下向分层充填进路稳定性数值模拟中网格划分的探讨

Discussion on Mesh Division in Numerical Simulation of Stability of Downward Layered Filling Drift

为探究网格尺寸对下向分层充填进路稳定性数值模拟结果的影响,建立了3种不同尺寸的进路采场模型,基于室内不同尺寸充填体力学试验结果,模拟分析了进路开挖后采场的稳定性。数值模拟结果表明,网格尺寸越小,模型进路顶板位移变化量越小;随着上覆充填体与顶板表面间距离增加,上覆充填体由受拉向受压状态转变;网格尺寸越小,模型对应顶板表面最大主应力越大;在进路两帮,3种尺寸对应模型均受压应力作用,且三者区分度不大;3种不同尺寸模型的塑性区均位于进路顶板两端,呈长条形,且深度随模型网格尺寸增加而增加。网格尺寸划分的不同使下向分层充填进路稳定性发生了改变,故在矿山进行优化方案设计时,不同的优化方案数值模型的网格尺寸应保持一致。

In order to study the influence of mesh size on the numerical simulation results of downward layered filling drift stability,three drift models with different mesh sizes were established.Based on the mechanical test results of indoor backfill with different sizes,the stope stability after drift excavation were simulated and analyzed.The numerical simulation results are concluded as follows.Firstly,the smaller the mesh size,the smaller the variation of the roof displacement of the drift model.Secondly,with the increase of the distance between the overlying backfill and the roof surface,the overlying backfill changes from tension to compression.Thirdly,the smaller the mesh size,the greater the maximum principal stress of the roof surface corresponding to the model.Fourthly,at the two sides of the drift,the corresponding models of the three size meshes are under the action of compressive stress.The difference among the three of them is not obvious.Lastly,the plastic zones of the three mesh models are located at both ends of the drift roof,which are long strips.And with the increase of mesh size,the depth increases.The stability of downward layered filling drift will change with the change of mesh sizes.Therefore,the mesh size of the numerical model of different optimization schemes should be consistent in designing the optimization scheme of the mine.