Materiały konferencyjne SEP 1992

Szkoła Eksploatacji Podziemnej * 92 457 four. The empirically developed method of test-drilling works very wel 1 in German coał mines, but out of the problems ment i oned before there are some other principle disadvantages. The results of a test drilling are vałid only for the time and location of this special drilling. Thus, a considerable amount of drillings has to be carr i ed out to get enough i nformat i on. And dur i ng these dr i 11 ings the working at the face usual ly has to be stopped, so that out of security problems also productional restrictions are yielded. Therefore it would be very usefuł, to develop a system, which produces continuous Information about the stress conditions both in space and time. Such a system could complete the test-dril1ing data and possibły avoid a lot of "uncritical" test-drillings^ so that test-drillings could be concentrated in really dangerous areas, and thus such a system could possibly avoid unnecessary production stops too. One of the most proraising approaches to find such a continuous "watch-over- system" is to use registration and evaluation of seismoacoustic events, which occur underground in highly stressed areas. The fifth chapter of this paper will give some informations about the basie research, the design of suitable eąuipment, and about results of practical measurements. The i nves t i gat i ons deser i bed here have been carr i ed out at the Institut fur Geophysik of the Westfalłsche Berggewerkschaft- skasse, Bochum, mainly with the help ajid the partial sponsorship of the Ruhrkohle AG, different mines of the Ruhi—area and mining offices. They are part of research-progreims of the ministry of "Wirtschaft, Mittelstand und Verkehr von Nordrhein-Westfalen" and of the "Bundesministerium fur Forschung und Technologie der Bundesrepublik Deutschland". The authors express thełr thanks to all sponsors, helpers and active contributors. 2. Regulations for Recognlzing Outburst-Prone Areas The regulations of the mine office of Nordrhein-Westfalen spec i fy var i ous parameters to i dent i fy areas t hat may be out - burst-prone. The most important of these depend on the mining conditions and on the geological structure.