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dc.contributor.authorThomas, Pamela J.en_US
dc.date.accessioned2014-03-14T20:21:44Z
dc.date.available2014-03-14T20:21:44Z
dc.date.issued1998-04-15en_US
dc.identifier.otheretd-32398-73623en_US
dc.identifier.urihttp://hdl.handle.net/10919/30441
dc.description.abstractA study of 12 expansive soils in four major physiographic provinces in Virginia was initiated to examine and quantify the relationship between shrink-swell potential, shrink-swell indices, and soil properties. The mineralogy classes, soil series, and (physiographic provinces, parent materials) examined include smectitic -- Jackland and Waxpool (Triassic, diabase), Iredell (Piedmont, hornblende); vermiculitic -- Kelly (Triassic, thermal shale); kaolinitic -- Cecil (Piedmont, granite gneiss), Davidson (Triassic, diabase); and mixed -- Carbo and Frederick (Valley and Ridge, limestone), Craven and Peawick (Coastal Plain, fluvial and marine sediments), and Mayodan and Creedmoor (Triassic, sandstones). Three sites in each of the 12 map units were described and major horizons sampled for physical, chemical, and mineralogical laboratory analysis. An expansive soil rating system, termed the Expansive Soil Index (ESI), was developed using the soil properties best correlated with shrink-swell potential. The sum of swelling 2:1 minerals, swell index, liquid limit, and CEC gave expansive soil potential ratings (ESI) for each soil series. The higher the ESI, the greater the shrink-swell potential. Smectite distributions within the soil profiles were investigated. Smectite concentration in the clay fraction increases with depth in soils formed from diabase and thermally altered shale. Smectite weathers to kaolinite and hydroxy-interlayered vermiculite with increasing proximity to the soil surface thus accounting for the observed decrease in smectite toward the soil surface. The highest amount of smectite from the granite gneiss, limestone, sandstones and shales, and Coastal Plain sediments were in the Bt2 horizon where maximum expression of the argillic horizon occurs. Smectite contents decrease away (upwards and downwards) from the maximum in the Bt2 horizon. A satellite study focused on locating and quantifying the variability within five map units in the Culpeper (Triassic) Basin in northern Virginia. Variability of the shrink-swell indices and related properties are high in all map units. Dissimilar inclusions could adversely affect foundations if a home is sited on both moderate and high shrink-swell soils. Although there is extreme variability in the map units, the variability occurs within the delineations of each map unit. Each delineation within an individual map unit contains similar levels of variability.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartthomas.pdfen_US
dc.relation.haspartappendixA.pdfen_US
dc.relation.haspartappendixB.pdfen_US
dc.relation.haspartvita.pdfen_US
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectexpansive soilsen_US
dc.subjectshrink-swellen_US
dc.subjectsoil variabilityen_US
dc.subjectmineralogyen_US
dc.subjectsoil propertiesen_US
dc.titleQuantifying Properties and Variability of Expansive Soils in Selected Map Unitsen_US
dc.typeDissertationen_US
dc.contributor.departmentCrop and Soil Environmental Sciencesen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineCrop and Soil Environmental Sciencesen_US
dc.contributor.committeechairBaker, James C.en_US
dc.contributor.committeememberPersaud, Naraineen_US
dc.contributor.committeememberMartin, James R. IIen_US
dc.contributor.committeememberDaniels, Walter Leeen_US
dc.contributor.committeememberZelazny, Lucian W.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-32398-73623/en_US
dc.date.sdate1998-04-15en_US
dc.date.rdate1999-04-24
dc.date.adate1998-04-24en_US


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