Surface subsidence mechanisms theory and practice - Part III - mine design for stability and subsidence control

In recent years, there has been a significant increase in Australia in the use of partial extraction mining methods for the purpose of controlling surface subsidence. There is an increasing tendency to base the design of these methods primarily on surface subsidence measurements and observations. This approach does not ensure regional mine stability nor longterm surface subsidence control. In this paper, a number of basic rock mechanics principles which govern mine stability and thus subsidence control, are presented and illustrated with examples. It is concluded that there is a need to identify fundamental mechanisms of local strata behaviour to compliment subsidence observations and ensure the permanent stability of partial extraction workings. 25 refs., 30 figs., 2 tabs.