近几十年来,苏联和其他一些国家(例如捷克、西班牙、法国等)的煤炭工业采用放顶煤或层间煤工艺来开采厚煤层。传统的厚煤层开采工艺要将10～12米厚的缓倾斜厚煤层分成3～4层倾斜煤层,并用保护煤层将这些煤层加以圈定,而采用放顶煤开采工艺,只装备靠近煤层底板的一个回采工作面 In recent decades, the coal industry in the Soviet Union and some other countries (such as the Czech Republic, Spain, France, etc.) has adopted the use of caving coal or inter-strata coal mining for thick coal seams. The traditional thick seam mining technology should be 10 to 12 meters thick gently inclined thick seam is divided into 3 to 4 layers of inclined coal seam, and with the protection of coal seam to be delineated by these coal seams, and the use of caving mining technology, only equipped with a coal seam floor near Mining face