我矿原采用浅孔留矿法,(矿体倾角60°,厚度2.2米,老顶为破碎辉绿岩),由于中段高度增加(由30米增加到50米)、地压增大、顶板破碎、矿柱爆裂等因素,尽管几年来对浅孔留矿法在底部结构、采场要素及采场管理等方面进行了一些工作,但都未从根本上解决安全性差、回采率低这两个关键问题。为此,从1971年开始,组织了技 I mine shallow shallow retention method (ore body angle of 60 °, the thickness of 2.2 meters, the old top broken crushed diabase), due to increased height (from 30 meters to 50 meters) increased pressure, the roof Crack and pillar burst, although some work has been done on the bottom structure, stope elements and stope management in recent years, they have not fundamentally solved the problems of poor safety and low recovery rate A key issue. To this end, since 1971, organized a technical