| dc.description.abstract | In this thesis, previous research on discontinuity geometry, in-situ block size
distribution (IBSD), blasted block size distribution (BBSD), and blastability of rock
mass is discussed. The IBSD with special reference to discontinuities with a fractal
spacing distribution is investigated using computer simulation, from which a set of
empirical equations is derived for predicting the IBSD of a rock mass with
discontinuities of fractal spacing distributions. The goodness-of-fit of theoretical as
compared with real spacing distributions is discussed and a grey correlation analysis
technique is introduced into the goodness-of-fit.
An estimation of mean trace length of discontinuities with lognormal and fractal
distributions is derived. A numerical algorithm and associated computer program for
estimating the discontinuity size distribution is developed from which empirical
equations for estimating the mean size of discontinuities with negative exponential,
lognormal and fractal trace length distributions have been derived. A factor which
accounts for the discontinuity impersistence is incorporated into the estimation of
IBSD.
Combining both Ross-Ram and Schuhmann models, a reasonably accurate and
user-friendly "photo-scanline" technique is devised for the estimation of BBSD of
the blastpile.
Blasting results, as a function of both the intact rock properties and the
discontinuity structures are investigated, and an energy-block-transition model
characterising the blastability of rock masses is developed. It is argued that the
blastability of rock mass is governed by a comprehensive range of both intact rock
properties and discontinuity parameters, and that the fractal dimension of the IBSD of
a rock mass could be an indicator of blastability. Taking into account that blastability
is a complex property, a methodology of assessing blastability of rock masses is
introduced using a Rock Engineering Systems method.
Published data from the literature has been used wherever possible to support the
validation of the new techniques of analysis and two case histories in which
applications of the developed methodologies and techniques are presented. | en_US |
