基于Hoek-Brown准则的圆形洞室围岩流变变形研究

Rheological Deformation of Surrounding Rock of Circular Tunnel Based on the Hoek-Brown Criterion

  • 摘要: 在许多情况下非线性Hoek-Brown经验准则比较符合实际,但对采用该准则且考虑围岩流变特性的洞室变形解析解研究较少。基于此,在前人基础上采用广义Hoek-Brown准则研究理想弹-脆-塑性岩石流变效应下的围岩变形。首先,为了简化推导过程,假设围岩体积不变,依据广义Hoek-Brown准则推导了围岩的流变变形解析解;其次,为了接近工程实际,考虑体积的变化,采用非关联流动法则推导了围岩的流变变形解析解;最后,分别选取宾汉姆体和西原体作为流变模型计算了两种推导的情况。结果表明,h值越大即膨胀角越大,围岩的流变变形越大;若不考虑体积变化,计算的流变变形偏小。

     

    Abstract: In many cases, the nonlinear Hoek-Brown empirical criterion would be appropriate for engineering practice, however, there has been little research on analytical solutions for tunnel deformation by the nonlinear Hoek-Brown empirical criterion that considers the rheological behavior of the rock. Therefore, based on previous studies, the generalized Hoek-Brown criterion was used to research surrounding rock deformation under the rheological effect of an ideal elastic-brittle-plastic rock. First, in order to simplify the deduction process, an analytical solution for the rheological deformation of the surrouding rock was determined by the generalized Hoek-Brown criterion based on the assumption that the volume of the surrounding rock remains constant. Secondly, according to engineering practice, volume changes were taken into account while deducing the analytical solution for the rheological deformation of the surrouding rock by the nonassociated flow rule. Finally, the Bingham and visco-elastoplastic models were used, respectively, as the rheological models to calculate the two deductions, and it was concluded that the larger the dilatancy angle, the higher the h values as well as the rheological deformation of the surronding rock. Provided volume changes are not considered, and the calculated rheological deformation is smaller than that in practical cases.

     

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