With the downward movement of crebody mining depth in Meishan Iron Mine, the ground cave-in area hasbecome larger and the ground pressure more evident and the undergrou ad joints, fissures, faults and drift cave-in more serious.
英
美
- 梅山鐵礦隨著(zhù)礦體開(kāi)采深度的下移，地表塌陷面積越來(lái)越大，地壓顯現越來(lái)越明顯，井下節理、裂隙、斷層、巷道跨冒現象越來(lái)越嚴重；
