关键词: 多中段回采, 充填采矿法, 围岩稳定性, 有限元分析

Abstract: Aiming at the problem that the geological reserves of an iron mine are reduced due to the complex occurrence of ore bodies，which is difficult to reach the design capacity by single-level mining，a in order to reveal the influence mechanism of multi-level collaborative mining on the stability of surround‐ ing rock in the mining area，by combing the mine exploration report，preliminary design and other data， combined with the geological field investigation of the stope，the finite element numerical simulation is used to construct a three-dimensional model. The model covers the Ⅰ # ，Ⅲ# ，Ⅳ# ore belts and key roadways， and includes the rock movement range defined by the 65° rock movement angle. The mining sequence and the dynamic characteristics of the filling body are coupled，and the rock mass strength coefficient and verti‐ cal displacement are used as evaluation indicators.The results show that the strength coefficient of each ore belt is greater than 1.33 ( higher than 1.0 safety threshold )，and the vertical displacement of surrounding rock is concentrated in 1~10 mm. The maximum displacement of the non-cemented filling body is 22 mm， which does not cause major damage.The disturbance between I# ore belt and other ore belts is weak. There is slight stress superposition in III# and IV# ore belts due to the close spacing，but the strength and defor‐ mation are controllable，and the deformation of key roadways does not exceed the allowable value. The study confirmed that after taking measures such as retaining pillars，timely filling，and monitoring during ground compaction，multi-level mining can ensure the stability of surrounding rock，which provide a sci‐ entific basis for mining design and safe production of similar complex ore bodies.

Key words: multi-level mining, filling mining method, stability of surrounding rock, finite element analysis