深埋圆形巷道围岩和衬砌相互作用解析解

ANALYTIC SOLUTION FOR ROCK-LINER INTERACTION OF DEEP CIRCULAR TUNNEL

  • 摘要: 围岩采用Mohr-Coulomb屈服准则、衬砌采用双线性本构模型,提出广义荷载作用下深埋圆形巷道中围岩和衬砌相互作用体系弹塑性解的解析表达式。在此基础上,研究了围岩的位移、位移灵敏度和塑性区等随广义荷载的变化规律。根据参数分析和实例计算得到:1) 围岩或衬砌由弹性进入塑性,位移灵敏度将发生突变;2) 位移灵敏度在弹性区和塑性区的交界面上发生突变;3) 根据位移灵敏度的变化情况,可判断围岩和衬砌共同作用体系的稳定状况,并由临界塑性区半径比判断失稳区域的范围。

     

    Abstract: In order to analyze the plastic evolution characteristic of rock-liner interaction for a deep circular tunnel, the elastic-plastic analytic solution for rock-liner interaction is developed under general loadings,in which the constitutive models of surrounding rock and the liner are the Mohr-Coulomb and bilinear model respectively. Based on the analytic expression, displacement, sensitivity of the displacement and plastic zone of surrounding rock varying with general loading are determined. The results of parametric investigation and example computation show that: 1) provided that the surrounding rock or the liner is transformed from an elastic stage to a plastic stage, the sensitivity of displacements will have a significant change; 2) the sensitivity of displacements varying with positions will be discontinuous in the interface of the plastic and elastic zone; 3) according to the sensitivity of displacements, the stability of a rock-liner interaction system can be decided, and the unstable zone can be defined by the ratio of a critical plastic radius .

     

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