@misc{Vu2005, type = {Master Thesis}, author = {Vu, Manh Quynh}, title = {M{\"o}glichkeiten zur Bewertung des Zustandes von Straßenbauten (Bau und Rekonstruktion) unter Einbeziehung seismischer Messungen .}, doi = {10.25643/bauhaus-universitaet.649}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6498}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Central point of this study is to evaluate stiffness properties of pavement, specifically the E or G- modulus determined by different testing methods. Stiffness of soil is both stress and strain dependent property and otherwise different methods usually affect the material in different ways. The Young's modulus E0 and shear modulus G0 correspond to the very small strain level are regarded as the initial or maximal stiffness of the relevant stress-strain curves of a given material. The modulus decay curve is called the degradation curve, which also reviewed in this study. With the results of different measurement methods applied for a reclaimed mining site in Klettwitz for determining of stiffness parameter of subsoil, author have tried to find a unification between the results considering the relationship between stiffness parameter and the range of strain levels. The testing methods executed at plant S9 in Klettwitz-S{\"u}dfeld are: laboratory oedometer test, static plate load test, dynamic plate load test, and seismic testing methods (spectral analysis of surface wave, SASW). Some results getting from this study are: one receives different absolute values of stiffness parameter from different testing methods. The reason is different testing methods produce different range of strain levels in soil during their execution. Conventional and non-destructive testing methods should be combined together for investigating of subsoil characteristics. This means, the soil parameters must be adjusted to the current range of strain level. Especially for settlement calculation it is recommended that different values of stiffness modulus, Es, resulted by different testing methods should be simultaneously utilized along the depth beneath loading surface. Accuracy for determining of stiffness degradation curves depends a lot on the determination of maximal stiffness parameters (E0, G0) at the range of very small strain level, and it still requires much further studies.}, subject = {Straßenbau}, language = {en} } @misc{Buechner2005, type = {Master Thesis}, author = {B{\"u}chner, Stefan}, title = {Methoden zur Ermittlung von Materialkennwerten f{\"u}r numerische Berechnungen in der Geotechnik}, doi = {10.25643/bauhaus-universitaet.552}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-5524}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Bei der Bearbeitung geotechnischer Aufgabenstellungen treten h{\"a}ufig Probleme bei der Vorhersage des Setzungsverhaltens von B{\"o}den auf. Numerische Methoden auf Basis finiter Elemente oder finiter Differenzen werden oftmals als Hauptinstrumente der Prognose verwendet. Dabei erzielen sie jedoch nicht selten Ergebnisse, die im Nachhinein als unbefriedigend bezeichnet werden m{\"u}ssen. Eine Begr{\"u}ndung daf{\"u}r liegt in der Verwendung linearer Stoffgesetze, die auf Ans{\"a}tze aus der Elastizit{\"a}tstheorie beruhen. Werden h{\"o}herwertige Stoffgesetze eingesetzt, so fehlen oftmals gesicherte Aussagen zu den erforderlichen Bodenkennwerten. Diese m{\"u}ssen durch ein umfangreiches Versuchsprogramm mit einer aufwendigen Auswertung bestimmt werden. Ziel dieser Arbeit ist es daher, eine robuste Methode zu entwickeln, die in der Lage ist, aus Messwerten (Feld) und Versuchsergebnissen (Labor) geeignete Parameter f{\"u}r Modelle mit nichtlinearer Konsolidationstheorie zu ermitteln. Dazu werden die M{\"o}glichkeiten der Mathematik ausgenutzt, welche inverse Methoden zur Verf{\"u}gung stellt, mit denen man mehrere Bodenkennwerte (haupts{\"a}chlich Steifigkeiten und Durchl{\"a}ssigkeiten) gleichzeitig unter Be-r{\"u}cksichtung ihrer Wechselbeziehungen zueinander bestimmen kann. Als Instrumentarium daf{\"u}r steht das Programm AdConsol-1D zur Verf{\"u}gung, welches die inverse Parameterermittlung auf Basis mathematischer Optimierungsmethode erm{\"o}glicht. Ein Test- und Versuchsdamm, der im Finnischen Haarajoki (Haarajoki Test Embankment) errichtet wurde und {\"u}ber l{\"a}ngeren Zeitraum messtechnisch {\"u}berwacht wurde, dient als Validationsbeispiel. Dieser wurde auf sehr verformungsempfindlichem Boden errichtet. Durch Aufbereitung und Auswertung der Feld- und Laborversuche am Haarajoki Test Embankment wurden die Grundlagen f{\"u}r die inverse Parameterermittlung geschaffen. Dazu wurde eine Methode zur Konstruktion plausib-ler Porenwasser{\"u}berdr{\"u}cke aus Setzungsmessungen und Laborversuchsdaten entwickelt. Mit den Werten der Optimierung wurde ein Modell im 2D FEM Programm Plaxis erstellt, welches die in Haarajoki gemessenen Setzungen und Porenwasserdr{\"u}cke m{\"o}glichst genau reproduzieren sollte. Es zeigte sich, dass sich Bodenparameter des eindimensionalen nichtlinearen Konsolidati-onsmodells nicht problemlos auf ein 2D FEM Modell {\"u}bertragen lassen. Insbesondere fehlen gesicherte Aussagen {\"u}ber die Gr{\"o}ße des horizontalen Durchl{\"a}ssigkeitskoeffizienten kx und des Referenzsekantenmoduls E50Ref aus dem Triaxialversuch. Die inverse Berechnung f{\"u}r sich betrachtet verlief dahingegen zufrieden stellend mit dem eindimensionalen Modell in AdConsol-1D. Auf dieser Grundlage ist die Erstellung einer realistischen Prognose des weiteren Konsolidationsverlaufes am Haarajoki Test Embankment m{\"o}glich.}, subject = {Konsolidation}, language = {de} } @misc{Khan2005, type = {Master Thesis}, author = {Khan, Muhammad Ibrar}, title = {HYDRAULIC PROPERTIES OF POLYMER-ENHANCED BENTONITE-SAND MIXTURE}, doi = {10.25643/bauhaus-universitaet.680}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6803}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {The hydraulic properties of the polymer-enhanced bentonite-sand mixtures (PEBSMs) investigated in this study consisted of the water retention behaviour (or the soil-water characteristic curve (SWCC)) and the saturated and unsaturated coefficients of permeability. The SWCCs of the compacted polymer-enhanced bentonite-sand mixtures were measured using two techniques; namely, axis-translation technique and vapour equilibrium technique. The results obtained from both methods were combined to establish a single SWCC for each specimen. The saturated coefficient of permeability of the material was measured using the constant-head flexible wall permeameter method. The unsaturated coefficient of permeability was computed from the SWCCs and the saturated permeability values using the statistical model. The study revealed that the wetting curves for the PEBSM and clay are above the drying curves. The fact is thought be due to the specimens being not saturated before starting the drying tests. Since the specimens are expensive soil such a trend can be expected. The permeability deduced from the oedometer test data over-estimates the actual water flow rate resulting in a higher computed saturated coefficient of permeability compared to the measured values. The nets of polymer and bentonite clusters are thought to retard the flow of water during the direct measurement. However, the net of polymer and bentonite clusters are compressed during loading and rebound during unloading. Hysteresis effect was found for the PEBSMs in the permeability versus degree of saturation curve. This is due to possible difference in the spatial distribution of water in the specimens depending whether the specimens were on drying or wetting path.}, subject = {Baustoff}, language = {en} } @misc{Remmert2005, type = {Master Thesis}, author = {Remmert, Frank}, title = {Bestimmung hydraulischer Eigenschaften von teilges{\"a}ttigten granularen Reibungsmaterialien in einem S{\"a}ulenversuch}, doi = {10.25643/bauhaus-universitaet.664}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6647}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Diese Diplomarbeit beschreibt die Durchf{\"u}hrung eines dynamischen Sands{\"a}ulenversuches zur Bestimmung der Wassercharakteristikkurven (SWCC) und der teilges{\"a}ttigten Durchl{\"a}ssigkeiten des Sandes. Als Messinstrumente wurden TDR-Sonden und Tensiometer verwendet. Die TDR-Sonden wurden eigens f{\"u}r diesen Versuch kalibriert. Messgr{\"o}ßen waren der volumetrische Wassergehalt und die Kapillarspannung im Sand. F{\"u}r die Auswertung kamen statistische Modelle zum Einsatz, insbesondere das Modell nach FREDLUND \& XING. Dar{\"u}ber hinaus wurde gepr{\"u}ft, in wie weit die Wassercharakteristikkurven (SWCC) auch {\"u}ber inverse Berechnungsverfahren ermittelbar sind.}, subject = {Bodenanalyse}, language = {de} } @phdthesis{Samingan2005, author = {Samingan, Agus Setianto}, title = {An Experimental Study on Hydro-Mechanical Characteristics of Compacted Bentonite-Sand Mixtures}, doi = {10.25643/bauhaus-universitaet.646}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20051007-7082}, school = {Bauhaus-Universit{\"a}t Weimar}, year = {2005}, abstract = {Nuclear and hazardous waste disposal issues have become universal issues and problems related to the final disposal of these waste including finding a suitable site, natural and engineered barriers used, construction of the repository, long-term performance assessment have gained increasing attention all over the world. High-level radioactive and hazardous waste are required to be buried in deep geological repositories. In Germany, the ongoing researches have assessed the suitability of salt-stone formation in the country as a host rock candidate for its nuclear waste repository. Bentonite-based materials have been proposed to be used as sealing and buffer elements for the nuclear waste repository. Several hydro-mechanical processes will take place in the field and influence behaviour of the sealing and buffer elements of the repository. In this dissertation, a study on the hydro-mechanical characterisation of bentonite-sand mixtures is presented. Mixtures of a calcium-type bentonite, named Calcigel, and quartz sand were used in the investigation. Series of experiments including basic and physico-chemical characterisation, microstructure and fabric studies, suction and swelling pressure measurements, wetting and drying test, one-dimensional compression-rebound test, one-dimensional cyclic wetting-drying test under constant vertical stress, and saturated permeability test were conducted. The experimental data obtained are analysed and several characteristics of the material are brought out in this dissertation. Conclusions regarding basic behaviour of the materials are drawn based on the results of microstructure and fabric studies. Factors influencing the magnitude of suction and swelling pressure of the materials are outlined and discussed. The suction-induced compression and rebound characteristics of the material are described. The wetting and drying behaviour as influenced by the material boundary conditions are discussed. Permeability characteristics of the materials are examined based on several available permeability models. Several mechanical and hydraulic parameters that can be used in modelling using some available constitutive modelling approaches are derived based on the experimental data. At the end, conclusions regarding the hydro-mechanical characteristics of the materials are drawn and suggestions for future studies are made.}, subject = {hydro-mechanics}, language = {en} }