在大江南北辽阔的国土下,蕴藏着千姿百态的煤炭。煤层形状各不相同,有层状形,波浪形,有分叉形、尖灭形,还有藕节形、条带形;就厚度而言,从只有几厘米厚的煤线到几十米甚至上百米厚的煤体;就倾角而言,有水平或近似水平的,有缓倾斜或倾斜的,还有急倾斜甚至直立的。真是变化万千!人们为了安全有效地开采宝贵的煤炭资源,曾经创造出数十种采煤方法,以适应复 Under the vast territory of the north and south of the river, it contains coal in different poses and with different meanings. Seam shape varies, layered, wavy, bifurcated, pointed out the shape, as well as Oujie shape, strip shape; thickness, from only a few centimeters thick coal line to dozens of meters Even about a hundred meters thick coal; in terms of inclination, there are horizontal or near horizontal, gently inclined or inclined, as well as steeply inclined or even upright. Really changing! People in order to safe and effective exploitation of precious coal resources, has created dozens of mining methods to adapt to complex