Page 11 - Rock Mechanics For Underground Mining

Preface to the third edition

Sometimes it is suggested that mining engineering and its supporting engineering
sciences have reached a state of maturity. However, this proposition is inconsistent
with major developments in the twenty years that have elapsed since the preparation of
thefirsteditionofthisbook,andthetenyearssinceithasbeensubjecttoanysubstantial
revision. Over those periods, innovations and improvements in engineering practice
in mining and mining rock mechanics, and advances in the engineering science of
rock mechanics, have been extraordinary. For these reasons the third edition, which
results from comprehensive and thorough revision of the earlier editions, has involved
the replacement or substantial modification of the equivalent of about half of the text
and figures of those versions of the book.
One of the key drivers for many significant developments in fundamental rock me-
chanics over the period has been the mining industry’s recognition of the economic
returns of better understanding and more rigorous application of the governing sci-
ences embedded in its industrial operations and processes. The result has been some
notable advances in mining engineering practice, involving improvements in mining
methods in particular. For example, caving methods are now more widely applied
as understanding of their scientific basis has improved and their economic and oper-
ational advantages have been realised. Whereas sublevel caving was once regarded
in some places as a method of marginal interest, the advent of very large scale sub-
level caving, made possible in part by improved drilling technology and in part by
understanding of the governing rock mechanics, it is now an attractive proposition for
many orebodies. Similarly, block caving is now conducted efficiently and reliably in
orebody settings that would have been inconceivable two decades ago. At the same
time, methods such as overhand cut-and-fill stoping and shrink stoping have declined
in application, replaced in part by open stoping and bench-and-fill stoping, where large
scale mechanisation, improved backfill technology, reliable rock mass reinforcement
of stope walls and the intrinsic advantages of non-entry methods of working have led
to superior economics and enhanced operational safety.
The scope of developments in mining rock mechanics science and practice has been
as impressive as that in mining engineering. Perhaps the most significant advance has
been the resolution of some longstanding issues of rock fracture, failure and strength
and their relation to the modes of deformation and degradation of rock around mining
excavations. The fact that the key research on this topic was conducted at the Under-
ground Research Laboratory of Atomic Energy of Canada Limited demonstrates the
extent to which mining rock mechanics has benefited from fundamental research in
other fields of rock engineering. The mechanics of blocky rock has also been a field of
impressive development, particularly in regard to formulation of a broad spectrum of
methods of analysis of block jointed rock and their application in excavation engineer-
ing and support and reinforcement design. More generally, improved understanding
of the mechanics of discontinuous rock has had a profound effect on simulation of
caving mechanics and therefore on the design and operation of block caving and
sublevel caving mines.

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