大冶铁矿象鼻山北帮滑坡体下采矿实践

Practice of Mining Under Sliding Mass of Xiangbishan North Wall in Daye Iron Mine

大冶铁矿东露天坑已于2000年闭坑,境界外矿量拟采用地下开采。象鼻山是拟定的4个挂帮矿开采点之一,其北帮曾发生过7万m3的滑坡。如何控制边坡的变形与稳定构成了挂帮矿安全回收的关键技术问题。为此,在边坡工程地质与水文地质调查的基础上,采用工程地质类比法、有限元法和极限平衡法预测了边坡失稳的可能性和破坏模式,论证了预留矿石挡土墙方案控制边坡变形和失稳的可行性,并且通过边坡监测变形的及时反馈,调整开采工艺,保障了挂帮矿资源回收的顺利进行。

The east open pit of Daye Iron Mine was closed in 2000 and its ex-boundary ore reserve was to be underground mined. Xiangbishan mining area was one of the four planned mining points of hang-up wall ore, and there had been a landslide of 70,000 m 3 in its north wall. How to control the slope deformation and stability became the key technical issue in the safe recovery of the hang-up wall ore. Based on the investigation of slope engineering geology and hydrological geology, the possibility and failure mode of slope instability were predicted using engineering geological analogy, finite element and limit equilibrium methods, and the feasibility of preserving ore as the retaining wall to control the slope deformation and instability was expounded and proved. The timely feedback of slope deformation monitoring helped regulate the mining technology, ensuring a smooth recovery of the resource of hang-up wall ore.