Experience in controlling the mining-induced seismicity in potash mining in the South-West Thuringia

The classification of mining-induced seismic events (rock bursts) into the two main types “mining rock burst” and ‘’tectonic rock burst” ( Knoll , 1981 ) showed to be very useful not only for controlling the rock burst danger in potash mining of the GDR but also in a lot of mines all over the world. It is the classification which is the basis to derive practical measures to prevent and combat the different burst types, using type-related measures. Results of investigations by Knoll, McGare and others demonstrate the principal possibility to discriminate the two main types by seismologic investigation of the focal process. The paper further shows the great importance of rock mechanical interpretation of the source parameter ‘’stress-drop” for classification purposes and for the characterization of the fracture process within the source. Examples for rock mechanical interpretation of seismologic source parameters of fracture processes in underground pillars in a potash mine are given. The new parameter “damage value” gives hints on the degree of destruction within the source using seismic information only.