Coal is a common porous sedimentary rock whose microstructure and mechanical behavior are often affected by high temperature. In order to deeply investigate the effect of high temperature on the structure and mechanical properties of coal, six groups of coal samples with different heating temperatures were prepared. Various testing methods, including ultrasonic test, scanning electron microscopy, nuclear magnetic resonance and uniaxial compression test, were used in this study. The results showed that the physical and chemical change processes of coal samples under high temperature can be divided into two stages: the stage of drying and degassing and the stage of pyrolysis of the coal matrix. With the increase of heating temperature, the total porosity of coal samples increases, while the integrity and the deformation resistance of coal samples decrease. In addition, the elastic modulus and uniaxial compressive strength of the coal sample decrease with the increase of heating temperature. The Poisson’s ratio decreases firstly and then increases with the increase of heating temperature.

煤是一种常见的多孔沉积岩，其微观结构和力学行为通常受高温影响。为了深入研究高温对煤结构和力学性能的影响，制备了六组加热温度不同的煤样品。本研究采用了各种测试方法，包括超声测试，扫描电子显微镜，核磁共振和单轴压缩测试。结果表明，煤样品在高温下的理化变化过程可以分为两个阶段：干燥和脱气阶段以及煤基质的热解阶段。随着加热温度的升高，煤样品的总孔隙率增加，而煤样品的完整性和抗变形性降低。另外，随着加热温度的升高，煤样品的弹性模量和单轴抗压强度降低。泊松比随着加热温度的升高先下降，然后上升。