在波兰煤矿中,55％以上的矿井存在着冲击地压危险,总产煤量的50％采自具有冲击地压危险的煤层(每年约9千万吨)。四十年代末,波兰煤矿发生冲击地压的次数是很多的。1949年发生350次,1950到1960年,每年约226次,1961到1965年,每年约88次,1966至1970年,每年约29次,近年来,每年约发生20次冲击地压。 In Polish mines, over 55% of the mines are at risk of rock burst and 50% of the total coal produced is taken from coal seams (about 90 million tons per year) that are at risk of rock burst. In the late 1940s, the number of rockbursts in Polish coal mines was very high. From 1949 to 350, from 1950 to 1960, about 226 per year, from 1961 to 1965, about 88 per year, from 1966 to 1970, about 29 per year, and in recent years, about 20 perihelical earthquakes took place in recent years.