覆盖层颗粒移动规律的PFC^(2D)数值模拟

PFC^(2D) Numerical Simulation in Velocity Law of Covering Layer Particles

露天转地下覆盖层对于地下开采工作具有防漏风、防渗水、防冲击地压等作用。探究覆盖层在下移过程中的运动机理,有利于覆盖层安全结构的控制,从而保护地下作业的顺利进行,对于转型矿山的安全过渡有着重要意义。结合某露天转地下矿山地下采场结构参数及覆盖层组成参数,对其进行PFC2D数值模拟,探究覆盖层内部散体颗粒在运动过程中的移动速度变化。结果表明:覆盖层内小颗粒的平均移动速度为大颗粒速度的1.6~2倍,而进路上方颗粒为非进路上方颗粒的2.5~3倍,并且在出矿后期进路上方颗粒的速度变化趋势较迅速,非进路上方颗粒在整个运动过程中速度变化较平缓。

The covering layer of transition from open-pit to underground plays an important role in preventing the air leak,seepage of water and pressure bump. The movement mechanism study on layer will be beneficial to control the structure of layer and to ensure the smooth of underground mining. It also has great significance for the transformation safety of mines. The numerical simulation was developed by using PFC2 Dcombined with the structure parameters of underground stope and the composition parameters of the layer in a certain mine to explore the movement speed change law of internal granular particles. It is shown that the average movement velocity of small particles is 1. 6 to 2. 0 times of big particles,and the velocity of particles above route is 2. 5 to 3. 0 times of other region. At the same time,the velocity variation trend of particles above route is faster relatively in the late phase of ore-drawing and the other region is relatively flat.