Samples of an over-consolidated saturated silty clay, Keuper marl, and a partially saturated granular material, Breedon gravel, have been used in a triaxial test programme, with a view to characterising certain aspects of the material behaviour for use in a flexible pavement design procedure. Samples of over-consolidated Keuper marl were subjected to repeated axial sinusoidal loads. In addition, further samples were tested under creep loads and standard slow rate of strain triaxial tests. The results from these tests are used to relate the plastic deformation under repeated loads to simple creep tests and to the standard undrained soil strength test. In addition, the resilient behaviour is shown to be a function of the stresses applied to the soil. The samples of granular material were tested drained and were subjected to cyclic vertical and horizontal stresses. The development of a method of lateral strain measurement allowed a fundamental analysis of the behaviour of this material under a cyclic lateral stress. The resilient and permanent deformations occurring under a cyclic horizontal stress have been related to those occurring under the simpler situation of a static horizontal stress. A review of previous work considers research carried out on flexible pavement design with special reference to the role of unbound materials. In addition, an outline is given of studies carried out on creep of clays and repeated behaviour of clays and granular materials. The behaviours of the silty clay and the granular material are analysed in the context of a theoretical pavement structure. The basic testing apparatus is outlined briefly, while developments to the apparatus including an automated computer based data collection system are described in the form of appendices. A summary of the test results is given in the conclusions together with suggestions for further work.

With ever increasing demands on land use large areas of land are being considered for development which due to past or present mining activities are covered by substantial depths of fill materials. The problem faced with the development of land infilled with open cast mining backfill is in predicting the behaviour of the fill upon development. To be able to design foundations suitable to withstand the movements that occur within opencast backfill or design a backfilling operation that produces land suitable for a proposed after development, a means of predicting backfill settlement is required. From the analysis of a considerable quantity of data collected from the monitoring of backfilling operations and backfill movement at a range of opencast coal sites located within the UK, the behaviour of opencast backfill has been examined and better understood. This information has enabled a method of predicting backfill settlement to be developed which has been subsequently implemented as a computer program running under the Windows operating system. Factors taken into consideration during the prediction process are the timing of backfilling operations, the compactive state of the backfill, the inundation of the backfill and the influence of surrounding material and a means of predicting differential settlement due to backfill heterogeneity is proposed. Examples are given demonstrating the significance of these factors upon settlement predictions made at a hypothetical site. Finally, a comparison is made between predicted settlements and those monitored at an actual site to demonstrate the validity of the method proposed.

With the increased availability of computers of various sizes, it is becoming more common to predict the responses of geotechnical structures using numerical analyses which incorporate more realistic models of soil behaviour. The main objective of this research is to develop and evaluate a series of unified critical state models. These models are then used to solve some typical boundary value problems in geotechnical engineering. The new models are based on a critical state model called CASM which was formulated based on both the state parameter concept and a non associated flow rule. The main feature of CASM is that a single set of yield and plastic potential functions is used to model the behaviour of clay and sand under both drained and undrained loading conditions. These models are developed by incorporating a new non-linear elasticity rule, the combined hardening concept and the bounding surface plasticity theory. A new non-linear elasticity rule for clay materials is introduced into CASM, this gives a better prediction on the behaviour of soil. The new combined volumetric-deviatoric hardening model is named CASM-d and provides a better prediction of the behaviour of lightly overconsolidated clays and loose sands. The new bounding surface model is named CASM-b and provides a more realistic prediction of soil behaviour inside the state boundary surface. The new cyclic bounding surface model is named CASM-c and provides a good prediction of soil behaviour under cyclic loading conditions. To evaluate their adequacy, CASM and its extensions are implemented into a finite element package called CRISP. This program was specifically developed to incorporate the critical state type of constitutive models. The analyses of a variety of typical geotechnical engineering problems are carried out to further check the validity of the new constitutive models. The models prove themselves to be very robust and useful tools for solving a wide range of practical geotechnical problems under different loading conditions.

Artificial ground freezing (AGF) provides a means by which excavations can be given temporary or permanent structural support. It may also be used to control the movement of groundwater without the risk of pollution of potable aquifers. As AGF is called upon to strengthen ground at ever increasing depths, the design process needs to be adapted to account for the greater stresses encountered. In strong materials, the prime consideration is the short term strength of the materials and closed-form formulae can be used in design. In weaker materials, the time dependent creep behaviour of the frozen ground predominates and more complex analysis techniques have been devised (e. g. finite elements). Previous works in this field have been chiefly concerned with uniaxial states of stress. In this thesis, consideration is given to the problem of modelling creep under triaxial stress conditions. An introduction is followed by an outline of the general applications and design procedures currently used in ice wall design. Descriptions are then given of a selection of soils and weakly cemented rocks which have been incorporated into a programme of tests to investigate both short and long term strength behaviour. The apparatus available at the start of this project was suitable for uniaxial and low pressure triaxial tests only. Equipment subsequently developed to extend the confining pressure capability to 12 MPa, is described in detail. Short term strength tests show the increase in strength on freezing of ground materials is almost entirely due to the cohesion contributed by the ice matrix. Analysis of the creep test results leads to the development of a new empirically based triaxial creep equation for frozen soils. A sensitivity analysis of the parameters in this equation is followed by its application to a simplified design. Suggestions for further work in this field are included.

Thesis (MS )--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Robert L. Mokwa. Includes bibliographical references (leaves 100-109).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Mary F. Wheeler. Vita. Includes bibliographical references. Also available from UMI.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dr. Brent Rosenblad, Dissertation Supervisor. Vita. Includes bibliographical references.

Title from PDF of title page (University of Missouri--Columbia, viewed on March 2, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dr. William Likos, Thesis Supervisor. Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 132-134). Also available via the World Wide Web.

The Arabian plate is classified as medium sized. It is surrounded by the Nubian, Somalian, Eurasian and Indian plates. Previous investigations of present-day kinematics of the Arabian plate using GPS measurements were primarily obtained from stations located on surrounding plates, with few stations actually located on the Arabian plate itself. Due to the inhomogeneous distribution of these GPS stations and the fact that some of these were actually located in the plate boundary zone, the motion of Arabia was only sensed in a few locations of the rigid plate interior. Through the establishment of GPS networks in Saudi Arabia, the aim of this study was to compute an updated estimate for the absolute and relative motion of the Arabian plate Euler pole and rotation rate. Then to investigate, at the regional scale, the strain rate accumulation within the Arabian plate. Then, to investigate, at a local scale, the strain rate accumulation in the tectonically active south-western part of Saudi Arabia. The results of this study are on absolute motion model for the Arabian plate which is significantly different from those obtained in previous studies, as a result of the number of stations used and their distribution. This does not mean that the previous studies were in error, but that they suffered from a lack of evenly distributed geodetic data for Arabia. Hence, this study result is a new contribution to the knowledge of Arabian plate motion. The results of this study for the relative motion model of the Arabian plate with respect to the Eurasian, Nubian and Somalian plates confirms the results from previous studies, and confirms that the Arabian plate motion is slowing down. This study has also shown that, in general, the strain values are low in most of the Arabian plate, where there is a compression in the north-east to south-west directions and an extension in the north-west to south-east direction, except in two areas, the north-west, close to the Aqaba Gulf and the Dead Sea fault, and the southwest where there are high strain values and variable directions for the principle strain. Furthermore, this study agrees with geologic studies in that there is a compression north-east to south-west and extension north-west to south-east between Farasan Island and the coast of the Red Sea.