考虑渐进性破坏的岩石损伤本构模型研究

根据连续损伤理论和统计强度理论,从岩石材料内部包含大量随机分布的微裂隙等缺陷的特点出发,采用修正的Harris函数作为岩石损伤参量的数学模型,并结合Hoek-Brown准则建立能反映岩石破裂全过程的损伤本构模型。通过引入损伤系数J,较好地反映了岩石的渐进破坏特性,也在一定程度上表征了这种准脆性材料的非均匀性和各向异性。利用多元函数极值理论,并依据试验曲线的特征参量,确定出损伤本构模型参数,最后用试验数据对模型进行了验证。通过比较分析说明了该模型的合理性和可行性,在此基础上,探讨了相关参数对理论曲线与试验曲线吻合程度的影响,从而对实际工程具有一定的参考价值。

Study on Damage Constitutive Model of Rock Considering Progressive Failure

Taking Hoek-Brown criterion as the distribution variable and making use of the damage mechanics theory and the statistical strength theory, a three-dimensional damage constitutive model reflecting the whole process of rock fracture is established under triaxial stress state based on the improved Harris distribution. In this paper, damage coefficient J, which can reflect the progressive failure and the inhomogeneity of the rock to a certain degree, is proposed by analyzing the shortage of the existing research results. Moreover,the model parameters are determined by extreme value method, and the experimental data from different confining pressures are conducted to verify the validity of model. The result indicates that this model is rational and feasible. On this basis,the influences of parameters on the rock damage constitutive model are discussed. Accordingly,the proposed constitutive model will provide certain reference to the engineering applications.