Refine
Document Type
- Master's Thesis (5)
- Doctoral Thesis (4)
- Conference Proceeding (2)
- Article (1)
- Report (1)
Institute
- Professur Bodenmechanik (13) (remove)
Keywords
- Architektur <Informatik> (2)
- Bender elements (2)
- CAD (2)
- Computerunterstütztes Verfahren (2)
- Shear modulus (2)
- Soil (2)
- Anomale Dispersion (1)
- Baustoff (1)
- Bentonit (1)
- Bentonit-Sand (1)
- Bentonit-Sandgemische (1)
- Bentonite-sand (1)
- Boden (1)
- Bodenanalyse (1)
- Bodenmechanik (1)
- Dispersion <Welle> (1)
- Durchlässigkeit (1)
- Ebener Dehnungszustand (1)
- Energieübertragung (1)
- Geochemical modeling; Soils; High-pressure behavior; bentonite; clays; expansive clays (1)
- Hostun-Sand (1)
- Hydraulic properties (1)
- Hydromechanik (1)
- Inverses Problem (1)
- Inversionsalgorithmus (1)
- Inversionstheorie (1)
- Kennwertermittlung (1)
- Konsolidation (1)
- Parameterschätzung (1)
- Quelldruck (1)
- Quellen (1)
- Sandsäulenversuch (1)
- Saugspannung (1)
- Seismik (1)
- Shear wave (1)
- Soil dynamics (1)
- Sraßeninstandhaltung (1)
- Straßenbau (1)
- Straßenplanung (1)
- TDR-Kalibrierung (1)
- Temperatur (1)
- Time domain reflectometry (1)
- Ton (1)
- Ungesättigte Zone (1)
- Unsaturated soil (1)
- Wellenausbreitung (1)
- Zustand von Strassenbau (1)
- bentonite-sand mixture (1)
- bentonite-sand mixtures (1)
- biaxial – sand (1)
- biaxial-sand (1)
- determination of soil properties (1)
- drying-wetting (1)
- evaluation (1)
- hydro-mechanics (1)
- hydromechanische Prozesse (1)
- inversion procedure (1)
- inversion theorie (1)
- mathematische Optimierungsmethoden (1)
- nichtlineare Konsolidationstheorie (1)
- non-linear consolidation (1)
- numerical methods (1)
- numerische Berechnungen (1)
- plane-strain conditions (1)
- polymer-enhanced (1)
- road (1)
- seimic measurements (1)
- seismische Messungen (1)
- soil column test (1)
- soil mechanics (1)
- soil water characteristic curve (1)
- suction (1)
- swelling (1)
- swelling pressure (1)
- teilgesättigte Böden (1)
- temperature (1)
- unsaturated permeability (1)
- unsaturated soils (1)
- wave field dispersion (1)
- wave propagation (1)
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.
In this dissertation, a new, unique and original biaxial device for testing unsaturated soil was designed and developed. A study on the mechanical behaviour of unsaturated sand in plane-strain conditions using the new device is presented. The tests were mainly conducted on Hostun sand specimens. A series of experiments including basic characterisation, soil water characteristic curves, and compression biaxial tests on dry, saturated, and unsaturated sand were conducted. A set of bearing capacity tests of strip model footing on unsaturated sand were performed. Additionally, since the presence of fine content (i.e., clay) influences the behavior of soils, soil water characteristic tests were also performed for sand-kaolin mixtures specimens.
Heat, gas, and leachate are primary by-products of landfill processes in municipal solid waste landfills. In nuclear waste repository, temperature of the waste also raises due to radioactivity processes. Temperature increase in the repository induces hydro-mechanical processes of its sealing material. Moderate to high temperature is expected to be encountered in the field situation. In this thesis, a study on the thermo-hydro-mechanical behavior of compacted bentonite-sand mixtures which are among the materials proposed to be used as sealing material for landfills and hazardous waste repository is presented. Mixtures of a calcium-type bentonite, Calcigel, and quartz sand were used in this study. Series of tests including suction and swelling pressure measurement, drying-wetting under unconfined and confined conditions were conducted at a moderately high temperature. Tests at room temperature including basic and physico-chemical characterization, microstructure and fabric studies, and osmotic suction were conducted in order to provide insight into understanding the hydro-mechanical processes taking place in the bentonite. The experimental data obtained are presented and compared to the result of the previous tests for the same material performed by other researchers at room temperature. The changes in hydro-mechanical behavior due to elevated temperature were analyzed and discussed based on the suction components of soil which are influenced by temperature. At the end, conclusions concerning the temperature effects on the hydro-mechanical behavior of the materials are drawn and suggestions for future studies are made.