was analyzed the effect of the accumulation of permanent deformation in the values of resilient module from tests performed before and after the permanent deformation tests, as well as it was verified the occurrence of Shakedown. It was concluded that an increase of stress causes an increase in permanent deformation, but it was not possible to evaluate the effect of the variation of moisture content in permanent deformation. It was also observed the occurrence of Shakedown, but it was not possible to set its limit. Furthermore, it was not possible to fit the permanent deformation testing data in the model of Monismith, being proposed, by means of multiple regression, a model for the assessment of permanent deformation considering the variables moisture content, number of load applications and state of stress.

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Toure, Cheikh Sidia. "Elimination de la pollution carbonée dans deux réacteurs à biomasse fixée sur support de laterité et quartz en conditions climatiques tropicales sahéliennes : possibilités et limites de réutilisation des effluents pour l'irrigation des sols locaux /." [S.l.] : [s.n.], 1986. http://library.epfl.ch/theses/?nr=653.

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Junior, Paulo Roberto Reschetti. "Avaliação do comportamento mecânico de um solo arenoso fino laterítico reforçado com fibras para uso em pavimentação." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-23042009-152038/.

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O objetivo do estudo apresentado nesta dissertação é avaliar a influência da inserção de fibras curtas, dispostas aleatoriamente, nas resistências à compressão e tração, na deformabilidade e no módulo de resiliência de um solo arenoso fino laterítico (SAFL) visando sua utilização na base de pavimentos. Foram estudadas fibras de vidro e de polipropileno. A primeira foi adicionada nos teores de 0,5%, 1,0% e 1,5% com comprimentos de 13 mm e 24 mm, já para a segunda, utilizaram-se os teores de 0,2%, 0,4% e 0,6% com comprimentos de 12 mm e 30 mm. O ensaio de compactação resultou em pouca variação da umidade ótima e leve decréscimo da massa específica máxima para as duas fibras. Para se determinar o comportamento mecânico do solo e dos compósitos, realizaram-se ensaios de compressão simples, compressão diametral e compressão triaxial cíclico. Previamente à realização destes ensaios, os corpos-de-prova eram mantidos ao ar durante um dia e posteriormente em câmara úmida, selados, durante dois dias. Esta condição procura aproximar a situação de laboratório às condições de campo. Ensaios complementares na umidade ótima de compactação foram realizados com algumas misturas. Para os ensaios de compressão simples, observou-se que a adição de fibra de polipropileno não influencia a tensão de ruptura, aumenta a deformação de ruptura e diminui o módulo tangente inicial e máximo. Já a adição da fibra de vidro, reduz a tensão de ruptura, aumenta a deformação de ruptura e diminui o módulo tangente inicial e máximo. No caso dos ensaios de compressão diametral, não houve alteração na resistência para a fibra de vidro, enquanto que para a fibra de polipropileno, observa-se um ganho de resistência para os teores mais elevados de fibra. Foram calibrados quatro modelos para representação do módulo de resiliência com o estado de tensão, sendo que o modelo composto foi aquele que apresentou melhor desempenho. Resultados de uma simulação numérica de um pavimento constituído com base de SAFL mostraram que a inclusão de fibras, em qualquer das condições acarreta em diminuição do módulo de resiliência. Finalmente conclui-se que, nas condições e com os materiais utilizados, o emprego de fibras não seria indicado para o reforço de SAFL destinado à base de pavimento. The propose of this study is to evaluate the effect of the randomly distributed fiber reinforcement in the compression and tension resistances, deformability and resilient modulus of a fine sandy lateritic soil (FSLS) for base layer of pavements. Glass fibers and polypropylene fibers were studied. The first was added in contents of 0,5%, 1,0% and 1,5% with lengths of 13 mm and 24 mm. For the second, the contents of 0,2%, 0,4% and 0,6% were used with lengths of 12 mm and 30 mm. The compaction tests show slight variation of optimum moisture content and a decrease of the maximum dry unit weight for both fibers. Unconfined compression tests, brazilian tension tests and cyclic triaxial compression tests were carried out to determine the mechanic behavior of the soil and composite materials. The samples were dried in ambient condition for 24 hours and than wrapped up in film paper and stored for 48 hours in humid camera to homogenize the humidity. This procedure was adopted intending to simulate the constructive process adopted in pavement with lateritic soil bases. With some mixtures, complementary tests in the optimum moisture content were carried out. For the unconfined compression tests, the reinforcement with polypropylene fiber did not influence in the rupture tension, increased the rupture deformation and decreased the initial and maximum tangent modulus. The glass fiber reduced the rupture tension, increased the rupture deformation and decreased the initial and maximum tangent modulus. In the diametrical compression tests, there was not any alteration for the resistance adding the glass fiber, while for the polypropylene fiber there was an increase of the resistance for highest fiber contents. Four models were used to represent the resilient modulus behavior with relationship to the tensions state, and, between those, the compost model had the best performance. A simulation of a pavement composed with FSLS bases show that adding fibers, in any condition, the resilient modulus decrease. Finally, concluded that, with the conditions and materials used I this research, the fiber reinforcement would not be indicated for a FSLS apply in a base layer of pavement.

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Zanon, Thiago Villas Bôas. "Avaliação da contaminação de um solo laterítico por lixiviado de aterro sanitário através de ensaios de laboratório e de retroanálise de campo." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3145/tde-21102014-113317/.

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Esta dissertação de mestrado tem como objetivo principal avaliar o transporte de poluentes de um lixiviado real de aterro sanitário em um solo laterítico do estado de São Paulo. A pesquisa objetiva também comparar dois métodos de avaliação de transporte de poluentes: ensaios laboratoriais e análise de dados de contaminação de campo. No aterro sanitário de Botucatu houve, comprovadamente, percolação do lixiviado pelo subsolo durante aproximadamente 15 anos, sob uma lagoa de acumulação de lixiviado sem revestimento de fundo. Foram coletadas amostras de solo subjacente à lagoa, uma areia argilosa, em três perfis verticais na superfície e nas profundidades de 0,25 m, 0,50 m, 1,00 m, 2,00 m e 4,00 m. Os poluentes investigados foram: arsênio, cádmio, carbono orgânico total (COT), chumbo, cloreto, cobre, cromo, ferro, manganês, níquel, nitrogênio Kjeldahl total (NKT) e zinco. Amostras indeformadas do solo local não contaminado foram também coletadas para ensaios de permeabilidade à água e ao lixiviado, assim como para ensaios de coluna. A condutividade hidráulica do solo é da ordem de 10-6 m/s, porém significativamente influenciada pelo gradiente hidráulico aplicado e pela duração da percolação. A condutividade hidráulica diminuiu com a percolação de lixiviado para ordens de grandeza entre 10-8 e 10-6 m/s, dependendo do gradiente hidráulico. Os ensaios de coluna mostraram concentrações efluentes dos elementos pesquisados superiores às afluentes, impossibilitando a obtenção de parâmetros de transporte de poluentes. A análise das amostras contaminadas coletadas in situ mostrou que, embora o solo local seja poroso e apresente alta permeabilidade, as concentrações dos elementos estudados eram inferiores aos limites legais de contaminação do órgão de controle ambiental estadual. O cloreto e o nitrogênio, para os quais não há limites legais, apresentaram-se no subsolo em concentrações elevadas, superiores às concentrações no solo natural e, em algumas amostras, às do lodo depositado no fundo da lagoa. The aim of this research is to evaluate transport of pollutants from a sanitary landfill leachate through a Brazilian lateritic soil by two methods: laboratory tests and analysis of field contamination. In Botucatu Sanitary Landfill, leachate stored in an unlined pond infiltrated into the subsoil for 15 years. Samples of the subjacent soil, a porous clayey sand, were collected in three profiles located inside the area of the leachate pond at the following depths: surface, 0.25 m, 0.50 m, 1.00 m, 2.00 m and 4.00 m. The investigated pollutants were arsenic, cadmium, chloride, cooper, iron, lead, manganese, nickel, Kjeldahl nitrogen, total organic carbon (TOC) and zinc. The hydraulic conductivity measured in undisturbed and uncontaminated samples of the local soil, around 10-6 m/s, is significantly influenced by the applied hydraulic gradient and the percolation duration. When leachate substituted water as percolation fluid, the hydraulic conductivity decreased to values between 10-8 and 10-6 m/s depending on the hydraulic gradient. Chemical analysis of contaminated samples showed that concentrations of the researched elements in the subsoil were lower than legal maximum contamination limits established by the environmental agency of São Paulo state, in spite of the fact that the local soil is porous and has high hydraulic conductivity. On the other hand, chloride and Kjeldahl nitrogen, pollutants for which there are no legal limits, were found in concentrations much higher than background values, and in some samples even higher than those measured in the leachate sludge deposited in the bottom of the storage pond.

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Fall, Meïssa. "Identification et caractérisation mécanique de graveleux latéritiques du Sénégal : application au domaine routier." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL119N.

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Les sols latéritiques compactés sont très largement employés comme remblais et matériaux de construction routière dans la plupart des pays tropicaux. Certaines caractéristiques techniques habituelles, sont déjà bien connues et ont fait l'objet d'études antérieures. Le travail actuel porte sur l'examen plus détaillé du comportement mécanique de trois graveleux latéritiques du Sénégal occidental compactes à l'optimum Proctor modifié. L'étude commence par une partie bibliographique qui traite de la formation et de la genèse des sols résiduels tropicaux. Par la suite, on aborde l'utilisation de ce matériau dans les travaux routiers, les différentes spécifications routières qui existent sur ce genre de sols et enfin quelques études faites sur les moyens de leurs identifications géotechniques et la connaissance de leurs propriétés geomécaniques. La deuxième partie du travail est consacrée à une étude statistique sur une banque de données géotechniques. Cette étude dégage d'abord des généralités sur les latérites du Sénégal et aboutit par une analyse de données statistiques qui conclut par la proposition de nouvelles spécifications routières avec les graveleux latéritiques du Sénégal. L'étude des interconnexions simples et multiples avec le CBR (recherches de corrélations entre le CBR et les caractéristiques physiques d'identification), montre que le facteur de portance est indépendant des autres caractéristiques. Une bonne évaluation de l'indice CBR passerait par une meilleure connaissance des qualités mécaniques de ces sols. La troisième partie de la thèse est expérimentale. Nous avons utilisé trois sols latéritiques compactés à l'optimum Proctor modifié et pour lesquels des essais triaxiaux ciu ont été faits sous des sollicitations monotones et cycliques. Une évaluation préliminaire a été faite à la boite de cisaillement de grande taille et montre des pertes de caractéristiques mécaniques en passant de l'état non imbibé à l'état imbibé, selon les conditions de l'essai CBR. Le comportement des sols est différent selon que l'on soit sous faibles contraintes (50 à 150 kpa) ou sous grandes contraintes (200 à 600 kpa), ce phénomène étant lié aux paramètres d'état initiaux. L'approche sous chargements répétés a montre que ces sols sont assez performants dans les conditions de variation de teneur en eau faible

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Santos, Roberto Aguiar dos. "Comportamento anisotrópico de um solo laterítico compactado." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-22032016-104302/.

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A compactação de aterros pode gerar comportamento anisotrópico, a depender do teor de umidade de compactação, entre outros fatores. O principal objetivo deste estudo foi investigar alguns aspectos relacionados à anisotropia inerente induzida pela compactação de um solo laterítico. Após realizar a caracterização mineralógica, geotécnica e microestrutural deste solo, estudou-se a resistência ao cisalhamento, condutividade hidráulica, compressibilidade e deformabilidade. O solo estudado foi classificado como laterítico arenoso (LA\') e apresentou agregação relativa da ordem de 12%. A metodologia desenvolvida no intuito de corrigir o aumento na massa específica seca das camadas inferiores, causado pelo processo de compactação, mostrou-se eficaz. A partir da curva de compactação foram consideradas amostras representativas das três condições de umidade de compactação: ramo seco, umidade ótima e ramo úmido. Corpos de prova foram talhados paralelamente e ortogonalmente às camadas de compactação. Os ensaios de porosimetria revelaram um comportamento bimodal na distribuição do tamanho de poros e também que o teor de umidade de compactação não interferiu no tamanho dos microporos. Para o solo compactado no ramo seco e na umidade ótima, a resistência ao cisalhamento correspondente à direção ortogonal se mostrou superior àquela correspondente à direção paralela às camadas de compactação. Por outro lado, a resistência ao cisalhamento no ramo úmido mostrou-se praticamente independente da direção de talhagem dos corpos de prova. Este comportamento se deve à maior capacidade do solo, em um dado teor de umidade, em absorver a energia aplicada e distribuí-la na direção paralela e ortogonal. Com relação às propriedades elásticas do material, observou-se que o aumento do teor de umidade de compactação contribui para redução da anisotropia de deformabilidade. Dentre as propriedades investigadas, a anisotropia de condutividade hidráulica das amostras correspondente ao ramo úmido foi a mais pronunciada, exibindo fluxo oito vezes maior na direção vertical que na horizontal. Finalmente, as discussões e análises presentadas nesta pesquisa mostraram que o grau de anisotropia depende diretamente do teor de umidade de compactação e que diminui com incremento das tensões aplicadas no solo. Compacted embankments can have anisotropic behavior, depending on several factors, including the compaction water content. The aim of this study was to investigate some aspects regarding the inherent anisotropy of a lateritic soil, caused by the compaction process. After performing the geotechnical, mineralogical and microstructural characterization, properties of shear strength, hydraulic conductivity, compressibility and deformability were investigated. This soil this soil was classified as lateritic sand. The grainsize distribution curve indicates 12% the fine particle aggregation. The methodology developed in order to correct the increase in dry density of the lower layers, generated by the compression process, was effective. From the compaction curve, representative samples corresponding to the three compaction water content conditions, representing the dry side, the optimal water content and the wet side were considered. Specimens were trimmed parallel and orthogonally to the compaction layers. The porosimetry tests showed a bimodal behavior in the pore size distribution and also that the compaction water content did not influence the size of the micropores. For the compacted soil sample corresponding to the dry side and optimum water content, the shear strength corresponding to the orthogonal direction was higher than that corresponding to the parallel direction to the compaction layers. However, they were almost equal for both the orthogonal and the parallel directions to the compaction layers. This behavior is due to the higher capacity of the soil at a given moisture content, to absorb the energy applied and distribute it in parallel and orthogonal direction. The analysis the values of maximum shear modulus of the material showed that increasing compaction water content reduces the anisotropy degree. Among the investigated properties, the hydraulic conductivity anisotropy of the samples corresponding to the wet branch was the most pronounced, showing permeability eight times higher in the vertical direction than that in the horizontal direction. Finally, the discussions and analyzes presented in this study showed that the degree of anisotropy directly depends on the compaction water content and decreases with increase confining stress applied to the soil specimens.

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CARDOSO, Ricardo Alves. "Cadastro Geotécnico dos solos finos lateríticos para fins de pavimentação no município de Goiânia- GO." Universidade Federal de Goiás, 2010. http://repositorio.bc.ufg.br/tede/handle/tde/654.

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Made available in DSpace on 2014-07-29T15:03:32Z (GMT). No. of bitstreams: 1 Dissertacao Ricardo Alves Cardoso.pdf: 84040 bytes, checksum: 709198a5f0c45658ebfc111df474a0dc (MD5) Previous issue date: 2010-08-24 This work aims at the register of geotechnical areas in Goiania-GO, showing the occurrence of fine lateritic soils with potential for use in flooring. The methodology is based on work developed by Nogami and Villibor (1995). From surveys and collecting 17 samples in field tests were conducted from MCT (Mini-MCV, Loss of mass by immersion, compression and Mini-CBR) and verified the mechanical and hydraulic properties of these soils. The samples were collected at sites previously chosen using as reference the pedological map of Goiania, trying to distribute them to all soil units of this map. The surveys were performed to a depth of 2 m in each hole the soils were mixed, representing what occurs in practice during the operation of a loan area. The samples collected for the study were those who had only fine soil grains with diameters of less than 2 mm (sieve nº. 10). Tests were also carried out conventional characterization (particle size, Atterberg limits and specific gravity) of the samples collected to better identify these soils. The results obtained with all samples have the intention to form a database for future research in the area of pavement. It was found that in Goiania most soils are lateritic clay and can be applied in the construction of paviments with low traffic volume. Este trabalho tem por objetivo o cadastro geotécnico de áreas no Município de Goiânia-GO,que apresentem a ocorrência de solos finos lateríticos com potencialidade para serem utilizados em pavimentação. A metodologia utilizada se baseia no trabalho concebido por Nogami e Villibor (1995). A partir de sondagens e coletas de 17 amostras no campo foram realizados ensaios da Metodologia MCT (Mini-MCV, Perda de Massa por Imersão, Compactação e Mini-CBR) e verificadas as propriedades mecânicas e hidráulicas desses solos. As amostras foram coletadas em locais previamente escolhidos utilizando-se como referência o mapa pedológico de Goiânia, procurando distribuí-las em todas unidades de solos deste mapa. As sondagens foram executadas até a profundidade de 2 m e em cada furo os solos foram misturados, representando o que ocorre na prática durante a exploração de uma área de empréstimo. As amostras coletadas para o estudo foram somente aquelas constituídas por solos finos com diâmetros dos grãos inferiores a 2 mm (peneira nº 10). Também foram realizados ensaios convencionais de caracterização (granulometria, limites de consistência e peso específico) das amostras coletadas para melhor identificação desses solos. Os resultados obtidos de todas as amostras objetivaram formar um banco de dados para pesquisas futuras na área de pavimentação. Verificou-se que em Goiânia a maioria dos solos estudados são lateríticos argilosos e podem ser aplicados na construção de pavimentos com baixo volume de tráfego.

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Franco, Kar?sia Larice Bezerra. "Caracteriza??o do comportamento geot?cnico de mistura de res?duo de pneus e solo later?tico." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15988.

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Made available in DSpace on 2014-12-17T15:03:29Z (GMT). No. of bitstreams: 1 KarisiaLBF_DISSERT.pdf: 5553904 bytes, checksum: bd332662da6ffbc4e0c2609d1d3928c7 (MD5) Previous issue date: 2012-01-27 A technological alternative for the correct disposal of tires is the use in the construction of embankment with soil and shredded tires. The use of waste tires in tropical soils requires prior knowledge of the properties and limitations of these materials. In this work, the results of an experimental program was devised to characterize the behavior of mixtures of waste tires and a lateritic soil. The residue used in this study is classified as tire buffings with an average size of 1.4 mm. The laboratory program included testing of particle size analysis, Atterberg limits, compaction, direct shear tests, permeability and confined compression tests with pure soil, pure tire and the mixtures. Proportions of 0% (pure soil), 10%, 20%, 40%, 50 % and 100% (pure tire) by weight were used. For the confining stress levels used in the study, the presence of tire residue provided a considerable increase in shear strength of the mixture. The maximum shear strength was obtained for a residue content of 40% by weight. Permeability tests on samples of waste under a confining stress of 100 kPa showed that the permeability increases significantly with increasing residue content until a residue content of 20%. The increase in permeability after that value showed to be negligible. Confined compression tests showed that the soil mixed with tire residue becomes more compressible than the pure soil. The secant constrained modulus (Msec) for the same vertical stress decreases with increasing percentage of residue. Dentre as alternativas tecnol?gicas para a destina??o correta de pneus est? o uso na constru??o de aterros de misturas de solo e res?duo de pneus triturados. A utiliza??o de res?duo de pneus em solos tropicais requer o conhecimento pr?vio das propriedades e limita??es desses materiais. Nesta disserta??o, apresentam-se os resultados de um programa experimental para caracteriza??o de misturas de res?duo de pneus em um solo later?tico. O res?duo utilizado neste estudo ? classificado como desbastes de pneus, com tamanho m?dio de 1,4 mm. O programa laboratorial incluiu ensaios de an?lise granulom?trica, limites de consist?ncia, compacta??o, cisalhamento direto, permeabilidade e compress?o confinada com as misturas de solo res?duos de pneus. Foram utilizadas propor??es de 0% (solo puro), 10%, 20%, 40%, 50% e 100% (res?duo puro) em peso. Para os n?veis de tens?o confinantes utilizados no estudo, a presen?a do res?duo de pneu proporcionou um aumento consider?vel da resist?ncia ao cisalhamento da mistura. A m?xima resist?ncia ao cisalhamento foi obtida para um teor de res?duo de 40% em peso. Os ensaios de permeabilidade em amostras de res?duos sob uma tens?o confinante de 100 kPa revelaram que a permeabilidade cresce significativamente com o aumento do teor de res?duo at? um teor de 20%, estabilizando-se em seguida. Os ensaios de compress?o confinada evidenciaram que o solo misturado ao res?duo de pneus torna-se mais compress?vel que o solo puro. O estudo demonstra que o m?dulo de compress?o confinada secante (Msec) para uma mesma tens?o vertical diminui com o aumento da porcentagem de res?duo.

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Koti, Joël. "Valorisation des coques de noix de palmiste dans la construction des routes à faible trafic." Thesis, Limoges, 2022. https://aurore.unilim.fr/theses/nxfile/default/f79d4974-f3cb-47d7-8a60-ec5e92d65af9/blobholder:0/2022LIMO0062.pdf.

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La production de l’huile de palme génère plusieurs déchets dont les coques de noix de palmistes (CNP). Face à l’épuisement des ressources naturelles, utilisables en technique routière, la valorisation des déchets agricoles comme les coques de noix de palmiste constitue une solution alternative d’avenir pour les pays producteurs du palmier à huile. Cette thèse étudie l’utilisation des coques de noix de palmiste comme agrégat grossier dans la formulation des composites, proposables comme matériaux de couches d’assises des chaussées à faible trafic. La première partie du manuscrit traite de l’élaboration des mélanges des coques de noix de palmiste et de la terre de barre (terre latéritique abondante dans le sud du Bénin) pour une utilisation en couche de fondation. Les proportions volumiques de chaque composite sont déterminées par la loi parabolique de Fuller-Thompson. Au laboratoire, les essais géotechniques sur le sol latéritique et sur les composites ont montré que l’ajout de 61% des CNP à la terre de barre augmente l’indice CBR de 76% à 95% de l’optimum Proctor Modifié. L’ajout de 15% de sable lagunaire dans la formulation a permis de réduire la plasticité de 29%. Ainsi, le composite (39 % de sol latéritique + 61 % de CNP) avec un indice CBR égal à 30 et le composite (45 % de sol latéritique, 40 % de CNP et 15 % de sable de lagune) avec un indice CBR égal à 41 sont utilisables en couche de fondation des routes à faible trafic. La deuxième partie est consacrée au remplacement dans un béton bitumineux semi grenu 0/10 utilisable en couche de roulement des gros granulats classiques par les coques de noix de palmiste. Les différentes compositions granulaires sont obtenues par le modèle d’empilement compressible de De Larrard. La tenue à l’eau, étudiée à travers l’essai de Duriez montre que les CNP peuvent remplacer les granulats grossiers dans les enrobés des chaussées à faible trafic. La valorisation des coques de noix de palmistes en technique routière, constitue une grosse solution technico- économique dans le désenclavement des milieux ruraux des pays tropicaux et surtout pour le transport des produits des zones de production vers celles de transformation et de consommation The production of palm oil generates several wastes including palm kernel shells (PKS). Facing the depletion of natural resources that can be used in pavement construction, the recovery of agricultural waste such as palm kernel shells is an alternative solution for the future for oil palm producing countries. This thesis studies the use of palm kernel shells as coarse aggregate in the formulation of composites materials. The latter can be used as subbase course materials for low-traffic pavements. The first part of the manuscript deals with the production of mixtures of palm kernel shells and lateritic soil (lateritic soil abundant in the south of Benin) for use as a foundation layer. Parabolic law of Fuller-Thompson is utilized to determine the volume proportions of each composite. In the laboratory, geotechnical experiments on lateritic soil and on composites have shown that the addition of 61% PKS increases the CBR index from 76% to 95% of the Modified Proctor optimum. The addition of 15% lagoon sand in the formulation decreases the plasticity by 29%. Thus, the composites with a CBR index of 30 (39% lateritic soil + 61% PKS) and 41 (45% lateritic soil, 40% PKS and 15% lagoon sand) can be used in the foundation layer for low traffic roads. The second part focuses on the substitution of the traditional coarse aggregates by palm kernel shells in a semi-grained bituminous concrete 0/10. This type of asphalt is usable in surface wearing course. The different granular compositions are obtained by the compressible stacking model of De Larrard. The moisture resistance, studied through the Duriez test, shows that PKS can be a good alternative of coarse aggregates in lightly trafficked pavement mixes. The valorization of palm kernel shells in transportation technology is a major technical and economical solution to provide a better access to the rural areas in tropical countries. Especially, it can be useful for the transport of products from production areas to those of processing and consumption

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KAN-MING, CHEN, and 陳冠閔. "Influence of Soil Plasticity on Shear Strength of Unsaturated Laterite Soils." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/04309064333367841827.

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Kuo, Tong-Yung, and 郭東陽. "Influence of Gravel Content and Gravel Orentation in Laterite Soils on the Biaxial Effective at Rest Lateral Earth Pressure." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/97817592074889201709.

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碩士 逢甲大學 土木及水利工程研究所 87 In this research, a biaxial true K0 consolidumeter is presented and used to measure the two mutual orthogonal effective lateral earth pressures under the action of the effective vertical pressure for samples of lateritic gravel. Therefore, the characteristic of anisotropy for the effective lateral earth pressure at rest conductions can be studied. Three conclusions are obtained from the results of this research. There are: (1) Behavior of lateritic gravel is related to the gravel content. When the gravel content is less then or equal to 30%, behavior of lateritic gravel is governed by laterite. However, when the gravel content is higher than 30%, behavior of lateritic gravel is controlled by gravel. (2) Anisotropy of the effective lateral earth pressure at rest conditions is varying with the content of gravel. The most favorable condition for anisotropy to happen is when gravel content is equal to 40%. (3) Anisotropy of lateritic gravel is also influenced by the orientation of gravel. When the angle between the long axis of the gravel and the first principle direction (defined as the one which is parallel to the lever of the loading) is equal to 45 degrees, the anisotropy for the effective lateral earth pressure at rest conditions is almost negligible.

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LI, CHUN-CHANG, and 李淳昌. "Applying the two surface model in the study of the dynamic & static mechanical properties of remolded Linkou laterite soils." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/61529716182016726065.

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Ting, Kai-En, and 丁楷恩. "Relationship between Soil Velocity, Shear Strength and Soil Modulus of Unsaturated Compacted Lateritic Soils." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/j3ckn6.

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碩士 國立臺灣科技大學 營建工程系 106 Surficial soils of slopes and terraces in Taiwan are often below the groundwater table and belong to the unsaturated soil. The traditional saturated soil mechanics cannot interpret its behavior. In addition, the compacted soil in the field may change its water content due to rainfall or sun shine, resulting in changes in matric suction, strength and stiffness. In order to investigate the mechanical properties of the unsaturated compacted soil, this study conducted a series of laboratory experiments to investigate the relationship between soil velocity, strength and modulus. This study will conduct ultrasonic wave velocity measurement test, unsaturated unconfined compression test and unsaturated multistage triaxial test with the embedded bender element. Test results show that soil velocity and soil strength are significantly affected by the matric suction. However, the variation trends vary with the initial compaction conditions. The difference is probably due to the difference in soil structure and the different volume expansion of the specimen in the saturation process. However, regardless of the initial compaction condition, the relationship between soil velocity and soil strength increment is linear. The trend of the strain-dependent secant modulus obtained from the stress-strain relationship of the unsaturated unconfined compression test is reasonable. However, the initial stiffness is underestimated. Therefore, this study proposes a correction method. The results after the correction look reasonable and may be used to estimate the strain-dependent secant modulus of unsaturated soils.

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Chiou, Wen-Yu, and 邱文宇. "The Influence of Stress History and Soil Structure on the Soil-Water Characteristics of Compacted Lateritic Soils." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/edx63r.

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碩士 國立臺灣科技大學 營建工程系 95 For many engineering project such as highway, airport or slope engineering, compacted soils are often used. But the degree of saturation of the compacted soils usually lies in between 70%~90% and belongs to unsaturated soil . Additionally, the soil mechanical properties correlates closely with stress state, whereas in the field the soil usually exhibits a complex stress state and stress history. Therefore , stress state needs to be taken into account when considering unsaturated soil properties of the compacted soils.A series of laboratory tests were conducted to determine the complete soil-water characteristic curve of the unsaturated compacted soils. The influence of stress history and soil structure on the soil-water characteristics of the unsaturated compacted lateritic soils were also studied. The experimental results show that, soil structure of the compacted lateritic soils prepared at different initial water contents is different. Domain structure governs the soil-water characteristics behaviour for the dry-of-optimum compacted lateritic soils. The air-entry value and the degree of saturation of the specimens increase with increasing equivalent pressure, because the pore spaces which are located between the domain of the specimens decrease with the equivalent pressure. Massive structure governs the soil-water characteristics behaviour for the wet-of-optimum compacted lateritic soils. The soil-water characteristics behaviour is not significantly influenced by the equivalent pressure or stress history, the water storage capacity appears to be the same.

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Yang, Shan-Jen, and 楊善任. "The Influence of Compaction Condition on Soil-Water Characteristic Curve of Compacted Lateritic Soils." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/hw2as6.

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碩士 國立臺灣科技大學 營建工程系 94 Because the water content of the in-situ soil is usually in unsaturated state which lies in between dry and fully saturated conditions. For many engineering project such as railway, highway, airport or slope engineering, compacted soils are often used. So, in the engineering analysis, it is essential to consider the influence of compaction conditions on the unsaturated soil behavior. A series of laboratory tests were conducted to determine the complete soil-water characteristic curve of the compacted lateritic soils. The engineering parameters of the compacted unsaturated soils were also evaluated by the complete soil-water characteristic curves. In addition, the influences of different Proctor energy and water content on the soil-water characteristic curve of the unsaturated compacted lateritic soils were also studied. The experimental results of show that, because the dry of optimum compacted lateritic soils exhibit massive soil structure, the initial water content is larger than that of O.M.C, wet of optimum of compacted lateritic soils and the undisturbed lateritic soils. As a result, the volumetric water content is the largest at low matric suction for the dry of optimum compacted soils. The ability of holding water is the lowest for the dry of optimum compacted soils. So, when the matric suction increases, the volumetric water content decreases significantly. As a result, its volumetric water content is lower than that of O.M.C, wet of optimum and the undisturbed soils at high matric suction. The results derived from the empirical formula and laboratory suction measurements shows that the total cohesion of lateritic soils compacted at O.M.C. is larger than that of dry of optimum and wet of optimum.

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Chen, Yao-Fu, and 陳堯夫. "Effect of Fine Soil Content on Laterite Properties." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/34731103872898535755.

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碩士 國立臺灣海洋大學 河海工程學系 104 Adding fine soil in the Laterite and doing the Atterberg limit test , unconfined compression test to observe the variation of liquid limits , plastic limits and unconfined compression strength of Laterite . Koalinite , Bentonite and Laterite passing through 200 sieve are added in laterite to investgate the effect of fine content on the properties of Laterite . The results show that (1) liquid limits , plastic limits and plasticity index (PI) increase gradually as content of Koalinite , Bentonite and Laterite passing through 200 sieve increase , (2) unconfined compression strength decrease as water content increase and plasticity index increase , (3) standard deviations of liquid limits are significantlylarge , but unconfined compression strength are not .

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Lin, Yu-Po, and 林郁博. "A Study on Relationship between Soil Velocity and Mechanical Properties of Unsaturated Compacted Lateritic Soils." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ddad58.

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碩士 國立臺灣科技大學 營建工程系 105 In recent years, global warming leads to abnormal weather conditions, causing continuous change of the water content of compacted Linkou lateritic soils. As a result, matric suction and engineering properties such as soil modulus, shear strength, etc. may be affected. Therefore, the effect of matric suction and soil velocity on the mechanical properties of compacted lateritic soils upon drying and wetting is an interesting issue. Soil specimens were compacted at three different initial water contents including the dry side, the optimum moisture content (OMC), and the wet side. They were then subjected to designated water content and matric suction using the environmental simulation apparatus. Subsequently, following the SWCC to reach the target matric suction, then a series of laboratory tests were conducted including the bender element test, the ultrasonic test, and the unconfined compression test. Based on the test results, the relationship among matric suction, soil velocity, and unconfined compression strength was studied. Test results demonstrated that the soil compacted at dry side exhibits the lowest soil velocity and soil modulus. Although the suction characteristic of OMC and the wet side is similar, the OMC shows larger volume expansion and dry density decrease, thus the weakening of engineering properties is more significant when compared with soils compacted at the wet side. Test results also illustrate that the regression function can predict the soil modulus reasonably based on matric suction or p-wave velocity. On the other hand, the results of the p-wave velocity and the unconfined compression strength show that the unconfined compression strength increases linearly with the p-wave velocity as matric suction increases. Because the regression lines for all compacted sides are approximately parallel to each other, a normalized regression function can be established using the coordinate conversion. This normalized function can be used to estimate the unconfined compression strength using the p-wave velocity and it has a good application potential for geotechnical engineering.

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Li, Hao-Chih, and 李豪智. "Influence of Matric Suction on Strain-dependent Soil Modulus of Unsaturated Compacted Lateritic Soils upon Drying and Wetting." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/53390800331416181845.

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碩士 國立臺灣科技大學 營建工程系 104 The water content and matric suction of unsaturated compacted lateritic soils are affected by wetting and drying. The strain induced by external loading include static and dynamic may also influence soil modulus. Therefore, the behavior of soil modulus varying with matric suction and strain is an interesting issue. Soil specimens were compacted at three different initial water contents including the dry side, OMC, and wet side. They are then subjected to designated drying and wetting paths using the environmental simulation apparatus. Subsequently, a series of laboratory tests were conducted including the pressure plate test, the filter paper test, the bender element test, and the unconfined compression test to assess the relationship among soil fabric, water content, matric suction, and strain-dependent soil modulus. Test results demonstrated that soil modulus of dry side decreased substantially after wetting and increased less significantly as suction increase upon drying. In addition, soil modulus of OMC increased less rapidly than wet side upon drying due to the weakening of fabric upon saturation. Test results also exhibited that the degradation rate of strain-dependent shear modulus become smaller as matric suction increasing. At the same suction, shear modulus degradation of the wet side is the smallest, the dry side is the largest, and OMC is in between.

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Li, Jun-Ying, and 李俊瑩. "Extension Strength of Unsaturated Lateritic Soil." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/77e7ky.

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碩士 國立臺北科技大學 土木與防災研究所 99 In some practical applications, such as the investigation of the soil strength in the base of deep excavation and the tensile crack propagation at the crest of slope, the use of triaxial extension test in soil behaviour simulation is more appropriate than the triaxial compression test. This study aimed at finding the triaxial extension strength of unsaturated lateritic soil, which can be found in many places in tropical countries. To be able to understand the mechanism of tensile crack development at the crest of slope and the subsequent slip failure associated to it, a series of triaxial extension tests have been conducted on unsaturated lateritic soil specimens. Detailed description of equipment and testing procedures used in the tests has first been outlined. The extension shear strength of the study soil has been obtained and compared to its compressive shear strength. An extended extension strength envelope for the study soil has been proposed; and finally, reasons for the unexpectedly low extension shear strength of the tested material were also discussed.

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Hsu, Min-Yang, and 許閔揚. "Electrokinetic remediation of laterite soil contaminated by bisphenol A using sodium persulfate." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/49783336932140852063.

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碩士 國立中興大學 環境工程學系所 104 BPA is used widely in the industrial sector. That is commonly used endocrine disrupter substance in environment. Endocrine disrupter substances make some effects on human’s body such as reproductive system, endocrine system, thyroid, metabolism and cardiovascular. Electrokinetic is newer In-situ remediation process. It has a most effective treatment process for low permeability soil. Sodium persulfate is used commonly oxidant on In-situ chemical oxidation. Its physical and chemical properties are stable and high solubility. Sodium persulfate doesn’t produce other harmful substances after hydrolysis, but its oxidation rate is slowly, and need activated by light, heat, and transition metal. Persulfates is strong oxidant with a redox potential of 2.01 V, upon activation, persulfate can produce sulfate radicals (E0 = 2.6 V). This study prepares three kinds of soil and uses 0.5M HAc as the electrolyte. Soil 1, investigating removal effect when no iron in soil, added different SPS concentration in cathode reservoir. Soil 2 and Soil 3, investigating removal effect when soil contains iron, added different SPS concentration in cathode reservoir. Laterite is iron-rich soil. It proportionally added in Soil 2 and Soil 3, which contained 4.7 mg Fe/Kg and 9.4 mg Fe/Kg respectively. Group I (Test 1, Test 5, Test 7) is study different soil just uses 0.5M HAc to removal effect difference. As the results, the removal rates from solid phase were 51.12%, 53.52% and 55.86%, removal rates due to oxidation were 33.37%, 28.96% and 27.42%. When no added SPS in electrolyte, difference of removal rates is related to the solid phase and the composition of the soil. When the more kaolin content of the soil in the soil, the BPA adsorption increase and removal rates decrease. When no added SPS in electrolyte, a few BPA was oxidized and removed. The possible cause is that near the anode occurs electrolytic oxidation, then remove a few BPA by oxidation. Group II (Test 1 to Test 4) is to study Soil 1 added different SPS concentration in cathode with concentration from 0 to 1000 ppm. As the results, the removal rates from solid phase increase from 40.48% to 55.53%, and removal rates due to oxidation increase from 32.51% to 48.15%. Since there is no iron content in the soil 1, SPS only rely on electronic activate of the cathode, ferrous activate cannot be used. However, when added more than 500 ppm SPS that oxidation removal rates increase significantly over 10%. Group III (Test 7 to Test 12) is to study compare Soil 3 added different SPS concentration in cathode. With concentration from 0 to 4500 ppm. As the results, the removal rates from solid phase increase from 49.94% to 90.6%, and removal rates of oxidation increase from 27.42% to 78.43%. There is content 9.4 mg/kg iron in the Soil 3. When activated, SPS concentration increase the slid phase removal rates and oxidation removal rates. Group IV (Test 3, Test 6, Test 9) is to study compare removal rate of different iron content soil for using 0.5M HAc electrolyte and adding 500 ppm SPS in cathode. The results showed that removal rates from solid phase were 55.53%, 44.61% and 53.67%, oxidation removal rates were 48.15%, 24.61% and 37.98%, respectively. According to the result, 500ppm of SPS for soil had no significant treatment effect.

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HUI, LAI SHU, and 賴淑惠. "Mass balance analysis on the lateritic soils of Taoyuan tableland." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4w2z4y.

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碩士 國立彰化師範大學 地理學系 102 There are terrace landforms in the Taoyuan tableland. Previous studies has correlated these geomorphic surface based on various methods. The most recently documented result was based on the technique determined by the time-depending physical properties. However, the equivalent results on chemical properties has not been proved or tested. In this study, five soil profiles sampled from the Taoyuan tableland were examined for the degree of chemical weathering by applying the theorem of mass balance. The soil prosperities of volumetric density, volume, and chemical composition were measured and used in the calculation for the comparison of soil before and after weathering. Titanium is the trace element considered immobile from leaching during soil development, and serves as a reference during the calculation of mass balance. The continuity of whole profile was examined by checking the concerned ratios of texture and element. With the bottom soil of sampled profile as parent material and the titanium element as reference for mass balance calculation, the variation of elements in soil before and after weathering was measured to explore the extent of evolution and chemical weathering of the sampled soil from Taoyuan plateau. From results of this study reveals that there is continuity among these five soil samples, representing no obvious incidents that interfered with the evolution process. Mass balance calculation shows that, among base cations, ions such as potassium, sodium, and magnesium are easy to weather and leach from the soil samples. The increase of TY-SF sodium is probably due to the neighborhood of sample location with sea. The elements of sodium might relevantly come from ocean, rainfall and the atmosphere. As to elements such as iron, aluminium, manganese, etc., among them, the loss of iron element is relatively obvious. The iron elements mostly run off and increasingly deposited to the lower layer. The silicon is the element with the most concentration in soil samples. Moreover, with less variation, the titanium elements are more significantly stable than the others in the soil. The evolution extent of five soil profiles were estimated in this study by judging the quantity of lost iron in soil, which was summarily found to be TY-SF> TY-BGG> TY-PJ and TY-2d> TY-3a. Among them, the iron elements run off the most in TY-SF profile and the least in TY-3a profile, which are perhaps due to an older and younger stratum respectively. These results agree with that of Guo’s study (2013), which investigated the formation of cascaded terraces in Taoyuan plateau based on physical properties. This also indicates that the analysis approach based on chemical properties is feasible and complementary to the analysis approach based on physical properties.

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紀正良. "The soil chronosequence in Tsaotun lateritic terraces." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/78510871851596799212.

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碩士 國立彰化師範大學 地理學系 98 Tsaotun lateritic terraces are located in central Taiwan. Most scholars compared the use of traditional methods to study the topography of the area landscape evolution of the cause and process. Therefore, this study viewed the soil topography; five of the six pedons Pingding, Dingcheng, Santsengchi, Erpingtzai, Leigung were described and calculated the development index to establish soil chronosequence.They were also analyzed for physical and chemical properties to discuss the soil genesis and soil classification. Furthermore, the study investigated which soil properties were suitable for indicators to established soil chronosequence, and used them to compare the northern and southern Pakua tableland terraces, and Chushan terraces with Tsaotun lateritic terraces. The results showed that the degree of difference in soil genesis, mainly in soil color, soil texture, sand content, clay content, Fed content, horizon index,and weighted profile development index, were used to establish soil chronosequence. However, the process of landscape evolution is complicated and it’s often subject to interference. If we aim to make use of the concepts of soil topography to do comparison, we must use a number of indicators of soil chronosequence to support comparison. In this way, it won’t be underestimated and lead to misjudgment. Thereforethe, results of this study indicated that that soil development has the following sequences: Pingding（TTN-1a、1b）＞Dingcheng（TTN-2）＞Santsengchi（TTN-3）＞Erpingtzai（TTN-4）＞Leigung（TTN-5）. The study found Pingding in the process of soil genesis, soil erosion has occurred, then re-genesis resulting in thinner soils, and led to Slightly lower than Dingcheng in some soil properties. If through the view the soil genesis, the comparative results of Tsaotun lateritic terraces was in line with previous studies. In this study, according to clay content, soil texture and weighted profile development index, the results suggested that the northern and southern Pakua tableland terraces formed the earliest time possible, followed by Tsaotun lateritic terrace, the last group for the Chushan terraces.

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Hsu, Chun-Sen, and 許俊森. "Coefficient of Permeability of LinkouUnsaturated Lateritic Soil." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/p2w9w2.

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碩士 國立臺北科技大學 土木與防災研究所 94 Many geotechnical and geo-environmental problems takeplace incoporating with water flow through unsaturated soils. Water flow through the unsaturated zone in a residual hillside or earth dam is the problem where permeability of the unsaturated soil is involved. The effects of the properties of unsaturated soil are usually ignored in the engineering practice and numerical analysis. The coefficient of permeability for an unsaturated soil may be a function of void ratio or volumetric water content (matric suction) which is represented by the soil-water characteristic curve (SWCC). A triaxial permeameter system was developed to measure the coefficient of permeability of unsaturated lateritic soil at Linkou terrace. Because the measurement of the SWCC and the coefficient of permeability of unsaturated soil is time-consuming and costly empirical models were used to estimate both the SWCC and the coefficient of permeability. The estimated values were found to compare well with the experimental data obtained in laboratory. Hopefully that the empirical models would help engineers in carrying out their analysis and design in practice.

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szu-tzu, Chen, and 陳思慈. "Mass balance analysis on the lateritic soils of Tsaotun river terraces." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87716773189146564839.

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碩士 國立彰化師範大學 地理學系 98 Mass balance analysis of soil provide relationship among bulk density, volume changes and soil chemical composition in relation to parent material. By estimating the gain, loss and translocation of elements in soil profile or horizons allows us to investigate the interactions between the soil evolution and the environments. Six soil pedons were sampled from Tsaotun river terraces in central Taiwan. This study based on the ratios of particle size and elements to identify parent material uniformity. The bottom (least weathered) horizon of the soil profile was assumed for the parent material. Zr was used as immobile element to calculate mass balance analysis. The comparison of the variation in elements during weathering in different partize size fraction, help to understand the degree of soil evolution. The six pedons didn’t indicate LDs (Lithologic Discontinuities), which suggest no disturbing events occurred in pedologic process. The result of mass balance analysis indicated that gain and loss of elements varied in the soil profiles. K and Mg are the easier leaching loss of base cations than others from the soil profile in the weathering process. Fe, Al and Mn loss from the upper horizons, redistribute to the lower horizons, and transform form sand fraction to silt and clay fraction, whereas Fe and Al are more significant. Si has the most concentration in the profile; thus Si has the most mass flux. The slight loss of Ti indicates that Ti is more immobile than other elements. The volumetric change of the profile TTN-1a and TTN-1b are collapsed. It maybe resulted from the loss of primary elements or erosion, and causing the thickness less than the profile TTN-2 and TTN-3. By using the property that Fe and Ti are gradually enriched in silt and clay fraction in long term weathering, the evaluation of the degree of soil development is TTN-1a≧TTN-1b＞TTN-2≧TTN-3＞TTN-4＞TTN-5. By comparing the negative mass flux, the negative mass flux of the highest pedon of studied Tsaotun river terraces is less than Pakua tableland. Thus, according to the degree of soil development and the calculated results of chemical weathering, the age of studied soil on Tsaotun river terraces is probably younger than the soil evolution on Pakua tableland.

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Chun-Sen, Hsu. "Coefficient of Permeability of Linkou Unsaturated Lateritic Soil." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0006-1708200619104500.

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LIi, Gu-Yi, and 李家逸. "The Engineering Properties of Slag- Lateritic Soil Mixture." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/29096538548076399330.

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碩士 建國科技大學 自動化工程系暨機電光系統研究所 99 The “lateritic soil” is a highly weathering rocks of terrace in Taiwan area. It has been widely used as a back filled material. Slag is the by-product of steel plants. A series of tests was performed to study the engineering properties of slag-lateritic soil mixtures. Results show that these properties are changed with slag content. The specific gravity (Gs) increases when slag content increases. For Atterberg limits, when slag is 0% (totally lateritic soil), there exist maximum plastic index (PI) and liquid limit (LL). According to the compact curves of the standard and modified Proctor tests, the maximum dry unit weight (γd,max) increase when slag content increase to 30%. The swelling test shows a obvious trend that increasing slag content could reduce the amount of swell during soaking. The unconfined compression strength has a clear raise while slag content reaches 30%, and decreases lower than slag content = 0% while slag content = 50%.

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Chu, Hsin An, and 朱信安. "Engineering Properties of Linkou Terrace Unsaturated Lateritic Soil." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/55556300878279195440.

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碩士 國立臺北科技大學 土木與防災技術研究所 92 Rapid economical development, the enhancement of living quality and the demands of leisure traveling have all resulted in massive hillsides developments. Potential hazards such as improper water conservation and sliding of slopes are also followed. Therefore, the special unsaturated engineering properties - of the soil on these slopes have become the most talk-about topic recently. Lateritic soils have been found to be widely distributed in Taiwan and they cover almost 60 % of all the usable hillsides and terraces. Due to the requirements of hillside development and the relevant engineering design for unsaturated soil slopes, this study aims at studying the unsaturated properties of the lateritic soils of Linkou Terrace. The unsaturated engineering properties included the soil-water characteristic curve, matric suction, and undrained shear strength. In addition, a commercially available software is also used to back analyze the laboratory results. The theoretical formulations for estimating the soil-water characteristic curve and unsaturated permeability, which may be useful to design engineer analyzing lateritic soil slopes, are then suggested.

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LIN, DA-CHENG, and 林大成. "Effects of soil additives-to compacted laterite on permeability and attenuation for phenol compound." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/34042076356761343942.

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