Hydro Mechanical Coupling And Creep Behaviours Of Geomaterials

GeoProc2008 collects the proceedings of the International Conference on Coupled T-H-M-C (thermal, hydraulic, mechanical, chemical) Processes in Geosystems.

(4). The next three papers extend these views by taking a closer look on parameters that govern hydraulic diffusivity in sandstones and other types of rocks. Specific targets addressed are the influence of differential stress on permeability (5), imaging of the fracture geometry (6), and pressure induced variations in the pore geometry (7). Contributions no. 8 to 10 cover investigations of permeability-porosity relationships during rock evolution (8), of the formation, propagation, and roughness of fractures in a plexi-glass block (9), and pressure oscillation effects of two-phase flow under controlled conditions (10). The subsequent four articles focus on diverse modeling approaches. Issues considered are how the geometry and the mechanical behavior of fractures can be characterized by mathematical expressions (11), how the evolution of permeability in a microcracking rock can be expressed by an analytical model (12), deviations from the cubic law for a fracture of varying aperture (13), and the numerical simulation of scale effects in flow through fractures (14). Three further papers refer to in situ observations, being related to topics as the assessment of in situ permeability from the spatio temporal distribution of an aftershock sequence (15), to the scale dependence of hydraulic pathways in crystalline rock (16), and to the significance of pore pressure - stress coupling in deep tunnels and galleries (17).

Creep behaviour, especially for underground radioactive waste disposal facilities, whose storage period far exceed the service time of most of the civil engineering underground facilities, is very significant. Boom Clay, an argillaceous rock chosen as a reasonable geological barrier in Belgium is first systematically studied in this book. A series of research tools such as laboratory experiments (4 years), field measurements (20 years), theoretical studies, back analysis and numerical simulations are used to study the mechanical behavior of this rock. Firstly, laboratory studies such as oedometer tests, HM triaxial tests, HM triaxial creep tests and SEM tests, etc. intuitively show the nonlinear behaviour of the argillaceous rock and it provides a basis for the theoretical studies. Secondly, considering the anisotropic mechanical properties and nonlinear creep potential of Boom Clay, a relatively complete theoretical system has been established. Thirdly, based on the field measurements in the last few decades, using back analysis method, the theoretical studies are verified. Finally, based on the study above, long term stability analysis of the underground disposal facilities is implemented and the risks facing future generations in the event of failure in the disposal system are also quantified through numerical simulation.

Special emphasis is given to the constitutive behaviour of rock material, including rock mechanics and partial saturation, chemo-mechanics, thermo-hydro-mechanics, weathering and creep. Theoretical concepts, laboratory and field experiments and numerical simulations are discussed. Multiphysics coupling and long-term behaviour has practical applicat

Among the most important and exciting current steps forward in geo-engineering is the development of coupled numerical models. They represent the basic physics of geo-engineering processes which can include the effects of heat, water, mechanics and chemistry. Such models provide an integrating focus for the wide range of geo-engineering disciplines. The articles within this volume were originally presented at the inaugural GeoProc conference held in Stockholm and contain a collection of unusually high quality information not available elsewhere in an edited and coherent form. This collection not only benefits from the latest theoretical developments but also applies them to a number of practical and wide ranging applications. Examples include the environmental issues around radioactive waste disposal deep in rock, and the search for new reserves of oil and gas.

This book presents a state-of-the-art exposition of the broad subject of the mechanics of geomaterials, from rocks and soils to concrete and reinforced concrete. Its approach is interdisciplinary, with an emphasis placed on the fundamental problems of mechanics which are common to structural and civil engineering, geotechnical and mining engineering, nuclear engineering, offshore engineering and geology. The consideration of these problems emphasises the importance of experimental observation, and concentrates on the use of numerical methods, particularly the finite element method, for their solution.

Advances in Multi-Physics and Multi-Scale Couplings in Geo-Environmental Mechanics reunites some of the most recent work from the French research group MeGe GDR (National Research Group on Multiscale and Multiphysics Couplings in Geo-Environmental Mechanics) on the theme of multi-scale and multi-physics modeling of geomaterials, with a special focus on micromechanical aspects. Its offers readers a glimpse into the current state of scientific knowledge in the field, together with the most up-to-date tools and methods of analysis available. Each chapter represents a study with a different viewpoint, alternating between phenomenological/micro-mechanically enriched and purely micromechanical approaches. Throughout the book, contributing authors will highlight advances in geomaterials modeling, while also pointing out practical implications for engineers. Topics discussed include multi-scale modeling of cohesive-less geomaterials, including multi-physical processes, but also the effects of particle breakage, large deformations on the response of the material at the specimen scale and concrete materials, together with clays as cohesive geomaterials. The book concludes by looking at some engineering problems involving larger scales. Identifies contributions in the field of geomechanics Focuses on multi-scale linkages at small scales Presents numerical simulations by discrete elements and tools of homogenization or change of scale