To investigate the internal moisture migration patterns and mechanical damage characteristics of water-bearing coal, X-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) spectroscopy, acoustic emission (AE) tests, and conventional triaxial tests were carried out on coal samples saturated at different water pressures. The results showed that the saturated water content of the samples increased exponentially with the water pressure and reached a threshold value, from which the limiting water pressure and limiting water height were approximated. Under non-destructive immersion, the water absorption process of the coal samples was a combination of layer-by-layer saturation and downward water transport. As the water pressure increased, the number of pores indicated by the NMR analysis increased, and the degree of internal damage defined by the integrated area of the T₂ curve also increased. These results were used to quantitatively characterize the damage degree of the samples. The triaxial test results showed that the peak strength, residual strength, modulus of elasticity, and Poisson's ratio of the saturated coal samples all decreased linearly or exponentially upon increasing the water pressure. The breaking angle and number of shear cracks increased, and localized deformation damage eventually developed in the form of narrow shear zones. A modified Mohr-Coulomb criterion based on water pressure and water level was proposed after the experimental results were verified by theoretical derivation. This work provides a scientific basis for studying rock weakening mechanisms in water environments.

为了研究含水煤的内部水分迁移模式和机械损伤特征，X射线衍射（XRD），扫描电子显微镜（SEM），核磁共振（NMR）光谱，声发射（AE）测试和常规三轴对在不同水压下饱和的煤样进行了试验。结果表明，样品的饱和含水量随水压呈指数增长，并达到一个阈值，由此逼近极限水压和极限水高。在无损浸泡下，煤样的吸水过程为逐层饱和和向下输水相结合的过程。随着水压的增加，核磁共振分析表明的孔隙数量增加，T ₂曲线也有所增加。这些结果用于定量表征样品的损伤程度。三轴试验结果表明，饱和煤样的峰值强度、残余强度、弹性模量和泊松比均随着水压的增加呈线性或指数下降。剪切裂纹的断裂角度和数量增加，局部变形破坏最终以狭窄剪切带的形式发展。通过理论推导验证了实验结果，提出了一种基于水压和水位的修正莫尔-库仑准则。这项工作为研究水环境中的岩石弱化机制提供了科学依据。