三山岛海底金矿开采充填体与围岩变形规律的数值模拟

Numerical Simulation of Mine Backfill and Surrounding Rock Deformation when Exploiting Sanshandao Seabed Gold Mine

为合理解释三山岛金矿新立矿区海底开采充填体和围岩变形特征,建立了假二维的矿山开挖充填力学模型,并将其简化为平面应变问题。根据对充填体力学特性的研究,在模型建立过程中,对充填体采用了双屈服模型,对矿柱及围岩采用了应变硬化/软化塑性模型。利用FLAC3D数值模拟软件,并在模型中的相应位置设置位移监测点,分析了真实矿山开采过程中上下各采场充填体和围岩的移动变形规律。研究结果表明,新立矿区充填体变形主要为水平方向上的压缩变形,且具有累积效应,当充填体达到垂直方向的最大压缩量后,顶板围岩在水平构造应力作用下有向充填体上山方向滑动的趋势。

In order to interpret the deformation behavior of mine backfill and surrounding rock when mining Xinli deposit of Sanshandao gold mine, a quasi-two dimensional mechanical model was built as a plane strain problem. According to the mechanical behavior of fill mass, double-yield plasticity model was adopted for the body of the fill mass and strain-hardening or softening plasticity model was used in the grid of pillars and surrounding rocks. Several displacement monitoring points were set in positions of interest in a FLAC3D model and their results relatively really reflected the movement and deformation rules of the backfill and surrounding rock in cut-and-fill stoping by overhand method.The results showed that the body of fill mass was mainly subjected to compressive deformation in horizontal direction and had a cumulative effect on its volume deformation.And after the compressive deformation of the backfill in vertical direction reaches a maximum value,roof surrounding rock have a vertical upward component of movement under the action of horizontal tectonics stress.