为了研究复杂原位应力状态下浸水泥岩的力学响应特性和能量演化机制，选取山西义堂煤矿底板泥岩为研究对象，开展不同浸水时间、不同围压下的三轴压缩试验。结果表明：浸水对泥岩的峰值强度和弹性模量有显著的劣化作用，劣化作用呈现出明显的时间效应；随着浸水时间的增加，泥岩试样的应力应变曲线由“弹−塑”型转变为“弹−塑−蠕变”型，且浸水对泥岩的围压效应也表现出一定的弱化作用；随着围压的增加，试样的弹性能、耗散能和总能量均减小，但耗散能所占比例增大，并与塑性破坏呈正相关关系；随着围压的增大，水对泥岩的弱化作用减小；随着浸水时间的增加，试样的破坏形态由剪切破坏转变为以环向鼓胀为主的塑性破坏；随着围压的增加，试样的破坏形态由单剪切面破坏转变为耗散能较高的共轭剪切面破坏。

To investigate the mechanical properties and energy evolution mechanism of water-immersed mudstone under complex in-situ stress conditions, we selected the floor mudstone in Yitang Coal Mine as the research object and conducted triaxial compression tests under different immersion time and confining pressure conditions. The experimental results show that water immersion significantly degrades the peak strength and elastic modulus of the mudstone, and this degradation exhibits apparent time-dependent effects. With increasing immersion time, the stress-strain curve of the mudstone specimen transitions from an “elastic-plastic” to an “elastic-plastic-creep” behavior, and the confining pressure effect on the mudstone is weakened to some extent by water immersion; with increasing confining pressure, the elastic energy, dissipated energy, and total energy of the specimens all decrease; however, the proportion of dissipated energy increases and is positively correlated with plastic failure. The weakening effect of water on the mudstone diminishes with increasing confining pressure; with the increasing of immersion time, the failure mode of the specimen changes from shear failure to predominantly plastic failure characterized by radial swelling; with increasing confining pressure, the failure mode shifts from single shear surface failure to conjugate shear surface failure with higher dissipated energy.