为保证云南某铜矿后期的开采安全,采用岩石力学试验与数值模拟相结合的方法,研究在大型水体下分步开采对采空区的安全稳定性影响及破坏规律。本文通过室内岩石力学试验得到矿区的岩石力学参数,再结合现场调查情况,使用霍克布朗(Hoek-Brown)准则对室内岩石力学参数进行折减,得到数值模拟所需的岩体力学参数。采用有限元软件ANSYS模拟开采矿区已开采的1 367~1 245 m之间的矿体,未开采的1 245~1 200 m及1 367~1 409 m之间的矿体。结果表明:对矿区安全造成威胁的主要因素为采空区上下盘围岩中的拉应力、采空区下部和上部的采场隅角处的应力集中;当采空区向下延伸的时候,不会对采空区的安全造成显著影响,但当回采向上由1 394 m水平进行到1 409 m水平时,采空区的安全性显著恶化。结合矿区目前的状况,不继续向上回采,在采空区被充填满的状态下,矿区不会发生采空区顶板大规模冒落破坏致使江水涌入矿井的安全事故。

In order to ensure the safety of later-stage mining in a copper mine in Yunnan, a combined method of rock mechanics testing and numerical simulation was adopted to investigate the influence and failure patterns of stepwise mining in the goaf under large-scale water body. The rock mechanical parameters required for numerical simulation were then obtained by combining the field investigation and discounting the indoor rock mechanical parameters using the Hoek-Brown criterion. The mined-out ore body between 1 367~1 245 m, as well as the unmined ore bodies between 1 245~1 200 m and 1 367~1 409 m, were simulated using the finite element software ANSYS. The results indicate that: The main factors threatening the safety of the mining area are the tensile stresses in the surrounding rocks above and below the goaf and the stress concentration in the corners of the mined-out areas in the lower and upper parts of the goaf. Extending the goaf downwards does not significantly affect its safety, but when mining was carried out upward from the 1 394 m level to the 1 409 m level ,the safety of the goaf deteriorates significantly. Considering the current condition of the mining area, it is recommended that upward mining be discontinued and the goaf be filled to prevent major roof collapse in the goaf, thereby avoiding safety accidents involving water inflow from the nearby water bodies.