As for the seams with different mine geological conditions, a site measurement should be made for the area of the seam pressure released zo...

• 对于不同矿山地质条件下的煤层,必须实测其工作面煤层卸压带和塑性极限应力区范围,才能准确确定钻孔瓦斯涌出初速度合理的测试深度。