西部煤炭资源以侏罗纪煤田为主，侏罗系煤系地层普遍受到顶板复合水的影响，因此，顶板砂岩含水层的富水性评价是矿井安全开采的前提。以隆德煤矿为研究对象，通过氮气吸附试验分析了砂岩孔隙结构特征；基于FHH分形模型，分析了分形维数与岩石组成、孔隙结构、埋深等参数的相关性。研究结果表明：隆德煤矿砂岩具有较强的非均质性，分形维数D₂>D₁，表明砂岩内部孔隙结构比表面孔隙复杂；岩石组成成分是主要影响孔隙复杂程度的重要因素，其中黏土矿物与石英是主要影响分形维数的因素；区域内砂岩吸附滞环近似H₃和H₄型，以狭窄型和平板状裂隙孔为主，孔隙以微−中孔为主；砂岩孔隙具有明显的分阶段分形特征，分形维数与黏土矿物含量、石英、BET比表面积、伊利石含量、水力半径呈正相关关系，与石英、BJH总孔体积呈弱的正相关关系，与造岩矿物含量、钾长石、斜长石、高岭石含量、平均孔径和孔隙度呈负相关关系，与渗透率呈弱的负相关性关系，而与绿泥石含量基本无相关性。

The coal resources in western China are mainly Jurassic coal fields, and the Jurassic coal measure strata are generally affected by roof composite water, so the water-rich evaluation of roof sandstone aquifer is the premise of safe mining. Taking Longde Coal Mine as the research object, the pore structure characteristics of sandstone were analyzed through nitrogen adsorption test and whole rock analysis. Based on FHH fractal model, the correlation between fractal dimension and rock composition, pore structure and burial depth was analyzed. The results show that the sandstone in Longde Coal Mine has strong heterogeneity, and the fractal dimension D₂ is larger than D₁, indicating that the pore structure in the sandstone is more complex than that on the surface. The composition of rock is an important factor affecting the complexity of pores, and clay minerals and quartz are the main factors affecting the fractal dimension. The adsorption hysteresis of sandstone in the region is approximately H₃ and H₄, mainly narrow and plate-like fissure pores, and micro-medium pores. Sandstone pores have obvious fractal characteristics in phases. The fractal dimension is positively correlated with clay mineral content, quartz, BET specific surface area, illite content and hydraulic radius, weakly positively correlated with the total pore volume of quartz and BJH, and negatively correlated with rock-forming mineral content, potassium feldspar, plagioclase, kaolinite content, average pore size and porosity. There was a weak negative correlation with permeability, but no correlation with chlorite content.