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When a rigid shaft such as a jacked pile or the sleeve of a cone penetrometer penetrates soil, the soil mass at the shaft tip fails. This failed soil mass flows around the shaft surface and creates a disturbed soil zone. The soil in this zone, which is at a failure or critical state (CS), flows and behaves like a viscous fluid. During continuous penetration, the shaft surface is subjected to an additional viscous shear stress above the static shear stress (interfacial solid friction). The total resistance on the shaft in motion is due to the static and viscous shear components. Current methods of calculating the penetration resistance in soils are based on static interfacial friction, which determine the force required to cause failure at the shaft-soil interface and not the viscous drag. The main aim of this research is to understand the viscous soil resistance on penetrating shafts in clays.This research consists of two components. First, a theoretical analysis based on creeping flow hydrodynamics is developed to study the viscous drag on the shaft. The results of this analysis reveal that the size of the CS zone, the shear viscosity of the soil and velocity of the shaft influence the viscous drag stress. Large increases in viscous drag occur when the size of the CS zone is less than four times the shaft radius.Second, a new experimental procedure to estimate the shear viscosity of clays with water contents less than the liquid limit is developed. Shear viscosity is the desired soil parameter to estimate viscous drag. However, there is no standard method to determine shear viscosity of clays with low water contents (or Liquidity Index, LI). Soils can reach CS for water contents in the plastic range (LI<1) and exhibit viscous behavior. The fall cone test is widely used to interpret the index (liquid and plastic limit) and strength properties of clays. In this study the existing analysis of the fall cone test is reexamined to discern the viscous drag as the cone penetrates the soil. This reexamination shows that the shear viscosity of clays with low water contents (LI<1.5) can be estimated from time-penetration data of the fall cone. Fall cone test results on kaolin show that the shear viscosity decreases exponentially with an increase in LI.The results of this research can be used to understand practical problems such as jacked piles in clays, cone penetrometer sleeve resistance and advancement of casings in soil for drilling or tunneling operations.

The effect of temperature on soil behaviour has been the subject of many studies in recent years due to an increasing number of projects related to the application of high temperature to soil. One example is the construction of facilities for the disposal of hot high level nuclear waste canisters (150-200C) several hundred meters underground in the clay formations. Despite this, the effects and mechanism by which temperature affects the soil properties and behaviour are not fully known. A limited amount of reliable experimental data, technological difficulties and experimental methods employed by different researchers could have contributed to the uncertainties surrounding the soil behaviour at elevated temperature. Also several thermo-mechanical models have been developed for soil behaviour, but their validity needs to be examined by reliable experimental data. In this research, efforts have been made to improve the experimental techniques. Direct displacement measuring devices have been successfully used for the first time to measure axial and lateral displacements of clay samples during tests at various temperatures. The thermo mechanical behaviour of two reconstituted clays has been investigated by performing triaxial and permeability tests at elevated temperature. Undrained and drained triaxial tests were carried out on normally consolidated and over consolidated samples of M44 clay and Kaolin C1C under different effective stresses, and at temperatures between 22C and 100C. Permeability tests were carried out on samples of M44 clay at temperatures between 22C and 50C. The effects of temperature on permeability, volume change, pore pressure development, shear strength and stiffness, stress strain response and critical state parameters for different consolidation histories have been investigated by comparing the results at various temperatures. The results are also compared with the predictions of two models. It has been found that at elevated temperature the shear strength, friction angle and initial small strain stiffness reduce whereas permeability increases. The slope of the swelling line in the v-p� plane has been found to reduce with temperature. The slope of the isotropic normal consolidation line (INCL) and critical state line (CSL) in the v-p� plane have been observed to be independent of temperature, but both the INCL and the CSL shift downwards to lower locations as temperature increases. The deformations during drained cooling and re heating cycles have been found to be elastic and to simply reflect the expansivity of the soils solid particles. The thermal volume changes during undrained heating have been observed to be direct results of the thermal expansion of water and clay particles. The internal displacement measuring devices have been found to produce reliable data for the variation of strains at elevated temperature.

In the recent years significant progresses in thedevelopment of high-temperature superconductors have been made.It is realistic to believe that power applications, based onthese conductors, in a few years will become available. To beable to utilise the conductors in an optimum way, theunderstanding of their behaviour under application-likecondition is essential. One important parameter that has to beoptimised is the power loss, which means that mathematicalmodels of these losses have to be developed. In a typicalapplication the superconductor is utilised in a coilconfiguration where the actual magnetic field is considerablehigher than for a straight structure. For power frequencies thelosses are dominated by hysteresis losses and flux flowlosses. In this thesis, mathematical models of the hysteresis andthe flux flow losses as a function of a transport current, anexternal magnetic field, the temperature and the frequency havebeen developed. The transport current and the magnetic field,which are assumed to be proportional to each other, includeboth an ac and a dc component. The models of the hysteresislosses are based on the critical state theory, and for twoidealised geometries, an infinite slab and a thin strip, newexact closed form equations have been derived. The equationsfor the two idealised geometries are then superimposed tofacilitate the description of a more realistic geometry, i.e. asuperconducting tape with a finite width and thickness. Themodel of the flux flow losses is valid for a tape shapedconductor and is based on both measurements and reasonablephysical assumptions. For the development and the validation ofthe models, a calorimetric measurement set-up has been used.From a limited number of relatively simple measurements, thedeveloped models can be adjusted to a certain superconductor,and the power losses for the actual superconductor can bepredicted in considerable more complicated cases. <b>Keywords:</b>high-temperature superconductor, hysteresislosses, flux flow losses, critical state model, calorimetricmeasurements

The objectives of this dissertation are to measure and calculate surface free energies of soil particles, to understand the mechanical behavior of unsaturated silty sand through first studying the stress-strain relationship, the effects of matric suction and pore water chemistry and second to interpret the behavior by the critical state frame work, to develop a method to predict cone tip resistance in unsaturated soils, and to present the concept of pseudo strain and dissipated pseudo strain energy. Universal Sorption Device (USD) is developed to measure surface free energies of soil particles. The test results on a soil sample shows that specific surface area increased with decreasing particle size. The components of surface free energies and the work of adhesion increased with decreasing particle size. A servo controlled triaxial testing device is developed to test 15.24 cm in height and 7.62 cm in diameter, recompacted specimens of unsaturated soil under varying matric suction and different pore chemistry. During the test, the matric suction is maintained constant. Results from the triaxial drained tests are used for validation of the constitutive models proposed by Alonso et al. (1990). Predictions from the model are in good agreement with experimental results. The critical state model for unsaturated soil is used to calculate cone tip resistance in unsaturated silty sand. The calculated cone tip resistance is used to evaluate the liquefaction potential of unsaturated soils. The results from the stress based liquefaction potential analysis reveal that even in an unsaturated condition soil is susceptible to liquefaction. By applying the pseudo strain concept, it is possible to account for the viscous resistance of water during cyclic loading. The results of undrained cyclic triaxial tests are used to calculate pseudo-strain and dissipated pseudo strain energy. The results of calculated dissipated pseudo strain energy suggest that the effect of initial matric suction is evident. On the other hand, the effect of surface tension increase or decrease due to existence of chemical on the pore water is negligible.

<p>In the recent years significant progresses in thedevelopment of high-temperature superconductors have been made.It is realistic to believe that power applications, based onthese conductors, in a few years will become available. To beable to utilise the conductors in an optimum way, theunderstanding of their behaviour under application-likecondition is essential. One important parameter that has to beoptimised is the power loss, which means that mathematicalmodels of these losses have to be developed. In a typicalapplication the superconductor is utilised in a coilconfiguration where the actual magnetic field is considerablehigher than for a straight structure. For power frequencies thelosses are dominated by hysteresis losses and flux flowlosses.</p><p>In this thesis, mathematical models of the hysteresis andthe flux flow losses as a function of a transport current, anexternal magnetic field, the temperature and the frequency havebeen developed. The transport current and the magnetic field,which are assumed to be proportional to each other, includeboth an ac and a dc component. The models of the hysteresislosses are based on the critical state theory, and for twoidealised geometries, an infinite slab and a thin strip, newexact closed form equations have been derived. The equationsfor the two idealised geometries are then superimposed tofacilitate the description of a more realistic geometry, i.e. asuperconducting tape with a finite width and thickness. Themodel of the flux flow losses is valid for a tape shapedconductor and is based on both measurements and reasonablephysical assumptions. For the development and the validation ofthe models, a calorimetric measurement set-up has been used.From a limited number of relatively simple measurements, thedeveloped models can be adjusted to a certain superconductor,and the power losses for the actual superconductor can bepredicted in considerable more complicated cases.</p><p><b>Keywords:</b>high-temperature superconductor, hysteresislosses, flux flow losses, critical state model, calorimetricmeasurements</p>

As an abundant sedimentary rock, shale is widely used as construction material around the world. However, shale is a fissile and laminated material and is therefore subject to deterioration due to environmental and chemical forces (i.e., weathering), which is possible to cause high maintenance cost on associated structures and failures of earth slopes and embankments. However, currently, there is lack of efficient method to monitor the weathering process of shale. This thesis uses several shale samples collected from the commonwealth of Kentucky to study the deformation and shear behaviors of weathered compacted shale. A new electrical approach was developed to access the deformation behavior of shale. The long term deformation behaviors, such as collapse and swell can be predicted from specific electrical parameters. The critical state theory was used to describe the shear behavior of weathered compacted shale. Some findings observed by previous researchers were confirmed, and new empirical equations were provided to estimate the shear strength parameters of weathered compacted shale.

Traditionally, void ratio, e has been used as a state variable for predicting the liquefaction behaviour of soils under the Critical State (Steady State) framework. Recent publications show that void ratio, e may not be a good parameter for characterizing sand with fines as the steady state, SS data points move downward in e-log(p) space up to certain fines content termed as threshold fines content, TFC. Thus, it was difficult to apply SS concept on sand with fines as a small variation of fines content may lead to different SS line. Many researchers proposed to used equivalent granular void ratio, e* as an alternative state variable (i.e. in lieu of void ratio, e) in attempt to obtain a narrow trend line for SS data points irrespective of fc provided fc  TFC. The e* is obtained from e. For the conversion from e to e*, one need a parameter b which presents the active fraction of fines in overall force structure of sand. However, predicting the b is problematic. Most, if not all, of the b reported were determined by case-specific back-analysis, that is, the b-value was selected so that the test results for a given sand-fines type could be correlated with the equivalent granular void ratio, e* irrespective of fines content. This thesis examines the factors that affecting the b value by examining published work on binary packing. This leads to a simple semi-empirical equation for predicting the value of b based onparticle size ratio,  and fines content, fc. Published data and experimental results on Sydney sand appears to be in support of the proposed equation. The single relation of SS data points in e*-log(p) space for sand with fines is referred as Equivalent Granular Steady State Line, EG-SSL. The EG-SSL is then used to define the equivalent granular state parameter,*. A good correlation observed between * and q-p, q- q responses in undrained shearing. The e* and * are also used to modified a state dependent constitutive model. Seven model input parameters are needed in addition four to critical state input parameters. These parameters are obtained from drained test. The model is used to predict q-pand q- q responses for flow, non-flow and limited flow behaviour for 0% to 30% fines contents. The model predictions are in good agreement with experimental results. The effect of fines types (in terms of plasticity and angularity) on the prediction equation of b are also examined with four different types of fines. A negligible effect of fines type on the prediction equation of b is observed. The link between monotonic and cyclic loading behaviour for sand with fines are also examined with emphasis on cyclic instability and strain hardening behaviour after quasi steady state, QSS for a range of fines contents (provided that fc < TFC). It is found that a single set of rules could be used to correlate monotonic and cyclic behaviour for a range of fines contents at same *.

The effect of temperature on soil behaviour has been the subject of many studies in recent years due to an increasing number of projects related to the application of high temperature to soil. One example is the construction of facilities for the disposal of hot high level nuclear waste canisters (150-200C) several hundred meters underground in the clay formations. Despite this, the effects and mechanism by which temperature affects the soil properties and behaviour are not fully known. A limited amount of reliable experimental data, technological difficulties and experimental methods employed by different researchers could have contributed to the uncertainties surrounding the soil behaviour at elevated temperature. Also several thermo-mechanical models have been developed for soil behaviour, but their validity needs to be examined by reliable experimental data. In this research, efforts have been made to improve the experimental techniques. Direct displacement measuring devices have been successfully used for the first time to measure axial and lateral displacements of clay samples during tests at various temperatures. The thermo mechanical behaviour of two reconstituted clays has been investigated by performing triaxial and permeability tests at elevated temperature. Undrained and drained triaxial tests were carried out on normally consolidated and over consolidated samples of M44 clay and Kaolin C1C under different effective stresses, and at temperatures between 22C and 100C. Permeability tests were carried out on samples of M44 clay at temperatures between 22C and 50C. The effects of temperature on permeability, volume change, pore pressure development, shear strength and stiffness, stress strain response and critical state parameters for different consolidation histories have been investigated by comparing the results at various temperatures. The results are also compared with the predictions of two models. It has been found that at elevated temperature the shear strength, friction angle and initial small strain stiffness reduce whereas permeability increases. The slope of the swelling line in the v-p� plane has been found to reduce with temperature. The slope of the isotropic normal consolidation line (INCL) and critical state line (CSL) in the v-p� plane have been observed to be independent of temperature, but both the INCL and the CSL shift downwards to lower locations as temperature increases. The deformations during drained cooling and re heating cycles have been found to be elastic and to simply reflect the expansivity of the soils solid particles. The thermal volume changes during undrained heating have been observed to be direct results of the thermal expansion of water and clay particles. The internal displacement measuring devices have been found to produce reliable data for the variation of strains at elevated temperature.

In a recent article Ulrich Brand has discussed how best to perform policy analysis. I reflect upon the paper as an interdisciplinary researcher experienced in public policy problems and their analysis with a particular interest in the relationship between social, economic and environmental problems. At the centre of the paper is the contrast between two existing methodologies prevalent in political science and related disciplines. One is the rationalist approach, which takes on the character of a natural science, that believes in a fully knowable objective reality which can be observed by an independent investigator. The other is a strong social constructivist position called interpretative policy analysis (IPA), where knowledge and meaning become so intertwined as to make independence of the observer from the observed impossible and all knowledge highly subjective. Brand then offers his model as a way forward, but one that he closely associates with the latter. My contention is that policy analysis, and any way forward, needs to provide more of a transformative combination of elements from both approaches. Indeed I believe this is actually what Brand is doing.