考虑炭质泥岩颗粒破碎的级配演化预测模型

Prediction model of gradation evolution considering particle breakage of carbonaceous mudstone

为准确预测炭质泥岩在冲击荷载过程中的颗粒破碎及级配曲线的变化,建立炭质泥岩“冲击能和含水率-破碎指标-级配分布”的数学模型。通过引入一个可以描述连续级配曲线的单参数级配方程,建立单参数级配方程和颗粒破碎率B w的数学关系表达式,实现了“破碎指标-级配分布”的转换。通过设置反S型和双曲线型两种典型炭质泥岩填料连续级配,开展了一系列不同含水率和冲击能的冲击试验。结果表明:无论炭质泥岩的初始级配是双曲线型分布还是反S型分布,当冲击能一定时,炭质泥岩的颗破碎率均随着初始含水率的增大而增大;当含水率一定时,炭质泥岩的颗粒破碎率随冲击能的增加而增加,当冲击能量达到6.075 kJ后,颗粒破碎率基本保持不变,各粒组的颗粒含量相对于初始含量的变化趋于一个稳定的比例。根据炭质泥岩在冲击过程中的颗粒破碎率B w与初始含水率和冲击能的关系,建立了颗粒破碎率与含水率、冲击能的数学关系式,实现了“冲击能和含水率-破碎指标”的转换。从而以破碎指标为媒介,建立了“冲击能和含水率-破碎指标-级配参数”的数学模型,并通过验证发现该模型可以较好反映不同冲击能和含水率条件下炭质泥岩级配曲线演化规律。

In order to accurately predict the change of particle breakage and gradation curve of carbonaceous mudstone during impact loading,a mathematical model of“impact energy and water content-crushing index-gradation distribution”of carbonaceous mudstone was established.Firstly,by introducing a single parameter grading equation that can describe the continuous grading curve,the mathematical relationship between the single parameter grading equation and the particle breakage rate B w is established,and the conversion of“crushing index-gradation distribution”is realized.A series of impact tests with different water content and impact energy were carried out by setting the continuous gradation of two typical carbonaceous mudstone fillers of inverse S type and hyperbolic type.The results show that the particle breakage rate of carbonaceous mudstone increases with the increase of initial water content when the impact energy is constant,regardless of whether the initial gradation of carbonaceous mudstone is hyperbolic distribution or inverse S-type distribution.When the water content is constant,the particle breakage rate of carbonaceous mudstone increases with the increase of impact energy.When the impact energy reaches 6.075 kJ,the particle breakage rate remains basically unchanged,and the particle content of each particle group tends to be a stable proportion relative to the initial content.According to the relationship between the particle breakage rate B w of carbonaceous mudstone in the impact process and the initial moisture content and impact energy,the mathematical relationship between the particle breakage rate and the moisture content and impact energy is established,and the conversion of“impact energy and moisture content-crushing index”is realized,A mathematical model of“impact energy and water content-crushing index-gradation parameter”was established by using the crushing index as the medium,and it was found that the model can better reflect the evolution law of the gradation curve of carbonaceous mudstone under different impact energy and water content conditions.