刘冲磷矿Ⅰ号矿体自1958年建矿至1985年,已开采27年,回采后的空区顶板未作处理。1978年7月发现局部地段井下矿柱发生变形。1980～1982年,井下顶板欠稳固区段出现采场冒顶、底板鼓起、支架压坏等地压现象。为防止空区大面积冒落造成灾害,保证深部开采安全,根据Ⅰ号矿体矿岩性质,地质构造与埋深等因素,将其分为六个区段(沿走向),采用不同方案予以处理。其中, Liuchong Phosphate Mine No. 1 ore body was built from 1958 to 1985, has been mined for 27 years, after mining the roof of the open area without treatment. In July 1978 found that the local mine underground pillars deformed. From 1980 to 1982, there was a phenomenon of underground pressure such as roof falling, swelling of the floor and crushing of the support due to the unstable top section of the underground mine roof. In order to prevent disastrous collapse of a large area and ensure the safety of deep mining, it is divided into six sections (along the strike) according to the nature of ore and rock of No. I orebody, geological structure and depth of burial, and adopted different schemes deal with. among them,