Content of th;s book 9properties are the same in a plane but different perpendicular to that plane)
and nine elastic constants for the orthotropic case (where the properties are
different in three perpendicular directions). However, for a fully
anisotropic rock, 21 such constants are needed. To the authors’ knowledge,
these 21 constants have never been used in a numerical analysis and
certainly have never been measured in a rock engineering project.
Establishing the balance between not including enough rock property
information and conducting unnecessarily complex analyses is difficult but
made much easier if the engineering rock mechanics principles are
understood.
Generalizing the problem described above, one should ask ‘What exactly
is it that we wish to know for the design of engineering projects?’ In this
book, we consider both the principles and the applications and we have
included discussions which address the question above and will assist in
the design process.
1.2 Content of this book
This book is intended for anyone involved in rock mechanics and rock
engineering. From the text in the previous section, the reader will have
noted that we are making a special attempt to present the principles and
then to place them in the engineering context. Thus, the book can be used
for both introductory and advanced rock mechanics teaching, and by rock
engineers of all persuasions. We feel that the rock mechanics subject does
not have to be project-specific and can therefore be generally directed to
all types of engineers working on or in rock masses.
The layout follows a logical course from chapters on the basic subjects
of rock mechanics such as stress, strain, discontinuities and permeability
through the generic rock engineering aspects of excavation and support to
specific engineering objectives and projects in the later chapters.
Anyone who has worked in rock engineering will know that all projects
have their own idiosyncratic components and are unique. Thus, whether
an engineer is involved with a conventional or an unconventional project,
it is always vital to understand and apply the principles presented in the
first 13 chapters.
This book is about the principles of engineering rock mechanics. The
book is not intended to be truly comprehensive in the sense of including
all information on the rock engineering subject. Readers requiring more
information are referred to the five volume compendium Comprehensive
Rock Engineering, edited by the first author and also published by Elsevier.