尾矿固化体力学性质预测的PFC模型研究

Study on the Prediction of Mechanical Properties of Tailings Solidified Body with PFC Model

以某铁矿项目为工程背景,选用离散元颗粒流程序(PFC)对尾矿固化体的力学特征进行模拟,确定了尾矿固化体细观力学参数,建立了尾矿固化体单轴压缩数值模型,并在此基础上研究尾矿粒径分布及颗粒数量的简化对模拟尾矿固化体的力学特征的影响。研究发现:数值模型单轴压缩计算结果与试验值平均误差为5.5%,证明采用该方法构建的数值模型能有效预测尾矿固化体单轴抗压强度,且对尾矿固化体柔性及脆性破坏形态的捕捉效果较好,进而证明了利用PFC数值模型对尾矿固化体进行模拟有效可行;由于不同工程条件下尾矿粒度分布差异比较大,若尾矿粒径分布较广,建立尾矿数值模型时,可对尾矿粒径分布及颗粒数量进行一定程度的简化。分析表明,当模型尾矿颗粒粒组范围选取比达到50%以上,能较好地模拟尾矿固化体应力应变曲线及破坏形态。

This paper takes an iron ore project as the engineering background,simulates the mechanical characteristics of the solidified tailings with PFC,determines the meso-mechanical parameters of the solidified tailings,and establishes the uniaxial compression numerical model of solidified tailings.On this basis,the paper studies the influence of particle size distribution and particle number simplification on mechanical characteristics of simulated solidified tailings.According to research findings,the average error between the numerical model and experimental results under uniaxial compression is 5.5%.It proves that the numerical model constructed by this method can effectively predict the uniaxial compressive strength of solidified tailings,and the effect of capturing the flexible and brittle failure mode of the solidified tailings is good.It further indicates that the PFC numerical model is effective and feasible to simulate the solidified tailings.Because of different engineering conditions,the size distribution of tailings is quite different.if the size distribution of tailings is wide,the particle size distribution and particle number of tailings can be simplified when the numerical model of tailings is established.Anal ysis shows that when the selection ratio of model tailings particle group range reaches more than 50%,the simulation of stress-strain curve and failure mode of solidified tailings can be well performed.