Modelagem da curva de compressão e da pressão de preconsolidação do solo
Autor(a) principal: | |
---|---|
Data de Publicação: | 2012 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/5561 |
Resumo: | The preconsolidation pressure (σp) is obtained from the curve of the soil compression visual graphical form, mathematical or associating both and is an estimate of its load-bearing capacity. In order to remove the subjectivity of the visual graphical method is need for mathematical description (models using) of the compression curve. However, research results do not provide subsidies for the choice of a model whose σp represents well the resulting load-bearing capacity of soil, but if some model to represent, the σp should be a function of density and water content soil, other properties remain constant. The objective of this study was to understand the variability in the preconsolidation pressure caused by different models and options to adjust these models to the compression curve and evaluate the relationship of preconsolidation pressure with bulk density (Ds), volumetric water content (θ) and macroporisity (Ma) . For this, we performed the uniaxial compression test of 300 samples from a Hapludox, clayey, with wide variation Ds and θ. The preconsolidation pressure was determined by strictly mathematical, from the set of ten models, where seven of them consisted of variations of the model van Genuchten (1980) and others have been proposed by Friton (2001), Assouline (2002) and Gregory et al. (2006). The model proposed by Gregory and Friton possible to obtain the σp for only 62 and 56% of the curves, respectively, the variations of the model van Genuchten were enable the calculation of σp at least 90% of the curves. In three of the variations of the van Genuchten model, it was possible to get σp in 100% of the curves. The range of σp produced by the various options described in compression curve affects the physical significant of σp to represent the load bearing capacity of the soil. Likewise, Ds, θ and Ma, which influence the same load bearing capacity of the soil, not explained more than 58% of the variation of σp produced using different models. With the criteria used, it is not possible to choose one model over the other which allows to estimate more adequately by σp, the load bearing capacity of the soil, which limits the use of this parameter as an indicator for soil management agricultural. Given this result, it was investigated whether the percentage of deformation of the sample as a function of the applied loads would be more closely related to Ds, θ, and Ma was considered a safe limit of deformation of the physical viewpoint, that Ma deformation where the remains higher than 10%. The use of maintenance limit of 80% of voids index (Mεi) displaces the deformation to the plastic region of the curves of all the density ranges and therefore cannot be used for soil with structure more affected by compaction. The load to achieve a certain percentage (Mεi) is best explained by the variation of Ds and θ. The pedotransfer functions to load in Mεi between 85 and 87.5% resulted in higher coefficients of determination (0.74), having potential use of such values as critical limits to maintenance of porosity without degradation of soil physical quality. |
id |
UFSM_cdb5f945bb6498cf47cffb48c8ef5108 |
---|---|
oai_identifier_str |
oai:repositorio.ufsm.br:1/5561 |
network_acronym_str |
UFSM |
network_name_str |
Manancial - Repositório Digital da UFSM |
repository_id_str |
|
spelling |
Modelagem da curva de compressão e da pressão de preconsolidação do soloModeling of curve of compression and of the soil preconsolidation pressureCapacidade de suporte de cargaCompactação do soloCompressibilidadeMecânica do soloFunção de pedotransferênciaLoad-bearing capacitySoil compactionCompressibilitySoil mechanicsPedotransfer functionCNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLOThe preconsolidation pressure (σp) is obtained from the curve of the soil compression visual graphical form, mathematical or associating both and is an estimate of its load-bearing capacity. In order to remove the subjectivity of the visual graphical method is need for mathematical description (models using) of the compression curve. However, research results do not provide subsidies for the choice of a model whose σp represents well the resulting load-bearing capacity of soil, but if some model to represent, the σp should be a function of density and water content soil, other properties remain constant. The objective of this study was to understand the variability in the preconsolidation pressure caused by different models and options to adjust these models to the compression curve and evaluate the relationship of preconsolidation pressure with bulk density (Ds), volumetric water content (θ) and macroporisity (Ma) . For this, we performed the uniaxial compression test of 300 samples from a Hapludox, clayey, with wide variation Ds and θ. The preconsolidation pressure was determined by strictly mathematical, from the set of ten models, where seven of them consisted of variations of the model van Genuchten (1980) and others have been proposed by Friton (2001), Assouline (2002) and Gregory et al. (2006). The model proposed by Gregory and Friton possible to obtain the σp for only 62 and 56% of the curves, respectively, the variations of the model van Genuchten were enable the calculation of σp at least 90% of the curves. In three of the variations of the van Genuchten model, it was possible to get σp in 100% of the curves. The range of σp produced by the various options described in compression curve affects the physical significant of σp to represent the load bearing capacity of the soil. Likewise, Ds, θ and Ma, which influence the same load bearing capacity of the soil, not explained more than 58% of the variation of σp produced using different models. With the criteria used, it is not possible to choose one model over the other which allows to estimate more adequately by σp, the load bearing capacity of the soil, which limits the use of this parameter as an indicator for soil management agricultural. Given this result, it was investigated whether the percentage of deformation of the sample as a function of the applied loads would be more closely related to Ds, θ, and Ma was considered a safe limit of deformation of the physical viewpoint, that Ma deformation where the remains higher than 10%. The use of maintenance limit of 80% of voids index (Mεi) displaces the deformation to the plastic region of the curves of all the density ranges and therefore cannot be used for soil with structure more affected by compaction. The load to achieve a certain percentage (Mεi) is best explained by the variation of Ds and θ. The pedotransfer functions to load in Mεi between 85 and 87.5% resulted in higher coefficients of determination (0.74), having potential use of such values as critical limits to maintenance of porosity without degradation of soil physical quality.Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorA pressão de preconsolidação (σp) é obtida da curva de compressão do solo de forma gráfica visual, matemática ou associando ambas e é uma estimativa de sua capacidade de suporte de carga. A fim de se retirar a subjetividade do método gráfico visual, há necessidade de descrição matemática (uso de modelos) da curva de compressão. Porém, os resultados de pesquisa não fornecem subsídios para a escolha de um modelo cuja σp resultante represente, de maneira confiável, a capacidade de suporte de carga do solo. Entretanto, se algum modelo a representar, a σp deverá ser uma função da densidade e conteúdo de água do solo, mantidas constantes outras propriedades. O objetivo deste trabalho foi conhecer a variabilidade na pressão de preconsolidação provocada por diferentes modelos e opções de ajuste desses modelos à curva de compressão e avaliar a relação da pressão de preconsolidação com a densidade do solo (Ds), conteúdo volumétrico de água (θ) e macroporosidade do solo (Ma). Para isso, foi realizado o ensaio de compressão uniaxial para 300 amostras provenientes de um Latossolo Vermelho Distroférrico típico, com textura argilosa, com ampla variação Ds e θ. A pressão de preconsolidação foi determinada por meio estritamente matemático, a partir do ajuste de dez modelos, onde sete deles consistiram em variações do modelo de van Genuchten (1980) e os demais foram propostos por Friton (2001), Assouline (2002) e Gregory et al. (2006). Os modelos propostos por Gregory e Friton possibilitaram a obtenção da σp para apenas 62 e 56 % das curvas, respectivamente, já as variações do modelo de van Genuchten viabilizam o cálculo da σp para no mínimo 90 % das curvas. Em três das variações do modelo de van Genuchten, foi possível obter a σp em 100% das curvas. A variação da σp produzida pelas diferentes opções de descrição da curva de compressão compromete o significado físico da σp para representar a capacidade de suporte de carga do solo. Da mesma forma, Ds, θ e Ma, mesmo que influenciem a capacidade de suporte de carga do solo, não explicaram mais que 58% da variação da σp produzida com o uso de diferentes modelos. Com os critérios utilizados, não é possível eleger um modelo em relação aos demais que possibilite estimar de maneira mais adequada, através da σp, a capacidade de suporte de carga do solo, o que limita o uso desse parâmetro como um indicador para o manejo dos solos agrícolas. Diante desse resultado, foi investigado se a porcentagem de deformação da amostra em função das cargas aplicadas estaria melhor relacionada com Ds, θ e Ma. Considerou-se um limite de deformação prudente do ponto vista físico, aquela deformação onde a Ma permaneça maior que 10%. O uso do limite de manutenção de 80 % do índice de vazios inicial (Mεi) desloca as deformações para a região plástica das curvas de todas as faixas de densidade e, por isso, não pode ser utilizado para solos com estrutura mais comprometida pela compactação. A carga para atingir determinada porcentagem de Mεi é melhor explicada pela variação da Ds e θ. As funções de pedotransferência da carga para a Mεi entre 85 e 87,5% resultaram em maiores coeficientes de determinação (0,74), havendo potencial da utilização destes valores como limites críticos de manutenção da porosidade sem haver degradação da qualidade física do solo.Universidade Federal de Santa MariaBRAgronomiaUFSMPrograma de Pós-Graduação em Ciência do SoloReinert, Dalvan Joséhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4793527A1Minella, Jean Paolo Gomeshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4760855H0Suzuki, Luis Eduardo Akiyoshi Sancheshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4702465Z1Goulart, Rafael Ziani2017-04-062017-04-062012-08-24info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfapplication/pdfGOULART, Rafael Ziani. Modeling of curve of compression and of the soil preconsolidation pressure. 2012. 67 f. Dissertação (Mestrado em Agronomia) - Universidade Federal de Santa Maria, Santa Maria, 2012.http://repositorio.ufsm.br/handle/1/5561porinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2022-08-08T16:06:24Zoai:repositorio.ufsm.br:1/5561Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2022-08-08T16:06:24Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Modelagem da curva de compressão e da pressão de preconsolidação do solo Modeling of curve of compression and of the soil preconsolidation pressure |
title |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
spellingShingle |
Modelagem da curva de compressão e da pressão de preconsolidação do solo Goulart, Rafael Ziani Capacidade de suporte de carga Compactação do solo Compressibilidade Mecânica do solo Função de pedotransferência Load-bearing capacity Soil compaction Compressibility Soil mechanics Pedotransfer function CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
title_short |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
title_full |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
title_fullStr |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
title_full_unstemmed |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
title_sort |
Modelagem da curva de compressão e da pressão de preconsolidação do solo |
author |
Goulart, Rafael Ziani |
author_facet |
Goulart, Rafael Ziani |
author_role |
author |
dc.contributor.none.fl_str_mv |
Reinert, Dalvan José http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4793527A1 Minella, Jean Paolo Gomes http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4760855H0 Suzuki, Luis Eduardo Akiyoshi Sanches http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4702465Z1 |
dc.contributor.author.fl_str_mv |
Goulart, Rafael Ziani |
dc.subject.por.fl_str_mv |
Capacidade de suporte de carga Compactação do solo Compressibilidade Mecânica do solo Função de pedotransferência Load-bearing capacity Soil compaction Compressibility Soil mechanics Pedotransfer function CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
topic |
Capacidade de suporte de carga Compactação do solo Compressibilidade Mecânica do solo Função de pedotransferência Load-bearing capacity Soil compaction Compressibility Soil mechanics Pedotransfer function CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
description |
The preconsolidation pressure (σp) is obtained from the curve of the soil compression visual graphical form, mathematical or associating both and is an estimate of its load-bearing capacity. In order to remove the subjectivity of the visual graphical method is need for mathematical description (models using) of the compression curve. However, research results do not provide subsidies for the choice of a model whose σp represents well the resulting load-bearing capacity of soil, but if some model to represent, the σp should be a function of density and water content soil, other properties remain constant. The objective of this study was to understand the variability in the preconsolidation pressure caused by different models and options to adjust these models to the compression curve and evaluate the relationship of preconsolidation pressure with bulk density (Ds), volumetric water content (θ) and macroporisity (Ma) . For this, we performed the uniaxial compression test of 300 samples from a Hapludox, clayey, with wide variation Ds and θ. The preconsolidation pressure was determined by strictly mathematical, from the set of ten models, where seven of them consisted of variations of the model van Genuchten (1980) and others have been proposed by Friton (2001), Assouline (2002) and Gregory et al. (2006). The model proposed by Gregory and Friton possible to obtain the σp for only 62 and 56% of the curves, respectively, the variations of the model van Genuchten were enable the calculation of σp at least 90% of the curves. In three of the variations of the van Genuchten model, it was possible to get σp in 100% of the curves. The range of σp produced by the various options described in compression curve affects the physical significant of σp to represent the load bearing capacity of the soil. Likewise, Ds, θ and Ma, which influence the same load bearing capacity of the soil, not explained more than 58% of the variation of σp produced using different models. With the criteria used, it is not possible to choose one model over the other which allows to estimate more adequately by σp, the load bearing capacity of the soil, which limits the use of this parameter as an indicator for soil management agricultural. Given this result, it was investigated whether the percentage of deformation of the sample as a function of the applied loads would be more closely related to Ds, θ, and Ma was considered a safe limit of deformation of the physical viewpoint, that Ma deformation where the remains higher than 10%. The use of maintenance limit of 80% of voids index (Mεi) displaces the deformation to the plastic region of the curves of all the density ranges and therefore cannot be used for soil with structure more affected by compaction. The load to achieve a certain percentage (Mεi) is best explained by the variation of Ds and θ. The pedotransfer functions to load in Mεi between 85 and 87.5% resulted in higher coefficients of determination (0.74), having potential use of such values as critical limits to maintenance of porosity without degradation of soil physical quality. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-08-24 2017-04-06 2017-04-06 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
GOULART, Rafael Ziani. Modeling of curve of compression and of the soil preconsolidation pressure. 2012. 67 f. Dissertação (Mestrado em Agronomia) - Universidade Federal de Santa Maria, Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/5561 |
identifier_str_mv |
GOULART, Rafael Ziani. Modeling of curve of compression and of the soil preconsolidation pressure. 2012. 67 f. Dissertação (Mestrado em Agronomia) - Universidade Federal de Santa Maria, Santa Maria, 2012. |
url |
http://repositorio.ufsm.br/handle/1/5561 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Agronomia UFSM Programa de Pós-Graduação em Ciência do Solo |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Agronomia UFSM Programa de Pós-Graduação em Ciência do Solo |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
_version_ |
1805922173974478848 |