采空区多孔介质空隙率与渗透特性三维空间动态分布模型*

为揭示采空区垮落后堆积体及上覆岩层空隙率与渗透率三维空间的动态分布规律，基于开采空间守恒理论，构建采空区的空隙率与渗透率三维空间动态分布模型。利用该模型，得出不同空间位置与不同开采结束时间下空隙率和渗透率分布图。结果表明:采空区垮落岩体的空隙率和渗透率在水平方向呈“凹”状分布，采空区两侧巷道附近空隙率和渗透率较大，中部较小；在垂直方向随着与底板距离的增大，空隙率和渗透率大幅度减小。该模型描述了采空区多孔介质空隙率与渗透特性三维空间分布随时间逐步压密实的过程，可为煤矿瓦斯预测与防治提供一定的借鉴和参考。

Three dimensional spatial dynamic distribution model on porosity and permeability characteristics of porous media in goaf

In order to reveal the dynamic distribution laws of porosity and permeability in the three dimensional space of collapsed accumulation body and overlying strata in the goaf,based on the conservation theory of mining space,a three dimensional spatial dynamic distribution model of porosity and permeability in the goaf was constructed.Using this model,the distribution of porosity and permeability under different spatial positions and different mining end time was obtained.The results showed that the porosity and permeability of the collapsed rock mass in the goaf presented the concave distribution in the horizontal direction,the porosity and permeability were larger near the roadways on both sides of the goaf,and smaller in the middle.In the vertical direction,with the increase of the distance from the floor,the porosity and permeability decreased greatly.The model described the step by step compaction process for the three dimensional spatial distribution of porosity and permeability characteristics of the porous media in the goaf with time,which can provide certain reference for the gas prediction,prevention and control in coal mines.