Study on the microstructure and fractal characteristics of sandstone in complex tectonic mining areas

In this study, the microstructure and fractal characteristics of the near-fault sandstone of Bailiang Xusheng Coal Mine in Chenghe Mining Area with complex geological structure were analyzed, and the purpose of this study was to gain an in-depth understanding of the distribution structure characteristics, basic physical properties and pore structure characteristics of the sandstone. The basic physical properties such as density, porosity and permeability of the sandstone in the tectonic area were measured by physical property testing instruments, the pore size distribution of the sandstone was analyzed by nuclear magnetic resonance （NMR） technology, and the quantitative results of porosity and fractal dimension of the sandstone in the tectonic area were analyzed by scanning electron microscopy （SEM） technology. The results show that the pore radius of the sandstone in the tectonic area is mainly concentrated in the range of less than 0.1 microns, and most of them belong to the microporous type, and the closer the sandstone is to the fault, the greater the porosity, and the fractal dimension of the sandstone in the tectonic area shows a good linear relationship, with certain fractal characteristics, and the fractal dimension is large, the pore distribution is uneven, and the structural morphology is complex.