以锦屏二级水电站大理岩室内三轴压缩试验结果为基础，推导了考虑体积应力效应的塑性内变量公式，并研究了大理岩强度参数及剪胀特性随内变量的变化规律，结果表明，大理岩在峰前阶段凝聚力稍有降低，在峰后阶段迅速减小；内摩擦角随内变量增加而增大，并在内变量为0.8～0.9时达到最大值；不同围压下大理岩剪胀角均随内变量增大，且表现为先增大后减小的变化趋势，但低围压和高围压条件下剪胀角变化趋势不同。在此基础上建立了大理岩考虑体积应力效应的力学模型，并通过FLAC3D模拟了大理岩室内常规三轴压缩试验，模拟结果与室内试验结果吻合很好，表明该模型可较好地反映大理岩的主要力学特性。研究方法和成果可为其他深部脆性岩体的变形破坏分析提供重要的参考价值和借鉴意义。

Based on the results of compression test of marbles from Jinping Ⅱ hydropower station, an expression of plastic internal variable considering the volumetric stress effect is derived, and the evolutions of strength parameters and dilatancy with the internal variable are studied. The results show that: the cohesion of marbles decreases slightly in pre-peak stage while the cohesion decreases rapidly in post-peak stage; the internal friction angle increases with increasing internal variable and it reaches the maximum value when the internal variable reaches 0.8-0.9; the dilatancy angle increases firstly and then decreases with increasing the internal variable under different confining pressures, and the variations of dilatancy angle are different under low and high confining pressures. A mechanical model of marbles is established considering the effect of volumetric stress based on the above results, and the laboratory triaxial compression test is simulated with the established model using FLAC3D. The simulation results show a good agreement with the test results, indicating that the established model can reflect the main mechanical properties of marbles. The research methods and results will provide an important reference to the analysis of deformation and failure of other deep brittle rock masses.