为了研究应力补偿对单面卸荷砂岩力学特性与变形破坏特征的影响，采用真三轴扰动卸荷岩石测试系统对砂岩进行不同中间主应力单面卸荷试验和应力补偿路径下岩体破坏试验，基于Mg-C强度准则研究了2种应力路径对卸荷岩石强度参数的影响，分析了应力补偿后卸荷岩石的力学特性和变形特征。结果表明：在本研究范围内，即使是在非常规真三轴状态下，中间主应力σ₂的增大同样可以有效提高岩石的承载能力和稳定性，使岩石由塑性向脆性转化；2种应力路径下卸荷岩石的破坏模式存在差异，岩石的整体破坏模式随着σ₂的梯次增大由张拉向张拉−剪切复合再到剪切破坏发展，卸荷面附近的破碎区逐渐由深部向浅部转移，而随着卸荷面补偿应力$sigma'_3 $的梯次增大，整体破坏模式由张拉−剪切复合破坏向剪切破坏转变，卸荷面附近的破碎区逐渐由浅部向深部转移；岩石在单面卸荷与应力补偿支护过程中，伴随着ε₃的扩容与压缩，ε₂基本上无明显变化，但是ε₁和ε_v发生2次明显的回弹变形，且ε₁和ε_v的变形与ε₃同步；应力补偿可以有效补偿卸荷引起的岩石应力损失，提高砂岩的黏聚力和破坏强度，使砂岩加卸载期间的补偿系数η_(m1)、η_(m3)、η_(mv)逐渐增大，但对内摩擦角和η_(m2)影响较小；在任意补偿应力条件下压裂系数ξ_(m2)和ξ_(m3)均为负值，岩石在σ₂和σ₃方向处于扩容状态，而ξ_(m1)和ξ_(mv)正好相反，在任意补偿应力条件下均为正值，岩石处于压缩状态。

To study the effect of stress compensation on the mechanical properties and deformation damage characteristics of unloading sandstone, a true triaxial perturbation unloading rock testing system was used to carry out unloading experiments on sandstone with different intermediate principal stresses and rock damage experiments under stress compensation paths, and the effects of the two stress paths on the strength parameters of unloading rock were investigated based on the Mg-C strength criterion, and the mechanical properties and deformation damage characteristics of unloading rock were analysed after the stress compensation. The results show that the increase of the intermediate principal stress σ₂ can effectively improve the bearing capacity and stability of the rock and transform the rock from plasticity to brittleness in a certain range, even in the unconventional true triaxial state; There are differences in the damage patterns of unloading rocks under the two stress paths. The overall damage pattern of rocks develops from tension to tension-shear composite to shear damage with the gradient increase of σ₂, and the crushed area near the unloading surface gradually shifts from deep to shallow, while the overall damage pattern changes from tension-shear composite to shear damage with the gradient increase of compensating stress $sigma'_3 $ at the unloading surface, and the crushed area near the unloading surface gradually shifts from shallow to deep. During the unloading and stress-compensated support of the rock on one side, accompanied by the expansion and compression of ε₃, there is no significant change in ε₂, but ε₁ and ε_v undergo two significant rebound deformations, and the deformations of ε₁ and ε_v are synchronized with that of σ₃; Stress compensation can effectively compensate the rock stress loss caused by unloading, improve the cohesion and damage strength of sandstone, and gradually increase the compensation coefficients of sandstone during loading and unloading, η_(m1), η_(m3), and η_(mv), but have less effect on the internal friction angle and η_(m2); The fracturing coefficients ξ_(m2) and ξ_(m3) are both negative under arbitrary compensating stress conditions, and the rock is in dilatation in the σ₂ and σ₃ directions, whereas ξ_(m1) and ξ_(mv) are just the opposite and are both positive under arbitrary compensating stress conditions, and the rock is in compression.