Environmental geomechanics. CISM course, Udine, Italy, October 1999 (Q5960933)

The book includes seven lectures which review the up-to-date developments on the title subject. \textit{W. Ehlers} and \textit{P. Ellsiepen}, ``Theoretical and numerical methods in environmental continuum mechanics''. Based on the theory of porous media, the authors consider soils, rocks and temperature ice with elastic, plastic, viscous and frictional properties under tensional and micropolar conditions. The theoretical introduction is illustrated by numerical analysis of two phases of incompressible material in strong formulation which can be transformed into a weak one, a fact which allows the subsequent discretization and application of finite element method. The biaxial test on elastic consolidation, and an elastic disk with hole are used to study the coupled solid-fluid sheet piling in a fluid-saturated domain, and to investigate the slope and base failure. The differential equations are formulated with adaptive time integration involving mesh refinement and coarsening. 45 figures illustrate the solution procedure and final results. \textit{H. R. Thomas} and \textit{S. W. Rees}, ``Isothermal flow''. Here the authors give an overview of the theory of moisture flows in partially saturated soils, together with solution techniques of transfer equations by finite element methods. Conductivity, capillarity, hysteresis and variation of material parameters are taken into account. Numerical simulations lead to the prediction of moisture content; the corresponding results are plotted in diagrams. \textit{H. R. Thomas}, \textit{M. Sansom} and \textit{S. W. Rees}, ``Nonisothermal flow''. For a coupled moisture-temperature model with liquid, water and heat transfer, the authors solve the governing equations by finite difference and finite element technique, with applications to thermophysical soil processes and to heating tests. A set of diagrams presents the results. \textit{R. de Borst} and \textit{O. Heeres}, ``Computational plasticity''. Standard elasto-plasticity is presented with a return mapping algorithm and linearization of equations. Further, the authors discuss generalized plasticity, integration procedures and granular materials. The analysis also includes hypoplasticity. \textit{A. Gens} and \textit{S. Olivella}, ``Numerical analysis of radioactive waste disposal''. Here, using a thermo-hydromechanical formulation, the authors examine specific features of nuclear waste and deep geological disposal waste. A finite element analysis allows to obtain numerical results which are again plotted in diagrams. The determination of engineered barriers in soils with salt or in rocks is performed implicitly. \textit{B. A. Schrefler}, ``Modelling of subsidence due to water or hydrocarbon withdrawal from the subsoil''. The author uses Biot model and Terzaghi stress principle to justify a two-phase medium model (solid and water). Different previous models are also discussed. The first-generation models refer to a separate study of fluids and solids with evaluation of subsidence displacements induced by a uniform pressure. The presented geometric models considers the medium with nonlinear parameters, time effects, with a real description of reservoir pressure variation etc. The model also includes capillarity effects due to the presence of oil and gas. Numerical results are related to confined layers in Ravenna, and to oil reservoirs. \textit{F.-J. Ulm} and \textit{O. Coussy}, ``Environmental chemomechanics of concrete''. In view of concrete engineering affected by alkali-silicon reactions in early-aged structures, the authors analyze the cross effects between chemo-physical processes and deformation or cracking of material, which leads to a thermodynamic approach to irreversible behaviour of concrete due to internal reaction. Such effects may be exo- and endothermal. Also are considered the chemical shrinkage, the hardening-softening due to the internal pressure generated by chemical reaction, and hydration kinetics. The application concern gravity dams, massive structures and composite bridges.