Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-3159 Wissenschaftlicher Artikel Schanz, Tom; Tripathy, Snehasis Swelling pressure of a divalent-rich bentonite: Diffuse double-layer theory revisited Physicochemical forces are responsible for the swelling pressure development in saturated bentonites. In this paper, the swelling pressures of several compacted bentonite specimens for a range of dry density of 1.10-1.73 Mg/m3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na+ ions. The theoretical swelling pressure-dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-layer theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m3, a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-layer theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m3, whereas at higher dry densities the use of the equations was found to be limited. Water Resources Research urn:nbn:de:gbv:wim2-20170425-31592 10.1029/2007WR006495 Professur Bodenmechanik OPUS4-2985 Konferenzveröffentlichung Stoimenova, Eugenia; Lins, Yvonne; Datcheva, Maria; Schanz, Tom Gürlebeck, Klaus; Könke, Carsten INVERSE MODELLING OF SOIL HYDRAULIC CHARACTERISTIC FUNCTIONS In this paper we evaluate 2D models for soil-water characteristic curve (SWCC), that incorporate the hysteretic nature of the relationship between volumetric water content θ and suction ψ. The models are based on nonlinear least squares estimation of the experimental data for sand. To estimate the dependent variable θ the proposed models include two independent variables, suction and sensors reading position (depth d in the column test). The variable d represents not only the position where suction and water content are measured but also the initial suction distribution before each of the hydraulic loading test phases. Due to this the proposed 2D regression models acquire the advantage that they: (a) can be applied for prediction of θ for any position along the column and (b) give the functional form for the scanning curves. 12 urn:nbn:de:gbv:wim2-20170327-29858 10.25643/bauhaus-universitaet.2985 Professur Bodenmechanik OPUS4-2913 Konferenzveröffentlichung Schanz, Tom; Wuttke, Frank; Dineva, Petia Gürlebeck, Klaus; Könke, Carsten HYBRID APPROACH OF WAVE NUMBER INTEGRATION-BOUNDARY INTEGRAL EQUATION METHOD FOR SITE EFFECT ESTIMATION OF A LATERALLY VARYING SEISMIC REGION In this paper we evaluate 2D models for soil-water characteristic curve (SWCC), that incorporate the hysteretic nature of the relationship between volumetric water content Θ and suction Ψ. The models are based on nonlinear least squares estimation of the experimental data for sand. To estimate the dependent variable Θ the proposed models include two independent variables, suction and sensors reading position (depth d in the column test). The variable d represents not only the position where suction and water content are measured but also the initial suction distribution before each of the hydraulic loading test phases. Due to this the proposed 2D regression models acquire the advantage that they: (a) can be applied for prediction of Θ for any position along the column and (b) give the functional form for the scanning curves. 15 urn:nbn:de:gbv:wim2-20170327-29132 10.25643/bauhaus-universitaet.2913 Professur Bodenmechanik