Contribution to the Problem of the Optimal Size of Model Experiments on Rock Control.

Model experiments on rock control are indispensable for mine planning and cost estimation. A series of experiments is described which explains the correlation between depth and floor creeping. In a further series, stress relief drilling for the diminution of gas outburst risks is analyzed. A third series investigates caved roofs in tunnels of shallow depth and weak rock. Finally, the author discusses the problem of the optimal model size and the costs of laboratory investigations.