Soil mineral particle size analysis: Validation of Stokes' Law

dc.contributor.advisorVoroney, Paul
dc.contributor.authorZhang, Xiaowei of Environmental Sciencesen_US of Guelphen of Philosophyen_US Sciencesen_US
dc.description.abstractParticle size analysis (PSA) is one of the most important and fundamental parameters in the soil science as texture affects the hydrological, chemical, physical, and biological properties of soils. The accuracy of PSA measurements has direct effects on almost all inherent soil related properties, such as water holding capacity, and cation exchange capacity, as well as engineering properties such as Atterberg limits and shear strength. The current sedimentation-based measurement methods, including the hydrometer (HM), pipette (PM), and Integral suspension pressure methods (ISPM), are based on the application of Stokes’ law, however, application of Stokes’ law to PSA is limited by its assumptions. The overall goal of this research was to further understand some of the relationships between particles in suspension and particle-particle interactions when conducting PSA measurements. The interactions between particles were evaluated with various particle size fractions, using a Pario meter, which records the suspension pressure at 10 seconds intervals within a 24-hour time frame. These measurements show that the interactions between particles increased with increasing mass concentration in suspension and had significant effects on the measurements of PSA, especially when the soil samples contain large quantities of non-expandable clay and sand-sized particles. Removal of the sand fraction (>10 g/L) prior to conducting any sedimentation-based measurements is recommended to obtain a more accurate measurement of PSA. The effect caused by the presence of clay fractions is highly dependent on the type and concentration in suspension. Moreover, the accuracy of the ISPM and HM was evaluated by comparing measurement results with soil mixtures with known particle size composition. The results show that both methods overestimate the clay content and underestimate the silt content, but HM gives more accurate results compared to ISPM. The effect of density of the suspension solution was tested in experiments using clay- and silt-sized particles and recommended that they be specified in Stokes’ equation, especially for predicting the settling velocity of clay-rich soil samples. en_US
dc.description.sponsorshipMar-Co Clay Product Inc.
dc.publisherUniversity of Guelphen
dc.rights.licenseAll items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectParticle size distributionen_US
dc.subjectexpandable clayen_US
dc.subjecthindered settlingen_US
dc.subjectParticle size distributionen_US
dc.subjectParticle size analysisen_US
dc.subjectStokes' lawen_US
dc.subjectinteractions between particlesen_US
dc.subjectISP methoden_US
dc.subjecthydrometer methoden_US
dc.subjectpipette methoden_US
dc.subjectsedimentation theoryen_US
dc.titleSoil mineral particle size analysis: Validation of Stokes' Lawen_US


Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
2.26 MB
Adobe Portable Document Format