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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

[en] PRIMARY CONSOLIDATION SETTLEMENT DUE TO RAMP LOADING / [pt] RECALQUE DE ADENSAMENTO PRIMÁRIO DEVIDO A CARREGAMENTO LINEARMENTE CRESCENTE NO TEMPO

VITOR DOS SANTOS ALBUQUERQUE 11 April 2022 (has links)
[pt] O método empírico de Terzaghi (1943) para cálculo do recalque de adensamento primário com carregamento dependente do tempo é comparado com dois métodos propostos nesta pesquisa: o primeiro, baseado na alteração da fração de tempo em que cada incremento de carregamento é aplicado de forma instantânea, e o segundo mantendo a proposta inicial de Terzaghi (1943), porém realizando reduções percentuais do grau médio de adensamento para o período de construção e obtendo novas frações de tempo para o período pós-construção. Os resultados mostram que com a adoção das frações de tempo, apresentadas em tabelas, a diferença entre os valores do grau médio de adensamento determinados pelas curvas teórica e empírica varia entre 1,50 por cento a 3,50 por cento, dependendo das condições iniciais de excesso de poropressão. O segundo método, mais exato, apresenta diferenças menores, com ambas as curvas praticamente sobrepostas. Adicionalmente, outras duas soluções alternativas são investigadas considerando o carregamento em degraus e discretizado. Uma solução matemática rigorosa também é apresentada para representar o problema de adensamento com drenos verticais, considerando a hipótese de deformações livres. Uma comparação com a solução proposta por Olson (1977), fundamentada no conceito de deformações iguais, mostra que a hipótese de deformações iguais subestima o grau médio de dissipação dos excesoss de poropressão entre 1,15 por cento a 4,84 por cento, e que essa diferença tende a diminuir para tempos de construção elevados. Finalmente, soluções para fluxo vertical e radial combinados também são obtidas, considerando a hipótese de deformações livres e a formulação proposta por Carrillo (1942). / [en] Terzaghi s (1943) empirical method for calculating primary consolidation settlement due to ramp loading is compared with two methods proposed in this research: the first one, based on changing the fraction of time in which each loading increment is applied instantly, and the second keeping Terzaghi s initial proposal (1943), but making reductions in the average degree of consolidation for the construction period and determining new fractions of time for the post-construction period. The results show that with the hypothesis of time fractions, the difference between the values of the average degree of consolidation determined by the theoretical and empirical curves varies between 1.50 percent to 3.50 percent, depending on the initial conditions of excess poropressure. The second method is even more accurate with both curves practically overlapping. Additionally, two other alternative solutions are investigated considering step and discretized loadings. A rigorous mathematical solution is also presented to represent the consolidation problem with vertical drains, considering the hypothesis of free deformations. A comparison with the solution proposed by Olson (1977), based on the concept of equal deformations, shows that the hypothesis of equal deformations underestimates the average degree of consolidation between 1.15 percent to 4.84 percent, and this difference tends to decrease for long construction periods. Finally, solutions for the vertical and radial flow combined is also obtained, considering the hypothesis of free deformations and the formulation proposed by Carrillo (1942).
2

CONSOLIDATION ANALYSES OF GREATER CINCINNATI SOILS CINCINNATI, OHIO

DAYAL, NISHANT January 2006 (has links)
No description available.
3

Faktorių, darančių įtaką pastato ir pagrindo sąveikai, vertinimas / Evaluation of factors influencing on soil - structure interaction

Skuodis, Šarūnas 10 June 2011 (has links)
Magistrinio darbo tikslas – įvertinti konstrukciją veikiančias apkrovas, apskaičiuoti konstrukcijos pamatų matmenis, apskaičiuoti pastato atskirų pamatų nuosėdžius, palyginti nuosėdžių reikšmes tarpusavyje, rasti santykinių nuosėdžių reikšmes ir įvertinti gretimų pamatų ir geologinių sąlygų nevienodumo įtaką šalia esantiems pamatams; įvertinti skirtingų smėlio frakcijų suspaudžiamumo savybes ir išskirti staigiųjų nuosėdžių dalį, atsirandančių smėliniuose gruntuose apkrovimo metu; pateikti išvadas bei pasiūlymus. Šiame darbe naudojami metodai, sprendiniai ir programos: sumavimo metodas, Businesko sprendinys, programos „STAAD.Pro“; „SCAD“, „MathCad“, „AutoCad“, „Exel“. Magistrinio darbo praktinė reikšmė – praplėsti supratimą apie konstrukcijas veikiančius faktorius, kurie gali labai skirtingai nulemti pagrindo ir pastato tarpusavio sąveiką. Pamatų nuosėdžių skaičiavimai parodė, kad atskirų pamatų nuosėdžiai bei santykiniai nuosėdžiai neviršija leistinų ribų, o gretimų pamatų įtaka gali būti nevertinama, kai atstumas tarp pamatų yra didesnis kaip 7,00 m. Smėlinių gruntų spūdumo savybių, dalelių formos įtakos, smėlinių gruntų elgsenos tyrimai parodė, kad smėliniuose gruntuose staigiosios deformacijos pasireiškia per pirmas 5 s, todėl galima teigti, kad statant statinius ant smėlinio grunto prognozuojami nuosėdžiai įvyksta statybos laikotarpiu. / This masters work purpose is to estimate loadings in construction; calculate foundations dimensions; calculate separate foundations displacements; compare separate foundations displacements between themselves; find relative displacements values and estimate contiguous foundations via geological difference; estimate sand different partical size compression and find primary compression limits when soil is under load; present a report of calculations and laboratory investigations. In this final work was used Businesque problem, summing method and programs: “STAAD.Pro”, “MathCad”, “SCAD”, “AutoCad”, “Exel”. From practical view this work importance is to increase understanding of construction loadings and and factors influence on soil – structure interaction. Calculations of foundations displacements showed that separate foundations and contiguous foundations displacements did not reached their critical magnitudes. Contiguous foundations evaluation to each over could not be accounted then betweeen each over foundation is more than 7,00 m. Sand compression characteristics and sand fraction shape investigation showed that primary compression appears only in first 5 seconds. Because of primary compression all prognosis about total foundation displacement in sand soil estimates when construction is in building period.
4

Influence de l'hétérogénéité géologique et mécanique sur la réponse des sols multicouches / Influence of the geological and mechanical heterogeneity on multilayered soils response

Badaoui, M'Hammed 30 March 2008 (has links)
Dans cette thèse nous nous sommes intéressés à établir une formulation probabiliste pour l’analyse du comportement d’un sol multicouche avec des caractéristiques aléatoires. Deux grands axes sont traités : ?la consolidation primaire et ?la réponse sismique des sols multicouches ayant des caractéristiques aléatoires. Nous utilisons les simulations de Monte Carlo associées à des méthodes semi-analytiques adaptées aux sols multicouches avec une stratification horizontale. Nous avons aussi comparés les résultats obtenus à partir de cette formulation à ceux fournis par les règlements parasismiques suivants : RPA 99 (version 2003), UBC 97 et l’EC8. Cette étude a montré que les valeurs maximales des forces de cisaillement à la base des bâtiments variaient substantiellement en fonction de la variation de la hauteur du profil de sol ainsi que de son hétérogénéité pouvant atteindre un rapport relatif de l’ordre de 3 dans les cas les plus défavorables. Ce rapport peut également être inférieur à 1 conduisant à des structures moins économiques / In this thesis we are interested to establish a probabilistic formulation for the behavior analysis of a multilayered soil with random characteristics. Two main axes are treated: ?primary consolidation and ?seismic response of multilayered soils with uncertain characteristics. We use Monte Carlo simulations associated with semi-analytical methods adapted for the multilayered soils with horizontal stratification. We have also compared the results obtained from this formulation with those provided by the following seismic codes: RPA 99 (version 2003), UBC 97 and EC8. This study showed that the maximum values of the shear forces at the base of the buildings vary substantially according to the variation of the soil profile height as well as its heterogeneity which can reach a relative ratio of about 3 in the extreme cases. This ratio can also be lower than 1 leading to less economic structures
5

[en] BEHAVIOR OF A REINFORCEMENT LANDFILL FOR MINING WASTE CONTAINMENT BUILT ON SOFT SOILS / [pt] COMPORTAMENTO DE UM ATERRO DE REFORÇO PARA CONTENÇÃO DE RESÍDUOS DE MINERAÇÃO CONSTRUÍDO SOBRE SOLOS MOLES

MIRYAN YUMI SAKAMOTO 26 June 2023 (has links)
[pt] Na presente pesquisa, foi realizada a interpretação de comportamento da obra de reforço em um dique de contenção para resíduos de mineração construído sobre solos moles. Foram definidos o perfil geotécnico e as etapas de alteamento a serem analisadas pelo método de elementos finitos, no software Plaxis 2D. Para definição dos parâmetros, foram interpretados ensaios de campo e laboratório, sendo que nos ensaios de laboratório em que as curvas eram conhecidas, foi possível aplicar a otimização de parâmetros com a simulação de ensaios em uma extensão do Plaxis (Soil test). No caso dos solos silto arenosos e dos materiais de aterro, as interpretações foram feitas com o modelo Hardening Soil Model. Já para as camadas argilosas, foram simulados cinco diferentes cenários com os modelos: Soft Soil Creep, Hardening Soil e Mohr Coulomb com parâmetros de resistência efetivos e Hardening Soil e Mohr Coulomb com resistência não drenada. Os resultados de deslocamentos foram comparados entre si e com os dados do monitoramento de campo. Para análise da estabilidade os cinco cenários foram comparados entre si e com os resultados de uma análise convencional com equilíbrio limite em termos de tensões totais. Foi realizada também a aplicação do Método dos Volumes Deslocados como uma forma de verificar sua adequação para acompanhamento in situ da estabilidade da obra em cada etapa construtiva. / [en] In this present research, it was done an interpretation of the reinforcement work s behavior in a containment dike/dam for mining waste built on soft soils. It was defined the geotechnical profile and the heightening steps to be performed using the finite element method in the Plaxis 2D software. To define the parameters, the field and laboratory tests were interpreted, and in the laboratory tests in which the curvatures were known, it was possible to apply parameters with the simulation of tests in an extension of Plaxis (Soil test). In the case of sandy silt soils and embankments materials, as was done with the Hardening Soil Model. For the clay layers, five different scenarios were simulated with the models: Soft Soil, Hardening Soil and Mohr Coulomb with effective strength parameters and Hardening Soil and Mohr Coulomb with undrained strength parameters. The displacement results were compared with each other and with field monitoring data. For the stability analysis the five scenarios were analyzed among themselves and with the results of a conventional analysis with limit equilibrium in terms of total strength. Also the application of the Displaced Volumes Method as a way of verifying its suitability to in situ monitoring of the stability of the work at each constructive stage.

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