Boundary Element Techniques In Geomechanics

This text provides an understanding of the role of Boundary Element Methods (BEM) in the numerical analysis of problems in geomechanics. Topics covered include: computer implementation; wave propagation due to seismicity or to man-related causes; and soil-fluid-structure interaction.

Numerical techniques for solving many problems in continuum mechanics have experienced a tremendous growth in the last twenty years due to the development of large high speed computers. In particular, geomechanical stress analysis can now be modelled within a more realistic context. In spite of the fact that many applications in geomechanics are still being carried out applying linear theories, soil and rock materials have been demonstrated experimentally to be physically nonlinear. Soils do not recover their initial state after removal of temporary loads and rock does not deform in proportion to the loads applied. The search for a unified theory to model the real response of these materials is impossible due to the complexities involved in each case. Realistic solutions in geomechanical analysis must be provided by considering that material properties vary from point to point, in addition to other significant features such as non-homogeneous media, in situ stress condition, type of loading, time effects and discontinuities. A possible alternative to tackle such a problem is to inttoduce some simplified assumptions which at least can provide an approximate solution in each case. The validity or accuracy of the final solution obtained is always dependent upon the approach adopted. As a consequence, the choice of a reliable theory for each particular problem is another difficult decision which should be 2 taken by the analyst in geomechanical stress analysis.

The first volume of this series dealt with the Basic Principles of Boundary Elements, while the second concentrated on time dependent problems and Volume three on the Computational Aspects of the method. This volume studies the applications of the method to a wide variety of geomechanics problems, most of which are ideally suited for boundary elements demonstrating the potentiality of the technique. Chapter 1 deals with the application of BEM to three dimensional elastody namics soil-structure interaction problems. It presents detailed formulations for rigid, massless foundations of arbitrary shape both in the frequency and time domains. The foundations are assumed to be resting on a linearly elastic, homogeneous, isotropic half-space and be subjected to externally applied loads on obliquely incident body. The chapter reviews the major advances in soil foundation interaction presents a series of numerical results and stresses the practical application of BEM, pointing out the high accuracy and efficiency of the technique, even when using coarse mesh discretizations.

"This Handbook is intended to provide boundary element practitioners - users and scholars - with a reference book detailing the most important boundary element publications and the most up to date codes. The book is divided into four sections. The first describes the development of the method and gives over 300 milestone references. The second lists the BE books written up to now, giving a brief description of their contents. Section three deals with BE codes now available including general and some special purpose programs. Each entry occupies a page with a full description of the code. In addition, tables have been compiled to provide at a glance the capabilities of each code. The last section is a "Who's Who" of Boundary Elements with details of the best known practitioners in industry and academia." --Back cover.

2D/3D Boundary Element Programming in Petroleum Engineering and Geomechanics, Volume 72, is designed to make it easy for researchers, engineers and students to begin writing boundary element programs. This reference covers the fundamentals, theoretical developments, programming and applications. Both fluid flow through porous media and structural problems are used for coding exercises. Included computer programs may be used as starting codes; after modifications, they can be applied to real world problems. The book covers topics around mesh generation, 3D boundary element coding, and interface coding for controlling mesh generation, and plotting results. Includes interactive 2D and 3D coding exercises that readers can modify based on need Features research on the most recent developments in indirect and dual boundary element methods Contains case studies showing examples and applications of the theories presented in the book