软弱矿体中巷道围岩稳定控制技术及应用

Stability control technology of roadway surrounding rock in soft ore body and its application

为获得软弱矿体中巷道围岩的稳定状态,采用地质雷达无损检测技术对和睦山铁矿软弱矿体中采矿进路与开拓巷道进行围岩松动圈探测,确定采矿进路围岩松动圈范围为1.5~2.0 m,以及穿脉巷围岩松动圈范围为2.0~2.5 m。基于对采矿进路与穿脉巷的井下现场调查,总结归纳井下巷道典型的3种破坏模式。针对和睦山铁矿具体的工程与地质条件,结合巷道围岩松动圈分类方法与巷道使用时间,建立和睦山铁矿巷道围岩综合分类表。采用FLAC3D开展采矿进路时效性支护技术优化分析,揭示不同支护形式对采矿进路围岩位移影响的时效性规律,提出不同围岩类型采矿进路合理的支护形式和参数,建立采矿进路时效性支护成套技术。针对软弱矿体中穿脉巷与上盘巷道围岩整体失稳的特点,提出深浅孔与高低压耦合注浆技术;并采用自钻式内注浆锚杆将锚固与注浆技术相结合,构成底角锚注加固结构,有效地控制巷道底鼓。现场工业性试验表明,各类支护技术方案有效地解决了和睦山铁矿巷道围岩稳定控制难题,保证了采矿进路在使用期限内的基本稳定和矿体回采安全及永久大巷的长期稳定。

In order to obtain the stability state of roadway surrounding rock in weak ore body,the geological radar nondestructive testing technology has been used to detect the loosening zone of surrounding rock of mining working faces and roadways in Hemushan soft ore mine.Through field tests,the loosening zone range of the mining working face is determined to be 1.5-2.0 m,and that for the roadway is 2.0-2.5 m.According to the field investigation of the mining working faces and ort roadway,three kinds of typical failure modes of underground roadways have been summarized.In view of engineering and geological conditions of Hemushan iron mine,a comprehensive classification table of roadway surrounding rock has been established,combined with the classification method for surrounding rock loosening zone and service time of the roadways.The finite element software FLAC3 D has been used to carry out optimization analysis of time-dependent support technology of the mining working face.Time-dependent rule in displacement of surrounding rock affected by different supporting forms has been revealed.Reasonable support forms and parameters of mining working faces with various surrounding rock types have been put forward,and the time-dependent supporting technology of the mining working faces has been established.The coupling grouting technique of deep/shallow holes with high/low pressures has been put forward,in view of the overall instability characteristics of the surrounding rock in the ort roadway and the hanging wall in the soft ore mine.A self-drilling internal grouting anchor bolt has been used to combine anchoring with grouting technology,and a corner anchor reinforcement structure is generated.Consequently floor heaving is effectively controlled.The field industrial tests indicate that all kinds of supporting schemes can effectively solve the stability control problems of the roadway surrounding rock in Hemushan iron mine and ensure the long-term stability for the mining working faces and permanent roadways during the service period.