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 some fundamental concepts behind the basic theories and tools of discrete element methods (DEM), its historical development, and its wide scope of applications in geology, geophysics and rock engineering. Unlike almost all books available on the general subject of DEM, this book includes coverage of both explicit and implicit DEM approaches, namely the Distinct Element Methods and Discontinuous Deformation Analysis (DDA) for both rigid and deformable blocks and particle systems, and also the Discrete Fracture Network (DFN) approach for fluid flow and solute transport simulations. The latter is actually also a discrete approach of importance for rock mechanics and rock engineering. In addition, brief introductions to some alternative approaches are also provided, such as percolation theory and Cosserat micromechanics equivalence to particle systems, which often appear hand-in-hand with the DEM in the literature. Fundamentals of the particle mechanics approach using DEM for granular media is also presented.
- Presents the fundamental concepts of the discrete models for fractured rocks, including constitutive models of rock fractures and rock masses for stress, deformation and fluid flow
- Provides a comprehensive presentation on discrete element methods, including distinct elements, discontinuous deformation analysis, discrete fracture networks, particle mechanics and Cosserat representation of granular media
- Features constitutive models of rock fractures and fracture system characterization methods detaiing their significant impacts on the performance and uncertainty of the DEM models

Mechanical properties and fluid transport in rocks are intimately linked as deformation of a solid rock matrix immediately affects the pore space and permeability. Part I of this topical volume covers mainly the nucleation and evolution of crack damage in rocks, new or modified techniques to measure rock fracture toughness and a discussion of upscaling techniques relating mechanical and fluid transport behaviour in rocks at different spatial scales.

Mechanical properties and fluid transport in rocks are intimately linked as deformation of a solid rock matrix immediately affects the pore space and permeability. This may result in transient or permanent changes of pore pressures and effective pressures causing rock strength to vary in space and time. Fluid circulation and deformation processes in crustal rocks are coupled, producing significant complexity of mechanical and fluid transport behavior. This often poses severe technical and economic problems for reservoir and geotechnical engineering projects involved in oil and gas production, CO2 sequestration, mining and underground waste disposal. For example, the depletion of hydrocarbon and water reservoirs leading to compaction may have adverse effects on well production. Solution/precipitation processes modify porosity and affect permeability of aquifers and reservoir rocks. Fracture damage from underground excavation will critically influence the long-term stability and performance of waste storage.

Part I of this topical volume covers mainly the nucleation and evolution of crack damage in rocks, new or modified techniques to measure rock fracture toughness and a discussion of upscaling techniques relating mechanical and fluid transport behaviour in rocks at different spatial scales.

Part II, to be published later in 2006, will include studies investigating the coupling of rock deformation and fluid flow.

Stress Field of the Earth's Crust is based on lecture notes prepared for a course offered to graduate students in the Earth sciences and engineering at University of Potsdam. In my opinion, it will undoubtedly also become a standard reference book on the desk of most scientists working with rocks, such as geophysicists, structural geologists, rock mechanics experts, as well as geotechnical and petroleum en- neers. That is because this book is concerned with what is probably the most pe- liar characteristic of rock - its initial stress condition. Rock is always under a natural state of stress, primarily a result of the gravitational and tectonic forces to which it is subjected. Crustal stresses can vary regionally and locally and can reach in places considerable magnitudes, leading to natural or man-made mechanical failure. P- existing stress distinguishes rock from most other materials and is at the core of the discipline of "Rock Mechanics", which has been developed over the last century. Knowledge of rock stress is fundamental to understanding faulting mechanisms and earthquake triggering, to designing stable underground caverns and prod- tive oil fields, and to improving mining methods and geothermal energy extraction, among others. Several books have been written on the subject, but none has atte- ted to be as all-encompassing as the one by Zang and Stephansson.

Rock joint behaviour impacts many branches of engineering including surface and underground mining, dam foundations, tunnelling for hydro power and transport, petroleum reservoirs and nuclear waste storage. The subject is in a very active stage of development, and engineers, geologists, and scientists involved in these developments have indicated by their 110 papers that rock joints are of great importance in many fields of engineering. Selected papers span five continents and thirty countries. The subjects covered include geological aspects of joint origin and morphology, mechanical behaviour such as shear strength and deformability, hydraulic behaviour, and dynamic behaviour. The influence of water flow on frictional strength and the effect of joint deformation on water flow are also strongly represented. Great activity is evident in many countries in computer modelling for solving complicated engineering problems where joint behaviour is important. Articles describe the modelling of joints under dams, around wellbores, in petroleum reservoirs, in open pit mines, and around tunnels, shafts and nuclear waste repository excavations. The conference proceedings forms a unique collection of keynote and specialist articles on all aspects of rock joint behaviour.