倾斜中厚矿体卸压开采应力迁移规律

Numerical Studies on Stress Migration During Depressurized Mining for Inclined Medium-Thick Ore Bodies

针对金属矿床围岩破碎、采准巷道受地压影响破坏严重的现象,应用数值模拟的方法,对不同开挖方式下岩体应力场变化规律和分布特征进行了分析,探讨了通过卸压工程调控应力场迁移的力学机制,为采场结构参数的优化提供了理论依据.研究表明:开挖矿体会造成附近岩体内的应力重新分布,采用增大空区跨度和减小空区高度的回采方案,可以实现卸压开采的目的;结合某铜矿倾斜中厚矿体条件,进路布置在距矿体下盘6 m处,进路附近的垂向应力降低18%,能够满足卸压及经济效益的要求.

To solve the problems that mining tunnels along vein often destroyed by the poor stability of surrounding rock of metallic mineral deposit and ground pressure,the distribution characteristics and changes of ground stress in rock mass due to different mining methods were studied numerically.The mechanism of stress field migration controlled by depressurization was discussed to provide theoretical basis for the optimization of structural parameters of stopes.The results showed that mining ore-body will induce ground stress re-distribution in rock mass nearby,and increasing the span or decreasing the height of goaf can lead to obvious vertical stress drop so as to implement depressurized mining.For the medium-thick ore-body of a copper mine,the numerical results showed that when the roadway is located 6m away from the footwall of the ore-body,the vertical stress in the vicinity of roadway is decreased by 18% after mining,which can meet the requirements of depressurized mining and economic benefits.