DYNAMIC SYMPTOMS OF GROUND PRESSURE ACCOMPANYING THE HARD COAL AND COPPER ORE MINING IN POLAND

摘要

Basing on the statistical data , it has been stated that over 40% of hard coal production and 100% of copper ore output in Poland come from the bounce-exposed regions. In majority of events, high-power ground tremors make a direct reason of bounces. Considering their genesis, the preventive methods have been discussed in the aspect of control of this greatest natural hazard in Polish underground mining.