凹山铁矿边坡自动监测下的靠帮开采

The Steep End-slope Mining of Washan Iron Mine Based on Automatic Slope Monitoring System

针对马钢集团铁矿石需求和凹山露天矿生产条件,提出了通过边坡自动监测保证露天矿靠帮开采回收残余资源期间生产安全的方法。通过矿山动态地质数据库分析凹山露天矿残余铁矿资源的赋存形态、储量、采剥关系等信息,确定回收范围为东南帮。在露天矿西北帮边坡稳定区域布置1台边坡雷达,对东南帮资源回收区及边坡影响区进行分区域、连续、反复扫描,实时反馈边坡位移和速度,为靠帮开采生产计划编制提供安全保障。通过边坡雷达的连续监测,掌握了边坡形态变化、爆破震动、连续降雨等因素对边坡变形的影响规律。控制爆破会打破原有裂隙的力学平衡状态,但边坡变形只发生在爆破时段,后期通过加强监测可保证爆破影响区边坡安全;降雨对凹山露天矿边坡变形的影响是可逆的,强降雨期间可根据边坡监测结果采取人员、设备疏散等措施。凹山露天矿安全回收挂帮残余铁矿石资源逾5 Mt,创直接经济效益逾1.2亿元。

In view of the iron ore demand of Maanshan Iron and Steel Group and the production conditions of Aoshan Open-pit Mine,a method of ensuring the production safety of open-pit mine during the period of recovery of residual resources by steep end-slope mining through automatic slope monitoring is put forward.The information of residual iron ore resources,such as the occurrence form,reserves and mining-stripping relationship,is analyzed through the dynamic geological database of the Aoshan Open-pit Mine,and the recovery range is determined to be in the southeastern side.A slope radar is deployed in the slope stability area of the northwest slope of open pit mine to scan the resource recovery area and the slope influence area of the southeast slope regionally,continuously and repeatedly,and to feedback the displacement and velocity of the slope in real time,so as to provide a safety guarantee for the preparation of the production plan of the side-by-side mining.Through continuous monitoring of slope radar,the influence law of slope shape change,blasting vibration,continuous rainfall and other factors on slope deformation is grasped.Controlled blasting will break the mechanical balance of the original cracks,but the slope deformation only occurs in the blasting period,and the safety of the slope in the blasting affected area can be ensured by strengthening monitoring in the later period;the effect of rainfall on the slope deformation of the open pit mine in Aoshan is reversible,and measures such as evacuation of personnel and equipment can be taken according to the monitoring results of the slope during the heavy rainfall period.AoshanOpen-pit Mine has recovered more than 5 Mt of the residual iron ore resources in the hanging wall safely,which has generated more than 120 million yuan of direct economic benefits.