Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Scientia Agrícola (Online) |
Texto Completo: | https://www.revistas.usp.br/sa/article/view/141403 |
Resumo: | The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the linear viscoelastic range, LVE range (γLVE), shear stress at the end of the LVE range (τLVE), deformation at yield point, YP (γYP), storage and loss moduli at YP (G′G″YP), maximum shear stress (τmax), and integral z. In general, soil elasticity (γLVE and γYP) and microstructural strength (τLVE and τmax) were greater in the Oxisols and the Vertisol, which both possess high clay content, while the latter also contains expansive clay minerals. The lowest structural strength was observed in the Ultisol which had a high sand content. As rheological properties are related to soil properties such as particle size distribution and carbon content, they can be applied in the evaluation of the microstructural strength of clayey and sandy soils and allows for inferences regarding inter-particle shear strength. However, the test is not applicable to very dry soil samples and sample preparations can affect the results. We suggest a number of approaches to find solutions for these difficulties/problems. |
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Scientia Agrícola (Online) |
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Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunitiessoil mechanicsoscillatory shearamplitude sweep testsoil structure The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the linear viscoelastic range, LVE range (γLVE), shear stress at the end of the LVE range (τLVE), deformation at yield point, YP (γYP), storage and loss moduli at YP (G′G″YP), maximum shear stress (τmax), and integral z. In general, soil elasticity (γLVE and γYP) and microstructural strength (τLVE and τmax) were greater in the Oxisols and the Vertisol, which both possess high clay content, while the latter also contains expansive clay minerals. The lowest structural strength was observed in the Ultisol which had a high sand content. As rheological properties are related to soil properties such as particle size distribution and carbon content, they can be applied in the evaluation of the microstructural strength of clayey and sandy soils and allows for inferences regarding inter-particle shear strength. However, the test is not applicable to very dry soil samples and sample preparations can affect the results. We suggest a number of approaches to find solutions for these difficulties/problems.Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz2018-04-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://www.revistas.usp.br/sa/article/view/14140310.1590/1678-992x-2016-0267Scientia Agricola; v. 75 n. 2 (2018); 154-162Scientia Agricola; Vol. 75 Núm. 2 (2018); 154-162Scientia Agricola; Vol. 75 No. 2 (2018); 154-1621678-992X0103-9016reponame:Scientia Agrícola (Online)instname:Universidade de São Paulo (USP)instacron:USPenghttps://www.revistas.usp.br/sa/article/view/141403/136433Copyright (c) 2017 Scientia Agricolainfo:eu-repo/semantics/openAccessPértile, PatriciaHolthusen, DörtheGubiani, Paulo IvonirReichert, José Miguel2017-12-07T19:20:08Zoai:revistas.usp.br:article/141403Revistahttp://revistas.usp.br/sa/indexPUBhttps://old.scielo.br/oai/scielo-oai.phpscientia@usp.br||alleoni@usp.br1678-992X0103-9016opendoar:2017-12-07T19:20:08Scientia Agrícola (Online) - Universidade de São Paulo (USP)false |
dc.title.none.fl_str_mv |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
title |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
spellingShingle |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities Pértile, Patricia soil mechanics oscillatory shear amplitude sweep test soil structure |
title_short |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
title_full |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
title_fullStr |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
title_full_unstemmed |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
title_sort |
Microstructural strength of four subtropical soils evaluated by rheometry: properties, difficulties and opportunities |
author |
Pértile, Patricia |
author_facet |
Pértile, Patricia Holthusen, Dörthe Gubiani, Paulo Ivonir Reichert, José Miguel |
author_role |
author |
author2 |
Holthusen, Dörthe Gubiani, Paulo Ivonir Reichert, José Miguel |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Pértile, Patricia Holthusen, Dörthe Gubiani, Paulo Ivonir Reichert, José Miguel |
dc.subject.por.fl_str_mv |
soil mechanics oscillatory shear amplitude sweep test soil structure |
topic |
soil mechanics oscillatory shear amplitude sweep test soil structure |
description |
The structural strength of soils has been extensively described by physical and mechanical properties evaluated on the mesoscale for different soils and management conditions. However, changes in the organization of the soil matrix at the microstructural level, which can be obtained by rheometry, are still seldom used in soil mechanics. Our aim was to use the amplitude sweep test, a rheometry technique, to investigate the microstructural strength of four subtropical soils (two Oxisols, an Ultisol and a Vertisol) and to discuss difficulties with respect to the samples, water content, soil density and vertical force. The various rheological properties which reveal the soil microstructural strength were determined: deformation at the end of the linear viscoelastic range, LVE range (γLVE), shear stress at the end of the LVE range (τLVE), deformation at yield point, YP (γYP), storage and loss moduli at YP (G′G″YP), maximum shear stress (τmax), and integral z. In general, soil elasticity (γLVE and γYP) and microstructural strength (τLVE and τmax) were greater in the Oxisols and the Vertisol, which both possess high clay content, while the latter also contains expansive clay minerals. The lowest structural strength was observed in the Ultisol which had a high sand content. As rheological properties are related to soil properties such as particle size distribution and carbon content, they can be applied in the evaluation of the microstructural strength of clayey and sandy soils and allows for inferences regarding inter-particle shear strength. However, the test is not applicable to very dry soil samples and sample preparations can affect the results. We suggest a number of approaches to find solutions for these difficulties/problems. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-04-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://www.revistas.usp.br/sa/article/view/141403 10.1590/1678-992x-2016-0267 |
url |
https://www.revistas.usp.br/sa/article/view/141403 |
identifier_str_mv |
10.1590/1678-992x-2016-0267 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://www.revistas.usp.br/sa/article/view/141403/136433 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2017 Scientia Agricola info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2017 Scientia Agricola |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz |
publisher.none.fl_str_mv |
Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz |
dc.source.none.fl_str_mv |
Scientia Agricola; v. 75 n. 2 (2018); 154-162 Scientia Agricola; Vol. 75 Núm. 2 (2018); 154-162 Scientia Agricola; Vol. 75 No. 2 (2018); 154-162 1678-992X 0103-9016 reponame:Scientia Agrícola (Online) instname:Universidade de São Paulo (USP) instacron:USP |
instname_str |
Universidade de São Paulo (USP) |
instacron_str |
USP |
institution |
USP |
reponame_str |
Scientia Agrícola (Online) |
collection |
Scientia Agrícola (Online) |
repository.name.fl_str_mv |
Scientia Agrícola (Online) - Universidade de São Paulo (USP) |
repository.mail.fl_str_mv |
scientia@usp.br||alleoni@usp.br |
_version_ |
1800222793339502592 |