深部岩体圆形巷道围岩松动圈形成机理数值试验研究

NUMERICAL SIMULATION OF MECHANISM OF CIRCULAR ROADWAY LOOSE ROCK ZONE IN DEEP ROCK MASS

  • 摘要: 采用损伤力学和统计理论的单元本构模型,探讨深部岩体巷道围岩破坏规律,利用岩石破裂过程分析软件RFPA^\rm 2D, 对深部岩体中的圆形巷道的变形及非线性渐进破坏特征、巷道周边关键部位的位移和应力变化进行了分析,研究了圆形巷道围岩松动圈的形成机理. 研究表明:巷道开挖后,其周边形成应力集中带,随着围岩压力的持续作用,巷道周边产生塑性变形区,并沿径向形成裂纹;随着裂纹的不断扩展,巷道周边出现松动破裂区,即松动圈. 产生破裂区后,应力集中程度减弱,应力高峰点向远处转移.

     

    Abstract: To study the failure laws of surrounding rocks forthe roadway in deep rock mass, in view of the heterogeneity of rock, weuse a constitutive model based on damage mechanics and statisticaltheory and the RFPA^\rm 2D, to analyze the deformation and nonlinear gradualfailure characteristics of circular roadway in deep rock mass as well as thedisplacement and the stress variations in the key positions in the peripheryof the roadway, and also the mechanism of loose rock zone inthe surrounding rock of the circular roadway. The studyindicates that the stress concentration occurs in the periphery of theroadway after evacuation and plastic deformation zone is engendered under thepersisting stress of the surrounding rock, then the cracks appears andextends continuously, the loose fraction zone (loose rock zone) appears atlast and the intensity of the stress concentration decreases as well as thestress field shifts beyond.

     

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