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在考虑拉伸截断及非线性屈服准则的自定义本构模型中,又考虑了弹性模量(弹模)受围压的影响,模拟了两种网格、不同本构模型及加载方式条件下的洞室围岩的破坏行为。在第1种网格中,洞室围岩被剖分为辐射网格,采用“先挖洞,后加载”的方式及理想弹-塑性本构模型进行计算;在第2种网格中,洞室围岩被剖分为矩形网格,采用“先加载,后挖洞”的方式及弹-脆-塑性本构模型进行计算。计算结果表明,对于第1种网格,随着弹模的围压影响系数的增加,洞室围岩的应变、位移及塑性区半径均有所减小,被监测单元的环向应力的峰值有所降低,不同本构模型的计算结果的差别逐渐显现。对于第2种网格,当弹模的围压影响系数较低时,围岩中形成了4个对称的V形坑,随着弹模的围压影响系数的增加,V形坑的个数及尺寸明显减少,这可由洞室围岩的应力、位移及剪切应变增量均有所减小得到解释。
In the self-defined constitutive model considering the truncation of tension and the nonlinear yield criterion, the influence of confining pressure on the elastic modulus (elastic modulus) is also considered. The effects of two kinds of grids, different constitutive models and loading methods The destruction of the surrounding rock in the cavern. In the first kind of grid, the surrounding rock of the caverns is divided into radial grids, which are calculated by the way of “first burrowing and then loading” and the ideal elastic-plastic constitutive model. In the second kind of grid , The surrounding rock of the cavern is subdivided into rectangular grids, which are calculated using the method of “first loading, then digging holes” and the elastic-brittle-plastic constitutive model. The results show that for the first kind of grid, the strain, displacement and plastic zone radius of the surrounding rock decrease with the increase of the confining pressure influence coefficient. The peak value of the hoop stress The difference between the calculated results of different constitutive models gradually appears. For the second kind of grids, when symmetric V-shaped pits are formed in the surrounding rock when the confining pressure influence coefficient is low, the number of V-shaped pits And the size is obviously reduced, which can be explained by the reduction of the stress, displacement and shear strain increment of the surrounding rock in the cavern.