Abstract:
This paper explores possible synergies between techniques used to minimise seismicity in deep South
African gold mines and their applicability to control coal bumps. The paper gives a summary of the techniques
used in the deep gold mines and a critical appraisal if these are useful in coal mines. The techniques
typically include control of mining rate, preconditioning, optimisation of extraction sequences
and centralised blasting. Of particular interest to the coal bump problem is an experimental limit equilibrium
fracture zone model implemented in a displacement discontinuity code. This was recently developed
for the gold mines to enable the interactive analysis of complex tabular mine layout extraction
sequences. The model specifically accommodates energy dissipation computations in the developing
fracture zone near the edges of these excavations. This allows the released energy to be used as a surrogate
measure of ongoing seismic activity and addresses a number of the weaknesses in the traditional
usage of this quantity as a criterion for the design of seismically active layouts. This paper investigates
the application of the model to a hypothetical coal longwall layout and the specific problem of coal
bumps.
