深部煤层顶板砂岩的人工制岩模拟研究

Simulation study on artificial rock formation of deep coal seam roof sandstone

为了研究人工砂岩与深部煤层顶板砂岩的力学性质及微细观结构的异同,对不同材料配比的人工砂岩与平煤十二矿深部顶板砂岩进行声波波速测量、单轴压缩、覆压渗透、CT扫描、高压压汞等试验,得到其力学与孔隙结构性质。试验结果表明:人工砂岩弹性模量与石英砂占比及粒径大小正相关,人工砂岩的骨料及孔隙结构分布均匀,孔隙度和渗透率均与所含黏土质量分数负相关;顶板砂岩的弹性模量介于大粒与粗粒人工砂岩之间,岩体密度分布离散性较明显,渗透率及孔隙半径分布比人工砂岩小1~2个数量级;人工砂岩能够在力学性质上较好地模拟深部顶板砂岩,而在孔隙结构上与深部顶板砂岩具有较大差异。

In order to study the similarities and differences of mechanical and internal fine view of the structure between artificial sandstone and deep coal seam roof sandstone, artificial sandstone of different material proportions and deep roof sandstone in No.12 Coal Mine of Pingmei Company were measured by a series of tests, including acoustic wave velocity test, uniaxial compression test, CT scanning, and high-pressure mercury injection test. The experimental results show that the greater the particle size and the higher the mass ratio of the quartz sand, the greater the elastic modulus of the artificial sandstone. For the artificial sandstone,aggregate and pore structure are uniform distribution, both the porosity and permeability are negatively correlated with the mass fraction of clay. The elastic modulus of roof sandstone is between large-grained and coarse-grained artificial sandstone, and the density distribution of rock mass is more discrete. The permeability and pore radius distribution are 1 to 2 orders of magnitude smaller than that of artificial sandstone. Comparison results show that artificial sandstone can better simulate on mechanical properties of deep roof sandstone, and on the pore structure artificial sandstone and deep roof sandstone has bigger difference.