采空区垮落带遗煤区域作为煤、氧低温反应的主要场所，其应变、孔隙率和渗透率演化模型的研究对深入认识煤自燃发展过程与规律有重要意义。基于团队自主研发的承压破碎煤体气体渗流实验装置，开展了单一粒径与混合粒径煤体承压渗流过程应变、孔隙率和渗透率演化规律研究。对不同粒径下的应变、孔隙率和渗透率随应力变化情况进行分析，结果显示：相关变化过程可以分为2个阶段，即轴向应力≤6 MPa时的线性变化阶段与>6 MPa时的指数函数变化阶段，初步表明破碎煤体的变形、孔隙率和渗透率的变化机制一致、同粒径无关，轴向应力=6 MPa时的状态属于关键节点状态，其对应的应变、孔隙率和渗透率分别承接着各自上下2种不同的变化机制；轴向应力≤6 MPa和>6 MPa条件下三者变化的主要原因分别是颗粒的压缩作用和滑移填充作用；轴向应力=6 MPa时不同粒径破碎煤体承压过程中的应变、孔隙率和渗透率分别同各自的应变、孔隙率、渗透率变化路径有一一映射关系，据此建立了相应的应力−应变、应力−孔隙率和应力−渗透率关系的模型；模型对比、验证结果表明，所建模型虽源于多种粒径破碎煤体实验，但摆脱了粒径因素的影响，同实验结果有着良好的匹配性，达到了较为理想的效果。相关研究成果可为采空区煤自燃早期预防与控制提供科学依据。

Residual coal areas in caving zones of goaves in coal mines serve as primary sites for low-temperature reactions between coal and oxygen. Hence, exploring the evolutionary models of the strain, porosity, and permeability of coals in these areas holds great significance for gaining a deep understanding of the spontaneous combustion process and regularity of coals. Based on the self-developed experimental device for gas seepage in compacted broken coals, this study explored the evolutionary patterns of the strain, porosity, and permeability of compacted coals with single/mixed particle sizes during gas seepage. Furthermore, this study analyzed the variations in the strain, porosity, and permeability with stress under different particle sizes. The analysis results show that the variation process can be divided into two stages: the linear variation stage in the case of the axial stress ≤ 6 MPa and the exponential variation stage under the axial stress >6 MPa. The variation process preliminarily indicates that the deformation, porosity, and permeability of compacted broken coals exhibited consistent, particle size-independent variation mechanisms. The axial stress of 6 MPa was proved to be a critical node connecting two different variation mechanisms of strain, porosity, and permeability. Under axial stress ≤ 6 MPa and >6 MPa, the varia-tions in the strain, porosity, and permeability primarily resulted from the compression and slip of coal par-ticles, respectively. In the case of axial stress of 6 MPa, the strain, porosity, and permeability of compacted broken coal with different particle sizes exhibited one-to-one mapping with their variation paths. Accordingly, this study established the stress-strain, stress-porosity, and stress-permeability models. As revealed by the comparison and verification results, the models, despite being derived from experiments of broken coals with various particle sizes, were not influenced by the coal particle sizes and agreed well with the experimental results, yielding satisfactory effects. The results of this study can provide a scientific basis for the early prevention and control of the spontaneous combustion of coals in goaves of coal mines.